How many GW of wind, solar, and nuclear can we bring online in the next 28 years?
28 times that, ignoring the shutdowns (I don't actually know how long wind lasts, IIRC nuclear is "about 50-70 years" and PV is "about 30 years"), gives a total of: 5124 GW PV, 2800 GW wind, 218 GW nuclear.
But that's a lower bound for PV, as that's growing with what looks like an approximately exponential long-term trend (since 1992) of 36.5% per year.
While such a growth rate is physically possible to maintain for 28 years even without going into space, given that if we did make so much we wouldn't merely give everyone an American lifestyle but also be able to get the entire human population continuously flying[3], I'm assuming it will turn into a sigmoid before then.
[0] https://en.wikipedia.org/wiki/Growth_of_photovoltaics
[1] https://en.wikipedia.org/wiki/Wind_power
[2] https://en.wikipedia.org/wiki/List_of_commercial_nuclear_rea...
[3] https://www.wolframalpha.com/input?i=%28105*1.365%5E%2828%2B...
Storage seems hard and expensive. We're going to need a whole lot of approaches:
- Wind taking a bigger share of renewables
- Whatever storage we can reasonably build, including some exotic stuff like power-to-gas-to-power.
- Nuclear filling in a little bit
- PV comically overbuilt and routinely throwing away a lot of power midday on most days.
- Still peaking off natural gas, a little bit.
> Renewables' capacity factor is much greater than 10%, in practice. If you need falsehoods to make your case, you have no case.
Residential/commercial PV -- e.g. rooftop solar-- very often is 10% or less.
If you want to only look at utility-scale fixed tilt, instead, recent deployments average near (not quite) 20%.
https://emp.lbl.gov/pv-capacity-factors
Nuclear's capacity factor is 93%. In which case, 183GW from utility-scale, fixed-tilt PV is like 183/.93 * .20 = 39GW. Which, admittedly, is outside of my range of 20-30, but also relies on generous assumptions (utility scale projects only-- which are only ~25% of US solar wattage).
If you consider only tracking, you can get all the way to 49GW, which still doesn't eliminate the point.
Perhaps the bigger point is looking at the eastern seaboard. Shipping power 2000 miles is not super practical for various reasons, and the capacity factors for a whole region of the US are pretty poor.
Nuclear should be part of the equation (it has it's own issues with wastewater) but if adding nuclear means not investing equally or more in solar/wind renewables, that's completely misguided.
I'm not sure how much is residential, but about 25% is utility-scale projects. The rest is stuff on commercial buildings and homes-- which have an average capacity factor around 12%.
> Nuclear should be part of the equation (it has it's own issues with wastewater) but if adding nuclear means not investing equally or more in solar/wind renewables, that's completely misguided.
I totally agree. I think our priorities should be, in order:
- Wind
- Pumped storage
- Improved utility interties
- Demand-side management
- PV
- Nuclear
- Battery storage
- Electrolyzers, etc
But even the lowest priority item should be aggressively pursued.
Your graph shows in total generated energy per year it's roughly even--- not in nameplate power. Because the capacity factor is worse, you need a lot more nameplate power at non-utility installations to get the same energy out.
> This is good, because utility scale solar is cheaper per unit output than small scale solar.
Yup. Small scale solar really needs to stop, other than for installations that have special requirements (e.g. need for power backup / diversity).
Better that production go to installations that have good capacity factors than to your roof.
It's also time to reconsider how good an idea net metering at retail electrical prices is. Grandfather existing customers, but ... sure looks like we need a grid, so maybe only buy power from new end customers at wholesale rates (this further incents storage!)
China has a project to send it 8000 miles from solar farms they are building in Chile, for use during nighttime in China.
DC interconnect makes it more practical, and it's better than storage, but losses and costs accumulate.
> China has a project to send it 8000 miles from solar farms they are building in Chile
Chile has proposed a project to do just that. It is in exceptionally early conceptual planning stages-- but look at you acting like it's a fait accompli!
I doubt it will end up built, but that will not be because it is impractical. It will be because local generation and storage will turn out to be cheaper and less vulnerable to geopolitical upset.
Almost all current utility storage is gravity. That probably won't change.
I definitely don't see any other gravity batteries being useful on this scale.
[0] specifically I suggested that there was a lot of room for a lot of additional pumped hydro — I don't mean my more recent claim, which is merely that existing pumped hydro is cool
People like to insist pumped hydro is badly limited by geography, but hills are very common, and need not be nearby: transmission lines work very well. Transmission losses matter little when top-line generation has zero opex and minimal capex. You just build a little more of it.
Chile proposes it, hoping that Asia invests a very large amount of money into Chile to make it happen. Thus far, this latter bit has not happened.
https://www.gob.cl/en/news/president-pinera-presents-proyect...
Any evidence it has progressed past the Chile-showing-other-countries-Slideware-phase?
You tend to uncritically read the most positive, tentative stuff about PV/storage and accept it as absolute fact.
Nukes will shortly be mothballed, to perhaps be fired up once in a while in response to spiking demand.
It doesn't lead to productive conversation.
From what I've seen, the cheapest solution is a few square meters' cross section of HVDC encircling the planet, but that would almost certainly take a big increase in global metal mining even on these time scales and even when ignoring the political issues.
Note non-utility scale solar is 75% of the installed watts, too-- so you have a huge share of it pulling towards that 10-12% number.
Storage cost being excessive means it's early adoption timeframe. As the need for it becomes clear options will open up.
PV throwing off excess during peak is fine even if we don't have storage, because it means PV is adequate for a bigger fraction of the morning and evening (and in turn, the needs for storage become a little less because of the over-provisioning of production).
Batteries will only ever be a tiny fraction of storage.