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Comment by Jedd | Hacker News Reader

They lost me at their second sentence:

  > In order to fill these gaps [ night, cloud ] , a storage solution
  > or a backup infrastructure of fossil fuel power plants is required
  > -- a factor that is often ignored when scientists investigate the
  > sustainability of PV systems.

If you're approaching the problem with solar power with the assumption you need storage or fossil fuel, you're basically arguing with yourself.

Note they did say 'solar power', not 'solar cells / PVC / etc'. Solar thermal plants ride through periods of cloud, and well into the night, reasonably well. But the big problem is that assumption that you must either store solar, or you burn coal / oil ... followed by a complaint that scientists ignore important factors.

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I'm not sure I follow your point? Even without solar power, storage is an important part of many grids e.g. meeting peaks with pumped storage hydro.

Are you saying that solar thermal is enough storage for a predominantly solar grid? I'd suggest it isn't. I'd also suggest that solar thermal is a type of storage solution and it's time-shifting properties are one of the things that make it useful.

You don't need pumped hydro. The wonderful thing about hydro is it throttles easily, and leaving water in the lake is equivalent to putting more water into the lake.

When the reservoir is full, Cruachan Power Station in Scotland can operate for 22 hours before it is emptied. Also, it is required to leave 12 hours water in the lake at all times to provide emergency cold start backup on the grid. If it wasn't pumped hydro and was only working from runoff, then it wouldn't work.

You're right that solar thermal is technically a type of storage system for solar. But that wasn't countenanced in the article -- wherein we're told the (availability) problem of solar can only be solved by either fossil fuel power plants or storage systems.

My point is that this is either a flawed or a disingenuous premise.

There's myriad ways we could deal with gaps in sunlight availability: nuclear fission (not a fan, but undeniably one way), biofuels (also not a fan, but ditto), reduced demand / opportunistic usage patterns (to ameliorate the effect - not easy, but disturbs me that questions about energy usage never include 'reduce' or 'adapt' in the list of considered answers), and, most importantly, a stack of renewable options that are not constrained by the vagaries of sunlight -- geothermal, wind (terrestrial and tethered), wave, tidal, and hydroelectric spring to mind.

I don't agree with this argument. The sun doesn't shine at night, period. Any solar system which supplies energy after the sun is down relies on storing residual energy collected during the daytime. Solar thermal is storing energy in heat just as a lithium battery would using chemical reaction.

> But the big problem is that assumption that you must either store solar, or you burn coal / oil

So your plan is to turn the electricity off at night?

Not helpful.

Read the original article. Read my original response.

Almost as an aside -- electricity does happen to be available a good way into the night with solar thermal.

But the big point (again) is that it's not a matter of 'solar + batteries' as the only option to burning fossil fuels.

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