Solar and battery storage

[kin]

I’m interested in the solar and battery storage, I’ve registered with First4solar after watching Electric vehicle Man on YouTube, but they still have not got in touch yet?
Could anyone recommend me a reputable supplier/installer in the NW area, I’m based in Manchester.
I also have one question, should we have black out, would the battery storage takes over and power the house up?

Any advices would be much appreciated.

 

[Jomarkh]

Hi, I went for a GivEnergy inverter and battery so search forcan installer in my area who fitted them. You could visit the GivEnergy site and get a link from there.

 

[D1no]

Same location and contacted the same supplier last week and they got back to say they were very busy, but asked for a few more details. Think it was an automated email,so check your spam.

I've also been in touch with a few other suppliers (only on Friday), so waiting to see what comes back. There's two different trade bodies (can't recall them) that have websites listing the suppliers who are with them and that's where I got my list of contacts from, so worth doing the same.

In terms of a black out, I think it would, although for how long would depend on batteries and load. I assume the preferred use will always be solar->battery ->grid, although I'm assuming at that and haven't spoken to any suppliers yet.

I've also just downloaded an app called Loop, which will apparently suggests what savings solar and batteries could make. It connects to your smart meter and also gets your location, angle of roof etc. Can't be 100% accurate but assume it pulls in weather data. Only just signed up this morning (it's free, i.e. it'll be selling me something or my data somewhere) so haven't got any data yet, but would be nice to have something that backs up my guesswork of the difference panels and batteries could make

 

[BugEyed]

I also have one question, should we have black out, would the battery storage takes over and power the house up?

Most don't for safety reasons. To do it you need to "island" (disconnect) from the grid, swap to a local Earth, then connect specific circuits only to the inverter via a changeover switch with the correct type of RCD (B type for DC blinding protection). The alternative that some (including me) have is a separate "emergency" socket that I can connect specific devices via extension leads. More faff at the time but a lot simpler.
There's an option on the Powerwall (called Gateway IIRC) to do this but they are very difficult to get hold of and to program unless you want the standard Tesla solution.

 

[kin]

. The alternative that some (including me) have is a separate "emergency" socket that I can connect specific devices via extension leads. More faff at the time but a lot simpler.

I have just posted a comment on another thread, if I fit an emergency socket to the combi boiler, then at least I have heating and hot water to use.
Would the battery storage able to power two sockets, one for combi and another for fridge/ freezer.
Failing that, I’ll just use the MG V2L to power one of the appliances?

 

[dirk362]

If you have some form of power backup when the grid is down, it is critically important that a qualified electrician does the work to ensure your house fully isolates from the grid. Failure to do so can mean engineers fixing the fault on the utility supply side are exposed to electrocution.
And as @BugEyed mentioned, this needs its own earth as you can no longer benefit from the utility supply earth.
Some inverters have an EPS feature which supplies power when the grid is down, but this must not be connected to your main fuse box. In reality, it is designed to provide a double socket somewhere so that you can manually plug something in (e.g. freezer).

Proper electrical supply when the grid is down is somewhat complicated and needs multiple isolators and switches, and unless it's in line with your normal supply there will always be a break in supply anyway. It takes very little time to switch over, but it's still a break in supply so the house will go off before it then comes back on again if you have this sort of set-up.

If you want to use the MG4 to power the house, it's important to note MG has V2L which is not rated for this capability. And if you did do this, you still need an isolator somewhere between your fuse box and the main utility supply.

(Note: I am not an electrician, so the above is purely an opinion).

 

[BugEyed]

Spot on. V2L appeals to me as a backup as I've only 9.6kWh of battery storage at most yet rarely have less than that in the MG5 (the current non-V2L version) when I've finished for the day (for example about 30kWh at the moment on a Sunday afternoon, my house battery is at 8 kWh).

 

[dirk362]

I have a mere 6.5kWh of battery storage, which provides between 12 and 15 hours based on an average day. I'm attempting to find someone to add another 6.5kWh battery in series, as the unit I have supports up to 8 batteries like that. Two obvious challenges at the moment are no one wants to sell just the battery (it's often sold as a bundle with an inverter), and all companies are ridiculously busy as everyone has suddenly woken up to the fact that solar is worth doing with the current energy crisis.
It was worth doing before that of course. But with the massive increase in interest, supply and demand will affect solar in much the same way as electric cars

 

[kin]

I have a mere 6.5kWh of battery storage, which provides between 12 and 15 hours based on an average day. I'm attempting to find someone to add another 6.5kWh battery in series, as the unit I have supports up to 8 batteries like that. Two obvious challenges at the moment are no one wants to sell just the battery (it's often sold as a bundle with an inverter), and all companies are ridiculously busy as everyone has suddenly woken up to the fact that solar is worth doing with the current energy crisis.
It was worth doing before that of course. But with the massive increase in interest, supply and demand will affect solar in much the same way as electric cars

Sounds like it may be a good idea to increase battery capacity while you order solar and battery.
When I rang First4solar asking info on the battery, the lady took my details and said someone would ring me, but she also told me that they’ve ran out of batteries until next year, so it’d seem that you’re right they must have massive demand!

 

[dirk362]

In an ideal world, you order battery capacity to match your needs, or to cover you for 24 hours of everyday usage, as part of your original install. That way the whole system is commissioned at the same time and battery usage is normalised.

Alternatively, you can elect to not go with a hybrid inverter and actually just have a normal inverter for your solar PV. Then later you add another battery-specific inverter and your battery (or batteries). This has a couple of big advantages in that you can mix manufacturers for the different sets of PV and battery, and also you can monitor the battery separately from the PV. Makes for a better overall setup, and gives you more flexibility, but of course that comes with a downside which is slightly more cost (not as much as you'd think though).
If I was doing my solar again, this is why I'd do. Hindsight eh

 

[KAS118]

Hmmm...I'm interested in this as I was thinking that if I got an EV with Vehicle to Grid, then rather have to spend £4-5k on a separate Solar Battery I'd just plug the car in and use that to store excess energy - on the basis that I usually catch a train into work and my wife doesn't drive - and during the week we'd only use it for local trips in any event.

Does anyone have any experience with doing something similar (or any observations)? However, by the sound of it I'd have to get something other than an MG4 if it doesn't have vehicle to Grid?

 

[dirk362]

The output from the MG4 with the V2L is 2.2kW and can be used to power anything. V2G is subtly different.
You can use the MG4 to power some extra sockets, not connected to your main fuse box, easily with a cable that connects from the car to say a 2-way 3-pin socket. Something like this might be what you're after.

If you want to actually use the MG4 to connect directly to your main fuse box for the house, then that is where you need an electrician to advise.

 

[KAS118]

Cheers. I was thinking about using the car too act as storage and feed into the grid at peak times; hence reduce the payback period of the solar panels.

In other words use the Car in exactly the same why a battery would be used on a battery solar system.

I had quotes for £6k Solar Only, £10k for 5kWh battery and £12k for 10kWh battery - hence my eagerness to use the car as the battery instead

But you're right, I need to speak to an installer. My current utility supplier - who was offering a solar system, was a bit reluctant to speak about anything other than the norm.

 

[dirk362]

Best to get your thoughts down about what you want to achieve, and why. And then get some advice from independent electricians who can deal with both DC and AC work (some cannot work on the DC side as it needs additional certification).

Note that charging a car battery, even with something like Octopus Go cheaper energy rates, will always be much higher than anything you'd get from a utility supply provider via the SEG (Smart Export Guarantee). The best in the UK at present for SEG is 4.1p per kWh. The best in the UK for a cheap overnight unit rate is 7.5p per kWh.

 

[kin]

Cheers. I was thinking about using the car too act as storage and feed into the grid at peak times; hence reduce the payback period of the solar panels.

Despite I had a solar fitted to my last house with FIT payment about 9 yrs ago?
This export back to grid at peak times is all new to me?
So basically you charge your MG battery using solar during day and export the electric back to grid via MG battery?
Do you not need some special cables connect it to the inverter or similar export electric back to grid?
What about battery life as you’re cycling the battery much more frequently?

 

[KAS118]

Note that charging a car battery, even with something like Octopus Go cheaper energy rates, will always be much higher than anything you'd get from a utility supply provider via the SEG (Smart Export Guarantee). The best in the UK at present for SEG is 4.1p per kWh. The best in the UK for a cheap overnight unit rate is 7.5p per kWh.

Thanks - yes I will.

My idea/hope was that the car could be charged up to a certain level; say 50%; during the day and then anything over that I could sell to the Grid.

If I then needed to do a long journey I'd just charge it with Solar.

So the plan is not to use the Grid to charge the car; but use the car to store excess and flog to the Grid.

 

[KAS118]

Despite I had a solar fitted to my last house with FIT payment about 9 yrs ago?
This export back to grid at peak times is all new to me?
So basically you charge your MG battery using solar during day and export the electric back to grid via MG battery?
Do you not need some special cables connect it to the inverter or similar export electric back to grid?
What about battery life as you’re cycling the battery much more frequently?

To be honest - I don't know as I'm not an electrician - but one of the claimed advantages of Vehicle to Grid is that Vehicles can be used to balance the grid - so what I'm proposing should be possible - but until I've spoken to someone about it in detail I can't confirm for sure.

However, I don't think you'd receive much of a charge at night?

I believe cycling the battery can actually help with their life.

 

[KAS118]

There's also this

Can V2G Improve EV Battery Life? |Vehicle to Grid UK

 

[kin]

I’m confused now, MG4 had V2L, not V2G?

So how do you export energy back to grid?

 

[KAS118]

I’m confused now, MG4 had V2L, not V2G?

So how do you export energy back to grid?

That's what I was querying at Post 11.