It's not a scam. Connecting to the grid has enormous value, and keeping the grid up has real costs. A model where your generation pays you retail prices doesn't make sense.

California's current net metering system, which is more reflective of the true benefits and costs of solar to the power system, has been incentivizing people to add storage to keep their solar rather than get paid big money to feed back midday low-value solar, which is a big win.

Similarly here in Australia.

Electricity prices keep increasing, daily supply charge keeps increasing (this ones supposed to pay for the transmission network), while the solar feed-in tariff keeps decreasing.

With the added stupidity that, obviously the sun works during the day and so do you.

Now tax payers are forced to subsidies residential batteries as well as rooftop solar, which results in a wealth transfer from everyone else to home owners, and isn’t a policy that helps low income earners and / or renters.

It’s also government picking winners, which historically has never worked, rather than letting private enterprise pick winners, and potentially failing, in an open and free market.

Wild.

The new rule here requires you to pay for part of your imports (up to ~60%), even if you export more. I know people who installed batteries in the inverters because of this. It is more expensive overall (hybrid inverter + LFP batteries) but has other benefits (blackouts are not a problem, most months you don't even use the grid). I imagine that once sodium-ion battery production scales and costs decline, this will become the "default" option for a solar installation.

In more well-run locations, power companies are providing incentives to install batteries because they help reduce the load on the grid.

These are plug-in solutions, though. The whole idea is that a permit isn’t required. If approved in your area, you don’t need to work with the power company at all. You just buy one and plug it in.

The plug-in stuff doesn’t play by the same rules as the big installs.

The solar situation in CA is truly mind boggling for a state that is ostensibly progressive.

> Why bother? Power companies will complain they are losing money and regulators will allow them to buy energy from residential solar panels basically for free (NEM 3.0).

The way I would see this working is that you charge the batteries when electricity is cheap (generally, midnight through early afternoon), and then run the house (not supply the grid) the rest of the time.

LFPs are cheap enough now that a strategy like this would pay back after about 2 years.

If they try to adapt with a “NEM 4.0”, the whole thing will collapse because solar and LFPs are so cheap that everyone will just pay their mandatory $50/month grid connection fee and not buy any electricity from the grid.

Completely agree with you, Govts sacred duty is to protect the super rich and utilities are the biggest monopolized cash cows (Eg: Warren Buffet). However,if people work with their local governments and change the building code to allow plug-in solar and plug-in batteries, that will continuously upgrade every home to become more and more energy independent and with the explosion of products, eventually be grid free. The biggest costs are labor, permits and delays; if its just products that people can plug and play, the adoption will be faster than just rooftop solar (or rooftop + batteries).

Also, most utilities have tiered rates (higher utilization at higher rates), if you can have plug in systems that can bring the total kwh down, it immediately lowers the peak rate.

The only bottleneck is making products that are safe to plug in, and this will happen as building code creates a standard to plug-in.

If being connected to the grid is a "scam", then disconnect. Buy 100 grand worth of batteries (which still may not get you through the winter), and pull the ol' plug.

NEM 3.0 is more fair. The grid is expensive and just as expensive if it is needed to be fully utilized 1% of the time or 100% of the time.

The problem is California forcing new construction to buy overpriced solar from builders that makes little sense compared to commercial solar installations + grid.

These are problems not inherent to solar, but to places that are underdeveloped and under-regulated.

Plenty of places in modern and developing countries don’t have these issues.

When we got our solar system in CA, our electric bill went to zero. We calculated the payback to be 9 years. Eventually, they stopped buying back electricity and changed the way they metered and our bill was as high as ever. We save a bit because we're able to charge our electric car at times of peak PV output.

We left California last year for this and many other reasons. They just don't want anyone to be productive here.

That’s largely correct but misses the point that the battery+pv system is legally only allowed to feed in 800W [1]. On our circuits you can draw ~3.5kW without tripping the breaker. This brings you to 4.3kW max load, which - as far as I understand - is still what all the circuitry must be rated for anyways.

The downside is that we have three phase power supply anywhere halfway recent. And that only gives you a single phase. In _most_ cases that’s fine, because you get a net-sum of all three phases at the meter, but technically you are only drawing/supplementing one out of three phases. In practice this likely doesn’t matter since different house put theirs on different phases and it all washes out.

[1] the DC side can have up to 2kW of panels. But that’s not visible to the grid

Well, yes generally speaking. But the way this works with these plug in panels is that the micro inverter won't actually start delivering power to the grid in the absence of an energised plug in the first place. So just sitting there, the contacts are completely harmless. Obviously actual physical safety where you literally can't touch the contacts would be better.

What percentage of buyers do you imagine are gonna buy a battery big enough to saturate 15A*120V=1800W for long? The average home uses 30 kWh per day = 1250W. Batteries don't need to handle peak load. Approximately nobody has a whole home UPS.

Also 240V power strips are fairly common in my circles because GPU server PSUs tend to be more efficient at 240V. They're marketed as PDUs, not strips. You're not gonna install a new outlet for every server. One dryer outlet in the garage is enough for most people

What makes it easier on 240v systems is that your entire household is on the same “circuit”.

If you’re on a 120v system, there’s a ~50/50 chance that your load is on the wrong side (except for 240v loads where you’ll imbalance things a tad but it should average out).

Unless you’re in an apartment/conso and have 208v instead of 240v… dunno what happens then.

The plug in "balcony panels" are usually limited to 800W here in Europe, so having them without a battery can make sense because you're probably going to use that power on the spot most of the time.

Can give free advice, contact in profile

800W peak * 3 is only 2400W which is fine, it's very unlikely to be pumping out that for long. Now if you put in 6 of them you will have problems, but this is the same problem as people plugging in multiple loads, and circuit breakers handle this fine in practice.

Perhaps the bigger risk is a mix of loads and supplies on the same circuit, which could result in large currents on runs without a circuit breaker. Cheap extension cords are are possible problem too.

Arguably the plug in PV should have to talk to a house bus controller, which controls generation and loads. Unfortunately the standardisation process is impossible.

Millions of households have plug-in solar. The payoff is something like 1.5-5 years. Of course, this should be tens or hundreds of millions, but this isn’t vaporware

It's already been a thing for a long time. People in the UK are talking about it more because it's about to be legalized(up to 800W) by the end of August.

The power grid has the potential to be insanely dangerous. We largely have eliminated that danger because of tight regulations and codes.

Look up backfeeding, which is a huge concern with this stuff. It is entirely possible for anyone sharing a transformer with you to send power back up the lines to your house in a dangerous way. That’s why you shouldn’t just plug a generator in with a suicide plug when the power’s out.

A grid tied battery without the right protections is electrically identical to a generator with a suicide plug. We want some standards here.

Not really. If it was off grid it wouldn’t be a problem, but connecting to the grid requires that all of the power generating equipment get along and operate safely.

Anything that starts getting into shared territory requires regulations. Similar to how wireless equipment needs to comply with regulations so we can use the frequency spectrum.

The standard governing this is UL 1741 in the US or VDE-AR-N 4105 in the EU. both require certified inverters to detect grid loss and immediately cut off.

yeah, it’s called anti-islanding. UL 3700 is the thing to look at if you want to read more about some of the safety precautions

How many houses in Britain have wiring that is less than 800 W away from starting a fire? How many of those houses have the disposable income to buy a plug in battery?

Yes, more electricity means more risk of fire. But 800W batteries do not seem like a major safety issue

The new sodium batteries are a lot safer than the lithium chemistries. And we already do have type of home batteries they are just called UPS systems. The real game changer will be when 3-5kwh plugin batteries fall below $150-200pkwh as at those prices batteries will make sense even for apartment owners/renters with no solar to use it to demand shift as time of day electricity prices get more common.

While the potential for fires shouldn't be dismissed, for batteries designed to be stationary rather than mobile (such as in an e-bike), you can use a chemistry optimized for stability rather than optimizing for compact weight and size.

Because there are not enough of these large battery banks, which require planning permission to build.

Whereas you can buy a battery that will save you money over a 5 year period and get on with it.

(I'm hoping that enough of the larger ones get built that having one yourself doesn't make economic sense, but I suspect we're ten years out from that)

https://news.ycombinator.com/item?id=49141066

LiFePO4 batteries generally sit upwards of 3000-8000 cycles to 80 percent original charge.... Depends on what your chemistry is.

As the batteries improve, you'll probably want to upgrade every 8-10 years or add/swap out a 1/4 to 1/2 storage by that time, still able to use effectively even if a little lower top end. Depends on your usage and if you're still on grid.

I assume these would be batteries that are relatively robust in terms of cycle count, like LiFePO4.

Lithium irons are often 4000 cycle now. For full cycles.

I forget who but I really want to say I was looking at some cells a year or three ago that were 10k cycle count.

And it's not like the battery is worthless at that point. It just means the battery is down to 80% max capacity. You can down cycle it, find some other consumer to use it, replace it, if you need the capacity. But should keep running for a long time.

I guess you've never come across electric heaters or if you want to go into the bedroom electric blankets ( 5000 fires per year in the UK in 2011 )

Presumably it helps that these things have their own fire suppression systems, time of use tariffs are cheap, and everybody needs a win.

(I'll be putting mine outside)