Posted by bookofjoe 19 hours ago
It works pretty well for my climate. I wonder how it compares to PV panels driving an electric heater though. Neither is going to work very well during the winter but the hydronic based system probably needs to get above some base level of solar input to meaningfully heat the water. Whereas PV will always produce some electricity in the winter which can always be converted to heat.
We don't have solar but we do have a solar energy plan from our power company, so power during solar hours is charged at 0.5x rate in trade for the solar during the duck curve hours being 2x. So we have the hot water heater set to only heat during the solar hours and A/C set to shut off during duck curve hours.
This has resulted in our electricity costs for our house being lower than the combined electricity+gas costs for the apartment we lived in before (which was much smaller).
https://en.wikipedia.org/wiki/Thermostatic_mixing_valve
I see these a lot in commercial domestic hot water systems, a lot of them use steam or boiler loop water to heat the domestic hot water.
They say £1/kWh is a Beta price, that makes sense as a way to burn investor money to get people interested. Their real price is TBD. Would you take 25p per kWh with a £5 per month guarantee ? That could be at least in the ballpark of working.
In the USA lots of early adopters of solar did so under net metering agreements where excess electricity is sold back at full price. After a number of years it was costing the utility companies too much money. So they updated the terms such that residents with solar buy electricity at retail prices (~$0.25) but sell it back at wholesale (~$0.04).
Not if you took out a $50k loan for an early gen solar system and it now only saves $30 a month.
My issue today is .. I cannot be paid market rate for giving back to the grid, even in hours when California needs the power.
Not exclusively. A few power companies (like SRP) innovated here with TOU plans that have variable costs throughout the day. You can save huge amounts of monthly spend by moving energy intensive work to off-peak hours and by “priming” things ahead of peak hours, like over-cooling your house ahead of the peak window.
The most costly part of an infrastructure build out is supporting peak-of-peak - that capacity exists year round to service the demand generated by peak mid-day usage during a heatwave in July.
If you can “lop off” that peak - it dramatically reduces the infra build out cost.
Peak-of-peak tends to correspond with sunny days: mid-day in summer. I could see battery-less solar being a useful tool there.
In my area natural gas is a consistent 40-60% of generated power, with solar rarely reaching more than about 30-35% at high noon in the summer.
Right now (as in at this very minute, high noon) in CA ~70% of the power being generated is renewable. That's 30% that could be solar, and isn't.
When there's excess renewable generation capacity (or about to be), sure, let's talk about installations for storing it.
In the meantime utilities are deploying battery systems for virtual grid inertia, to avoid having to use "peaker" plants, reliability when transmission lines go down, and for transmission line maintenance.
California is certainly curtailing a lot of energy. EIA report[0] said 3.4 TWh in 2024, which was a 29% increase over 2023. If I am reading this[1] chart correctly, the 2024 California demand was ~275TWh.
CASIO also has pages dedicated to curtailment with much of the data available[2].
[0] https://www.eia.gov/todayinenergy/detail.php?id=65364
[1] PDF https://www.energy.ca.gov/sites/default/files/2024-11/2024_C...
[2] https://www.caiso.com/about/our-business/managing-the-evolvi...
In my mind the ideal solution is in addition to daily BESS time-shifting is seasonal time-shifting: long term storage of April excess for use in July.
More solar (without batteries) makes that worse.
Edit: My state had a subsidy of 300€ when I bought mine, so the RoI was instant ;-)
Unfortunately for me my back garden has too much shade for panels and I don't think I could get away with them in the front.
So that leaves a roof top install and I think once you have scaffold that you might as well have a traditional install.
Wish plugin batteries were part of it.
Right now (well 27th August) you can plug your inverter into a battery but you can't connect the battery to a ring main you have to connect devices directly to it.
That is under assessment though so there's a good chance they could copy the way Germany does it, just like they're doing with the panels.
Microinverter: 400 Panels (used): 250 for both Cables: 50
I also picked up two LiFePo4 batteries and two Kasa smart plugs and time shifted my computing infrastructure's electricity usage. That made much more of a difference in my bill, since a few hundred watts moved to .09/kwh. If the bms was smarter i could charge the batteries with solar, but alas i can't cap the recharge current.
A better solution is to do this on a local or federal government level and build the required amount of power.
This is different from net metering at retail rates, which arguably does move costs from richer ratepayers to poorer ones.
This puts extra burden on government/poor electricity buyers who cant afford solar to now cover the cost of the grid.
There is the hiccup of universal distribution which needs regular maintenance, and is separate from electrical supply. But if this is remediated by charging solar owners base fees/connection fees, or if grid maintenance is only minority portion of electric utility bills (in the US it's about 40% with electricity production being 60%), the direction should still be poorer people proportionally benefitting.
The get to enjoy the best of all worlds free energy when its good and the safety of the grid while the grid gets the worst of all worlds a non paying household that will spike demand at the worst time.
In Australia there’s a ridiculous amount of household solar & now battery being installed. Despite all the attempts by companies/governments to do something, they just keep getting in the way of themselves.
I’m glad the option exists for people to go their own, that of course puts the bar at the individuals finances.
Then there's the prospect of the price dropping even lower in the next few years. Imagine 800w kits for $100. How can you ignore something like that?
Certainly over here in UK and Europe most people are using solar to reduce their usage of the grid but they're nowhere near going self-reliant, so they're still using the grid (and paying towards it).
Ask anyone who has had a system installed. Your system can be totally compliant with national and state electrical code, installed by a competent installer using staff who are licensed electricians, get a stamp of approval from your own's inspectors - and the utility will refuse to connect it and insist you meet an additional set of their own conditions.
And there's nothing you can do about it. No appeals, no review process, nothing.
It's not even consistent, with utilities seeming to just obstruct for the sake of obstructing. Over and over I've of systems going in, the utility comes out (eventually) to inspect, refuses to connect. They're called back out, nothing has changed, and the system gets approved.
This is legislatures getting tired of all that power company bullshit, and bypassing them. As balcony solar rules hit state legislatures, expect some really absurd scare campaigns by power companies, and lots of lobbying.
Power companies see every solar panel they don't own as a threat to the profits they make on their fossil fuel power plants.
Well, I am someone who had a system installed… I have a 14000 KwH per year system, and two 13 KwH batteries. It did take a while to get it inspected, which was annoying, although I was able to use it while I waited (I just couldn’t sent power to the power company until after), but they approved it the first time without any additional requirements.
What makes you so sure everyone has the experience you are talking about?
That took all of two weeks. To get their permission to operate, including having the city inspect my work and send the all clear to them.
Put some (or all) of your circuits on a transfer switch or generator interlock and connect your solar system to that.
Then legally your system is the same as a backup generator install. It should have permitting and inspection requirements similar to those of adding a circuit. That will just a city permit and a city inspection.
This didn't happen to me or anyone else I know with rooftop solar in multiple states, and I've never heard of it. What citations do you have?
If they're mounted on a roof then obviously you can't benefit from that so it would be cheaper to go with single sided panels.
They'll replace the line worker at the drop of a hat, and fight tooth and nail to grow profits, that's just how corporations work.