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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

#291

Post by iamtheworstdev »

mepiethree wrote: post #154
stevehawk wrote: post #68

Does anyone know the situation for putting these tiles on one side of the roof but not the other? I live in northern Indiana and would gladly put these on my southern facing roof, but my northern roof is particularly complex (a lot of joints/edges) and obviously not really ever going to get any sun.

You can do that with normal solar panels, or with these I recommend using project sunroof to see if doing so would make you money. They analyze your roof size and tilt, trees around your property, etc. For free. https://www.google.com/get/sunroof

Damn, neat site but they haven't done houses in my neck of the woods.

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

#292

Post by bestnameever »

taurath wrote: post #127
oefrha wrote: post #99

Earlier quoted context omitted.

I used to live in Palo Alto. There’s VTA (bus) and Caltrain. Stops are few and far between so getting to and from the stops are in and of itself a problem. Buses tend to arrive every 15 minutes (or longer) I believe? Pretty infrequent. And outside peak hours there’s usually like one Caltrain an hour, so missing one really sucks. I had a colleague who had to travel frequently between Stanford and Berkeley (slightly un…

Yup - and everything is 2 stories or less. Nothing gets built, not because of demand, but because zoning laws. There’s no reason other than the city of Palo Alto won’t allow tall buildings to be built - the less that is built the more wealth homeowners and real estate investors get.

> the less that is built the more wealth homeowners and real estate investors get.

that's not the motivation of many people who don't want tall buildings. Many of them don't want them because they don't like living near them.

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

#293

Post by aianus »

IshKebab wrote: post #190
dx87 wrote: post #12

I wonder where they're getting their average price from, because I've never heard of a new roof and solar panel installation being that expensive. EDIT: They're comparing it to concrete roof tiles, which a quick search say that they last for ~50 years, twice as long as the warranty for the Tesla solar roof. https://www.tesla.com/solarroof/design

Warranty is different from how long something will last.

I don’t know why you’re being downvoted, my last car, phone, laptop, all lasted much longer (3-6x) than their respective warranties.

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

#294

Post by Corrado »

One of the things I've always wondered about Tesla's Solar Roof is how is it to walk on? Do you have to be extra careful because it's glass? Is it more slippery?

I get up on my roof several times a year (inspections, etc.) and know how to move around on a traditional asphalt shingle roof. Will I slide off or damage the roof while putting up Christmas lights?

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

#295

Post by Retric »

xyzzyz wrote: post #289
Retric wrote: post #216

Earlier quoted context omitted.

The economics of residential solar is heavily tied to local conditions. But, for grid solar there is little reasons to build it in the north rather than just move electricity from the south. We are already below 2c/kWh for solar power in some areas, the average consumer price is 13.27 cents per kilowatt hour in the US. That’s a lot of wiggle room. Let’s assume 50% over production that’s 4c/kWh, backed up by 60h worth…

> We are already below 2c/kWh for solar power in some areas Yes, the power is very cheap exactly when nobody needs it. > Let’s assume 50% over production that’s 4c/kWh, backed up by 60h worth of batteries and transmission and your still cheaper than Nuclear while covering base load and peaking power needs. Can I see your calculations? Last time I did the math, building enough batteries to store 48 hours worth of US e…

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 like a reasonable baseline long term. Further, by having vastly more batteries than required they end up with fewer and longer discharge cycles which extends lifespan. Current system are also deigned for much shorter lifespans because of rapid battery price drops. Based on that and further tech progress a 20-30 year lifespan seems reasonable I will use 25. Capacity is also going to drop over time and installation and maintenance costs are > 0 so I am going to add 10% ‘other’ and ignore 7% of US grid electricity generation being hydroelectric.

US annual electricity usage is ~4,000TWh / 365.24 days per year / 24h * 60h = 1.7 trillion dollars that’s a lot of money but the US can easily borrow on that scale for cheap. Further over 25 years that’s 4,000 TWH * 25 = 96,000 TWH for 1.7 Trillion dollars or 1.70$ for 96kWh or ~1.78c/kWh * 1.1 so call it 2c/kWh. Most of this power would of course come directly from solar generation, but having that many batteries is what transforms intermittent solar into peaking power.

Add 4c/kWh for crazy overkill on solar and you’re at 6c/kWh to have both base load and peaking power power. Though you still need to add significant new transmission and would have significant losses associated with charging and discharging batteries etc. Still add another 2c/kWh for all the costs I am not including and your still cheaper than Nuclear though not by as much.

PS: At grid scale wind and hydro further reduce battery storage requirements. Combined with excess though more reasonable generation say 1.5x and averaging across huge geographic areas 15h of battery power is probably significant overkill.

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

#296

Post by BlueTemplar »

nostrademons wrote: post #206
BlueTemplar wrote: post #138

Earlier quoted context omitted.

The first one, at least for the next decades. (We don't have enough resources for the second option - due to the required number of batteries. )

We don't have enough housing or mass transit for the first option, and building more batteries has proven significantly easier than building either more housing or more transit.

This is where we'll have to disagree - the limitations to building housing and mass transit are mostly economical, while for batteries they are mostly physical.

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

#297

Post by BlueTemplar »

steelframe wrote: post #156
BlueTemplar wrote: post #138

Earlier quoted context omitted.

The first one, at least for the next decades. (We don't have enough resources for the second option - due to the required number of batteries. )

We know we can't quickly replace all gas combustion engines on the road today with batteries because of material supply constraints alone. However if the goal is to reduce carbon emissions by vehicles by 90%, we can probably get there by replacing 95% of all gas-only vehicles with plug-in hybrids, which require a small fraction of the amount of battery material than fully electric cars require. I'm probably off with…

Hmm, that's interesting - I thought that hybrids were less efficient, but maybe if they also require much less batteries they could be a great stepping stone ?

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

#298

Post by arethuza »

aidos wrote: post #261
arethuza wrote: post #47

Earlier quoted context omitted.

"UK homes are made of brick" I've lived in 11 properties in the UK (owning 4 of them) and most of them were made of stone and were 150+ years old - only the first one (a 1950s council house) was brick.

Where are you based? The majority of properties in the UK are brick.

Mostly in Edinburgh - I wasn't meaning to imply that all properties in the UK are like that, just that I've never lived in many.

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

#299

Post by nostrademons »

BlueTemplar wrote: post #296
nostrademons wrote: post #206

Earlier quoted context omitted.

We don't have enough housing or mass transit for the first option, and building more batteries has proven significantly easier than building either more housing or more transit.

This is where we'll have to disagree - the limitations to building housing and mass transit are mostly economical, while for batteries they are mostly physical.

Would definitely disagree on that. The limitations of building housing and mass transit are mostly political, while for batteries they're both economical and physical. I'd take physical problems over political ones any day.

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

#300

Post by xyzzyz »

Retric wrote: post #295
xyzzyz wrote: post #289

Earlier quoted context omitted.

> We are already below 2c/kWh for solar power in some areas Yes, the power is very cheap exactly when nobody needs it. > Let’s assume 50% over production that’s 4c/kWh, backed up by 60h worth of batteries and transmission and your still cheaper than Nuclear while covering base load and peaking power needs. Can I see your calculations? Last time I did the math, building enough batteries to store 48 hours worth of US e…

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 consider only electricity? It's only just above a third of US energy use. US uses about 101 quads[2] of energy annually, which is just under 30,000 TWh (BTW, US Energy Information Administration believes that we're using 11000 TWH electricity annually, which is again triple of what your numbers are).

So, by the numbers of US government agencies, we're at (30,000 TWh / 365 days) * 3 days = 246 TWh, which, again, using government estimates, is 246 TWh * 200 dollars/kWh, which is $50 trillion, which is 250% of US GDP. So, assuming that the lifetime of the battery installation is 20 years, it means that 12.5% of US GDP will need to be spent on maintaining battery infrastructure, in perpetuity. That's already 2.5 times larger than current energy sector, and that's only cost of battery construction, we haven't even started talking about generation or grid maintenance!

In comparison, two new US nuclear power plants in Georgia, which are already extremely expensive due to cost overruns (US cannot build stuff, and you should also expect cost overruns for battery plants too), are astimated to cost $23 billion, and planned to have 2.2 GW power, and, unlike renewables, they'll actually produce as much day and night. 30,000 TWh/year is 3500 GW of power, so we'd need about 2000 nuclear plants like the one in Georgia. 2000*$23 billion is $46 trillion, amortized over 50 years is less than trillion a year. But, of course, if we could build reactors as cheaply as, say, South Korea can today, we'd only need spend fifth of the cost, so with $200B/year of construction costs, we could satisfy all our energy use with nuclear, not even needing solar/wind for peaks.

[1] - https://www.nrel.gov/docs/fy19osti/73222.pdf

[2] - https://www.eia.gov/energyexplained//us-energy-facts/

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