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by ZeroGravitas 2539 days ago
Most research suggests that net metering is underpaying the households that deliver it. This seems very counteri tuitive to people, but remember you're paying an average cost. Gas peakers can cost thousands of times that when load is high. If you use AC then solar and high demand are correlated. At the extremes that means building a whole new powerstation that might only be used for literally hours per year.
3 comments

The utilities often don't want to buy this power - if they felt that they were underpaying, they'd want to buy it. Could you cite the "most research" you speak of? In fact I've read the exact opposite - that solar rooftop is economically possible only because the utility is often forced to buy it back at retail rates.
Utilities often get recompensated based on a percentage of what they spend.

If you assume they are rationally going to maximise their profit potential then saving money isn't really in their interest even before you get into externalities that they impose on others.

Another example of this is utilities moving coal and gas plants that are no longer economic into these kind of compensation deals to they get a guaranteed profit based on what the cost to run. This is why it's estimated that closing all coal plants in the US would save 10s of billions dollars just in lowered electricity costs, even before factoring in pollution and carbon.

For info on the research "value of solar" is the general term. It varies by geography and location (e.g whether demand is growing or falling, what the other power they displace is coming from etc) but it's generally pretty positive for solar. The number is even bigger when you include things that would save customers money rather than the utility, and as regulated industries they should probably be forced to consider those costs.

But what you said and what I said aren't strictly incompatible. You could get a prisoner's dilemma type situation in which it only makes sense for you to do something if someone else is forced to do something too, otherwise they would defect and gain even more. Doesn't mean it's not economically beneficial for both.

I have no real interest in whether solar makes economic sense for a household or for a utility. It clearly is at the society level and we should be organising ourselves so that we maximise the benefit, not throwing our hands up and saying "well, if it would involve changing a minor regulation on an already heavily regulated industry, then I guess I'm going to have to choose the more expensive option instead"

It’s overpaying if anything. Why should the utility be forced to pay retail RTM rates for power that they could have bought wholesale a month before if they actually needed it? Utility ratecase logic often has many ratepayer-unfriendly motivations but this line of reasoning is legitimate, imo.
We're talking about an average net-metering cost of about US$0.12/kWh, right? That's 3.3¢/MJ in SI units, US$120/MWh in the units used in most real-time electrical markets. LMPs do sometimes get as high as US$120/MWh and even higher — I've seen US$160 at times — but never anywhere close to US$12000/MWh, as your "cost thousands of times that" comment suggests. (US$40 is more typical, and sometimes prices go negative, so you can get paid to burn energy.)
RTM prices in ERCOT can easily spike to the price cap of $9000/MWh during bad days: https://www.spglobal.com/platts/en/market-insights/latest-ne...
Interesting! So even if the demand would justify paying $12000/MWh, ERCOT just permits brownouts or blackouts instead of paying that much? (I can't load the article you linked.)
Realistically a price higher than that wouldn't really have any effect on incentivizing generators any more, since there is a limit to how fast they can ramp up, how much spinning reserve capacity they have etc. So, it mostly just serves to protect the market from falling off the rails. The grid operation itself is actually largely disconnected from the market - the ISO primarily calls the shots with scheduling regardless of what the market is doing.