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Tesla’s new Solar Roof costs less than a new roof plus solar panels

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Re: Tesla’s new Solar Roof costs less than a new roof plus solar panels

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post #295

Earlier quoted context omitted.

Note as this is crazy overkill I am ignoring battery and lithium shortages of actually trying to do this. Any such transition would aim to minimize such costs. This is also not the kind of thing you do in a weekend long term pricing is required. Batteries are predicted to cost 62$/kWh or 62 Billion$ per tWh in 2030 assuming no supply shortages. We can’t build anywhere near that many batteries by then, so it seems lik…

> Batteries are predicted to cost 62$/kWh (...) Who predicts that? National Renewable Energy Laboratory[1] summarizes the predictions, and the average of predictions is $200/kWh in 2030, which is already more than triple of your estimate. > or 62 Billion$ per tWh in 2030 assuming no supply shortages. It is convenient to assume perfectly elastic supply, yes. > US annual electricity usage is ~4,000TWh Why do you consid…

23 billion for 2.2GW is just a building and some equipment you still need workers, fuel, repairs, decommissioning etc. Further Nuclear only has a ~90% capacity factor they can’t operate 24/7 365 for 50 years without turning off. Nuclear also has the opposite problem, it needs to scale up production in the day to cover peak demand, and even more to reach peak seasonal demand. Run the numbers assuming exactly the right amount of power based on an annual average and your shifting energy across months. At a 90% capacity factor nuclear costs ~12c/kWh, at a 45% capacity factor that jumps to about 24c/kWh though as peak instantaneous demand is over twice average demand you would still need batteries.

Also, pretending we suddenly need to replace all sources of energy from PV power that’s then stored in batteries is crackpot territory. Part of those 101 quads are fuel used to generate electricity at sub 40% thermal efficiency. We don’t need generate electricity to replace the energy from fuel used to generate electricity.

Further, batteries only store electricity and it’s silly to pretend they are part of the loop for jet fuel which is also part of that 101 quads estimate in these calculations. Hell even using electricity rather than fuel oil to heat your house uses less energy via a heat pump.

As to prices, I think we are comparing apples to oranges here. If you want to design a system that takes AC power from the grid coverts it to DC for storage on a battery and then back to AC your adding far more than just batteries. But, if you’re producing PV power on site that’s DC so it would need it’s own DC to AC converter as well as equipment to connect to the electric grid and regulate production. This all adds up to significantly reduced prices when packaged together. So when I say battery prices are already under 200$/mWh I mean Battery prices.

“In March, an analysis of more than 7000 global storage projects by Bloomberg New Energy Finance reported that the cost of utility-scale lithium-ion batteries had fallen by 76% since 2012, and by 35% in just the past 18 months, to $187 per MWh” So even today we are beating your 2030 estimate. https://www.sciencemag.org/news/2019/07/giant-batteries-and-...

PS: The article makes it’s own estimate at 900GWh of batteries being sufficient for 100% rentable electricity generation using some other set of assumptions.

Re: Tesla’s new Solar Roof costs less than a new roof plus solar panels

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post #301
post #300

Earlier quoted context omitted.

> Batteries are predicted to cost 62$/kWh (...) Who predicts that? National Renewable Energy Laboratory[1] summarizes the predictions, and the average of predictions is $200/kWh in 2030, which is already more than triple of your estimate. > or 62 Billion$ per tWh in 2030 assuming no supply shortages. It is convenient to assume perfectly elastic supply, yes. > US annual electricity usage is ~4,000TWh Why do you consid…

23 billion for 2.2GW is just a building and some equipment you still need workers, fuel, repairs, decommissioning etc. Further Nuclear only has a ~90% capacity factor they can’t operate 24/7 365 for 50 years without turning off. Nuclear also has the opposite problem, it needs to scale up production in the day to cover peak demand, and even more to reach peak seasonal demand. Run the numbers assuming exactly the right…

> 23 billion for 2.2GW is just a building you still need workers, fuel, repairs, decommissioning etc.

Workers, fuel, repairs, decomissioning etc. are very cheap, much cheaper than equivalent coal fired plant, for example. Levelised cost of electricity, which includes all of these plus construction costs, is still the lowest for nuclear energy, much lower than wind and solar even if you don't build any batteries at all.

> Further Nuclear only has a ~90% capacity factor they can’t operate 24/7 365 for 50 years without turning off.

??? How is this relevant for the discussion at all? If you have 2000 plants, then with 90% capacity factor, you'll have 10% of plants down at any given time, thus you simply need to have 10% more plants than what you need. The crucial thing is that with nuclear, down time can be scheduled, while with wind and solar, overcast sky and windless days are completely beyond your control.

> Nuclear also has the opposite problem, it needs to scale up production in the day to cover peak demand, and even more to reach peak seasonal demand.

You simply need to build enough for peak seasonal demand. The nuclear plants can scale up and down as needed, albeit slower than gas plants, so you just scale up to cover peaks, and have aluminium plants enjoy cheap electricity when you overshoot.

> Run the numbers assuming exactly the right amount of power based on an annual average and your shifting energy across months.

My 2000 plants for $200B/year was already 12% above average use, but sure, I could double my numbers to 4000 plants and still be below 10% of US federal government spending. Imagine how big of a boon would such plentiful and cheap off-peak energy be for US heavy industry or data centers.

> Also, pretending we suddenly need to replace all sources of energy from PV power that’s then stored in batteries is crackpot territory. Part of those 101 quads are fuel used to generate electricity at sub 40% thermal efficiency. We don’t need generate electricity to replace the energy from fuel used to generate electricity.

Sure, but note that the nuclear numbers also scale just as well, so even if the increased efficiency might make the whole batteries business a bit closer to the realm of feasible, it will make the nuclear approach even cheaper too. The inefficiencies you mention will probably amount to something like 30% of current energy use, so they don't change the calculations substantially: utility scale batteries still infeasible.

> PS: The article makes it’s own estimate at 2.25 trillion for 900GWh of batteries being sufficient for 100% rentable electricity generation using some other set of assumptions.

Yes, their estimates are 10 times higher than mine. That should make you make think really hard about feasibility of large scale batteries. For 2.25 trillion, South Koreans can build 900 GW worth of nuclear generating capacity -- which one you think is more sensible choice, one hour of 900 GW from batteries, or continuous 900 GW from nuclear plants, if your goal is "decarbonizing the grid"?

Re: Tesla’s new Solar Roof costs less than a new roof plus solar panels

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post #28

Earlier quoted context omitted.

I wonder if they should just skip comparing it with a normal roof or normal roof + solar. A Model 3 is way more expensive than the average ICE sedan; people buy it anyway.

They do similar TCO comparisons with their cars. They estimate fuel savings and include tax incentives etc. In both cases they're making a case that the upfront cost is less than it appears if the running costs are lower.

To what extent is their claim true?

Re: Tesla’s new Solar Roof costs less than a new roof plus solar panels

#304

Earlier quoted context omitted.

Wow, that seems quite high. Panels are around $0.50/Wh. Add in another $2000 in materials and labor cost $24k!

FWIW. The panels are $0.86/wh each with a micro-inverter that runs ~$160 per panel and 32 panels. So, ~$5000 for inverters, ~$11k for panels, which brings you to ~$16k and your not even tied into the power of the house, or adding the mandatory shutoff, or the new meters, or the Emphase system that tracks by the minute power consumption and usage of each panel, etc etc. So lets call the rest $4k Total of parts ~$20k.…

I didn't realize micro inverters were so expensive. Thanks for explaining it.

Re: Tesla’s new Solar Roof costs less than a new roof plus solar panels

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> And we’re actually going to have […] ‘installathons,’ ” Musk said, which will pit two teams against each other to see who can roof one of two similar-sized/designed roofs faster. Musk reiterated later that there’s “quite a bit of R&D just in the installation process itself.” Not a short seller, but that sounds a lot like: “We don’t yet know how to do this well, but in the meantime we are going to optimize for speed…

He prioritizes speed apparently at the cost of anything else. I wonder why he feels such urgency? I mean yeah he finally got a profit out of Tesla last quarter. But there’s really no tolerance for hiccups in a roof install.

I suspect, from what I've read of his early life, that he is a flow addict and runs his companies to force employees into flow as well. 'Impossible' deadlines are an easy way to hack a team's flow, see e.g. the games industry.

Re: Tesla’s new Solar Roof costs less than a new roof plus solar panels

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post #91

I have a friend in America who has a fairly large PV set up on part of his property. Listening to the all the obstacles he's had to overcome and all the surprising limitations he's saddled with, I can't help but suspect that the power company in his area that he's selling the power to would rather that these sorts of installations simply not exist. Coupling that with the fact that off-peak pricing isn't the norm in a…

I had a professor who worked for the electrical utility in Ontario for years before teaching. They definitely would prefer if they didn't exist. Not so much for the competition with their own generation, but their distribution infrastructure gets more complex as more small generators tie into it, hence more work for them.

Re: Tesla’s new Solar Roof costs less than a new roof plus solar panels

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post #301

Earlier quoted context omitted.

23 billion for 2.2GW is just a building and some equipment you still need workers, fuel, repairs, decommissioning etc. Further Nuclear only has a ~90% capacity factor they can’t operate 24/7 365 for 50 years without turning off. Nuclear also has the opposite problem, it needs to scale up production in the day to cover peak demand, and even more to reach peak seasonal demand. Run the numbers assuming exactly the right…

> 23 billion for 2.2GW is just a building you still need workers, fuel, repairs, decommissioning etc. Workers, fuel, repairs, decomissioning etc. are very cheap, much cheaper than equivalent coal fired plant, for example. Levelised cost of electricity, which includes all of these plus construction costs, is still the lowest for nuclear energy, much lower than wind and solar even if you don't build any batteries at al…

> cheap

Far from it.

“Areva, the French nuclear plant operator, offers that 70% of the cost of a kWh of nuclear electricity is accounted for by the fixed costs from the construction process.” https://en.m.wikipedia.org/wiki/Economics_of_nuclear_power_p...

However, that’s including loan financing which inflates the construction costs further. Similarly, decommissioned might cost 1 Billion, but as it takes place so long after construction it’s easy to set money aside which can then compound for decades. https://www.reuters.com/article/idUS178883596820110613

Looking at pure construction costs in a steady state environment without loans it’s a significantly smaller fraction which continues to increase with age. This is why several viable nuclear power plants have been decommissioned early, their operating costs are to expensive even after construction has been paid off.

> ??? How is this relevant for the discussion at all?

Rather than a 2.2 GW power plant producing 2.2 * 24 * 365 GWh it gives you 90% as much energy. So if you want 2.2 TW 24/7 you need to build ~1,112 of them not 1,000 of them. Further this also multiples every other cost.

> down time can be scheduled

Up to a point, your talking days of downtime not hours so you still need peaking power. The cheapest approach is for a steady state of workers smoothly moving from one project to the next. That’s hard to pull off, and you end up needing even more generation to cover scheduling issues and unexpected problems.

Re: Tesla’s new Solar Roof costs less than a new roof plus solar panels

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post #307
post #302

Earlier quoted context omitted.

> 23 billion for 2.2GW is just a building you still need workers, fuel, repairs, decommissioning etc. Workers, fuel, repairs, decomissioning etc. are very cheap, much cheaper than equivalent coal fired plant, for example. Levelised cost of electricity, which includes all of these plus construction costs, is still the lowest for nuclear energy, much lower than wind and solar even if you don't build any batteries at al…

> cheap Far from it. “Areva, the French nuclear plant operator, offers that 70% of the cost of a kWh of nuclear electricity is accounted for by the fixed costs from the construction process.” https://en.m.wikipedia.org/wiki/Economics_of_nuclear_power_p... However, that’s including loan financing which inflates the construction costs further. Similarly, decommissioned might cost 1 Billion, but as it takes place so lon…

> “Areva, the French nuclear plant operator, offers that 70% of the cost of a kWh of nuclear electricity is accounted for by the fixed costs from the construction process.”

Yes, this exactly means that operating costs are very cheap: if 70% of the cost per kWh is amortization of construction costs, and only 30% is operating costs, and the kWh from nuclear plants are still the cheapest, or exactly means that the operating costs of running a nuclear power plant are very, very low, much lower than coal plants.

> Looking at pure construction costs in a steady state environment without loans it’s a significantly smaller fraction which continues to increase with age. This is why several viable nuclear power plants have been decommissioned early, their operating costs are to expensive even after construction has been paid off.

Which ones? What were their operating costs?

> So if you want 2.2 TW 24/7 you need to build ~1,112 of them not 1,000 of them.

Sure, but as I noted, we can build twice the amount we need rather easily, while building enough of utility scale batteries to ride out the variations in solar/wind production is just infeasible. Of course nuclear isn’t perfect, but I thought your alternative is solar/wind, which has all the same problem, but worse - instead of predictable and controllable 90%, you get 40-50% of installed capacity on average, and it can be all down at times beyond your control.

> Up to a point, your talking days of downtime not hours so you still need peaking power. The cheapest approach is for a steady state of workers smoothly moving from one project to the next. That’s hard to pull off, and you end up needing even more generation to cover scheduling issues and unexpected problems.

That’s okay, since we can build twice our peaks and still be firmly in the realm of feasible.

I note, however, that you gave up on the idea of utility scale batteries being feasible approach to work around the inherent unpredictability of solar and wind. Good.

Re: Tesla’s new Solar Roof costs less than a new roof plus solar panels

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Earlier quoted context omitted.

> cheap Far from it. “Areva, the French nuclear plant operator, offers that 70% of the cost of a kWh of nuclear electricity is accounted for by the fixed costs from the construction process.” https://en.m.wikipedia.org/wiki/Economics_of_nuclear_power_p... However, that’s including loan financing which inflates the construction costs further. Similarly, decommissioned might cost 1 Billion, but as it takes place so lon…

> “Areva, the French nuclear plant operator, offers that 70% of the cost of a kWh of nuclear electricity is accounted for by the fixed costs from the construction process.” Yes, this exactly means that operating costs are very cheap: if 70% of the cost per kWh is amortization of construction costs, and only 30% is operating costs, and the kWh from nuclear plants are still the cheapest, or exactly means that the opera…

> Which ones? What were their operating costs?

“Each nuclear power plant employs 500 to 1,000 workers. Nuclear worker salaries are 20 percent higher on average than those of other electricity generation sources.” 40 mill x 50 years = 2 Billion dollars just for wages. https://www.nei.org/advantages/jobs

As giant complex mechanical systems over time moving components like pumps and turbines need to be replaced. Due to contamination some of these costs are crazy high.

Insurance is a big one. They need normal insurance for stuff like fires and workplace accidents, plus government subsidized insurance for the rare major accidents that could be horrifically expensive.

While cheap relative to coal they still need fuel which adds up to 14% of operating costs. While U3O8 is $68 by the time it’s ready to be used the costs increase to $1390 per kg (https://www.world-nuclear.org/information-library/economic-a...) and a 1GW reactor goes through ~25,000kg of enriched uranium per year. https://www.nuclear-power.net/nuclear-power-plant/nuclear-fu... That’s 35 million dollars per year and 1.75 billion over 50 years. (As a sanity check. If it’s 14% of total operating costs then it’s operating costs are 12.5 billion for a 1GW nuclear power plant operating for 50 years. If 12.5 billion operating costs = 30% of total costs then a 1GW Nuclear reactor costs 41.5 billion over 50 years or 830 million per year and at 90% capacity factor it’s 10.6c/kWh which is close to the 12.5c/kWh I have seen quoted frequently.) With reprocessing it’s about only 3kg for 1GW of electrical power per day at 33% thermal efficiency, but without repressing they need significantly more fuel. Unfortunately repressing is not currently cost effective.

They also need the basics like office equipment like computers and supplies, as well as the normal costs associated with buildings like lightbulbs, roof repair, water and sewage etc. Plus the normal taxes etc.

They also need to set aside money for decommissioning.

PS: Digging into those fuel costs where really interesting it’s interesting to see how 68$/kg and 3kg per day which I have seen quoted before gets transformed in a much larger expense.

Re: Tesla’s new Solar Roof costs less than a new roof plus solar panels

#310

Earlier quoted context omitted.

> Will the sun start shining at night in 20 years? Do batteries stop working at night? > No. Because we know we can power an economy with fossil fuels, and do it in any weather, day or night. ...and irreparably destroy the planet by doing so > Here's what works: Nuclear, Hydro, Geothermal I agree! But I think we are perfectly capable of utilizing these AND solar, wind, and storage?

>Do batteries stop working at night? There is no battery technology (now or forthcoming) that can store enough energy to power a moderately sized city for a few hours, much less days or weeks. >..and irreparably destroy the planet by doing so I wasn't making a case for natural gas. I was a case that solar needs to be paired with natural gas. >But I think we are perfectly capable of utilizing these AND solar, wind, an…

Nuclear is great in your part of Canada, but where I live in California there are several advantages to solar...

1) solar is distributed. In the past couple years, California has had massive fires caused by transmission lines. Right now, millions of people are without power because the utility can't safely deliver electricity. Distributed solar obviates the need for huge transmission lines, and is more durable in a disaster.

2) utility scale solar is cheaper than nuclear here.

3) There are large earthquakes here that make it less obvious that we should run 70% of our economy on nuclear.

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