Battery storage and solar.

[pulhamdown]

I am currently in the process of having a heat pump installed, and asked the installer for a quote for Givenergy battery storage.  The house is 10 years old, and near passive.  They came back saying they couldn't provide a quote, since my solar panels are on an agricultural shed some 50 metres from the house, although connected to the house.  So my question is - can a battery storage system be devised to operate with the solar panels and inverter being situated away from the house?  I assume the battery has to be located next to the solar panels. The electrical system in the house is up to date, and I have a Zappi car charger in the integral garage.    Any help appreciated.   

Edited March 7 by pulhamdown
typo

[DamonHD]

I know of no particular reason why the batteries need to be close to the PV if everything is AC coupled and all impedances are in spec.

 

Rgds

 

Damon

[JohnMo]

I would just go elsewhere for a quote. I have panels on a hill 70m from the inverter, it's then another 20m to house, plus panels on the roof again about 15m to the inverter. Mine are all coupled to a GivEnergy All in one.  Works great.

[Bramco]

1 hour ago, DamonHD said:

I know of no particular reason why the batteries need to be close to the PV if everything is AC coupled and all impedances are in spec.

 

If the GivEnergy inverter is a hybrid inverter and your PV inverter is near to the panels, then this may be the reason - although I thought GivEnergy had both hybrid (PV and battery) as well as normal single source inverters.

Assuming your PV inverter is close to the panels and the system is ac connected to the main house, then you'd need battery with single source inverter system - there are plenty around and many cheaper than the GivEnergy systems.  The downside of having 2 inverters, is the interplay between them - you really need to be able to manage when the battery is charging and discharging in relation to the solar PV output. Inverters from the same supplier generally have ways to manage this.

 

One thing to bear in mind, is that hybrid inverters use the DC side to charge the batteries from solar, so there is little loss. If you have separate inverters, then the PV has to pass through both inverters to charge the batteries with the associated losses.  DC to AC and then back again to DC.

 

There must be other installers you can ask for  a quote.

 

Simon

[SteamyTea]

As @Bramco says.

It is probably more to do with sensing and reporting which way currents are flowing, and when, and the ability to react to it.

Edited March 7 by SteamyTea

[pulhamdown]

Thanks for your replies.  There are indeed other installers who I can approach, but I just wanted a second opinion on whether it was feasible or not.  I suspect the original quote was from a company just wanting the easy jobs, rather than someone who fully understands the issues involved.   

[sharpener]

 

 

2 hours ago, pulhamdown said:

So my question is - can a battery storage system be devised to operate with the solar panels and inverter being situated away from the house?

 

Yes. Where and what type is your existing inverter? If in the shed and it is connected via AC cable to the house there is no particular problem. Even if there are other loads in the shed, a CT in the house will measure the net inflow.

 

The GivEnergy Gateway is a quite flexilble solution for connecting it all up though not the cheapest.

 

Alternatively you could lay DC cables back to the house and connect them to a hybrid inverter in the house.

 

This forum also has a lot of good stuff on it and some members have very large and very complicated systems.

[pulhamdown]

17 minutes ago, sharpener said:

 

 

 

Yes. Where and what type is your existing inverter? If in the shed and it is connected via AC cable to the house there is no particular problem. Even if there are other loads in the shed, a CT in the house will measure the net inflow.

 

 

The inverter and solar panels are both in the shed.  It's a Sunny Boy string inverter, and connected to the house via AC cable.  We are  lucky enough to still have the old disc electricity meter in the house which runs backwards when we are generating, but not using the electricity.

[RobLe]

A ‘gold dust’ spinny wheel meter!  Technically theft when it spins back, so using the grid as storage.  Morally fine imho to do so, you’re probably on average exporting when the country needs electric.  Or get a hybrid battery, smart meter, Octopus tariff, jump through loads of MCS hoops, and be back more or less where you were with the spinny wheel meter.  
So long as the dno is aware, afaik it’s not your ‘fault’.  Don’t send meter readings lower than the previous, that’s asking for it!  Elec car charge point, give elec away in summer ?  😈

[Dillsue]

Maybe I'm missing something but there seems no point in battery storage if youve got a disc meter?? If you've got 10kwh spare PV and it runs to grid then there's 10 units "credit" on the meter for later use when you draw from the grid. Put the same 10 units into your own batteries and youve got to spend £1000's and suffer the charging/inversion losses when you want to use your PV later.

 

Just make sure your usage is more than generation in the summer so the meter has a small net increase in the reading.

 

Not sure how legit your set up is but net metering seems a reasonable thing to me

[Roger440]

5 hours ago, RobLe said:

A ‘gold dust’ spinny wheel meter!  Technically theft when it spins back, so using the grid as storage.  Morally fine imho to do so, you’re probably on average exporting when the country needs electric.  Or get a hybrid battery, smart meter, Octopus tariff, jump through loads of MCS hoops, and be back more or less where you were with the spinny wheel meter.  
So long as the dno is aware, afaik it’s not your ‘fault’.  Don’t send meter readings lower than the previous, that’s asking for it!  Elec car charge point, give elec away in summer ?  😈

 

Thats interesting. Does that mean you are effectively exporting at the same cost as purchase.

 

I ruled out exporting, partly because i have a spinny wheel meter.

[RobLe]

We have a hybrid battery system, smart meter, octopus go.  Import 7.5p  (from 00:30 to 04:30), export 8p.

Lots and lots of effort, octopus took forever to gets things right(it’s still not), it’s now almost as good as the spinny meter would’ve been. 👿.  There are better rates, octopus io notably, we would need another meter upgrade and no doubt lots of time talking to octopus, gah.

 

We must’ve lost our spinny meter 15+ years ago - if you have one it’s like a magic 100% efficient, infinitely big battery😈.

I guess if you import a lot more than export (all elec house + car) then there is an incentive to go smart and get a tou tariff.

[Roger440]

1 hour ago, RobLe said:

 

We must’ve lost our spinny meter 15+ years ago - if you have one it’s like a magic 100% efficient, infinitely big battery😈.

 

 

Sorry, i dont understand this?

[SteamyTea]

Most of the old mechanicals meters have a ratchet that stops the disk reversing.

I also think that a meter has to be changed every 20 years, not that they always do get changed.

[pulhamdown]

This meter was installed in 1969 when my parents built a Colt Cedarwood house. It rotted, so we built a new house on the site in 2012. Scottish Hydro took out the meter when we demolished the house, then put it in as a temporary supply, then put it into our new house in 2012! So they are aware of the situation.