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Comment by Pxtl | Hacker News Reader

The day/night performance of Solar is pretty interesting in the South, where solar's cycle nicely correlates with air-conditioning.

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Even outside of air conditioning, generally the demand is higher during the day than during the night. It's often off by one hour or so though as there is often a peak in the evening.

In Texas they're currently seeing some solar plants producing above nameplate capacity exactly at the time when air conditioning demand is at record levels.

There's a simple technology called a battery that is being produced at twh scale per year now that addresses this. On sunny days, charge the batteries from sunrise until sunset. And then people can cook, run the AC, etc. Fairly easy problem to solve. Charge during the day, cool at night. Battery prices keep on getting more and more attractive.

Solar in the US is easy. Most of the US is south of most of Europe. If people in Germany at 52.5 (Berlin) degrees latitude can economically use solar, it should be no issue whatsoever for people at 40.7 degrees latitude (New York). Not to mention those lucky people blessed with long, warm sunny winter days at 25 degrees latitude (Miami), 29.7 (Houston) or 37 degrees latitude (San Francisco). Plenty of light there all year round. Most of the US actually matches Northern Africa in terms of latitude. Marakesh for example would be at 31 degrees latitude. That means a relatively stable and longish amount of time between sunrise and sun set. About 9 hours of daylight in New York around Christmas. More for anything south of there. Texas should be more than fine. There's a reason temperatures are so toasty there in the summer. It's at the same latitude as the Sahara desert. Plenty of light in other words.

For most of the US, solar should be usable throughout the year. It being cold doesn't mean it's dark. Also, solar panels actually work better when they are cool. So cold temperatures and sunny days are a good combination. Clouds are more of an issue, of course. But they are more of a local thing and they you don't have those every day. And even they let through some light. If you have to wear sun glasses to protect your eyes when you go skiing, it's an excellent day to be generating solar power as well.

We also have new battery technologies (suitable for grid style storage).

Such as Vanadium Redox flow batteries;

There was a big push for local salt reactors for cities or neighborhoods, but Vanadium Redox flow batteries could be a local solution to level demand from Solar/Wind -- or more simply, to balance load during the day; ie run ACs off of liquid batteries that charged last night.

More simply, there are thermal storage technologies that address it. Just precooling a building below the desired temperature at the peak, for example. Or, make ice. A cube of ice a meter on a side would be quite adequate for a single family dwelling.

It would help if Texas buildings had better insulation. The more insulated, the less quickly they heat up when the A/C is turned off/down, and the less storage needed.

That's actually a good question. Assuming need for energy storage, what would be more efficient? An insulated heat-capacitor (eg: a bunch of pans full of ice) inside the AC to be used when energy is in short supply, or a battery?

I think cost of the storage system would be more important than the efficiency.

Winter is not only worse for solar because the sun is less intense, but also because its cloudier.

variable pricing (within reason) will quietly solve all kinds of problems organically.

At 45 degrees north solar also nicely correlates with air conditioning needs.

it does not cycle well with heat in the North though.

It will also be interesting to follow how the development of solar and wind power will affect the stability of the electricity grid and the ability to prevent large fluctuations in frequency.

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