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Plug-in solar is coming. Plug-in batteries should follow

regen.co.uk

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Re: Plug-in solar is coming. Plug-in batteries should follow

#121

Post by gambiting »

angry_octet wrote: post #118
gambiting wrote: post #106

Earlier quoted context omitted.

Sure, but now we're talking about some freak situation where you have multiple sources with a combined allowed load of more than 32amps with 3 or more connected devices drawing at their max rating or above, but only when on battery power when you have no grid connection. Like, it could happen but we're entering the "fun to think about" territory.

If you have no grid connection then everything will go offline, unless you do something illegal. The situation can occur if loads and sources are on the same circuit, e.g.: Grid | Meter | CB | |--battery1 |--battery2 | | | This is not daisy chained (HN markup hates diagrams) but hanging off wall circuits and power boards. With a situation like this (in 240v) the batteries will sink 2x10A and the PV will supply 16A th…

I mean sure but right now in the UK you can only add one 800W source without planning permissions.

I'm just not sure what we're trying to say here - can someone create a dangerous situation for themselves by ignoring the rules? Yeah of course.

My example above was for a 32+ amp source(or a collection of sources) which can operate with the grid off, like most battery systems in the UK can - they just have a relay that disconnects the grid when the grid is offline. So it's not illegal, but it's also something that would require a planning permission to have. Can someone just go any buy themselves 10x800W modules, plug them all into one ring and burn their house down? Yes,but that was never a legal setup in the first place.

Re: Plug-in solar is coming. Plug-in batteries should follow

#122

Post by vvbull »

angry_octet wrote: post #98
vvbull wrote: post #81

What happens when a consumer buys three and sticks them on the same 20 amp circuit? Cause people will definitely do that. Going to be some warm walls.

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 e…

Right. The problem is the kitchen outlets or some other heavily loaded circuit. Running the microwave and kettle and fridge. And powering via these plus the wall. Or putting three of these on an extension cord.

Re: Plug-in solar is coming. Plug-in batteries should follow

#123

Post by vvbull »

perpetuallunch wrote: post #105
vvbull wrote: post #72

Earlier quoted context omitted.

Australia emits 1-1.5% of greenhouse gases. Tripling that would absolutely impact global concentrations, especially over human time scales. But agree, Australia exporting fossil fuels should be reflected. If you counted their export of fuels it would be closer to 5% of global emissions. IMO, getting to zero would knock over a whole integer percent off the global goal, that's notable. And if you stopped exporting oil,…

Your argument seems to boil down to: What we’re doing isn’t working, so let’s do more of it . There’s a cost of living crisis in this country effecting the majority of Australians. So let’s make energy more scares, more expensive. I’m with Gad Saad here, in that the one thing that astounds me the most about other people is their inability to change their opinions in the face of overwhelming evidence to the contrary.

Ah, so you are taking the anti capitalist stance. Interesting to see that pop up here.

Australia sells its fossil fuels on the global market rather than prioritizing its local market. So when disruptions (like the various wars around) drive up prices, Australia sells the gas at a higher rate. This, in turn, drives up prices locally.

Combined with aging and failing coal infrastructure, which isn't producing as much or as reliably, you have a marginal rate that can get quite high.

Meanwhile, Australia has retail electricity providers and not a single government owned utility. Those retailers must make a profit, and they've invested heavy capex into smart metering. So they charge customers as much as customers will tolerate.

You might be right, it might be time to nationalize some of that fossil fuel usage, and remove the profit motive from energy retailing. That could drive down costs for end users.

But I don't think solar is really a major input here beyond replacing baseload. Expensive marginal priced peaker plants are one of the key drivers of high energy costs. When the sun sets, those plants have to come online. Better battery storage would smooth that demand significantly, as in parts of Australia solar production is already producing negative energy prices.

Re: Plug-in solar is coming. Plug-in batteries should follow

#124

Post by vvbull »

xbmcuser wrote: post #102
vvbull wrote: post #73

Earlier quoted context omitted.

The problem isn't the battery catching fire, it's that you no longer have a circuit breaker between your appliances and the generator. Meaning you could, especially if you have several batteries, push load through wires in the wall in excess of what is rated for.

it is the same as the balcony solar though so what is the difference the batteries would be doing the same exact thing?

Yes. We have circuit breakers for a reason, and rooftop solar is not risk free.

Re: Plug-in solar is coming. Plug-in batteries should follow

#125

Post by angry_octet »

gambiting wrote: post #121
angry_octet wrote: post #118

Earlier quoted context omitted.

If you have no grid connection then everything will go offline, unless you do something illegal. The situation can occur if loads and sources are on the same circuit, e.g.: Grid | Meter | CB | |--battery1 |--battery2 | | | This is not daisy chained (HN markup hates diagrams) but hanging off wall circuits and power boards. With a situation like this (in 240v) the batteries will sink 2x10A and the PV will supply 16A th…

I mean sure but right now in the UK you can only add one 800W source without planning permissions. I'm just not sure what we're trying to say here - can someone create a dangerous situation for themselves by ignoring the rules? Yeah of course. My example above was for a 32+ amp source(or a collection of sources) which can operate with the grid off, like most battery systems in the UK can - they just have a relay that…

Traditionally we have been quite prescriptive about what people can do electrically on their side of the meter, in the name of protecting people from themselves. (Even with a grid isolation switch.) Allowing generation that isn't wired in by a licensed electrician is a big change in regulation, so people are jittery and vested interests are using that.

So it isn't no risk and it isn't a huge risk. Some people will do stupid things. I think we could do more to protect people using plug-in generation, and simultaneously improve grid regulation and reduce costs. As engineers I think we are duty bound to achieve these objectives, but accountants run energy companies now and donate to politicians, and politicians run policy. What we have left is technical innovation that creates economic impetus.

So I'm in favour of technology that makes low cost PV+storage safe and available, economically and with just enough regulation.

With the US banning Chinese inverters, it will be interesting to see if that spawns new tech, or if they just licence build/assemble Chinese junk. Prices will be higher initially but competition should be strong. Unfortunately US standards for software/interoperability seem absent. IEEE 2030.5 is not nationally mandated in the US AFAIK, and it is weak on cyber assurance.

IEEE 2030.5 is also designed for grid to consumer and doesn't anticipate having multiple PV devices that need to talk, let alone batteries. The Germans just exempted everything below 960W, so people routinely have several panels plugged in.

Re: Plug-in solar is coming. Plug-in batteries should follow

#126

Post by vvbull »

gambiting wrote: post #106
angry_octet wrote: post #99

Earlier quoted context omitted.

You can have multiple loads and sources that are in-spec but the wiring between them is overloaded.

Sure, but now we're talking about some freak situation where you have multiple sources with a combined allowed load of more than 32amps with 3 or more connected devices drawing at their max rating or above, but only when on battery power when you have no grid connection. Like, it could happen but we're entering the "fun to think about" territory.

Why not when grid connected? The problem arises when you are grid connected.

You draw 31 amps from the grid, you draw 6-7 per battery or solar installation behind the circuit breaker. The circuit never trips because the amount crossing the breaker is 31 amps, but the wires could be dealing with 37+. With battery and solar that could be 43+. Some idiot puts two or three of these in their house or puts them on an extension cord, wires are going to get warm.

Re: Plug-in solar is coming. Plug-in batteries should follow

#127

Post by angry_octet »

vvbull wrote: post #122
angry_octet wrote: post #98

Earlier quoted context omitted.

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 e…

Right. The problem is the kitchen outlets or some other heavily loaded circuit. Running the microwave and kettle and fridge. And powering via these plus the wall. Or putting three of these on an extension cord.

Where do PVs work best? Since you can't put them on the roof, out in the back yard. So you run a long extension cord and plug them into a power board. Or in an apartment, there might be one circuit with an outside outlet, so they all plug into that.

Usually it isn't sunny enough and the load on the circuit isn't large enough, so the wiring will be fine. But sometimes it won't be.

It's amazing that we actually have an IOT use case and the resistance to networking equipment is profound.

Re: Plug-in solar is coming. Plug-in batteries should follow

#128

Post by Aurornis »

skew-aberration wrote: post #23
Aurornis wrote: post #15

Earlier quoted context omitted.

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.

Yes, and non plugin-in batteries don't just need a permit - typically the power company also directly controls the battery, via a web API that the manufacturer provides (at least in Australia, this is a condition for access to the incentives).

For the incentive programs you need to submit to a virtual power program so the power company can coordinate the fleet.

For normal non-subsidized installations here you don’t need to let the power company control it.

Re: Plug-in solar is coming. Plug-in batteries should follow

#129

Post by luxuryballs »

dghlsakjg wrote: post #22
luxuryballs wrote: post #11

Wild that we have to ask permission to be able to make this stuff.

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 o…

Thanks for clarifying this, clearly I did not read enough into the details.

Re: Plug-in solar is coming. Plug-in batteries should follow

#130

Post by satiric »

hnaccount_rng wrote: post #94
satiric wrote: post #91

Earlier quoted context omitted.

How do you detect that it's plugged in? Just detecting voltage would mean that you'd unplug it and it would stay energized, right?

They need the grid frequency to generate AC. Those inverters are only allowed to be grid-following (at least for the plug-in part. I think there are systems that provide a -to-load socket that can be a PSU)

Ah I see, thanks.
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