Before Spring 2023, California's investor-owned-utility solar customers would get close-to-full retail credit for all extra (exported) solar power. Financially speaking: The electric grid was the customer's (almost) 100%-efficient battery. Those days are gone. New solar customers get near-wholesale credit... around 10% of retail credit.
A common assumption now is that new solar customers also need batteries... they need to store their extra daytime solar power, to use in the evenings. Batteries increase the system's cost and complication. Even without net metering, batteries are optional.
Instead of moving solar production to the evening thru batteries (losing some energy in the process)... move usage to the daytime (without annoying occupants). Take advantage of relatively cheap and durable thermal energy storage (i.e. a well sealed and insulated house, and hot water tank)... use an air-source heat pump to pre-heat the house in the winter afternoons... coast on that stored heat in the evenings. Same idea for hot summer days... pre-cool the house in the afternoons. Store extra hot water in a bigger-than-normal tank. Store even more hot water in a secondary tank... which could be typically available for a backyard soaking tub (the ultimate heat sink). These are flexible loads... from moment to moment, throw otherwise-wasted solar power into them. Some other flexible loads: electric cars, pool pumps, dishwashers. Prioritize running "synchronous" loads with solar power: induction cooktops, a toaster oven, a water kettle, lighting, etc (synchronous: available to occupants right when occupants want them).
Formally agree to never export power to the grid. Any extra solar power is obliterated by the inverter (so to speak). Don't feel bad about this, because the utility's public message is that your unreliable solar power is nearly worthless to society. ...They're not pursuing a new energy paradigm: a distributed 21st-century electric grid. Because you agree to never export, you can choose the time-of-use rate plan with the lowest evening electric rate (instead of being forced onto PG&E's new E-ELEC rate plan, that has a relatively-high evening electric rate).
For occupants that'd like to play an active role:
Have a simple little e-ink display in the house somewhere, to show 1) real-time solar production vs. usage, and 2) the percentage of the day's solar production that was used.
In the evening, enjoy power from the electric grid. After all, the electric grid is an awesome community resource. But evening grid-power usage will be minimal, because we ran our flexible loads during the sunshine hours. On the default time-of-use rate plan (E-TOU-C), there's a _minimum_ $12-per-month energy charge... might as well get something for that.
What about during power outages? ...No batteries means we'll be in the dark like the other chumps right? Yeah. The electric grid should be reliable. ...Especially under a utility that charges among the highest rates in the country. It seems that PG&E has been more focused on PR campaigns that blame others... versus creative adaptation to the new environment in which they operate. If the foot-dragging disfunction continues, we (as a society) need to get the electric grid under new management. Monopoly status with guaranteed earnings... comes with non-negotiable obligations. Let's be in the dark together, in symbolic solidarity. Have rechargable headlights and table lamps available. Keep natural gas for cooking (or have a camp stove readily available). As more houses reduce their daytime _and_ evening grid-power usage... the grid will be less stressed, so it should be easier for PG&E to provide reliable service thru existing infrastructure (right?).
I have more to learn on this, but I think "sunlight-only" backup can be practical. When the grid is down in the daytime: Control the significant loads, to ensure that the total load never exceeds the total solar power. A hybrid inverter with a built-in "microgrid interconnect device" will create a baby electric grid for your site -- while ensuring that no power will be exported to the downed electric grid. The fridge will keep running during the day... plan to open it less than usual in the gridless evening. Plug your internet equipment into a rechargeable battery. Pick up a book. Light a backyard fire. If y'all enjoy electricity-free camping... enjoy the comforts of your electricity-free house. Some will insist on full battery backup, so everyone can see them sticking their tongues out of bright windows. ...But I think (I hope) this more-affordable lower-impact stronger-solidarity approach will resonate with some. Please let me know if you're into it.
Update 2025-01-03:
Thanks to my friend Reuben for calming me down... There's no shame in having a battery. It's exciting how cheap and reliable they've gotten. My argument is that -- for many families -- it's possible to succeed without batteries. Consider seeing how far you can get by (conveniently) shifting usage into the sunshine hours, before you add a battery.
Reuben B. Ly on 2024-12-16
Mostly agree. I talk to clients about this a lot. Especially with EVs ("don't back up a battery with a battery").
The problem is Most people, even here in the Bay, don't have enough time, mental space, education or focus on this subject to center their lives around maximizing their usage of solar energy.
I think there's a role for battery, but it can be greatly reduced.
But I DEFINITELY agree that bending over backwards to play nice with PG&E is not worth the time and energy. Non-export systems are where it's at.
I love your comments on the rate plan structure.
A lot depends on client's budget and what they're trying to achieve.
"Let's shift usage to the day, schedule your heat pumps, and have a battery that's reasonably sized to offset your pre-dawn and post-sunset loads."
Self consumption maximize.
Big solar
Little battery
Smart habits....