No wonder all commercial efforts have failed
No wonder all commercial efforts have failed
Posted Feb 27, 2025 12:00 UTC (Thu) by paulj (subscriber, #341)In reply to: No wonder all commercial efforts have failed by NRArnot
Parent article: Building an open-source battery
Currently, have to sell excess solar energy in the day to the grid at about half the price (or worse) that we then have to buy that energy back at in the evening / night. Which.... sucks. If we could store that energy with >70% efficiency, that'd be nice. In an *ideal* world, I'd want ability to store at least a few months worth of energy, for at least 6 months - cause (obviously) our excess solar production is biased to one time of year (summer), while much of our energy demand is biased to another (winter, heating).
Posted Feb 27, 2025 15:44 UTC (Thu)
by jjs (guest, #10315)
[Link] (5 responses)
(electricity price) = (cost of electricity production) + (operating costs to include maintenance & upgrades of grid) + (profit)
Net metering sets (cost of electricity production) = (electricity price).
Converting the equation:
That equation only works if not only is (profit) = 0, but (operating costs) = 0. Which won't happen.
Net metering works when the percentage of customers on net metering is on the order of 1% or less. As the number of customers who also are providers grow, the grid operators have to either end net metering, or go out of business (i.e. you no longer get electricity).
The best way to store electricity long term is spread the cost - by both aggregating the storage (so any one customer only has a small amount of the cost), and spreading the location (i.e. interconnect) to minimize the storage actually needed.
Posted Feb 27, 2025 21:00 UTC (Thu)
by marekm (subscriber, #174682)
[Link] (4 responses)
Some examples:
Many washing machines and dishwashers have a feature where they can start automatically at preset time of day. Most ordinary households don't bother using this as they pay fixed price per kWh 24 hours a day. If they had reduced prices around noon in the sunny months of the year, they would have an incentive to read the fine manual and learn to use this feature to get some savings. It is possible to choose a tariff with lower off-peak prices, but then the peak prices are higher so on average there isn't much difference unless you can really put most of the energy demand during off-peak hours (not many people can).
People who drive electric cars for their daily commute from home to work and back (not all work can be remote), often charge their cars at home overnight because of very high kWh prices on fast public chargers. Instead the employers should get incentives to install more slow chargers (basically just simple AC power sockets) on their parking lots, for cheap slow charge during the day when there is excess solar. No need for high power fast charge as the car is parked when the driver is at work for a few hours, enough for the typical 20% to 80% slow charge to go home and back to work. Of course this assumes electric cars become cheap, small city cars - it needs to be literally the people's car (German: Volkswagen) and not a very expensive large and power-hungry SUVs and a status symbol to say "I'm rich". More like Dacia Spring or Leapmotor T03 (offered only recently), not Tesla or Mercedes.
Doing these fairly simple and cheap things would allow much more net metering, the problem is really that grid operators are monopolies and want to maximize their profits "because they can" and have too much political power, while net metering is good for the consumers and money saved on energy bills could be spend elsewhere which is good for the economy in general (of which grid operators are only a small part). But grid operators really want high profits, and prefer to shut down solar plants (waste the renewable energy) when their is too much sun, instead of putting that excess energy to real good use as shown above.
Poland (where I live) has had net metering until March 2022, PV installs made before that date can keep it for the next 15 years and it's a very good thing (basically storing energy in the grid for up to one year with 80% efficiency), sadly not an option anymore for anything new installed after that date. The only option for new installs is much less favorable net billing, which is also much more complex to calculate if it's profitable for the consumer at all. Before our 2023 elections the new ruling party promised to bring net metering back (item 84 of https://100konkretow.pl/wszystkie-konkrety/ ) but they haven't, instead trying a few times to patch the new net billing system with little real improvement, just trying to show they do something. Apparently impossible due to EU regulations as they say, but still was possible for the Netherlands which is also in the EU - it's just that their parliament was more in favor of the people, not the grid operators.
Posted Feb 27, 2025 21:26 UTC (Thu)
by malmedal (subscriber, #56172)
[Link]
Posted Feb 27, 2025 21:48 UTC (Thu)
by kleptog (subscriber, #1183)
[Link] (2 responses)
Why? Because net metering means that energy companies have buy expensive electricity in winter to match the cheap electricity they bought off you in the summer. (You get to net meter, but your energy company doesn't.) As a result, energy companies make a loss when customers have solar panels, which then has to be compensated by a higher per kWh price for everyone.
So the whole system is essentially a massive subsidy from people without solar panels to people with solar panels. One in three Dutch houses has solar panels, and since it's generally the more wealthy people who own their own houses that install solar panels, poor people are basically subsidising rich people. It also removes any kind of incentive to install batteries or manage your electricity usage.
Of course, the new government said they kept net-metering so that poor people could also benefit, except people renting or living in social housing or apartments can by construction never benefit from this scheme (facepalm).
So yeah, "net metering is good for customers" if you're rich enough to live someone where it's possible.
(Near as I can tell there's no EU directive explicitly forbidding net-metering, but the Renewable Energy Directive II does say things like that batteries should be promoted and costs of the energy transition fairly shared, and net-metering goes against both of those.)
Posted Feb 27, 2025 23:01 UTC (Thu)
by marekm (subscriber, #174682)
[Link]
Most people with their own houses are paying for them with high interest rate mortgages, so they are not really that rich (myself included), the interest rates here are among the highest in Europe, banks are making a lot of money "because they can" much like the utilities. It's often around 10% per year interest rate when you borrow from the bank, and next to nothing when the bank borrows from you (you keep your money in the bank, except short time promotions like "new money for the first month").
So it's the energy companies and banks who are very rich here (and they likely also sponsor some politicians to keep the status quo), while solar panels are quite popular among average-rich people (someone really rich doesn't need them, really rich people could simply pay their high energy bills and enjoy a cleaner looking roof).
Adding extra fees for those producing more solar power is downright evil, especially if based on total size of solar panels (their theoretical max power if always perfectly aligned to the sun) and not just peak power sent to the grid. So I'd be actually punished for adding more east/west panels (or vertical bifacial ones that could double as a fence) that make more energy during the early/late hours when there is more demand.
Posted Feb 27, 2025 23:27 UTC (Thu)
by Wol (subscriber, #4433)
[Link]
My home has effective "net metering", although that's because I've got an old-fashioned mechanical meter that runs backwards if I'm generating more than I'm using, and that's an "improper combination" - you're supposed to get a smart meter if you have an array, and they don't run backwards.
So if you get an array in the UK, what is (or was) supposed to happen is you got a "generation payment". There's a meter on your solar output and you get paid a decent sum for your generation (to pay back the capital cost of you installing the arrays). Because smart meters couldn't go (or measure) backwards, they then assumed that you kept 50% of your generation and fed the other 50% into the grid, for which you get paid a nominal sum. You can now get "feed in" meters so you get paid for the actual electric you feed into the grid.
Over the years the generation payment has dropped as panels have got cheaper, and you can't get it for new installs any more I don't think. The feed-in payments are pants, so basically you now pretty much want to use most of the power you generate.to get your money back. But the panels are cheap, so it's roughly worth it. I'm getting good money on all three arrays, but that's because they're old and the generation payments will expire in the not too distant future. So the only benefit I will get once that happens is a bit of feed-in money, and a bit of free electric. It is what it is, but it still seems economic for people to install panels ...
Cheers,
Grid operators would go out of business with lots of net metering
(electricity price) = (electricity price) + (operating costs to include maintenance & upgrades of grid) + (profit)
Grid operators would go out of business with lots of net metering
Grid operators would go out of business with lots of net metering
Grid operators would go out of business with lots of net metering
Grid operators would go out of business with lots of net metering
Grid operators would go out of business with lots of net metering
Wol