1) It vastly overestimated how big a solar system that could fit on my roof (by about 5x). It didn't care about chimneys or skylights (which are easily visible through Google maps), nor SF fire code which states that you need a 3-foot empty pathway on both sides of the crest of your roof . So for almost every roof with a single ridge, this will cut out a large percentage of the best solar real estate.
2) It didn't include local SF providers in the marketplace which are generally higher rated than national providers and can offer additional SF incentives and cost-savings.
So while the estimation of sunlight potential is really cool, the 3d modeling aspect and size of the marketplace leave a little bit to be desired. This site would probably be good at quickly seeing if your roof has any solar potential at all, but if it does, I'd recommend checking Yelp and having a highly-rated solar company come give you a detailed estimate (which would be free).
For the former it doesn't really matter how much you can cover, as it's simply an investment with a certain rate of return that has the amount you can invest limited by roof area.
However, the marginal cost of things like engineering, installation and inspection will certainly go down with the size of the system. How much of that passes to the consumer I don't know, but some of it certainly does. You can imagine the cost of putting 1 solar panel on your roof is not going to be 10x less than putting 10 of them up there.
It is hard to get exact numbers from solar sites as they are very sales-oriented, but it seems like the hardware cost is estimated at anywhere from 20-50% of the total cost of the solar system. The rest of it is engineering, installation, inspection, customer acquisition, profit, etc.
The people who think our current use of coal is "cheaper" are economically ignorant, as it generates many dollars of externalities in pollution that affect health. That cost is born by taxpayers, so by avoiding it, the country saves money and in return passes some on to the person with solar on their roof.
I personally would prefer the more direct and elegant solution of a revenue neutral carbon (& GHG) tax, rather than the current tangle of overlapping regulations, but the immediate result would be the same, people with solar installations would be better off than those who didn't since they'd not need to pay the cost of carbon for electricity they generate themselves.
Not to mention that huge ecological damage also has cost someone will have to pay eventually.
So as long as you still believe in your country (which will pay its toll) or your children (which will pay their toll) from that, there's a hidden cost there too.
You walked into a conversation about the impact The Beatles had on music recording technology and said "yeah but John Lennon was horrible to his wife". True, and it's an important point to make. Just not in this conversation.
First, the discussion is precisly what the "people jumping in" contribute. This is not some closed circle of pre-determined friends, it's a public forum. Anybody can jump in. Note how the subthread wasn't even about the original post (Project Sunroof) in the first place, it had been diverted in discussing costs.
Second, I don't see how saying essentially monetary costs are inferior to environmental costs is "changing the subject" much less "completely". It's still about costs in general, and it's still about monetary costs in particular (it's about whether the extra monetary costs are worth the environmental impact, and it's also about the hidden indirect monetary costs from environmental damage).
>You walked into a conversation about the impact The Beatles had on music recording technology and said "yeah but John Lennon was horrible to his wife". True, and it's an important point to make. Just not in this conversation.
In your contrived example, what Lennon did to his wife has no relation to impact of Beatles on the music recording technology.
Whereas environmental costs are still costs (and even have a dollar value, even if implicit). Plus, they are still something to think about when deciding if something is "too expensive" or not.
So nothing like what you suggest at all.
Do you only check the price to determine "expensiveness"? Not build quality, materials, features, and among them, social issues, like environmental impact and working conditions?
"the claims that these systems are "cheaper" prey on economic ignorance."
That's the original assertion. Now, if alternative power really was cheaper than coal or oil, we would already have it because businesses would be stupid not to flock to the cheaper option. Instead it's fringe enough that people hold serious debates about whether or not it's a good idea to invest in it. Everyone would drive a Prius if it was cheaper. Everyone would have solar on their roof. But hardly anyone does, because it's not cheaper.
You want to talk about externalities, let's do that: from an economic standpoint, they don't matter. Because the people who are paying for the power plant aren't paying for the pollution. Until the day we hold them accountable and make them pay for the cleanup, traditional power sources will always be cheaper.
So there's your discussion on environmental costs when you're talking economics of power sources. It doesn't even come into play. I drive a gas powered car because a gas powered car is cheaper. If I had an electric car, the power would come from coal, because coal is cheaper. The ship that transports the coal to my local plant is powered by diesel, because diesel is cheaper. And no where along the way is anyone forcing anyone to pay for the cleanup of their mess.
Now you want to talk morals? Yes we all should be embarrassed and we should be fined high and low for what we're doing to our environment. Shame on all of us. You know how often I drive my car when I could have walked? What the hell is wrong with me? I hate myself sometimes. But no one is making me pay for the damage I'm doing. Force me to pay for being lazy! Force the price of gas up, the price of coal! Force solar and wind to be major forces in power generation! But until that day happens, environmental costs are irrelevant when discussing the microeconomics of solar versus traditional power. Traditional power wins every time when you're talking real, direct dollars.
For example, Sunroof estimates that a 5.75kWh system would cost $21,500 before subsidies (about $15k after, but we're ignoring that), and that it will save you (gross) $60,000 over 20 years in utility bill costs. You can either:
a) Invest that capital. At a stable 7%, after 20 years, your balance would be about $86.8k.
b) Purchase a solar system for that $21.5k, and invest the difference on your power bill each month. Assuming a base power bill of $200, and the 2.2% annual rate increase that Sunroof uses, you would invest $2400 the first year, $2452.80 the second year, etc. At the same 7% return, then in 20 years your investment balance would be $122.8k, and your power bills would continue to be $0. Remember, these numbers assume an unsubsidized system.
The gain comes from the fact that after the break-even point (at year 12), you are continuing to invest your power bill equivalent, rather than paying it to the power company, whereas in the non-solar case, the increased power bill will never earn you a return.
The downside is that it (with those numbers) takes 12 years for you to come out ahead, and solar tech is moving so fast that the opportunity cost of committing capital to solar today rather than investing it and then liquidating that investment tomorrow to pay for a cheaper and more efficient system may be substantial, but is arguably specifically unknowable. If you don't offset your full cost, the numbers change a bit, as well (but you can certainly compute what happens at a 50% offset for a smaller upfront capital investment easily enough, as well). There are certainly scenarios in which solar is viable unsubsidized today, though.
Feel free to check my math and assumptions: https://docs.google.com/spreadsheets/d/1JoJxX5t7VmRhV1LDI1UF...
This addresses your point about upgrading. You can install the newer system on another roof, without incurring cost of removing the older system, and generate power (and therefore income) from both panels at once. As long as the older system is generating more power than its annual maintenance cost, it doesn't make economic sense to dismantle it.
Decoupling also means that if you decide to invest in solar energy, you can have it installed in whichever part of the world (or at least your country) gives the greatest ROI: the most sunlight, and the highest electricity tariffs. Maybe you live in a rented house or an apartment where you can't install solar panels. Giving a higher return will encourage more people to invest in solar.
Other advantages of decoupling will be the ability to invest the amount you want, whether $1000 or $100K, rather than the price of one solar system, the ability to make additional investments if you have more money later on, and the ability to liquidate an investment any time you need the money, or in a financial emergency. People will also be able to dip their toes into this market with a small investment, and see how it performs, before making a larger investment.
In essence SolarCity and everyone else bids for your roof and business through their pricing. (which currently undercuts utilities).
And SolarCity in return is creating solar bond products essentially, where the market can invest their capital in these roofs that SC is producing energy on, with the monthly bills as interest.
But it doesn't solve the issue the person you replied to highlighted, which is that it may or may not be financially advisable to 'hold out', and buy solar when the price has come down. After all, even if you don't buy and own the panels, the lease is still a 20 year contract. And there's no way SolarCity or any company would reduce those to short-term contracts because there are fixed costs that can't be recuperated in the short-term, meaning you need long-term contracts to get an ROI. (sending technicians to replace installations every few years wouldn't make financial sense).
So the end result right now is that yes, you could in a way (by investing in solar companies or their financial products) invest in other people's roofs, despite not dismantling panels on your roof, in say 5 years from now when new installations are financially better performing than your roof panels. But it doesn't magically make your investment in your own roof (or anyone's roof, 5 years ago, for that matter) disappear. The money is still locked up in that roof (whether you paid for it, or locked up money by signing a 20 year contract), and so merely decoupling everything doesn't solve that issue, and in many ways we're already decoupling to a large extent with the securitisation of roof installations.
As for money locked up in solar panels, that's no different from traditional investments. If a factory is built, a better factory may be built a few years down the line, rendering the first one an inefficient use of capital. That's an unsolvable problem (unless you have a crystal ball), and it doesn't deter people from making investments. What makes solar different?
The Google site is extremely thorough -- for the case where the consumer is buying the panels, they calculate the time to break even, but also a net present value given a 4% cost of capital. Same thing for the lease cases -- for an example I ran, the lease would cost $96 per month (fixed for the 20-year life of the lease), and offset $115 of a monthly $120 electrical bill at today's rates. So, it would generate cash savings for me from day one. Most solar leases in fact GUARANTEE that you will pay less for electricity after the install. So, "savings" should not be in quotes, it's a real savings for the lessee.
As for your argument that we might all be better off if we didn't have to pay higher taxes for the subsidy -- maybe, but my decision to install solar or not is going to have a negligible impact on my personal tax rate, so I should value any savings against a fixed tax rate that doesn't change as a function of my decision.
-- fossil fuel prices would drop, since demand would fall
-- we would spend less tax money on grants and subsidies for oil and gas marine terminals
-- fewer emergency responses, disaster clean ups, etc. for fuel transportation mishaps
-- maybe we could avoid or sit out the next land war in the Middle East ...
Additionally, even without a tax subsidy, installing solar on my roof in CA would generate a positive NPV over 20 years. Here in CA, it's just plain cheaper than the utilities, even without the (nice to have) tax subsidies.
Now how much electricity is generated from oil in the US? A whopping 1%.
Now while it is true that we import a lot of natural gas...
"Natural gas imports to the United States, 98% of which arrive via pipeline from Canada, have decreased almost every year since 2007, and in 2014 reached the lowest level (2,636 Bcf) since January 1995."
According to http://www.eia.gov/naturalgas/importsexports/annual/.
So if you think putting solar on your roof, or wind, is going to make any OPEC countries upset please think again.
For one, a major part of energy use today is non-electric because it makes more sense to use fossil directly, than to use fossil to generate electricity and use that. But once you have cheaper electricity than fossil, and cleaner, you can start to see these industries shift towards electric.
Not everything is susceptible to that, like say chewing gum made of oil partially will not go electric obviously. But transportation likely will, and heating could possible go renewable (not necessarily electric. e.g. geothermal, solar thermal etc).
And so the cleaner electricity is, the fewer barrels of oil one would need in some non/low electricity industries right now, transportation being the biggest.
Secondly, it's true that the majority of US oil isn't from the middle east, but that doesn't mean it doesn't matter to the US, that's a silly argument to make. What happens if the middle east produced 0 oil the next 100 years? You can't say 'who cares', obviously the world would go into a state of shock. Oil prices would skyrocket, production and consumption and worldwide trade would all drop sharply and recessions would break out. Which leads to unemployment, social welfare issues, friction, don't even get started on wars between countries, civil wars would be damaging enough.
The 1970s showed how brutal oil politics could be to the economy, and that was small-scale compared to the most far reaching scenario.
And beyond that, anyone who exports to the US, like Canada, would think twice, after all why not sell it to China who's willing to pay $500 a barrel, too?
Also, even if you don't import the energy yourself, that doesn't mean the US can't profit or doesn't profit when US companies are involved in the oil industry in the middle east, even if the region doesn't export the majority of its oil to the US.
And lastly, even if you don't import it yourself, you may want to control who has access to the oil, and in what currency it's sold. You wouldn't mind Germany selling Nuclear reactors to the Netherlands or vice versa, it's a different story for Iran. Just like you might want to have some control over oil reserves because your control means China doesn't have it, despite not being a top customer yourself.
As for the final point, the concept of petrodollars is real, and the fact oil trades are denominated in dollars, and the effect the standing as a reserve currency has on the US is significant.
The US doesn't have to be a customer of middle east oil to have a benefit in controlling it, that's naive and it's getting a bit tiring to see everyone act like you're a dumbass when you make this claim, always immediately pointing to charts of Saudi Arabian and Iraqi oil imports being so small compared to 'omg lol US production & Canadian imports, you're so dumb, bet you didn't know that'. Don't get me wrong not saying you do this but it's a common theme when discussing the issue.
And really just look at history. You don't have to be a conspiracy theorist to look at the middle east and conclude oil plays a role. When Iraq was getting decimated on forged evidence of WMD, guess who was developing WMD, admitted having WMD, and tested WMD, not just any kind but the nuclear kind? North Korea. Otherwise a beacon of democracy and human rights and quality of life. Comparing the eagerness and focus on invading this country and Iraq is telling.
I mean do you really think trillions of dollars were spent on an intelligence fluke? Or that the carter doctrine was some minor policy plan that has nothing to do with oil?
Besides it's not like this is a secret. People like Cheney openly talked about the importance of controlling oil reserves, how demand would outstrip supply in the coming decades, and talking about how 2/3rd of oil is in the middle east and that access is important. Which brings up the final obvious point, which is that the US isn't running energy policy because of today's needs, but the needs in 50 years from now, so pointing to today's import charts is not comprehensive enough an argument.
So hell yes, renewables have a substantial impact on all of that. They're not the entire story, but a substantial part of it.
Subtract out the $5028 Federal tax benefit, and you are still left with a $7000 20-year NPV (assuming 4% cost of capital).
Still a positive ROI over and above inflation, even without a rebate.
For example if you pay $50k for your installation, you could depreciate it within 5 years or so by 85%, which reduces your tax payments in total, at a 35% tax rate, by $15k.
That's $15k saved, whether you call that government support depends on whether you think that's 'normal business depreciation' or 'solar specific fiscal policy' I guess.
Same with RECs, they're government support in the sense the government sets requirements on companies to buy them, thus creating a market for solar producers to sell them. This isn't energy being sold, it's more like a carbon tax thingy. You could see that purely as a tax on non-renewables (which imo it is), or as government support to renewables (which it's technically structured as).
So the federal tax benefit, while large, is far from the only incentive.
... And again, to compare apples to apples, you'd have to tease apart the tax benefits given to existing energy companies over the years to get a real accounting.
And it's import to note that the biggest solar companies right now aren't residential, but utility, so we're not talking about some niche aspect of the industry here.
And even the biggest residential solar companies their main products are leases right now, meaning they do get to depreciate their installation costs and then either let you rent the panels or buy electricity from them.
So in the vast, vast majority of installed solar panels, depreciation plays a gigantic role.
As for SRECs, you could sell them actually, don't need to be a business to do so.
Bloomberg new energy finance talk slide deck:
Coal companies never pay for the damages to the environment their huge quarries do...
Subsidies for solar are just one part of it.
If you take these subsidies that you give the energy companies, and add them as tax to the electricity price, you end up with electricity costs like in Germany – 0.40$ per kWh
In Germany, the effect is even stronger: As we are taxed per kWh, the electricity is quite expensive. On the other hand, this money is then spent on subsidies for solar and wind. Overall making solar and wind so extremely cost effective that anything else becomes stupid.
And, at the same time, it leads to people saving really a lot of energy. A family of 4 using 3000kWh per year or less is common.
For example a cost of 15c per kwh cost from solar is pretty trivial in many parts of the world nowadays. But here's the thing, for example in the Netherlands, I pay 7c per kwh for electricity, and then about 13c in energy specific tariffs, and then VAT on the whole lot. My final electricity price is about 3x (22c) the cost of the electricity itself. But for every kwh I generate myself and don't buy, I save 22c.
In other words, at a hypothetical cost of 15c per kwh, twice as much as electricity from my utility, I save almost half of my bill.
That situation differs radically between countries and even states, but again, savings on solar are a very typical story nowadays. I'd say most solar buyers today are saving money. 5-6 years ago that was different, when most people who bought were still buying with a moral position in mind and paid a slight premium.
Mostly, I don't think people realise how incredibly subsidised solar is. Per unit of energy generated, direct taxes/subsidies are much, much higher than oil. The other part of that story is that we have path dependency in oil and that the carter doctrine has cost trillions of dollars, and that externalities aren't priced in much for fossil. (e.g. cost of pollution, droughts etc).
For example, here's an interesting thought. For every $1m you buy in solar, you get about half a MW in capacity, which generates a little under 1 GWH per year (rounding it up very heavily here but you'll see it's mostly irrelevant). Now here's what that means. First of all, you can get a 30% tax credit, which you can sell. That's $300k recuperated. Then on a portion of the cost, 85% iirc, you can depreciate within 5 years or so. At a tax rate of 35%, that's a total of $300k in tax avoidance due to depreciation. So right off the bat in tax structuring, you've already gotten more than 50% off. Then, your almost 1 GWH per year generates solar credits, which you can sell, too, for about $100k per year. And yes you can presell these for 10 years into the future.
And then and only then, after you've paid $1m, received $600k in tax back from the government and sold solar credits for just the first 10 years for $1m (on a system with 20-40 years of lifetime at least), when you already made $600k accounting profit without generating a single electron, then you can start to actually sell the energy to an offtaker (like an Amazon warehouse) for about 10c per kwh, making you a little under $100k a year.
So you invest $1m, you get $1m, you get $600k in tax benefits and annual income of a little under $100k. Sounds insane? Well it sort of is. It depends on the state, some states are crap (low cost of electricity, low price of solar credit market, little offtaker demand, few solar resources (sun), difficult regulations etc etc), some are great.
And beyond that, solar is simply becoming cheaper really fast. For example, SolarFirst just signed a contract for a 100 MW solar project at a kwh price of 3.8c. Pretty insane.
Anyway in short the notion that solar savings are disingenuous is completely false. In fact virtually all of the big solar companies offer leases right now, where you pay nothing upfront, you don't own the panels, but you lease them on your roof and pay an electricity bill that's lower in the vast majority of cases than your utility. That's their main selling point.
Though it hasn't been inspected or turned on yet (happens later this week), so I'll see how close their projections were to reality over the coming months as the juice is generated. I did my own projections independently and found that their projections seemed to be on the conservative side, so I'm optimistic.
granted it is in dutch and made by a completely boring governmental institution. OTH it's made with openstreetmap.
It is a very impressive site.
"1,960 hours of usable sunlight per year"
I wonder how they arrive at that number, and how accurate it is? Anyone in SF want to try a few addresses in Outer Sunset vs the Mission?
I'd be interested in seeing that number alone mapped out over the US on a zoomable map.
At one level this was "fine" in the sense they were totally ok with that and felt they were obligated under California law to do so. At another level, "solar rights" ala "water rights" or "mineral rights" for a property are probably going to become a thing at some point.
In your case, if the trees around you fell down for some reason, you install solar, and the landowners/city replant trees, by virtue of the fact that your solar is there it will impose a trimming burden on the new trees. But there is no requirement that people clear trees to make it possible for you to exercise your "solar rights". That is the next kerfluffle I expect in California.
Let's not be cutting down the carbon dioxide remover when we're trying to go eco-friendly. :)
Which reminds me. If anyone knows a good way to retrofit an house with no ducting and no natural gas for any form of efficient heating, let me know.
I have lived with such a system before for a year and it was both easy to use and did a good job of heating the space. I don't remember the electricity costs so I can't comment on the economic efficiency, but AFAIK it's moderately good. I wish I had it in this house instead of the noisy, draughty, and inefficient gas-powered duct heating which I avoid switching on whenever possible.
That said, I had a instructor who's friend bought a house out at the beach 30 years ago. He didn't know what to do about heating.
He decided to put a large diesel tank on his property, and use that fuel to run a boiler. He installed baseboard hydronic tubing. He was very happy with the heating set up.
His previous system was electric, and his monthly bill was
outragious.(electrical rates really do vary from area to area.)
He also had an old Mercedes diesel automobile. One day he used the heating grade diesel for fuel for his Mercedees. His car ran fine. He was paying someting like 35 cents a gallon for gas. He used that car to commute for years. There are no taxes on the heating fuel, or at that time.
(That 35 cent quote is from a story told to me 20 years ago. I don't know if heating diesel was ever that cheap? I was told this story from a instructor who I don't completely trust. He tended to embellish.)
That said I always thought if I lived in an area where I couldn't use solar, or natural gas; I would definetly use a boiler, with propane, or diesel fuel? They make condensing boilers that are very efficient. I installed one and it wasen't that hard. I don't know if a condensing boiler can use diesel fuel, but I know you can use them with propane.
If you decide to do the work yourself; buy the third edition of Modern Hydronics. It's expensive, but go for it. Hole yourself up in a room for a weekend, and read that book. It's geared for large hydronic installations, but will handle residential installations fine. Hydronic heating is really under utilized, especially on the west coast. It's a great, energy efficient way to heat a home. I bought a fancy condensing boiler and happy with it, but I have a feeling I could heat a house with a water heater if your have enough baseboard, or tubing? And you live in a temperate climate?
Of course, hire a professional if funds are tight. Make sure the professional knows about boilers, and hydronic heating. A good first question for the contractor is what brand of 02 sensor he/she uses to calibrate the boiler. If he doesn't immediately come up with a answer, or looks confused--run. The second question should be "could you write down the what a primary/secondary hydronic piping configuration would look like?" Verify he knows what a primary/secondary system looks like, and why it's important.
Hydronic heating is vastly underutilized in the U.S., at least in California? I don't know why it isn't used in more situations? I guess engineers feel that if you are going to need air conditioning, why bother with it? I have heard incorporating air conditioning with hydronic heating is not that difficult? As to keeping zones at different temperatures, I did not find that to be a problem if you run your zones correctly.
(One other painful lesson I learned by relying on wood burning too long. Don't buy a cord of wood off Craigslist. I guarantee a guy will show up with less than a cord. If you are forced to use the fireplace; put a insert in.)
Presumably you have to piss off a cop in your diesel-powered vehicle enough for them to test your tank.
I'm not very far from the gas lines, just on the wrong side of the street, and digging up the street is expensive.
Oil burning is more expensive than using a modern-day electric water heater, by the way. Oil has gone up in price and electric heaters have gotten much more efficient.
"25982. After the installation of a solar collector, a person owning or in control of another property shall not allow a tree or shrub to be placed or, if placed, to grow on that property so as to cast a shadow greater than 10 percent of the collector absorption area upon that solar collector surface at any one time between the hours of 10 a.m. and 2 p.m., local standard time."
There are a number of exceptions later in the act, including a notification requirement.
However, once a solar system is installed - a neighbor can't cause the system to be shaded with impunity.
EDIT: I also doubt the calculations are correct considering that city hall's roof is many times larger than the two homes I looked at, yet saves less money.
This has clearly been designed for residences and not larger buildings.
That said, it would be super helpful if they marked addresses as "already have solar" so I would stop getting robo-calls from solar companies trying to sell me solar panels.
I know nothing about solar technology developments. I am interested in adding solar to my house some day, but concerned about spending a lot of money today for solar panels that will either (a) be much cheaper in 5-10 years, or (b) be replaced by much more effective panels in 5-10 years.
Assuming that the economics of it are the only motivation for going solar, and that with current technology and pricing the panels pay for themselves only after ~10 years, am I better off waiting a few years to get more efficient/cheaper panels, or is it unlikely we'll make significant advancements in these areas, and/or do current government incentives (which may be ephemeral) make up for the advantages of future tech?
If you only care about the financial decision, then to be honest... not much beats investing in e.g. a broad S&P 500 tracking index. 7% inflation adjusted annual returns + dividends which you can reinvest to go up to 8-9%. Over a 20 year period that's 5x. I'd tune that down to 4x given there's risks and historical returns have been better than they probably will in the future. But it still means at 4x that your $15k solar installation could also have made $60k in the same period.
And there's no way a $15k installation will generate $60k worth of energy, somewhere between $10k and $20k depending on the cost per watt, solar capacity factor and local energy prices. (California does quite nicely and is on the upper end of this spectrum). About a third you get back from the gov, so in a 20 year period in Cali, investing $15k (subsidies included) you may get $30k-$35k in savings if you go solar.
It's really nice but it doesn't beat the market, and most states have cheaper rates than California which is like 30% above average and much fewer sun hours, and less competition, too. Wouldn't be surprised if installation costs were relatively more competitive in California.
So my point being is: 1) it's a great investment and I'd personally go for it. 2) it's, purely financially, not the absolute best way to spend your money, even if it saves you money. So there's still an element of 'I think solar is important' at play. 3) solar tech will get cheaper, but subsidies will fade out.
At the same time, tax subsidies are scheduled to start phasing out, and utilities are making noises about discontinuing some of the more favorable rate plans that allow 100% net metering (generated power is credited at the full retail rate, not at the wholesale rate). Either of those changes would negatively impact ROI.
It's hard to know what will happen in the future, but with the current environment, many people can lock in a favorable 20-year ROI for a system today.
No one can predict how much the landscape can change in that time and I wonder if Googles 20-year savings model tries to account for predicted advancements -- and also importantly if their "savings" accounts for the time value of money -- the amount that could be had just by investing generally instead of investing in your own solar. Time to investigate....
Edit: Google "Assumes 2.2% annual increase in electricity prices." That's interesting. We should be talking present value terms so inflation is irrelevant. Are they assuming no tech advancements in the next 20 years? What would be driving up those costs other than inflation?
Right now, I'm at a point where I need to use a FLIR to investigate more improvements after which will I then think about solar but it's nice to read up on solar improvements.
Modern lightweight truss construction fails so quickly under a fire load, we're unlikely to make an aggressive attack if the fire has been burning in the attic space for any length of time, panels or no.
My father in law did the volunteer fire dept thing in his rural area and its very depressing how quickly a typical house becomes unsaveable in a fire. So it is true that most houses with solar panels, in a fire, will end up a total loss, but that's true of most houses ... period, nothing to do with solar panels.
My advice from the frozen north is solar panels are extremely light weight compared to slush/snow covered shingle roofs, which don't seem to slow down firemen very much. The total mass of a couple inches of rain soaked slush snow is unbelievable, many thousands of distributed pounds on a typical roof.
I have no idea if this is a common thing or not. Anyway, thanks for the PDF, very interesting stuff. Assuming the car is energized seems sensible. Even with a loop like Tesla has, I imagine you can't count on that having the intended effect after the car has crashed.
You can watch a Tesla get cut up in this video:
I care little about the house in a fire. I do care about its occupants, and also the safety of the firefighters attempting to extract anyone still inside.
If the latter then the cost savings are a bit less impressive than stated.
Also can you put power back into the grid in San Francisco? Is that benefit included in the cost savings estimate?
You can sell power into the grid but PG&E only has to pay you wholesale rates, 3-4 cents per kwh, not what they are charging you to take the same amount of energy out, which is 34 cents per kwh at the top tier. It's basically a scam. You don't want to overbuild on the assumption that selling the surplus would be profitable.
Why is it a scam that PG&E won't pay you more for power than they can buy it wholesale?
Anyway, to my mind, any system in which current comes out of your PV installation at 3 cents and flows directly into your neighbor's air conditioner at 34 cents is a prima facie scam.
edit: I'm more familiar with the Texas grid, but beyond the cheapish price of modern peaker plants, in that case the most expensive input sources (small peaker plants, and esp. spot-market purchases) are rarely used at all. Demand prediction and management is good enough to avoid the more expensive inputs, through a mixture of local generation management and advance wholesale purchases on the DC interconnects. On the handful of days when some issue causes a shortfall, it would be valuable to buy residential solar inputs, but this happens about 5-6 days a year. To handle those days, most utilities have a savings-rebate program, where if you agree to reduce your usage between 2-5pm on these handful of days, you get a $0.60/kwh credit. So they solve their occasional peak problem by just turning your thermostat up 2º and "buying" the unused energy at a premium price.
This data may not be publicly available, but I'd love to see graphs of current flowing out of PG&E substations vs. time of day. At some point the PV generation capacity is going to make them have weird upside-down diurnal cycles.
Also in the winter if I have "free" electricity and have to pay for natgas to heat, I'll simply buy a raid array of plug in electrical heaters to eliminate that "free" electricity and eliminate paying for some natgas. Or maybe I'll just install a bigger raid array. Either way, I like free heat in the winter and typical analysis usually doesn't consider heating. If you pay me 3 cents per KWh in the winter, and charge me 15 cents equivalent in natgas energy, I'm not going to sell you a single KWh until my house is above 75F in January.
But you can use heat pumps, and you can do deep storage of summer heat, for use at winter (no idea about how well it works at your place). Both are very efficient.
Anyway, if your marginal price for electricity is zero, and the marginal externalities are also zero, there's not much problem in using it.
I'm not saying you can't do it, but even with today's cheap solar panels it's not likely to be a good value proposition.
In the limit of course (too cold outside), a heat pump is just as efficient as using the electricity for heat directly.
There are of course large-scale infrastructure costs (you get to fail-over to nuclear/coal/gas/wind/other), but it seems like all of those things should be accounted separately instead of all being lumped into two line items on a monthly bill from your local monopoly.
This actually works in your benefit if you have solar panels, because electricity prices are higher during the middle of the day (more demand). So you can "sell" daytime electricity (at high prices) , and then buy electricity at night which is much cheaper. This actually is the main benefit of the battery if you are connected to the grid, you can do the same thing.
1: You don't want to sell past your own consumption though otherwise you get paid very little for it
This is important with solar system sizing, because not only don't you want to be a net exporter of energy, the lower tiers of PG&E's energy rates are very cheap so you don't want to generate that power either. You really only want to offset the high-tier, high-demand electricity you use (or plan to use in the future).
For me it didn't really matter because my energy usage is highest during the peak times of the day, but this is my understanding of how it works. I'll know for sure in a couple of months when I see my bill :)
Right now in the Bay Area, almost everyone is using net energy metering (NEM). You get a bill once per year, and they balance out your usage vs generation, and any extra usage is charged.
There is a minimum you have to pay each year, so most installers aim for 85-95% of your usage to be generated by your system. As other folks have stated, it's not advantageous to sell back to the grid given the low price - as such, very very few people actually sell back to the grid, and instead make a small purchase each year, and mostly at off-peak rates.
The guys behind this apparently wanted to know the best place to go for a beer at any time of the day. They use the zenith of the sun, the surrounding landscape and the surrounding buildings and have it modeled throughout the year. I think they then realised there may be more useful ways to use this data.
It's a "start"
Edit: Note this: https://www.google.com/get/sunroof/faq/#financial-considerat...
> As with any investment, there are some risks, though a well-installed system will make most risks extremely rare. Risks include PV systems catching fire, installations leading to roof leaks, theft, obsolescence, and hail damage and/or wind damage to the solar system itself.
> Fast-growing trees can shade solar installations, reducing production over time. Utilities can change how much they charge their customers for electricity, changing the savings from solar.
1) Performance - best performance is when the wind blows in a straight line, houses and other features will deflect it making it turbulent.
2) Noise - turbines are noisy, you're not likely to have neighbors appreciate it.
3) Mounting - Mounting one requires either a pole, or it can be mounted to the roof. However, roof mountings tend to cause issues (read damage) due to vibrations transferred through the mounting.
Not good for a residential neighborhood, but perhaps if you've got several acres of clear land?
This is assuming you get adequate sunlight, which we do here in Denver.
The short version is this: Property owners now have shocking amounts of control over what their neighbors do with property. Owners, especially of single-family houses, elect officials who restrict development through zoning and similar means. Height limits and parking requirements effectively mandate single, detached housing in most of the U.S.
This only really got started in the 70s (see http://jakeseliger.com/2013/07/03/jane-jacobs-is-everywhere-...), and it didn't get really bad until the 2000s, when the shift back to cities ran into insane urban zoning rules to produce huge affordability crises. By now, most developers who dare to build condos or apartments have to build luxury apartments: http://www.wsj.com/articles/rents-rise-faster-for-midtier-ap... because that's the only way to make the economics work.
In the meantime, much of the population growth has shifted to Sun Belt cities in Texas, Arizona, Georgia, and Florida where development is easier and/or simply sprawls more.
If you want more economical, why not just have everyone live in barracks?
I wonder if this is this "not available" in many areas because Google is using machine vision to automatically compute roof metrics, or if it's because they don't have rebate & utility info for many markets.
OTOH, just because you have a generally accessible url, the video at that url must be addressed to the world?
It's the wording itself that makes me feel uncomfortable in a way that is hard to articulate.
I’d prefer if a mod would replace the URL with a link to either the About page or the video. Or to an archive.org cache of the site.
Linking to a site that 404's for almost everyone is inacceptable.
For society: I wonder if it is safe for so much power to be concentrated in one organization.
As a technical accomplishment: I'm impressed.
There are other sources for maps data, and many people have 3d modeling software.
So I'm not sure how this is "so much power" concentrated in one organization.
I've worked with aerial surveillance systems, the types used on police choppers. Put the crosshairs of the flir camera on a house and it will tell you all kinds of stuff: age/race of occupants, arrest records, warrants, tax status, etc. Amazing for LE, but a bit big-brotherly for my taste.
In the wrong hands, in the wrong circumstances, data fusion has incredible potential for abuse. IMHO. :-)
You can blackmail me if you know something no one else does. You can't if you know something everyone else does.
Services like this fix asymmetric access to information. They're not revealing anything new.
I believe the potential for abuse exists. Everything is fine now (here in California). But when the next crisis comes, data-fusion can be a powerful tool for authoritarians to control their opponents and suppress dissent.
If you're a normal citizen who has technical skills, yes, you can do exactly the same data extrapolation with publicly available datasources.
I worked with their stack for a bit and from my understanding their tool has been doing what this site does and then some extra stuff to actually get the panels installed.
In general, it's probably not. But in this particular case it's been working very well for us so far.