Overnight Battery Charging / Storage without Solar

coupleuk

STILL trying to get my head around the idea of using battery storage, which is charged overnight and used next day, then repeat.

Questions like;

1) What's the maximum size storage battery that will charge to 80% on a single-phase residential supply in (lets say) 4 hours.

2) Is that dependant on the size/power of an inverter?

3) As there is no solar at all, does that make choosing a battery any different?

4) Is there an inverter that will power a brief 8.5kw shower, 2kw convector heater and perhaps even a kettle at the same time?

My flat uses roughly 6kwh-12kwh per day - its electric only and has an under-sink water heater. Also a 8.5kw shower and 2kw electric heater plus microwave, kettle, toaster.

THEN, if I have 4 of these flats next to each other (with 4 incoming single-phase supplies) is there a decent way to link the batteries, inverters etc together so they can share the load and available stored electric?

And then, using the 4 flats combined situation, would 2 x single-phase supplies achieve the same result so I could remove 2 supplies and save 2 x £180/year standing charges.

Thank You

QrizB

coupleuk said:

1) What's the maximum size storage battery that will charge to 80% on a single-phase residential supply in (lets say) 4 hours.

2) Is that dependant on the size/power of an inverter?

3) As there is no solar at all, does that make choosing a battery any different?

4) Is there an inverter that will power a brief 8.5kw shower, 2kw convector heater and perhaps even a kettle at the same time?

1. You can charge an EV at 7kW from single phase, so a 28kWh battery pack would be feasible. Possibly bigger.

2. Yes, you'd need a 7kW charger/inverter (or two 3.5kW ones).

3. Yes. What exactly are you trying to achieve?

4. Yes, I'm sure there is but that isn't necessarily a good reason to buy/fit one.

Your wider questions about sharing supplies between flats depend on lots of other factors. Who will be living in these flats, and on what terms?

Solarchaser

1. If you had lots of spare cash and a 100a/25kw mains fuse then in theory you could store 100kwh over the 4 hours.
In reality not really, but most things are possible with the right amount of money.

2. Yes, or inverters, I have 2 lux 3600 inverters, so in theory I can store 7.2kwh per hour.
In reality it's more like 6.8-7kwh

3. Not really, but it does change the calculations involved as you will have no "free" energy as you would with solar.

4. Not that I'm aware of, however you can buy a few parallel lux to get there, but you would have to ask yourself how likely that is to pay you back, as the times where you will use over 3.5kw are very rare in comparison to your 24hour cycle.
I have 2 lux, but its very rare they are called to power 7kw, except for when the shower is on, and they cannot cover the shower.

5. Yeah you could have a central battery that powers each inverter, buy it would be pretty big, and stored in one person's flat

6. Not sure about that one, as removing 2 x supplies means you would have less available power overall.

ispookie666

The battery size is immaterial (sort of) there are a few inverters which will charge at 5000VA, would be useful to find out what charge current the battery would take.  Usually 1C, anything more will start degrading the batteries (will still take a good few years). 

 I would probably look at Victron Multiplus II -  been in the market for a lot longer, reasonable sized community(a lot of off grid), easily scalable.  
Victron is an expensive system.  I think you can use a good number of LiFEPO4 batteries(does not have to be Victron) or even Lead acid.  

If you are into DIY - might want to look at used Nissan leaf or Tesla or equivalent batteries and setup a plant.  There is a thriving online forum for this.  

coupleuk

Basically, I've got 4 flats that I rent out - all are next to each other and all wiring was new so their incoming supplies are all together in a secure corridor area with only my access.

Thinking is to buy energy at cheap tariff (Go if I can lol) to charge the batteries and then sell it on to the flats just below current prices - so tenants benefit and hopefully the system will pay for itself faster and lead to some profit.

I had previously got the all clear from Ofgem to say because the energy being re-sold was stored, it didnt fall under energy price regulation - but Im hoping to resell below utility provider rates anyway.

[Deleted User]

coupleuk said:

Basically, I've got 4 flats that I rent out - all are next to each other and all wiring was new so their incoming supplies are all together in a secure corridor area with only my access.

Thinking is to buy energy at cheap tariff (Go if I can lol) to charge the batteries and then sell it on to the flats just below current prices - so tenants benefit and hopefully the system will pay for itself faster and lead to some profit.

I had previously got the all clear from Ofgem to say because the energy being re-sold was stored, it didnt fall under energy price regulation - but Im hoping to resell below utility provider rates anyway.

Octopus now restricts its Go and Go Faster tariffs to to EV/PHEV owners only. 

QrizB

coupleuk said:

Basically, I've got 4 flats that I rent out - all are next to each other and all wiring was new so their incoming supplies are all together in a secure corridor area with only my access.

Thinking is to buy energy at cheap tariff (Go if I can lol) to charge the batteries and then sell it on to the flats

Under these circumstances yours won't be a domestic supply, so you'll need a commercial account. I don't know what options there are for split-rate commercial tariffs.

Undervalued

coupleuk said:

STILL trying to get my head around the idea of using battery storage, which is charged overnight and used next day, then repeat.

Questions like;

1) What's the maximum size storage battery that will charge to 80% on a single-phase residential supply in (lets say) 4 hours.

2) Is that dependant on the size/power of an inverter?

3) As there is no solar at all, does that make choosing a battery any different?

4) Is there an inverter that will power a brief 8.5kw shower, 2kw convector heater and perhaps even a kettle at the same time?

My flat uses roughly 6kwh-12kwh per day - its electric only and has an under-sink water heater. Also a 8.5kw shower and 2kw electric heater plus microwave, kettle, toaster.

THEN, if I have 4 of these flats next to each other (with 4 incoming single-phase supplies) is there a decent way to link the batteries, inverters etc together so they can share the load and available stored electric?

And then, using the 4 flats combined situation, would 2 x single-phase supplies achieve the same result so I could remove 2 supplies and save 2 x £180/year standing charges.

Thank You

Is the big problem here (and maybe cheap fix) to get rid of the 8.5kW shower and have a small(ish) hot water cylinder and a immersion heater? That would reduce your maximum total load.

Or, at one time you used to be able to get a simple either / or switch for small flats which meant you could use either the electric shower or cooker, but not both at the same time.

So, why must you be able to use the shower, heater and kettle all at once? 98% of the day you won't be in any case so can't you make that 100%?

coupleuk

Yes, electrician did say he could put a restrictor in so (lets say) only 2 of 4 showers worked at same time - but I guess would work same setting so either shower or heater worked - if shower on, then heater off and auto starts when shower power off

coupleuk

Dolor said:

Octopus now restricts its Go and Go Faster tariffs to to EV/PHEV owners only. 

How would they know? - from speaking with others, they were simply asked do you have an EV

Point is to remove energy use from daytime to night

ispookie666

Save the money and invest in Ripple energy under your LTD company name.