If you have a 5kW invertor you may have to inform the DNO incase you send power back to the grid.
Under 3.7kW is fine.

 

Any installation work of that kind has to be done by a qualified electrician. Better to find an installer, tell them what you want and they'll know what's available.

If you have a 5kW invertor you may have to inform the DNO incase you send power back to the grid.

OP is not installing solar. I don't think you're allowed to export to the grid from batteries, and can't see why you'd want to.

 

I don't know the in and outs of the proposed set up but I'm assuming they want to charge when cheap and run off the battery when expensive. I wouldn't think with such a set up there would be any intention of exporting anything.

Is such a system in existence and if so what would the need to inform the DNO be 🤷🏻‍♂️

Purely devil's advocating here!

 

I did some quick calcs based on me using 300w/hour for 15hours = 4.5kw - which is what I use in my lounge for the tech. (running everything in just this room from a 1kw inverter)

I'd need a 50amp 24v battery charger to put back 4.5kw in 4 hours. (probably actually more like >60amp)

5kw costs 25p currently, might cost 50p if Go increases to10p off peak.
5kw on the day rate assuming 50p by January is £2.50 so saving £2/day.

The cost of a charger, sine inverter and two Lion batteries is £2000min so it would take 1000days to break even.
By which time the batteries could well need replacing.

It doesn't make financial sense according to my calcs for my use.

 

1000 days is 3 years. Givenergy warrant their LFP batteries for 10 years. Even NMC batteries in EVs last for a decade or more.

 

The Squirrel Pod is a good “Agile aware” inverter. Any other inverter that can be controlled by a Raspberry Pi or whatever will work too. You just have to write your own logic.

Any battery inverter will work with Go (or Go Faster), charge in the cheap period discharge for the rest of the time is super-simple. I’d get a hybrid inverter so you can add solar later because the secret sauce is the combo of ToU, batteries, and Solar PV.

 

You need to work out the costs compared to the saving because you will find it could take years to break even and the batteries will need changing regularly. (save £1000pa, spend £5k =5years to break even)

 

I intended using Lifepo4 rack batteries, which should last longer than they would in an EV as the charging and use will be gentler. I would expect at least 10 years life but it could be a lot longer. Battery cost about £3000. I'll get an electrician to wire up the inverter/charger to the grid in and house load out. The battery DC wiring I'm used to from setting up boat systems. I guess the whole 10 kW system should cost around £4000. I know for the next year I would save £1000 as my Go contract has just renewed. The primary risk is if Go or other time of use contracts disappear. Another advantage of the system would be I'd stop thinking about the 40p per kwh hour it costs when I switch something on during peak. I want the system to work if the grid goes down, I think many inverters stop working if there is no grid power. A Victron inverter/charger would continue to work, but I not aware of them being Agile compatible. They will work with Go.

 

There are loads of pre-packaged LiFePO4 batteries you can buy. Pylontech is a popular brand and they come with the connecting wires pre made. As with all batteries, prices are high and waiting lists are long right now.

Pretty much all inverters have a UPS or EPS connection to use in the event of an outage.

 

With gas prices rising significantly above Go off peak rates from October maybe I should consider a larger battery and switch from gas to electric heating.

 

You can do what I plan to do - use cheap electric to prewarm the rooms in the 4hr period thus reducing gas consumption or in my case, oil.

Having said that, oil prices have fallen from 105ppl to 78ppl, (were 65p last winter) & are still falling so may bottom out by the end of the month, especially as the weather is looking very warm and dry.

 

Octopus are taking new customers but you have to phone them up and they still use referral codes.
Plus no exit fees.

 

Thanks, but I'll wait until I get my new car, and see what Ecotricity have to offer. The company is paying to charge my van, and I won't use nearly as much for my car. It'll only make sense to change when I get a battery, which won't likely be until next year, and things may have changed by then. I've also signed up to Ripple, and I'll have to change (probably to Octopus) when the 3rd one starts producing.

 

Just been reading the DNO regs re inverters and export. Looks like a 5 kW inverter needs to be G100 compliant to fit even without solar. Software control of export amount is not good enough. A sub 3.68kW inverter makes life simpler. Can't see any G100 compliant inverters for reasonable money.

 

I’m yet to understand why anyone with normal consumption would need bigger than 3.6kW of inverter.

 

Apparently need DNO approval for inverter of any size to operate in "Island mode" ie supply power when grid cut off. When Go is cheaper than gas, might want more than 3.6kW if using for heating.

 

I did the G99 myself. When I did it, it asked for your accreditation/qualification but I see Western Power have a new form that doesn't have that on it. They do also seem to have a lot of extra detail about the power generating plant that wasn't on the old version.

There was no fee and they processed it a couple of weeks from recollection. It was back before the battery was delivered anyway!

 

Just looked at UK Networks very complex forms, all seem to assume authorised installer completes. It sounds like Western Power is more consumer friendly. It's just like EV public chargers, the Government misdirects billions of pounds investment into a failed system. They want us to switch to green energy and load shifting, but then put bureaucratic hurdles in the way. I'm seriously wondering if home storage is worth the bother. A brief web search for authorised installers in my area Essex, shows its an industry with a good few cowboys with many self generated reviews.

 

I think of them the same way as fans. They change how warm/cool it feels, not the actual temperature. There is value in that, but not enough to make me abandon my wet central heating just yet.

 

What are the regulations required to self install home battery storage?

Is it similar to compliance with Part P (i.e. being NICEIC registered or similar, C&G course completed) or are there additional requirements?

I wonder if you could do almost all of the work yourself and just pay a regular sparky to put in the circuit and write the letter to the DNO. The battery systems are usually 50VDC so these are probably outside of the remit of most electricians certification (but they may not be mains-isolated if the inverter is transformerless!) 50VDC is within ELV, but the lack of isolation may push this into another category.

 

The battery systems are usually 50VDC

Is this the case? The batteries I've had installed are 110v DC, and with two batteries connected in series, that's 220v DC to the inverter.