Battery Storage

[Dave Jones]

11 hours ago, Dillsue said:

I believe Enphase do a battery to integrate with their micro inverters

 

yes we use a powerwall. microinverters  defeat the issue with shading string inverters suffer with i understand.

[Dillsue]

11 hours ago, JohnMo said:

Any AC coupled battery would do the job they  don't care how AC is made

Absolutely. The comment was clarifying that micro inverters can interface to a battery, same as any inverter can

[markharro]

On 27/08/2024 at 20:39, Nick Thomas said:

Prices have dropped off a cliff recently. The VAT zero-rating was passed on too, which is nice to see. You can get 9.4kWh for £3650, or double that for £5595 - list price, including the inverter. Things are nicer if you can assign the inverter to the solar PV payback period instead - £2200 for a 9.4kWh battery, £4200 for double that.

 

( https://homeenergygroup.co.uk/lux-ac-battery-storage-hanchu-ess-9-4kw/ )

 

Do you know if there is an option with this brand for a battery that is compatible with our 3 phase supply? I have never heard of the make?

 

Separately, can anyone advise on this......we have space in our utility for a battery but we are not fitting one yet. But I want to put in the wiring needed to future proof from the consumer unit to where any battery would be located. I understand I need to run a 32 A cable? What I don't understand is the specific cable needed for any future 3 phase battery?

[crispy_wafer]

I think, it's the inverter that's the key for 3 Ph. certainly according to givenergy...

 

3-phase battery storage | 3-phase inverters & batteries | GivEnergy

[crispy_wafer]

Probably a really noddy type question, but anyway, what should you need to look out for for say a UPS type install.  E.g  a pretty Seamless switchover when there's a power outage.  Or do they all do it, or is it something that needs specifying up front?

 

TIA

Marek

[RobLe]

18 minutes ago, crispy_wafer said:

Probably a really noddy type question, but anyway, what should you need to look out for for say a UPS type install.  E.g  a pretty Seamless switchover when there's a power outage.  Or do they all do it, or is it something that needs specifying up front?

 

TIA

Marek

It would need specifying up front, it is not the norm in the UK (it is in California and South Africa, where there are more frequent power cuts).

Quite a few hybrid inverters offer this, eg Sunsynk inverters tend to, and I think Victron.  The limitation is that all the current through the consumer unit is then sent through a relay in the Sunsynk all the time, ready for the occasion when it swaps to battery only.  The 3.6kW sunsynk that we have specifies a 40A input breaker - if we used it as a UPS, then although we have a 100A mains cutout we would be limited to 40A due to this UPS functionality.  I guess you could have two consumer units, a 40A one with and a higher power one without this UPS functionality.  

 

  

[Alan Ambrose]

>>> I guess you could have two consumer units, a 40A one with and a higher power one without this UPS functionality.  

 

I don't think that's a big problem in practice. I plan to have 2 CUs anyway, one for battery backed stuff (fridge etc) one for stuff you generally wouldn't run off a battery - heating, car charging, oven etc - all the big loads.

[JohnMo]

23 minutes ago, crispy_wafer said:

Probably a really noddy type question, but anyway, what should you need to look out for for say a UPS type install.  E.g  a pretty Seamless switchover when there's a power outage.  Or do they all do it, or is it something that needs specifying up front?

 

TIA

Marek

What I found when I started looking is the UPS function on most inverters is pretty useless, they can only output a very small kW so only likely to support a few lights not much. I went AC coupled because it would take over fully (6kW) and I can do just about whatever I want while I have battery power. Borehole pump, sewage system, MVHR, heat pump on, boil the kettle etc. When that runs out of power we also have a generator that can do the same.

[crispy_wafer]

6 minutes ago, JohnMo said:

What I found when I started looking is the UPS function on most inverters is pretty useless, they can only output a very small kW so only likely to support a few lights not much. I went AC coupled because it would take over fully (6kW) and I can do just about whatever I want while I have battery power. Borehole pump, sewage system, MVHR, heat pump on, boil the kettle etc. When that runs out of power we also have a generator that can do the same.

Right... So in your case that's the givenergy AIO 6, we dont have too many powercuts , it's more of a case of having a feature in place that would keep the necessary bits running for an hour or two, or four! without too much faff.  

[Thorfun]

2 hours ago, Alan Ambrose said:

>>> I guess you could have two consumer units, a 40A one with and a higher power one without this UPS functionality.  

 

I don't think that's a big problem in practice. I plan to have 2 CUs anyway, one for battery backed stuff (fridge etc) one for stuff you generally wouldn't run off a battery - heating, car charging, oven etc - all the big loads.

our battery inverter (LuxPower) has a 16A limit on the emergency power so we have a second garage-type CU next to the main CU for essential loads (like our sump pump in the basement!) and a couple of extra plug sockets that we can run an extension lead to in a long power cut. 16A = 3.68kW @ 230V so that's quite a hefty load.

 

eventually our Loxone system and the 24V lighting it controls will run from seperate lead acid batteries in a power cut so we can run 24V lights also that will be separate from the 230V battery system. should be enough to get us through a reasonable power cut

[mickeych]

Very interested in this discussion as I am going through the process of including batteries in the energy setup in our build. We have a 3 phase supply but don't currently have solar, although it is planned for longer term, and we expect to use the ASHP to heat the slab and HWC for water at low cost overnight. 

Working from home continuously using electricity (no gas) and with a fair number of power outages (around 5-6 per year up to 8 hours), with tanking pumps that need to be available in poor weather and with the drop in battery costs, we are looking at the option of including a battery backup.

Questions that come to mind:

1. What spec should I really be looking at to deal with the 3 phase?

2. Where should it be located?

3. Do we need an inverter (we are not intending to export it back into the grid at this point)

4. If we are looking at 'whole of house supply' replacement from a battery is this a) unrealistic, b)ridiculously expensive, c) unduly complex - or all 3!😉

 

Edited December 12 by mickeych

[JohnMo]

59 minutes ago, mickeych said:

Questions that come to mind:

1. What spec should I really be looking at to deal with the 3 phase?

2. Where should it be located?

3. Do we need an inverter (we are not intending to export it back into the grid at this point)

4. If we are looking at 'whole of house supply' replacement from a battery is this a) unrealistic, b)ridiculously expensive, c) unduly complex - or all 3

Are you using all three phases? Or just one in the house?

2. Our is in plant room. Some have them outside. But as temperature drops so does the battery output. Some will have inbuilt heaters. So you would need to check.

3. If it's a DC battery you need an inverter. If it's AC coupled they are already built in.

4.we have givenergy all in one, it generally provides the whole house straight out the box.

 

Battery size and tariff.

 

With heat pump running in cold weather the battery soon gets depleted. Charging slab in cheap periods is fine but once you get below zero, expect to charge in the evening also, otherwise it's a slippery slope of ever depleted slab energy over a few days. Then you end up running the heat pump for a lot of hours to catch up.

[mickeych]

54 minutes ago, JohnMo said:

Are you using all three phases? Or just one in the house?

2. Our is in plant room. Some have them outside. But as temperature drops so does the battery output. Some will have inbuilt heaters. So you would need to check.

3. If it's a DC battery you need an inverter. If it's AC coupled they are already built in.

4.we have givenergy all in one, it generally provides the whole house straight out the box.

 

Battery size and tariff.

 

With heat pump running in cold weather the battery soon gets depleted. Charging slab in cheap periods is fine but once you get below zero, expect to charge in the evening also, otherwise it's a slippery slope of ever depleted slab energy over a few days. Then you end up running the heat pump for a lot of hours to catch up.

OK I think that I understand about the slab. So in effect if we heat up the slab at night and it depletes too much during the day we will end up having to run it longer to catch up?

 

We've got 2 CU's one each end of the house and based on modelling, we will only need 2 phases at maximum load at any time (so probably not getting close in real terms!) 

There is room inside at/near both CU's for a battery as we have plant areas at both.

Assuming that since the delivery of electricity from the line in will be AC then it makes sense to go AC (or does this have an impact on our future desire to add solar which may be DC!?)

I like the Givenergy units as they were recomended by others, am I right in thinking that many batteries have limitations on the capacity to provide power?

[JohnMo]

4 minutes ago, mickeych said:

we heat up the slab at night and it depletes too much during the day we will end up having to run it longer to catch up

Trouble is if you have a heat loss in the property of 2kW, you then require 48kWh for 24 hrs. To deliver that in day 7 hours needs 7kW input. If you had a 4kW heat pump you need 12 hrs of running.

[FarmerN]

We have 2 separate consumer units, only one supplied by battery.

The heat pump ,towel rails and trearment plant are not supplied by the battery.

This is to preserve power in battery for lighting, fridge, freezer and other essentials.

If its cold we can light up the log burner.

 

During the recent strom, because an outage seemed highly likely,we put the battery at a setting to ensure it was at 100 % at the start of the outage.

The house was cooling but not serious after 12 hours, and we had only used 20% of a 13.5KWh battery. Boiled the kettle a few times, lights , tv and broadband on, and had one reheated meal.

We could boil a kettle and bake potatoes on log burner.

Outage lasted about 15 hours but was predicted as 48 hours.

[mickeych]

2 hours ago, FarmerN said:

We have 2 separate consumer units, only one supplied by battery.

The heat pump ,towel rails and trearment plant are not supplied by the battery.

This is to preserve power in battery for lighting, fridge, freezer and other essentials.

If its cold we can light up the log burner.

 

That makes sense. We have one consumer unit in the kitchen/breakfast area and the other covering the bedroom and living area (including the ASHP) so it probably makes most sense to fit a battery in this area as it also has it's own HWC as well as fridge freezers etc. If we really needed to, we could run power to the tanking pump near the living area) via an extension lead.