[dns_snek]

> Net metering lets me 'store' excess from summer and use it in winter

FYI net metering is unsustainable for the grid and policies will probably change (reducing rates for energy, increasing rates for delivery fees to offset the "freebies") as soon as adoption reaches a critical mass.

[glxxyz]

I’m not sure what you mean by ‘unsustainable’ nor ‘critical mass’ here. Of course not everyone can net meter- on a sunny but mild day with no-one using A/C nor heating and everyone contributing back to the grid it doesn’t work.

My local utility is well aware of that, applications for permits to net meter have to be made, and only a fraction (something like 15%) of properties in each area can net meter. Also the government is aware and there are no grants for net metering, only for battery systems.

I’m giving details about my personal system for one property in one location, not in any way making a statement about what works for anyone else.

[dns_snek]

Sorry, I should've been more specific, I can explain.

> My local utility is well aware of that, applications for permits to net meter have to be made, and only a fraction (something like 15%) of properties in each area can net meter.

Okay, that changes things. The way it worked here is that anyone in the country could install solar and get grandfathered into net metering (perpetually), and then at a certain point they decided to cut it off completely. So you have people from before with who have net metering, and anyone installing it later doesn't have it.

People would install 10-20kW worth of solar, overproduced massive amounts of energy in the summer and then in coldest part of winter (with heat pump COP dropping below 2), people expected to draw 4-10kW of power for heating and pay close to nothing all year round.

The government decided that this was unsustainable so they changed the distribution rates. In effect anyone who doesn't have solar pays roughly the same as they did before, but anyone who has net metering pays substantially more than they thought they would when they signed up.

Ultimately I think this is fair but many people felt cheated by this change. I'm assuming the same could happen elsewhere so I wanted to warn others who might be looking at net-metering deals that look "too good to be true".

[PaulDavisThe1st]

> People would install 10-20kW worth of solar, overproduced massive amounts of energy in the summer and then in coldest part of winter (with heat pump COP dropping below 2), people expected to draw 4-10kW of power for heating and pay close to nothing all year round.

So this is more or less the exact same position that I'm in in northern New Mexico. We have 6.7kW of ground mount PV; we generate roughly 3x what we need in the summer, and roughly 1/3 of what we need in the winter (air source heat pumps for heat). Overall generation is close to 100% of our annual use.

In some ways I agree with the analysis but there are some mitigating factors. We live in an old adobe home that requires almost zero cooling during summer. For better or for worse, most new construction in the area is stick frame wood construction which even with reasonable insulation requires cooling during the summer. Guess who provides the power for that?

New Mexico is in a good position to combine solar PV with wind and be able to meet base load demand more or less continuously. It likely requires storage facilities that are on the order of 5-7 days of load, which would be enough to bridge most gaps in generation.

Our local utility actually provided two options for metering: one was what you're calling net metering, the other was credits for surplus on a monthly basis, with the credits generally being priced slightly below the purchase cost for the same energy. I would have been happy with either - the latter is perhaps fairer. However, they also stipulated that if you took credits, they could claim your PV as part of their own PV-adoption goals. So we took net metering instead.

[glxxyz]

That makes more sense, but your utility's failings are not necessarily the same as mine nor anyone else's.

I wish I'd never mentioned solar nor net metering now- I'm not on some crusade to promote either, I was just explaining the economics of my personal setup.

[PaulDavisThe1st]

"All" it needs to be sustainable is a massive investment in storage systems (BESS, and/or others).

[dns_snek]

You can't store energy year-round. I explained the situation in more detail in a sibling comment but the tl;dr is that people expected to run net-metering households expected to run their brand new heat pumps full tilt in the winter for ~free, the economic reality disagreed, and rates were changed to reflect that.

[theoreticalmal]

What is an electrical delivery fee?

[dns_snek]

I meant distribution. Our electrical bill roughly consists of: energy production (per kWh) and distribution fee (per kWh). When you're using energy you accumulated through net metering, the "energy production" portion is free, but you still pay the full rate for distribution.

At some point our previous system became unsustainable and they were forced to rebalance the rates and those who have solar panels with net metering now pay significantly more than they expected they would. I explained in more detail in a sibling comment.