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Comment by nielsbot | Hacker News Reader

Always fun to check out the live CAISO grid chart showing where CA's energy is coming from:

https://www.gridstatus.io/live/caiso

At its peak today (May 29), solar was 75% of CA's power generation. And at the peak yesterday (7 PM, May 28), batteries provided 25%.

Seems like solar often produces more than 100% of CA's demand during the daytime and is curtailed. Maybe to charge batteries?

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Charging doesn't show up as curtailment, that is mostly due to grid congestion, as transmission lines reach their maximum capacity and physically can't get all the solar power to loads that need it. Also, nuclear plants can't be turned on and off very quickly so they stay on all the time, and some number of natural gas plants must stay running during the day so they are able to quickly ramp up when the sun goes down.

So on a nice sunny day that isn't too hot there is a lot of solar power that physically cannot be used and so has to be curtailed. In peak summer when ACs are blasting you'll see less curtailment, and in the future as they keep building out battery storage you'll probably see less curtailment in general.

> some number of natural gas plants must stay running during the day so they are able to quickly ramp up when the sun goes down.

Doesn't this only take a few minutes for a natural gas plant?

Combined cycle fossil gas units can take up to 12 hours from cold start to full output, roughly 25% can be up to speed within an hour (EIA). ~7-30MW/minute.

Once through peakers can ramp faster, but are less efficient (they’re essentially jet engines bolted to the ground), and more expensive than battery storage.

https://www.eia.gov/todayinenergy/detail.php?id=45956

https://www.lazard.com/media/xemfey0k/lazards-lcoeplus-june-...

In addition to what the sibling comment says, a few minutes is fine for predictable changes like sunset, but you also need enough dispatchable power online to deal with unexpected changes. What if a transmission line goes down and cuts off a big solar farm? Other plants must respond within a literal second to fill the gap and prevent a cascading failure of the whole grid like what happened in Spain recently.

That doesn't have to be natural gas, batteries and hydro and even other curtailed solar plants can fill this role if there are enough of them, but we're not there yet.

Turbines need be kept hot. Especially for steam, but probably for gas too. Don't want thermal stresses in 1000 ton fast spining objects.

Genuine question: If CA is mostly getting its energy from Solar why is my energy bill so high especially during winters? Or does solar energy while clean does not necessarily mean cheap?

Most of that is not generation, but for transmission, distribution, and grid upgrades.

Specifically burying the lines so they survive forest fires.

Go pick a few PG&E tariffs, look at the unbundled prices, compare them, and then try saying that it’s legitimate transmission and distribution costs again with a straight face…

Blame it on the continual rate increases for the sake of money if you’d like. But it isn’t expensive because generation is expensive.

I find the explanation that they neglected maintenance and upgrades in favor of dividends and stock pumping for years, and now we're paying off the last couple of decades of maintenance and upgrades in a new, more volatile wildfire climate for which PG&E has been assigned legal and financial liability.

I agree that it doesn't necessarily reflect the individual marginal cost of an additional customer, but that makes sense, things rarely do.

Last year they got twice as much electricity from gas as they got from solar.

They're doing well globally, and solar is generally ramping up quickly everywhere but headlines are more often about hitting 100% renewables for an hour or for a day, not over a year.

So what you're saying is you need a secondary competitor in the market.

Which would be home solar and storage

...which they're trying to kill. Because customers of home solar & storage are generally quite happy to not be paying PG&E.

If you need the hookup at any point during the year, you have to pay for the hookup for the whole year. That's just fair to everyone else that didn't have $20,000 (or didn't own property) and don't want to subsidize your solar upgrade with their own rates.

I'm confused; which one is it? The property owner pays 20k, or the ratepayers are subsidizing it?

Also, my pge statements now have a line item for transmission that's usually larger than my generation total. If I have 2x solar and I'm feeding my neighbor, are they paying the same "transmission" structure for the power I'm providing them?

It's one or the other. Under NEM 2, ratepayers are subsidizing. Under NEM 3, the property owner is paying (more of) their fair share of transmission costs, and are being subsidized less, which people complain "kills" rooftop solar.

NEM 3 makes rooftop solar worse than NEM 2, but it's not common to say it kills it. It's the new flat fees they have been trying to implement that would kill rooftop solar. For example, if 50% of an average bill was a flat fee and then energy was half off, that would kill rooftop solar + batteries on NEM 3.

Answered here: https://news.ycombinator.com/item?id=39487714

Most things in US are super costly because of monopolies, regulatory capture and perverse incentives: https://en.wikipedia.org/wiki/Perverse_incentive

I don’t think you’ll see the full cost benefits of solar (and wind) until after the transition to 100% renewables (and maybe nuclear) is complete. There’s just too many big investments needed in the transition. That’s expensive.

Repowering a solar or wind power plants is dramatically cheaper than building it from scratch.

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