Electric Versus Gasoline

 After the previous post, I got to wondering: since I said we weren't burning gasoline to make electricity (and so the comparison was not exactly fair), what would the real CO2 comparison actually be?

Let's crunch some numbers!

Basic Figures

For the purposes of this calculation, we'll make the following assumptions:

• We're going to send our gasoline and electric vehicles 50 miles.
• The electric will consume 350 watts per mile.
• The gasoline vehicle will go 15 miles per gallon (3.96 miles per liter).
• The electric will use coal-powered energy, at 2.32 lbs of CO2 emitted per kWh consumed.
• The gasoline vehicle will produce 5.09 lbs of CO2 per liter of gasoline consumed.

Why these numbers?  Because of the two vehicles I own, these are not outlandish and actually quite common consumption figures.  We'll play with numbers below.

The First Calculation

Given the above assumptions, our electric vehicle:

• will consume 17.5 kWh for the trip
• produce 40.6 lbs of CO2 (if powered solely by coal-generated energy)

Our gasoline vehicle:

• will consume 12.62 liters of gasoline
• produce 64.3 lbs of CO2

Some Codicils

Bear in mind these are estimates.  If the gasoline vehicle were to get closer to 20 MPG, it's CO2 output for the same trip would drop to 48.2 lbs.

There is also the reality that gasoline vehicles and electric vehicles operate almost opposite of one another: whereas an ICE engine increases efficiency as it runs at higher RPMs (such as when driving highways), electric vehicles benefit more from in-town driving (where they can use regenerative braking and are not going fast enough to incur meaningful air resistance).

If our electric is able to run at around 250 watts per mile, its CO2 cost drops to 29 lbs.  A comparable gasoline engine needs to attain 33 MPG to match that.  250 watts per mile is honestly rather low, but it can be achieved (as can 33 MPG or greater).

Conclusion

Bear in mind that all mileage ratings are based on very specific EPA standards, which are designed not to tell you how far you can really go on a tank of gas or a charge, but how one vehicle compares to another given certain standardized conditions.  These can include not running the air conditioning - and for those who live in hot climates, we all know how absurd that expectation is.

If we can power our electric vehicles with energy sources less-polluting than coal, our CO2 footprint drops.  For instance, if all our energy comes from natural gas, the same trip at 350 watts per mile will cost only 16.8 lbs CO2.  To get near that with gasoline, you now need to run at 57 MPGs - good luck with anything but the most fuel-efficient vehicles and the most careful driving!  If we switch to nuclear or renewable sources, game over.

While there is much left to be done to truly make electrics as functionally capable as ICE vehicles, the fact remains that in terms of power-options and their ramifications for the environment at large (which, of course, comes with a ton of assumptions we won't deal with here), electrics are quite literally the here-and-now future.

P.S.

I personally don't drive an electric because of environmental considerations.  I believe the interactions and inputs involved in our climate are significantly more complex than anyone is willing to discuss in open forum.  If we traded out all ICE vehicles for electrics tomorrow, we'd simply have a different set of problems, environmental and otherwise - not the least of which would include untold millions of tons of volatile lithium batteries in various stages of degradation.  Like I said, there is still far more work to be done on electrics, but we should not discount them or mock the people who own them.  There are economic opportunities afoot - the greatest fools are those who refuse to take advantage of them.

There was probably a time with everyone who owned horses scoffed at the new Model T rumbling down the road, and look at where we are today.

Electric Cars and Coal

 It's funny to me when people talk about filling electric cars up with coal.  Like so many other conversations these days, such simplistic statements and views obfuscate reality.  Are electric cars "no better for the environment than gasoline?"  Should we all go back to internal combustion engines (ICE)?

The Simplistic View

If we just run a few numbers, we can compare powering our vehicle with gasoline versus coal.

In order to have some common basis of comparison, let's say we need 50 kWh of power to drive somewhere.  That's actually a pretty long trip, or a not so long trip on a very hot day.

Sparing the actual calculations for now (the curious can try to replicate my math with some choice web searches), we find that powering our vehicle will cost us in lbs of CO2 as follows:

• coal: 116 lbs of CO2
• gasoline: 28 lbs of CO2
• natural gas: 48 lbs of CO2

So it seems that everyone who is puttering around in ICE vehicles is actually doing the world a favor!  Down with electrics!!

Not So Fast!

Our above calculation assumed that the gasoline was going to the generation of electricity, not to actually driving somewhere.  At best, you're cruising down a highway with your vehicle's engine at optimum efficiency.  At worst, you're sitting at stop-lights and chewing through your gas tank.  Anyone who has recorded their each and every fill-up and mileage can attest that in-town, slow and poke driving is significantly less efficient than highway, and so this wonderful estimate is already highly misleading.

There's also another problem.  A gasoline engine can take only one kind of fuel.  Anyone care to guess what it is?  (Variations on a theme don't count - almost no one fills up on 100% ethanol.)

The Alternative Conundrum

An electric vehicle doesn't care where the power comes from.  That's really one of the beauties of it.  

According to some sources, only 23% of the electricity generated in the United States during 2021 came from coal-fired plants.  The rest were... not coal-fired.  To make the argument that electric vehicle owners "fill up on coal" is like saying that people who eat meat "fill up on Burger King."  Surely we can all see that the not all meat comes from Burger King, and not all power comes from coal.

Let's see what our electric car can use, as opposed to an ICE vehicle:

• Electric
• coal
• natural gas
• oil
• nuclear
• wind
• solar
• tidal
• hydroelectric
• geothermal
• ICE
• gasoline
• diesel
• ethanol
• (propane, if you're driving a forklift)

If we're looking to rid ourselves of dependence on a limited selection of fuel sources, then certainly ICE engines can't compete.

But... The BATTERIES!

Yes, we all know the batteries are environmental disasters.  And what was the Exxon Valdez?  What is it that inspires people to protest and complain loudly to their representatives about on-shore and off-shore drilling, fracking, the transportation of oil via pipelines, oil exploration in general?

The battery situation is not a fixed one - it is subject to the evolution of the technology.  While ICE engines have evolved, their fuel has really not.  It's been made less harmful (i.e. no more lead in our gasoline), to be sure.  But it will always be gasoline.  Even ethanol, which is costly to produce, is not an improvement.  Just think of it in terms of the crops and the environmental impacts of growing them, then the refining, and finally the reality of ethanol's efficiency (or lack thereof) as a fuel.

We have made some great strides with battery technology, but more certainly needs to be done.  Whenever that happens, however, the batteries still won't care where the power comes from.

It should also be noted that the coal mining, the drilling, the fracking, the fuel refining are all very horrible activities, environmentally-speaking.  These don't go away because you're not using coal to power your ICE vehicle.  They're simply built into the price of gas, and cannot be avoided.

Speaking of Batteries...

One of the ironies I realized while typing this post is that gasoline does not have a long shelf-life.  It does go bad.  For this reason, I converted my little generator to use propane.  Propane may not produce as much power output as gasoline, but it doesn't go bad.  However, people don't use propane in their cars.  Sometimes you see it on forklifts.

Power, once produced, can be stored in a number of ways.  Everything from mechanical to chemical, and new methods are being developed every year.  One such recent initiative was taking place in Italy, where a company was developing a "battery" that consisted of a closed-loop CO2-based pressure system: CO2 would be compressed by way renewable energy sources.  The compressed CO2 is stored, then released later through a turbine to generate power.  The released CO2 enters another holding tank, so that it can be re-compressed once renewable energy sources come back online.  This is a kinetic battery, no harmful mining or chemicals required.

In my mind, our biggest inefficiency today is our inability to produce energy optimally.  We currently have to guesstimate our production, and often we overshoot it.  That yields waste.  Any sort of battery system that could buffer the varying load demands could reduce our current generative outputs.  Such systems could also capture significantly more benefit from solar and wind producers. 

Don't Forget Transmission

One other thing often forgotten is that every gas station needs power and fuel delivered to it.  The pumps don't operate without power, and neither do the cash registers or the lights in the station.  So if electric cars are burning coal, so are the gas stations.  The gasoline also doesn't arrive by pipe.  It arrives by tanker truck.  They burn diesel to get it there - a lot of diesel.  When gasoline in an area runs out (such as after a natural disaster), it can take a while for the trucks to get in and refill the stations.

We'll forgo talking about the transport of crude oil, the energy taken to refine it, and so forth.

Electric vehicles take electric power from electric lines.  The lines don't move.  They need no delivery trucks, and whatever power losses are incurred in power transmission, I would not believe them to be greater or even near that spent on tanker trucks.  In a natural disaster, people with solar on their homes or sufficiently beefy generators can still get charged up and go.  There is no need to wait for the gas station to get refilled.  Power lines can last years - possibly decades - without needing replacement.

In Conclusion

All of these options and technologies feed neatly into electric vehicles.  While electric vehicle tech still needs - in my opinion - quite a bit more refinement, it will get there.  But it can only get there if there is a market for it.  No market can exist where people are prevented from buying it, and we shouldn't be denied the option to use alternative energy sources.

Now, I've written all of this and probably sound like an electric car evangelist.  I'm not.  I own an ICE truck for hauling and long-distance travel (and because of having a sufficiently large family - long trips need extra room).  That said, the ICE truck's battery goes dead if I don't run it once a week.  That's how little we drive it. 

I've tried to keep what I've stated above limited to just the facts.  There are many instances where there is overlap between ICE and electric: the costs of drilling, refining, transporting, and burning of fuels for either energy production or to power an ICE engine, tend to be close to the same.  The cost of manufacturing the complex engines, cooling systems, catalytic converters, and so forth are replaced by the costs of manufacturing rare-earth-magnet motors, battery systems, and all the requisite electronics.  It's difficult to say if the cost exchange rate is 1-to-1.  I'm not sure anyone can accurately account for it all, and it's honestly silly to argue over it.  

What isn't disputable is the fact that an electric car offers far more choices in power source, than an ICE.  An ICE will never be able to make use of nuclear, whereas an electric can.  Energy underpins our modern world, and that is a fact that - barring an apocalypse - isn't changing any time soon.  The more efficient we are in transferring and storing it, the more we can do with it.

As a bit of inspiration, I watched a video of a US Congressman's Tesla battery upgrade for his house.  His house was completely off-grid, and he even wired up his Tesla charger to only operate when the sun was out.  When was the last time you could refine your own gasoline when the CO2 production in your local area was minimal?

My Perspectives on Cryptocurrencies

A recent conversation about an acquaintance's case against cryptocurrency gave me cause to write up this not-so-brief blurb.  Given that there's been a recent down-trend in the dollar-valuation of most cryptocurrency - especially Bitcoin - there are those who argue that cryptos are, or were, a "bubble", that they're not real, that it's all a bunch of garbage, that it's not an investment, and so on.

Let's ruminate!

Note: this is a very low-level primer/discussion.  Any mistakes in how stuff works in reality are entirely my own.  Not all blockchains operate identically, but for sake of brevity I have omitted these obtuse details.  If you want to learn about blockchains in greater detail, seek out their documentation.

What Cryptos Are Not

Cryptocurrencies - or cryptos, as everyone is calling them these days - are not intended to be an investment.  If you would invest in the currencies market, or the futures market, then yes perhaps you could consider cryptos yet another investment opportunity.  After all, an investment is anything anyone believes will be more valuable in the future than it is today.

Cryptos are also not tangible items.  You can't hold them in your hand like a gold coin, no matter how awesome the pictures on everyone's news articles look (and the coins they draw do look really great!).  Some consider cryptos as being non-fungible, in that with most currencies you can track the motion of coins from wallet to wallet.  Rarely currencies, such as Monero (which I have only recently been playing around with), are build with total anonymity from the start, such that you can trade them as you would any paper or metal money and no one outside of the transaction would be the wiser for it.  I don't think "non-fungible" is quite the right term to apply, when the lack of privacy in Bitcoin is considered, but we won't split hairs here.

Cryptos are not, in fact, independent of the algorithms that represent them.  The blockchain is the underlying mechanism for the storage and transference of value, the coin in question being simply a unit or a value component within the blockchain.

So What is the Blockchain, and Why Do I Care?

When you write a check - assuming you're old enough to be familiar with such a task - you typically record the amount you spent in the check register.  Likewise, in the accounting field, every income and expenditure is entered into some bookkeeping system.  The bank keeps a record of every transaction it processes, as do your credit cards.  Every statement is a list of transactions, all recorded and curated for your informational benefit (and many other reasons, legal and otherwise, as well).

A blockchain is a record of transaction that is designed to be immutable, and indisputable.  It is immutable because each record you add to the blockchain is cryptographically tied to the previous record.  The only record not tied to anything is the "genesis block" - the first record.  If you change any previous record in the chain, every record that follows would be affected.

Without going into gross detail, but we'll talk about it because it's cool, this all works because of a special cryptographic function called a "hash".  The hash is a simple tool: it's a little algorithm, and you put some data into it, and you get a big number out of it.  You can put as much or as little data as you want through it, and it will always output a number.  This number is the hash.  

The thing that makes hashes special is that when you change the input by even the smallest possible amount, the output changes dramatically.  Now, each record we add to the chain takes the hash of the previous record, and adds it together with the contents of the new record and then hashes the whole thing together.  After all, it's all just data.  We take the hash output and store it with the record.  The next record will use this hash as part of its input.  In this way, we can start at the genesis block and generate hashes for it and every block that follows - in order - until we get to the end, and validate the whole chain.  If someone mucks with the middle, the hashes will change from there down, and we can detect the change.

So Just Rewrite All the Rest of the Hashes!

This is where Bitcoin made its mark.  When you make a hash, it looks like a giant random number.  But the number is always the same length when the algorithm outputs it.  Remember, computers store numbers in bytes, a byte is eight bits, and we put multiple bytes together to make really big numbers.  The SHA-256 hash algorithm outputs 256 bits for it's hash when it's done hashing your input.  That's 32 bytes.  Even if the first 3 bytes (or 24 bits) are all zeros, it's still considered a 256-bit number.

And that's where things get interesting: if hashes are so random, is it possible to find a hash that starts with the first 10 bits as zero?  This is how proof-of-work basically functions.  

To make it work, in addition to the record data, and the hash from the previous record, we have to add a special value into the mix.  We get to choose this special value.  When we hash this special value with the record and previous hash, we want the resulting hash to have the first 10 bits as zero.  Any hash with the first 10 bits as zero will do.  This is, in fact, a very hard problem because you can't predict hashes and if you change even one bit, you'll wind up with some completely different hash, so at best you can only guess at this special value for a long time.

Thousands and thousands of miners do this, until one finds a special value - and a hash - that works.

Because this is so compute-intensive, in order to rewrite the blockchain from some prior point AND catch up to the newest blocks (records) being added, you'd have to have more computing power than all the miners currently participating in Bitcoin, combined.  If you can't catch up, your EvilChain will never be adopted by the rest of the Bitcoin community.  This is known as the 51% attack, because your computing resources would have to account for 51% of the overall participating community.

It's possible someone could do this someday, but there are a few other tricks up Bitcoin's sleeves to ensure that the blockchain integrity remains intact.  We're not going to cover those here.

A Brief Note on Keys

Modern cryptography often relies on something called asymmetric keys: a private key, and a public key.  If you encrypt something or digitally "sign" something with one of these keys, you can decrypt or "verify the signature" with the other key.  In this way, there is no difference really between the private and the public key.

But we need to keep one of them secret, so that anything we sign can only come from us, and anything encrypted to us can only be decrypted by us.  So we call one the "private key" and never share it, and the other the "public key" and everyone knows about it.

Cryptocurrency wallets require these keys.  Your private key lets you send your funds to other people, because when you add a record to the blockchain, you need to digitally "sign" it with your private key.  Your public key lets the blockchain and everyone else verify that it came from you.  Your public key might also represent your wallet online, for technological convenience.  What this means is that if you have your own wallet, you should have your own private keys.  If you use an exchange, however, the exchange runs the wallet and the exchange has the private keys.

ANALOGY: Back when banks used to store your cash (or gold) on-site, a bank robbery would mean your money went bye-bye, along with everyone else's.  An exchange is a glorified bank-of-olde.  If you kept your gold under your mattress or in a safe in your house, and your house got burgled, then sure you'd probably lose it all the same.  But, with a sufficiently mean safe or a sufficiently good hiding place, there's a chance the thief will be thwarted in this regard.

Your wallet private key is this special hiding place, this mean safe.  It's up to you to keep it well-secured so that someone can't just walk away with it.

 

OK, So What ARE Cryptos?

Now that we have a good idea why they work - or mainly why the blockchain works - how do they become considered currency?

Consider a gold coin in your possession.  No one else can possess it.  It's yours, until you give it away (or it stolen).  Each record in the blockchain records your possession of the coin.  If you send some of your coin away, this is recorded also.  If you receive some, it's recorded.  In every instance, the record becomes a fixed (immutable) part of the blockchain.  It's the digital analogue of handing a fistful of gold atoms over to someone else: the Universe knows you did it, and you can't suddenly wish those gold atoms back into your hand.  We assume magic does not exist.

When people trade gold atoms - I mean, gold coins - they do so usually in exchange for something else.  In times long past, you could buy food, supplies, houses, wagons, horses, and so on.  You could sell all this stuff in exchange for the gold as well.  Anything that becomes a medium of exchange has the potential to become currency.

The special/important thing about currency is that it doesn't disappear on you.  Flowers make a poor currency because they wilt.  Food makes a poor currency because it generally goes bad (unless it's canned food, in which in the zombie apocalypse you might be very rich if you're well prepared).  Water is poor currency because it falls from the sky, and evaporates.  In the right situations, any of these might become currencies, but generally we're not anywhere near those situations.

Bitcoin and other cryptos can act as currencies because once you receive your coin, it stays with you.  Only you can throw it away.  Even if you do, there's a chance you could get it back if you manage to recover your wallet keys.  But as far as the blockchain is concerned, the coins that are there will always be there.  You can't burn it, you can't bury it.  Sure, people have lost their private keys or tossed hard drives into the garage that contained the only access records for thousands of Bitcoins, but the blockchain still remembers them all.

In this way, Bitcoin is unlike gold in that gold can wind up at the bottom of the landfill and no one would know how much is there.  Bitcoin, on the other hand, never forgets, so someday we might look for accounts that haven't been accessed in the last lifetime and then we'll know exactly how much Bitcoin was "lost".

Because it's yours, and it doesn't deteriorate, and you can trade with it, and you are guaranteed that the record will be both honest and intact from the moment it's added to the end of, well, Bitcoin, it is pretty darn close to being currency.

So What is Missing?

What's missing is common adoption.  That's changing, and with actual point-of-sale appliances now integrating crypto payments, this last hurdle will soon be cleared.  The important thing to realize is that the only reason we conduct our business in USD (here in the US) is because everyone here conducts their business in USD.  We could conduct our business in CAD, or Euros, or yen, and demand payment from our customers in kind.  We'd have a hard time doing business that way, since most people don't have CAD or yen in their wallets - and they prefer to use USD-based credit cards anyway.  But that reality aside, there is nothing physically stopping us.

The catch, of course, is that we'd have to report our income in USD for taxes and whatnot.  Our government does its business in USD, so we have to eventually exchange to it and ante up.  This is not a terrible problem, however, and crypto exchanges make it remarkably easy to deal with.

One argument I've heard against cryptos is volatility.  I consider this as a strawman, however, and here's why.  If your only goal in life is to accept cryptos as a form of payment, only to turn them into USD then and there, then sure volatility is going to be unwelcome (when the value is low) or awesome (when the value is sky-high).  But if you're conducting your business in crypto, and paying your people in crypto, and buying your supplies with crypto, the only volatility you have to worry about is the volatility of your suppliers' prices (and your workers' wage demands).

We've watched the value of the USD go crazy, with inflation rocketing to the moon.  Another way to look at it is that the value of USD relative to goods has plummeted.  Decades ago you could buy a loaf of bread for, say, 5 cents.  Now it's 5 dollars.  We say the price of bread went up.  Or did the value of the currency go down?  Either way you slice it, you need more money for the same item.

The volatility of crypto is measured against USD.  However, crypto-against-crypto they are remarkably stable.  If you watch the trends of Bitcoin, Etherium, Monero, Solana, and others, you see them all rise and dip generally together.  They are rising and dipping with respect to USD, but not necessarily to each other.  So, if 1,000 Solana is worth one Bitcoin today, and tomorrow the value of Bitcoin in USD drops by half, what is the cost in Solana of one Bitcoin tomorrow?  Very likely still at or near 1,000 Solana.

Therefore, if we consider cryptos as their own currency system, then it makes no sense to judge them based on their value relative to a different fiat currency.  They are either a medium of exchange and a store of value on their own accord, or they're not.

ANALOGY:  Let's say that some foreign country's government-issued fiat currency - we'll call it the Foo, in the country of Fooland - undergoes wild swings one day in comparison to the USD.  If the USD doesn't change with respect to the Euro, yen, or yuan, and the Foo changes wildly with respect to them all, we would consider Foo as being highly volatile.  Does this mean it ceases to be a currency?  Not to the people who live in the Fooland.  They're still doing business in Foo, they have Foo stuffed under the mattress and stored in their local banks.  They expect to be paid in Foo.  It's a currency in spite of its volatility, to those who wish to continue using it.

I Want to Put My Life-Savings into Crypto!

Would you convert your life-savings to the ruble?  How about the peso?  Maybe some CAD, or Euro?  I know, pounds!  God Save the Queen!

If you wouldn't ordinarily do any of these things, you'd be a fool to do it with crypto.  While I personally think speculating in currency markets is a fools-errand, no one can stop you.  I just don't see the point: you can't guess the future value, no matter what the currency is.  You can't be in tune with all the worlds events in real-time to see a crisis coming, nor can anyone process that much data fast enough to even recognize a crisis.  If you are doing anything at all, you're playing roulette, and if that's the case you'd be better of running a bunch of statistics and hammering local casinos like one mathematician did.

If you are interested in conducting transactions in crypto, however, then converting some fiat to crypto isn't a bad idea.  The worst that can happen is that your local government forbids people from doing this.  But ironically, forbid as they may, your access to your crypto should be unfettered - assuming you have a private (also known as "offline") wallet.  This is in deference to exchange-hosted or custodial wallets, where someone else has the private keys.  In other words, they can forbid all they want, but as long as you have crypto to play with and can connect with the blockchain, you can move money and do business.

Crypto Isn't Backed by Anything!  Neh!!  I win!!

What is backing the US dollar?  How about the CAD?  Or the Euro?  Recently Russia took the "unprecedented" step (ha ha) of backing their ruble with gold, in a way.  It's not a gold standard, but it's also (apparently) no longer the free-floating fiat that it once was.  The US dollar has no backing.  Its value compared to other currencies is set by complex interactions between the Treasury's printing presses, the Fed's meddling, the various massive banks around the world, treaties, bond markets, wars, and so on.  There is really nothing concrete underneath the dollar.

Some argue that the dollar is backed by debt - that each dollar in circulation is backed by actual labor yet to be done.  But does this even make sense?  While it may be ostensibly true, the reality is that if I ask you for a loan of $10,000, and I promise I'll either pay it back or work it off, who are you to make me do either?  If I pack up and go, or suddenly become unable to work and unable to pay, your gamble that I would be able to pay or work fails completely.  What's more, to say that I have $10,000 worth of work in me (because of my loan that you gave me), this is not collateral.  This is a liability.  I can't justifiably take this $10,000 and show it to someone else and demand more money be loaned to me.  That $10,000 isn't really mine.  Anyone foolish enough to consider a liability as legitimate collateral is wearing their ass for a hat: I can now fail on two loans, make off with twice as much money and compound the pain I deliver to these two fools (sorry, one of them was you).

Unfortunately, it seems our major financial institutions do this all the time.  I suspect this is where derivatives get their name and calling, but I could be wrong.  It makes sense, though.  All debt comes with interest - in theory.  The debt plus the interest is future value.  If I request a loan based on future value of my returns (as the one who loaned the money), in theory I can pay it back once I get paid back.  But again, this is a liability, not an asset.  Future value is not guaranteed.  Repayment is not guaranteed.  

Anyone thinking that it's good having a currency founded in debt and the labor to work off that debt had better start learning Mandarin, because if you plan on paying off the country's debt to its debtors with your labor, one of our biggest debt-holders is China.  I'd be astonished if the average American would take on this duty willingly, and for choices they didn't directly or even indirectly make.  So much of modern fiat money looks like a shell-game, a play on words, a play on concepts, all designed to make things look stable and real and based on something tangible, but ultimately it's all a house of cards.

In this way, Bitcoin and other cryptos have the potential to be something quite different: while they are also not based on anything specifically tangible, well-build cryptos are also not things that can be counterfeit.  They cannot be manipulated the way the Fed manipulates the USD.  The coins - at least where Bitcoin is concerned - cannot currently be just printed off.  Yes, a change to the whole system could enable this, but it would take an amazing amount of consensus.  Right now, it takes only the Fed asking for more money to get the Treasure to print it.

So Are Cryptos the Future?

There is very likely going to be a digital currency soon.  China has been working on theirs.  The US is investigating their own.  Most people already use their USD in a digital form anyway - when was the last time you transacted in honest-to-goodness dollars and cents?  Credit and debit cards are easy.  Checks are not far behind.  Most bank transactions between banks are all digital.  In a way, it's amazing nothing gets lost or corrupted - or maybe it does and we never hear about it.

A central bank digital currency (CBDC) will have huge implications for privacy, trust, security, fidelity, reliability, government manipulation, and so on.  It's hard to say how long it will take to get there, but for what it's worth your bank account, being the digital record it is, is all but in the government's hands already.  One interesting idea with CBDCs is that of expiring currency: when the Fed wants to make people spend money, give them money that will lose value over time, so that they have to spend it before it disappears.  Can't do that with gold or even paper money.

The question becomes whom would you want in charge of your digital currency?  If you're fine with the government, the Fed, the banks, maintaining that power over what you hold, how much of it you have, and where you can spend it, then CBDCs should be exciting and wonderful news for you.  If you would prefer to manage your own money, buy and sell as you see fit, enjoy your privacy while doing so, and to be sure know that no one else can take your money unless you give them the power to do so, then cryptocurrencies are going to be the place to be.

I would envision a future where both CBDCs and cryptos exist.  How one gets along transacting in either or both worlds, it's hard to imagine.  But I think this is where things are going, and if I had to hedge my bets, holding a little crypto isn't a necessarily bad thing.

Solar And The Power Company

I Just Found Out, I'm Mad as Hell...

It's March of 2022, and a bill is set to go before the governor that will potentially upend residential solar in the state.

But what are the arguments, and what are the facts?

The local power providers in the state contend that it's "unfair" for solar customers to pay "less" than their non-solar neighbors for power.  It is said that residential solar generators are being "subsidized" by non-solar customers.  They also contend that they're not getting enough income from solar customers to offset upkeep costs.

Is it true?  Let us consider some numbers.

Based on Actual Data

I took an hourly data report from my Sense for the period of May 17 to June 16, of the year 2021, which recorded both solar production and overall energy usage.  From this I could calculate how much we sold back to our provider, and how much we would have purchased without solar.  

If anyone is interested, I can rerun this experiment with a whole year of data.  I picked this particular period somewhat at random: it had good solar production and represented a warm-to-hot time of year.  This production period is near the top - most elsewhere in the year, we will produce less energy from our system.  Anyone who complains that I cherry-picked data will receive nearly a year's worth of raw HOURLY data in reply.

At the end of the period, we had generated 3,265 kWh.  We used overall 2,392 kWh, leaving us with an energy credit of about 872 kWh.  Now, power isn't grain - unless you have huge batteries, you can't store it for long.  So what happened to all this extra power?

It Was RESOLD...

This power didn't just disappear...  Our provider resold it.  How they resold it, to whom they resold it, we do not know.  But they buy power from other providers, and they sell power to other providers, and of course they sell to us customers.  Solar customers, according to one report, represent 1% of that customer-base.

The power my system generated went to "the grid."  What does this mean?  Well, it went up and down the same power lines feeding all my neighbors, to put not too fine a point on it.  There is no way that I know of to differentiate power we generate from power the provider generates, if looking at someone else's meter box.  This is why we monitor usage at the residence, not at the provider or the substation.  Once power gets onto those two or three skinny pole-suspended wires, all trace of who produced it is lost.

So let's say there's one other neighbor on the immediate line that feeds my transformer.  They don't have solar.  Our provider is charging them at standard rates - the same rates they charge me when the sun doesn't shine or we don't generate enough to cover our usage.

Now, I'm going to simplify numbers here.  Our provider has tiered billing, but let's just consider usage costs up to 1000 kWh, which boils down to 13.266 cents per kWh of energy, fuel, and assets.

If our neighbor benefited from our solar generation, so did our provider, to the tune of at least $115 for the period in question.  That would've been our provider's income for the 872 kWh we supplied over our usage.  Our provider would have "sold" it to our neighbor, assuming our neighbor used it all (and they very likely did), and our provider charged them accordingly.  That's just income, not profit.  So what was our provider's costs?

What Does It COST?

We don't know what it costs to run a power company, but we can take a guess based on the changes presented in the legislation.  

Under the guise of making power bills more "equitable", the legislation reduces the value of kWh's supplied to power companies from 1-kWh-credit per kWh-generated down to 1/2 kWh-credit per kWh generated -- 50% of what is produced.  This means that if I generate 872 kWh over for the month, my provider will be able to say that I only produced 436 kWh for them.  They'll still get to sell 872 kWh, and charge others for 872 kWh, neither of which they produced.  I am, at worst, renting their power lines and maybe a few small transformers.

I, on the other hand, will be at a loss in both the short and long term: the energy credit I would be carrying into the darker months of the year won't be there, and my winter bills will skyrocket because I won't be "generating" enough power - by this bookkeeping - to offset my usage.  In my spreadsheet, for that period of May to June I wouldn't have "produced" enough power to even avoid "using" grid power, let alone carry a balance into next month.  Whereas I would have had 872 kWh of credit, I would have owed 171 kWh to my provider, with nothing banked for the next or any future month!

This is what we affectionately call "getting shafted."

It should be noted that after almost a year of production (my system came online in February), I was in the "negative" by the end of December - I had used up all my credits and had to pay a rather ugly power bill for my usage overages.

So, how much does our provider profit?  If they are willing to reduce the value of our production by upwards of 50%, then they must be able to produce power or buy power for around that rate.  This would mean they are charging a 100% markup on power sold (i.e. they buy for $0.05, and sell it for $0.10 - these are not actual values, just examples to be clear what I mean by the markup).

If they produced and sold 872 kWh of power (for $115), it should cost them around $57.  That gives them a $57 profit.  But they're not spending $57 in fuel, generation equipment and whatnot, when they get power from me.  My power might not even be making out to most of the equipment that they are otherwise using to transfer power from place to place.  It might be getting used by my numerous neighbors (not just the one in this example), and never touching any of the equipment located miles away.

My provider is already $57 better-off thanks to my generation.  If it actually costs them less to produce or buy power, then they are even better-off than that.  Why exactly do they deserve or need more?

Shafting the Future

Given that I had used up all my credits before the end of the year, and expect to do so again this year, I would expect that a system generating (or receiving credit for) only 50% as much power would have substantially higher power bills.  This doesn't benefit my pocketbook, to be sure, and might drive me to invest in batteries.  

I would even want to take it a step further and not even provide power back to the grid, if I could.  After all, why should they profit so pointedly at my expense?  They aren't paying for my panels, they didn't help with the install, they wouldn't be paying for battery installation and upkeep, they would basically just be getting super-cheap power and I wouldn't be able to negotiate a goddamn thing.

Free-Market Power

If we want a free market for power, we cannot live under the guidance of utilities.  They have a profit motive, as any good and successful business does.  But they have no competition - except from small-time residential solar providers.  A surefire way to dissuade people from "going solar" is to take their power and give them little-if-anything in return.

Here's a little-known fact: according to my provider's own "how to go solar" page, you can't build a system that generates more than you use on average.  I use a lot of power, so I was allowed a large system.  But most people don't, and so most people won't, even if they have the roof-space for it.  That lost real-estate in solar-generating-potential will now cost them even more.  

Do we assume our energy needs will stay the same or diminish over time?  Every time I plug in my car, I consume between 5 and 15 kWh of power.  Do that every day for a month, and suddenly my usage is through the roof.  With more people buying electric cars, using electric gizmos, and sucking power like there is no tomorrow, usage isn't going to go down.

Still, here we are with utility companies talking "equity."  Equity for whom?  Wouldn't it be more equitable to charge my neighbors less?  After all, why should they pay for fuel that the utility didn't consume?  Or maybe I should be receiving some of the profits as an incentive to keep my grid-tied system tied to the grid!  Where is my profit in all of this?  "Good Feels for the Planet" doesn't put food on the table.  But money back to customers makes cheap power available to the lowest-income groups and helps them more than charging local energy-producers over-and-above.

An Allegory

Can you imagine a gas station charging more for a fuel-efficient vehicle to fill there?  

If you drive up with a beastly, gas-guzzling and aging SUV, you pay $3 per gallon.  But if you arrive with a brand-new Toyota hybrid, the gas station charges you $6 per gallon.  

Why?  

Because your vehicle uses less fuel, which means you normally won't buy as much gasoline as the SUV, and it's not equitable to make the SUV pay more than you even though you paid a lot more money for that advanced fuel-efficient technology.  Plus, the gas station has to be able to do upkeep on their pumps, pay their attendants, and maybe occasionally paint the place.  Your more efficient vehicle, they say, costs everyone, and therefore you should pay for it.

How in the every-loving-**** does this make sense?

In Summary

To summarize: We analyzed collected data from an actual month of energy usage and solar production.  At the end of that period, we had - by original design - a surplus of 872 kWh of solar credits, to be used in the darker months of the year or whenever the sun doesn't shine.  

The legislation will eventually reduce this to 50%.  Our surplus is obliterated, and we end up owing 171 kWh to our energy provider for the month in question.  Other months, I predict based on observations, will be far worse.

Our provider profits from our 872 kWh of produced power, by reselling it to my neighbors.  They sold our generated power for $115, without incurring the estimated $57 of generation and fuel costs.  What's more, the tier structure means that if my 872 kWh reduced my neighbor's usage from above the 1000 kWh limit to below the 1000 kWh limit, my neighbors were then overcharged for fuel and energy that wasn't produced by the provider (since the provider makes no distinction on where my neighbors get their power).

As for infrastructure, power lines do not get "used up" like light bulbs, so the lines that supply their houses and mine are not likely to degrade significantly even if left hanging for 30 years.  After all, when was the last time your utility replaced YOUR power lines?  The upkeep here is minimal.

Other infrastructure does require upkeep (substations, transformers, and whatnot), and for that surely a base cost applied to everyone still applies.  There I think we can all agree, and it shouldn't matter if we're consuming the power or providing it.  Cables don't care which way the power runs.

My Convoluted Coffee Making Process...

...Because Java is Good

This is probably not the most elaborate way to make coffee, and I won't call it the best.  After all, the former assertion requires robust knowledge of coffee-making around the world, and the latter is a matter of taste (no pun intended).  However, this is what we now usually do every morning, and I'm recording (and sharing) it here for posterity - and just in case one day I lose my mind.

Beginning with the French Press

My French press holds about 750 grams of very hot water comfortably, enough to make two decent cups of coffee.  I use the French press' beaker to measure out water into my kettle, putting around 2.25 (two and a quarter) beakers-full of water in.  I then heat it up to 195 degrees F.  Use an instant-read thermometer, preferably a digital one, stuck into the spout to monitor the temp.

The Beans, The Grind

I measure around 38 grams of beans to my 750 intended grams of water.  Measuring the beans before grinding works fine.  This is about a 20:1 ratio of water to coffee.  The smaller your ratio, the more coffee you are adding to your water.  A 15:1 ratio will mean that you'll add 50 grams of coffee to the 750 grams of water.  You'll have to work out your favorite, or whatever gets you the most caffeine before your eyes start twitching.

Now, I realize most people use liquid measures for measuring water, but I do most of my measuring by weight, and it gives excruciatingly predictable and repeatable results.

We have an aging burr grinder.  But it works - for the moment.  I do a course grind on the beans, not the absolute coarsest setting, but just a little finer than that.  We've also used store-bought pre-ground coffee (coffee-maker grind), but it tends to be harder to press and might be a little more bitter.

Grind while the water is heating up, or during the preheating step (below) if you have decided to leave everything unattended until the kettle whistle blows.

Preheating the Beaker

By now, your water should be up to temp.  If it's too hot, that's fine.  If it's just below 190, that's probably fine too.  Now, you're wondering why I poured 2.25 beakers-worth of water into the kettle.  It's because now we're going to waste a little for preheating the French press' beaker.  

Pour in a good amount - since I heated up so much water, I pour in as much as I reasonably can.  Let the beaker sit for a few minutes to warm.  The glass will, predictably, get quite hot.  Do not touch it unless you need to wake up faster.  I will put the plunger in and slosh the water in the beaker around over the sink.  Sloshing too vigorously is a good way to test your pain threshold.

If you had heated the water to a full boil, you can either take this time to let the beaker get very hot while the kettle water cools down, or - to rush it - you can add cold water to the kettle until the temperature is around 195 degrees F.  Swirl your instant-read around in the kettle while adding the cold water, to help it mix and to not over-cool.

On my little portable induction cooktop, I often heat to 190, then fill the beaker and leave the kettle on the cooktop at the lowest level with the spout lid open - it keeps its temp and heats very slowly toward 195.

The Pour

Once the beaker is quite hot, dump the water down the drain.  Now add the grinds, zero your scale, and add water from the kettle - I aim for the aforementioned 750 grams.  The temperature should remain in the 190s if you pop your instant-read thermometer in there for curiosity's sake.  

At this point you can set the lid and plunger in place on the top of the press and set a timer for five (5) minutes.  At the end of that time, perform a standard very-very-slow-press (weight-of-hand / gravity-press, but I'm meaty) and pour the magical caffeine-laden tonic into a worthy and deserving cup.

Pouring for Two

I mentioned this makes two decent cups.  The grinds absorb about 50 grams of water in the process, so you can usually get out about 700 grams total.  I put the two cups on the scale and dump around 350 into each.  Or if I'm unsure, I'll shoot for 345 each and then start splitting the extra with back-and-forth pours between the cups.  This works well if the cups are different shapes, as most of ours are.

The Reasoning, and Variations

We had bought some special coffee once from a local bulk retailer, and the instructions on a couple of the bags indicated brewing between 190 and 200 degrees F.  After much playing with that, I now try to stay within that range.  Previously I always poured at 212 degrees and left it for four minutes, but it tended to leach out a lot more acidity.  There is a difference between excellent, dark, strong coffee and obliterated, dark, strong coffee.  Needless to say, I didn't realize what I was missing.

Brewing at or below 200 for the longer time seems to bring out significantly more flavor, without tasting watered-downed or harsh.  I have brewed for as long as six minutes, though I can't remember how I felt about it afterwards.

One site I revisited while typing this suggested pouring at exactly 200 degrees.  However, they did not appear to preheat whatever they were pouring into - which I think were the mugs themselves.  Maybe I skipped over that part, though.  Anyway, the minute the water hits the vessel, it loses temperature.  I did some informal testing of this back when I started preheating the beaker, and was astounded to find double-digit drops in temperature (say, from 190 degrees kettle temp to 160 degrees in the beaker, shortly after pouring, but don't quote me on that).

While we could get very scientific about all of this, and confirm my very impromptu and not very scientific findings, it also doesn't appear to hurt to preheat the beaker - aside from wasting a little extra water (hell, save it for tea later!).  The second pour with the grinds loses very little temperature, the glass of the beaker having already absorbed and not immediately lost much of the first pour's heat.  The result is a slightly lower-temperature water striking the beans, and a (probably) more sustained temperature throughout the brewing.

Also, in the past I used to stir the grinds right after pouring, and then right before plunging.  I don't do either of those now, I just make sure all the grinds are wet while I'm pouring.  A fast, dangerous pour will accomplish this.  

Stirring before plunging seems to just gum up the screen.  Stirring after the pour probably does no harm, other than dirtying another utensil.  And in the morning, I prefer not to have to wash extra things.

Further Study

There is obviously a lot more we could do to confirm all of this.  I could sneak in some temperature probes, monitor the water every 30 seconds for the five minute duration.  I could test also against a room-temp beaker, to see how the water temp varies.  I could try using a double-boiler with one of my glass measuring cups to maintain the brew at exactly 195 degrees, or exactly 200 degrees, or test with temperatures in between, although at that point I think we'd be splitting hairs...

One must also play with the concentration of coffee to water.  I find that - personally - pushing to 40 grams of coffee is just too much and I end up with shoulder and back pain from a strange muscle tension that has been too consistently observed after enjoying a delicious cup of intense java.  Dialing down to 35 produces quite acceptable results, also, so feel free to experiment.

Good luck!

Solar Panels and Heat

 Does Heat Impact Panel Production?

A friend asked me this question.  I felt compelled, as a result, to expound upon it here!

The short answer is: yes it does.  The more important questions:

• By how much?
• Are more efficient panels worth it?

A Tale of Two Panels

As I was doing my research, I wanted to know between the two candidates just how their panels would perform over the hypothetical long-run.  Actual production is affected by many factors:

• Overall panel efficiency
• Heat losses
• Age losses
• Soiling 
• Obstructions

Let's talk briefly about these.

Overall Panel Efficiency

The panels convert solar energy into electrical energy, but not at a 1-to-1 rate.  The photons striking the panel have to interact with electrically-complex junctions, and not all wavelengths are used evenly.  Beyond being a way to compare two panels for scientific purposes, this number is - to the consumer - little more than a curiosity.  

Most panels operate around 19% efficiency.  Some panels tout a 20% or 21% efficiency.  What does this mean to you, dear buyer?  Smaller panels, usually with a larger price tag.  A bigger 19% panel will generate just as much power as a smaller 21% panel.  Unless you're a solar farm and installing a cool million of them, those two percentage points probably won't be worth much.

Do we want more efficient panels?  Yeah, someday, when they're maybe closer to 40% or more, but only so long as they are still affordable.

Heat Losses

Panels lose efficiency as they get hot.  Conversely, they perform better as they get colder.  All panels are tested at a standard reference temperature - usually 25 C (77 F).  Most roofs during the day get hot, and that heat will belong to your panels after they're installed.  Some panels will advertise better resiliency against heat (lower losses).  Are they worth the superior price?

Age Losses

Panels also degrade over time.  This should be a no-brainer (Kansas nods slowly).  But the rate is usually guaranteed not to exceed some amount of loss over some amount of time.  A common standard is around 15% over 20 years.  The loss rate is usually given as a percentage of degradation per year, something like 0.8% per year.

Soiling and Obstructions

These two have no representation on the spec sheets, because the panels can't control where they're installed.  However, for the purposes of generating power effectively, these two factors must be borne in mind.  Panels need occasional cleaning (I'm told maybe once a year).  Obstructions, such as trees, clouds, and adjacent buildings, will affect their performance.

Evaluating

The last two losses - soiling and obstructions - we'll take as constants because no matter what panels we put on the roof, they're all going to be suffering the same fate.  In other words, there is nothing for us to calculate there.  We'll assume that all panels receive awesome, direct light, and focus on heat and age.

I punched in all the data from the data sheets, if for no other reason to see them side-by-side.  Data sheets, by their nature, do not make such a comparison otherwise easy.

The question under consideration, in my case, was "how does the SunSpark configuration compare to the REC configuration?"  We could argue fine points all day long, things like max power, overall efficiency, and annual degradation (which the REC panels all technically "won" on).  But our goal is to produce power over the long-run, and to do so affordably.

Considering Heat Losses

We're given that the SunSparks lose slightly more power (Temperature Coefficient of Pmax) for each degree C than the RECs.  How does this look for daily, monthly, and yearly production?  I present a somewhat unrealistic calculation below, since over the course of the year production varies with the sun's position and duration in the daytime sky.  I also hold constant the temperature through the "day", the "month", and the "year".

Is this a legitimate way to compare?  Well, panel temperatures are probably going to vary the same - or so we'll tell ourselves - no matter what panel we put up there.  Some might even be hotter from being placed directly on the roof shingles, but we'll assume the mounting is essentially identical.  So we can scratch hourly variation off the list.

If a panel is constructed in such a way as to not be as badly affected by the heat, that should be represented by the coefficient - and so there it is.

Second, panels are going to receive the same amount of incoming light no matter what panel is in place. The sun is the sun, clouds are clouds, and a panel can't make power out of nothing.  Even the most "efficient" panel won't convert darkness into power.  It'll just produce more in any light than a less efficient panel would.  For sake of comparison then, it seems fair to keep the incoming sun and the overall module temperature the same.

We see int he above that at evaluation temperature (25 C), our yearly production would provide 43,006 and 36,385 kWh for SunSpark and REC respectively.  Bear in mind there are two different panel populations, with two different costs and overall production targets.  But both arrays are intended to deliver 100% power replacement for my needs.

At 45 C (113 F), panel efficiency is predicted to drop by the given rates.  REC has better rates, slightly, but you can be sure a salesman will make sure you know it!  Our yearly production totals?  40,597 and 34,638 kWh, respectively.  SunSpark lost roughly 2400 kWh and REC lost 1740 kWh.

Considering Age Losses

The 5 year age loss estimate is listed in the table above, but for sake of reference here is the complete table:

At the toasty-hot temperature of 60 C (140 F), the arrays might produce 38,791 and 33,328 kWh for the year, respectively.  Our losses on the SunSpark are greater, but we're still producing quite a lot.  What's more, it hasn't dipped below the RECs, and of course it shouldn't given the specs.  But the aging effects are more considerable.

The SunSparks are expected to lose 0.8% per year, whereas the RECs should only lose 0.25% per year.  That will definitely be in the advertising slick.  But over twenty years, what are the results?  At the temperature we just considered (60 C), this comes to 32,585 and 31,662 kWh expected production for the year, SunSpark and REC respectively.

The Cost of Production

Ultimately, the question we find ourselves asking is: "Is it worth it?"  Over the course of twenty years, the slightly more-expensive array - at first glance - will still be out-producing the smaller, less-expensive array.

There are few things we could do here.  We could up-size the smaller array, albeit at a much more expensive price-point (a 22.4 kWh REC system, which is how large the SunSpark array is spec'd to be, would have cost around $69,753.60).  We could down-size the larger array (down to around $54,256.80 in case you're interested - remember these are rough estimates though).  We could even split the difference.

However, one thing to bear in mind is that panels that produce more watts are also usually larger.  Even with the slightly higher "efficiency," a 370 watt panel is going to be heftier than a 320 watt panel, which means potentially fewer panels on your roof.  Whether this is good or bad depends on your goals.  If you want to squeeze as much power as you can get out of your available space, larger panels might compromise that desire by being too large to fully utilize the available space - think having only a single row instead of a double row, or losing a few huge panels because of vent stacks, chimneys, roof joints, etc.

Another way to look at it is: are the cheaper panels a worse deal?  I think that is an easier to answer question, and the answer here is that they're not.  Yes, there are more of them.  Yes, they will degrade faster over time.  But they are not unreasonably priced and thanks to the larger overall system size, the long-term degradation is somewhat nullified.  That is to say, my overall needs will still be met, ideally, twenty years down the road.  Our goal is then to make sure we've received a good return on our investment, so as long as the system covers our power needs for the foreseeable future, that return will be solid.

Conclusion

This is obviously not a "you should buy this" article, and it wasn't meant to be.  It was only meant to explore and demonstrate some of the complexities when evaluating prospective panels and arrays, and to understand a few of the gimmicks that are used and based off of honey-colored statistics.  Overall, the simplest comparison for the price-focused consumer is simply the cost-per-watt, which is simple and direct to calculate.  If nothing else, hopefully the above shows that a panel can tout absolute awesomeness over the competition, and yes in the end it might not really amount to much.  

Maybe you're aesthetic-focused and can't bear the thought of panels on the front of your house: larger panels in the back might be superior for you.  Maybe a crazy roof is not conducing to large panels, and you need a more flexible layout.  Maybe you are driven primarily by price-point.  Maybe you want to check every efficiency box you can.  Those factors are going to drive your decisions more than the spec slicks probably will.

My First Solar Install - Notes and Experiences (Part 5)

The Ongoing Solar Install Journal 

This post is an update on how the system has been performing.

The Addition of Sense

Part of the way into March, I was talking with my solar company salesman and he mentioned whole-house power monitoring that included solar production - namely, Sense.  Since I'd been looking for a solution (and my desire to build one did not match up with my available time), I went for it.  About $400 later, we had whole-house power monitoring...again.  We used to, with the TED-5000, but it had died a few years ago after a very long and good run of monitoring.

Intense Tracking

Overall, I like it very much.  I prefer to warehouse my own data, which is the only detracting attribute of Sense: it requires a constant uplink and stores nothing locally.  Everything you do with your Sense, you tend to have to do via the webapp or the phone app.  The phone app is, however, very useful.

Aside from totals, it uses machine learning to identify device patterns and can detect when individual devices turn on and off.  With that info, it can tell you how much power a particular device uses over time.  It takes time to get a decent bunch of them found, but all in all it's pretty neat and quite functional.  But since this isn't a sales pitch for Sense (and they sure aren't paying me to talk about it), let's just focus on the graph above.  That's May's recorded usage, and for the most part (i.e. minus a couple hours one day when my firewall lost power before I woke up), it is a complete summary of our use (blue bars, green plug icon) and our daily generation (orange bars, sun icon).  

You can probably ignore the dollar figures - I do... it's based on a flat rate, so I punched in $0.12, which is in the neighborhood but doesn't account for the usage tiers my provider has.

May was, as you can probably tell, a good month.

Generated Credits

We have, so far, not had to pay for a single kWh since the February billing cycle.  We're already up to nearly a month's worth of kWh credits, or around 2,200.

I have been able to fill in a couple of months-worth of bills now, and here are the results:

Thanks to the detail that Sense captures, I can calculate what we would've paid if we hadn't had solar.  Basically, for May we saved around $80.  Once the system is paid off, that will look more like a $350 savings.

System Performance

So far the system is performing beyond expectations.  Lately the generation has been a little more spotty due to daily cloud-cover and thunderstorms, but even with those our worst day in the last seven was 52 kWh, our best 105 kWh, and the 7 and 14 day moving averages (as of today) were 81.8 and 95.7 (respectively).  The 14 day moving average for last week was around 105 kWh, and at the end of May it was 116 kWh.

I have a chart that tracks all of these figures, which of course I hand-enter daily from my inverters:

It's important to note that as long as we're generating more than we're using overall, we're in good shape.  A few bad days here and there does not break the bank, and right now we're continuing to increase our credits.

Our expected and actual power generation is tracked on the Sunny Portal (SMA's PV management site):

Note that for June, the month that we're in, obviously we're still in it and so the total yield bar is justifiably below the expectation.  Also note that January we were technically not online, and February we were turned on part-way through the month.

Comments, Considerations

The guy who came out to rebury our CATV cable had also used my solar provider, even the same salesman.  We had a good laugh and compared notes.  He managed to get his system installed during the 30% tax rebate days.

Overall, I am extremely happy and pleased with the system.  It is operating beyond my expectations and is now at the point of operating basically autonomously.  I only baby-sit it still because I'm neurotic like that.

Batteries

Would I invest in batteries?  At this time, no.  My situation unfortunately (or fortunately, given the cost of batteries) does not lend itself to such an investment.  For what it's worth, the power company is my "battery" and since I'm feeding in more to the grid than I'm using per day (most days), I really have no qualms about not running my own battery bank at the moment.

I would consider investing in them if the prices dropped dramatically, or an alternative energy storage solution (alternative to typical batteries) became readily available.  I've read about one that uses pumps and a special liquid, but the tech isn't really ready for production yet.  That said, the only time batteries would benefit me here is during a major outage.  So, let's hope we don't have one of those...

The Panels

Do I like my entire roof covered in panels?  Why yes, yes I do.  To be perfectly honest, I've never been a stickler for aesthetics, though I have developed a more critical eye in my older years.  That said, I want power...lots of power, and so I put as many panels up there as I legally could.  Given how much power we are able to produce, and the fact that we've zeroed our bill the last few months, I have no regrets.  And as long as we continue to zero our bill through to the end of the year, I will continue to have no regrets.

The Electric Car

I've had a few people now ask about our solar.  They also get excited when they see my little Focus Electric charging in the driveway.  "Oh man, and you charge this with your solar, don't you?" they ask.  No...not really.  Sorry.

The car doesn't care where it gets its power from, and my charger unit (an OpenEVSE box), runs off the mains.  The grid-tie doesn't give me the option to run separately, though I think SMA might offer some solutions to that effect.  That said, given the credit system with my energy provider, why bother?  Currently I don't drive it much, so it doesn't draw any more than what is necessary to keep the battery topped and cooled during hot days.  When I was driving it daily, I'd chew through the 22 kWh battery almost completely.  That said, it was probably more like 18 kWh, since you can't run it to zero.

18 kWh per day off our current generation totals would probably hurt a bit, but it looks like what we're generating would more than cover it.  Even if it didn't, even if we were breaking even with our usage and generation, and the car us over by 360 kWh onto the bill, that'd be only like $50 a month.  Still way cheaper than gas for doing 50 miles a day for 20 work days.

Other Solar Tech

One of the other companies I was looking into called me and wanted to know if they could close my file.  I'd already let the guy down once, but I guess he was a glutton for punishment.  And once again I filled him in on what I bought.  He let out a most annoying groan when I told him I'd gone with string inverters (his company does optimizers).

Now, here's the thing.  I've read the sales and specs sheets myself, I've studied the tech, and I've read what is apparently the only available research out there that bothered to compare these types of systems.  Obviously, the industry in general - and the solar research institutes in particular - need to do better here.  But given what I learned, and my specific situation of full sun all day long (barring clouds), I had and still have no reason to believe that optimizers or microinverters would win me much benefit.

For kicks I tried to figure out a way to perform a comparative calculation between the two proposed systems (the one I chose, and the one I didn't).  I decided that the two most sensible numbers to use were the system design watts, and the total expected production in kW.

Dividing total expected production by system design, we end up with two almost-dimensionless figures: 1.388 and 1.407 expected kW per design watt, chosen and not-chosen systems respectively.  What this basically says is that these two systems are nearly identical.  Over the course of a year, I should get almost the same kW per unit design watt.  In other words, the optimizers would have to do something very special to provide me additional benefit.

My system is the lower of the two numbers (1.388), and yet because we could afford more panels, we wound up with a better overall value.  We should generate around 4000 kW additional power over the course of the year, or about 1.6 months-worth.

Now, the problem with the above calculation is that I really don't know how well one can expected optimizers to...well...optimize panel output.  So many of the major worries that are thrown at prospective customers - such as "a single bad panel will take out a whole string" - are passe.  The better panels have bypass diodes, so that isn't a problem.  A weaker panel might slow things down a little, but the underlying question is: how much loss do you have to incur to make the optimizers worth it?

I won't go into a bunch of "what if's" here, if only to keep this readable and on-topic.  What I can say is that this is where we need more research, and unfortunately the only research I was able to find, when I made my decision, basically strongly supported the string inverter technology.  SMA also recently started advertising shade-fix boxes for individual panels, which are meant to act almost like optimizers but can be used on a panel-by-panel basis (instead of having to attach them to every panel in your array).  Do they work?  Are they worth the money?  I really can't say.

What I can say is that given the overall costs of the two candidate systems, and the expected outputs and performance to-date, I have no regrets with choosing the technology that we did.

Moving Forward

I'll update this blog again once a few more months have passed.  At this point, anyone following this should expect business to proceed as usual: the panels will keep generating power, my bill will remain practically zero, my electric car will be sitting in the driveway doing nothing much of anything.

Daydreaming

If I were to be in a position to build my own community, I would definitely do this:

• Put solar on every house and centralize the upkeep of them all - basically give the people living there nothing much to do other than enjoy the benefits.
• Work with the local energy provider to set up a local-to-the-community battery substation, sort of like what was done in Australia (though theirs was, like, state-sized).

The key benefits I'd be looking to extract from the above would be:

1. With solar on every roof, the community generation should be utterly fantastic - far more than what the community as a whole would or could use.
2. With a battery substation, we'd be in a position to offer community-wide power during outages, for as long as the batteries could hold out.
3. The battery substation could also be useful during brownouts or whenever the main energy provider needs a bit of a break on the grid, or to supplement the provider during the evenings/nights.

Of course, to achieve the above, you'd need the community to pay into it, either via HOA fees (egad, I hate HOAs), or as a community "power bill."  Without running the numbers on upkeep costs (mainly for the batteries), I couldn't say what that number would be.  But as soon as the solar was paid off, the batteries and other infrastructure would be all you'd be on the hook for - aside from the occasional re-roof job or when panels start to wear out.