California s New Solar Rules Greatly Cut Payback, But Could Power Trading Fix That?


New rules greatly increase the time until solar panels pay for their cost, making it more important to store the power in batteries or cars, and even sell to neighbors.

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The low return on solar for house owners simply reflects its low value because its peak generation period doesn't match the peak demand.
Rather than come up with a complicated arrangement of maximizing utility of rooftop solar, why not just use the power from the grid? They will be installing large scale solar anyway because we will be discouraging fossil fuel generation, and this will inevitable lead to cheap power around noon.
As long as the price to the consumer reflects the supply/demand accurately, there's little need to install your own solar and hope for electricity retailers or generators to support it.
End users can just change the time they charge their vehicles, aided by chargers at their workplace.
When power companies are installing solar in large amounts there seems little benefit in reproducing this capacity on your rooftop when it can be done more cheaply in a field somewhere.

California PG&E territory electrical prices are super high -- 24 cents/kWh at night, 54 in the peak day.

It's very easy for solar to beat those. Wholesale solar prices are indeed cheap but I have to pay fat PG&E delivery prices on top of them, making solar an easy win that will pay for itself very quickly.

If I did not have all the extra costs from permits and install, you can get solar to earn out in almost no time. You can get 1kW of panels today for under $1,000 and it keeps dropping. All the rest of the typical $3/watt price is install, permits, markup and other overpriced gear for inverting and grid tie.

That 1kW of panels will generate about 1.5 to 2 mWH per year, which costs around $400 to $600 at retail. In other words, the panels recoup their cost in 2 years and last for 25.

I have laid out that I would love to get a pool pump that has an input for solar panels, not grid tied. I could just nail them on my north fence in an hour, and they would only generate at about 60% efficiency for being vertical, but without all those other costs they would be very profitable. Pumping pool water is one of the magic solar loads --you don't care when you pump it, so pump when the sun shines.

In the US Amazon resells these kits.

Sounds like the electricity market is the thing that needs fixing.
But agree about the pool pump, and presumably pool heating as well (if desirable in the summer)

Is often best done with solar thermal, though in theory you can do it better at higher cost with PV and a heat pump.

The electricity market is broken in a number of ways, but many of its principles make sense. We think of electrical energy as a commodity, which you buy by the kwH like you buy gasoline or water. But it's really a service. The wholesale price of the energy is low -- 2-3 cents/kWh from the best sources -- but you can pay $1 to get it at certain times of day, and always quite a bit more. That's one reason that people are so interested in new ways to store it, to make it more like a cheap commodity than a service.

I still think it makes much more sense for storage to be on an industrial scale, and probably not using batteries which are hugely expensive.
If we already have EVs with long cycle lives, e.g LFP, then using the resource makes sense. Powerwalls and solar rooftop OTOH don't make sense to me because it can be done so much more cost effectively by industry rather than individuals.
Industrial scale storage should drastically reduce the fluctuations in price without the need for complicated home installations.

Cars don't make much sense as storage, though in future they might. However, the key thing about local storage is you don't use or pay for distribution. Right now that makes a huge difference. You will use whatever offers the best price. Grid storage close to your house that doesn't need much distribution could make sense if it can do a better price. Grid storage far from your house will have distribution cost.

Storage at your house also offers backup power if the grid fails, and while it doesn't fail often here, there are places where that's very valuable, and people attribute greater value to it even when the failures are rare.

Home installations are "complicated" but that's what computers are there for. For the user it's just install it and turn it on and let it run, most of the time, though if you want backup ability you want smarter devices in your home to shut off all non-necessary loads.

Right now grid solar is cheaper than roof solar to install -- but because of grid costs, it ends up costing more. Otherwise, roof solar would not make much sense.

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