On-grid domestic battery storage

Exiled_Tyke

I didn't have any problem at all getting another company to add a battery to my system. (The PV installer had ceased trading so I had to find a new company).   I added a new inverter to look after the battery side of things.  

saxon_viking

I added an extra 2 myself to my strings, easy enough, I've now got 14.2 kWh of UHome LFP2400's.

The main thing I'm hearing when people ask me for advice (and I'm no expert) is "Can you tell me if my quote is good etc.?" I ask them did they try and sell you a set piece PV / battery / finance deal? Yes. Did they tell you that you'd make plenty of money by selling your excess back to the grid? Yes. Ok did they ask you about your usage profile, kWh's used during the day, when are you home, when is the heaviest use of your big ticket items? No. I have always been told "No, why do you ask all those questions?" I just want a solar and battery installation. I try to explain but some people are just not interested. I explain that they will be £8k plus out of pocket and the installer will be laughing as they've sold you a system on finance and you'll be wondering why your electrical bill doesn't drop or goes up because your inverter outputs and batteries don't match your useage.

QrizB

rgannon45 said:

I found that most installers are wary about the existing installations, especially if they're over 10 years old. Most who we have contacted won't guarantee the work or want to replace the whole system.

That could just be a reflection of the current market conditions, where installers are fully booked and don't really want smaller jobs.

The only installer that seems to provide a retrofit solar battery solution is Dyson Energy

Tesla are an example that come immediately to mind. Powerwalls are commonly retrofitted.

And the don't seem to be any shortage of smaller installers who say they'll add batteries to existing systems.

Solarchaser

jamie07051975 said:

I've placed an order for our first EV and we'll be charging over night via Octopus Intelligent via an Ohme charger.  As the car will not be at home from about 7am to 5pm we're not going to get it charged via solar so I think that's a non-starter.

However, I do like the sound of batteries charging up off-peak and used throughout the day during peak.  We're generally using just under 10kWh daily.  With the off-peak tariff we'll start to use things like tumble driers and washing machines at night to alter our usage patterns but I think 10kWh of battery should do us and bring our costs down quite a bit.

Ideally it would be installed outside or in the loft as we have no space near the meter/consumer unit.

I have looked at GivEnergy as it can be installed outside.  I presume a loft installation would be cheaper as it would not need to be weather proof.  Just seen Lux inverter plus Pylontech batteries as well and they sound good.

There's just so many different options I'm hoping someone could give me some ideas.

Problem is finding someone to provide and install, basically everyone so far have said they will only do it with solar at the same time which I think is pointless at the moment for me.

Any ideas/thoughts/help would be gratefully received!

Thanks

My suggestion would be to definitely get solar.
For only 10kwh usage,  you will find for all but 2-3 months of the year your batteries will be charged by free solar instead of cheap rate leccy.
Also the car is out of the drive during work hours, understood, however its home at the weekend right? So you can maybe charge 30% of the time for free.

Solar makes sense before batteries imo.

Batteries are great for saving you changing your patterns, so run the machines when you want, as the batteries cover that.
My dear beloved likes it much better with batteries as I'm not asking she runs when it's sunny etc.
Happy wife = happy life

Solarchaser

thevilla said:

Maybe interesting to zappi owners in particular.

https://myenergi.com/libbi/

I have to say my experience of myenergi stuff has been very good.
If only their lead times were not forever being pushed out... thats on the eddi though, not the battery system.

Exiled_Tyke

Solarchaser said:

jamie07051975 said:

I've placed an order for our first EV and we'll be charging over night via Octopus Intelligent via an Ohme charger.  As the car will not be at home from about 7am to 5pm we're not going to get it charged via solar so I think that's a non-starter.

However, I do like the sound of batteries charging up off-peak and used throughout the day during peak.  We're generally using just under 10kWh daily.  With the off-peak tariff we'll start to use things like tumble driers and washing machines at night to alter our usage patterns but I think 10kWh of battery should do us and bring our costs down quite a bit.

Ideally it would be installed outside or in the loft as we have no space near the meter/consumer unit.

I have looked at GivEnergy as it can be installed outside.  I presume a loft installation would be cheaper as it would not need to be weather proof.  Just seen Lux inverter plus Pylontech batteries as well and they sound good.

There's just so many different options I'm hoping someone could give me some ideas.

Problem is finding someone to provide and install, basically everyone so far have said they will only do it with solar at the same time which I think is pointless at the moment for me.

Any ideas/thoughts/help would be gratefully received!

Thanks

My suggestion would be to definitely get solar.
For only 10kwh usage,  you will find for all but 2-3 months of the year your batteries will be charged by free solar instead of cheap rate leccy.
Also the car is out of the drive during work hours, understood, however its home at the weekend right? So you can maybe charge 30% of the time for free.

Solar makes sense before batteries imo.

Batteries are great for saving you changing your patterns, so run the machines when you want, as the batteries cover that.
My dear beloved likes it much better with batteries as I'm not asking she runs when it's sunny etc.
Happy wife = happy life

It really does depend on how large a solar system surely?  My medium sized (?) set up definitely isn't filling the small (?) battery at this time of year although will get a small top up on sunny days.  And to make sure I don't have to resort to peak time leccy I top up the battery overnight regardless of the forecast.   So I'm afraid it's rather more complicated.  I'd say a good argument for PV is that in the peak of summer it will charge the car battery.

orrery

Exiled_Tyke said:

I'd say a good argument for PV is that in the peak of summer it will charge the car battery.

I'd say that was a weak argument.

Firstly, most people don't want their car charging during peak solar hours - they are out at work or want to be driving it in the sun.

Secondly, you have to spend money on a charger that will do it. I've spend a lot, trying over the years: a low current granny cable (type 1, then needed a type 2 adapter), then an intelligent charger. I'm not convinced that I'll get my money back on that investment. You've got the downside of never knowing when the car will be charged and it is going to do little for you when it isn't summer.

For my money, get a cheap overnight tariff, charge overnight so you always have a full charge so you can make use of the car, and use the solar to offset the high daytime unit cost.Of course, you can improve matters by investing even more in a large battery system (which will also take a long time to pay back, if ever).

But hey, if you don't drive far, have the car in the drive all day and never go out in the sun, then solar charging makes a lot of sense (for the little charging you'll need).

Exiled_Tyke

orrery said:

Exiled_Tyke said:

I'd say a good argument for PV is that in the peak of summer it will charge the car battery.

I'd say that was a weak argument.

Firstly, most people don't want their car charging during peak solar hours - they are out at work or want to be driving it in the sun.

Secondly, you have to spend money on a charger that will do it. I've spend a lot, trying over the years: a low current granny cable (type 1, then needed a type 2 adapter), then an intelligent charger. I'm not convinced that I'll get my money back on that investment. You've got the downside of never knowing when the car will be charged and it is going to do little for you when it isn't summer.

For my money, get a cheap overnight tariff, charge overnight so you always have a full charge so you can make use of the car, and use the solar to offset the high daytime unit cost.Of course, you can improve matters by investing even more in a large battery system (which will also take a long time to pay back, if ever).

But hey, if you don't drive far, have the car in the drive all day and never go out in the sun, then solar charging makes a lot of sense (for the little charging you'll need).

It all depends on circumstances.  If you work from home  then on sunny days then a granny will work nicely.  I tend to know at least the day before if I need to make a long journey so can easily top up over night if I didn't get enough from the PV during the day.  

And my domestic battery is now doing very well and will recoup it's costs very comfortably although I didn't think it would when I got it. 

Solarchaser

Exiled_Tyke said:

Solarchaser said:

jamie07051975 said:

I've placed an order for our first EV and we'll be charging over night via Octopus Intelligent via an Ohme charger.  As the car will not be at home from about 7am to 5pm we're not going to get it charged via solar so I think that's a non-starter.

However, I do like the sound of batteries charging up off-peak and used throughout the day during peak.  We're generally using just under 10kWh daily.  With the off-peak tariff we'll start to use things like tumble driers and washing machines at night to alter our usage patterns but I think 10kWh of battery should do us and bring our costs down quite a bit.

Ideally it would be installed outside or in the loft as we have no space near the meter/consumer unit.

I have looked at GivEnergy as it can be installed outside.  I presume a loft installation would be cheaper as it would not need to be weather proof.  Just seen Lux inverter plus Pylontech batteries as well and they sound good.

There's just so many different options I'm hoping someone could give me some ideas.

Problem is finding someone to provide and install, basically everyone so far have said they will only do it with solar at the same time which I think is pointless at the moment for me.

Any ideas/thoughts/help would be gratefully received!

Thanks

My suggestion would be to definitely get solar.
For only 10kwh usage,  you will find for all but 2-3 months of the year your batteries will be charged by free solar instead of cheap rate leccy.
Also the car is out of the drive during work hours, understood, however its home at the weekend right? So you can maybe charge 30% of the time for free.

Solar makes sense before batteries imo.

Batteries are great for saving you changing your patterns, so run the machines when you want, as the batteries cover that.
My dear beloved likes it much better with batteries as I'm not asking she runs when it's sunny etc.
Happy wife = happy life

It really does depend on how large a solar system surely?  My medium sized (?) set up definitely isn't filling the small (?) battery at this time of year although will get a small top up on sunny days.  And to make sure I don't have to resort to peak time leccy I top up the battery overnight regardless of the forecast.   So I'm afraid it's rather more complicated.  I'd say a good argument for PV is that in the peak of summer it will charge the car battery.

Yes it's a good point,  it certainly does make a difference how large the array is.
I've always went with the idea of fill your roof, so even a relatively small roof would manage at least 4kw of panels these days, however I didn't convey that, so you are right to pick it up 👍

My 8 year old 4kw array makes 10kw a day or more for almost 9 months of the year.
In the most poor 2 months it's more like 3kw a day.

I top up my batteries on off peak for 4 months of the year, the rest of the time it's pure solar.
I have a large array and a large battery bank, I also have a large usage, much more than the posters 10kwh/day.

So can it be more complicated, sure, but I don't think it is given the criteria the poster presented.

orrery

Exiled_Tyke said:

If you work from home  then on sunny days then a granny will work nicely.

...

And my domestic battery is now doing very well and will recoup it's costs very comfortably although I didn't think it would when I got it. 

The granny is only guaranteed OK (even at 6 amps) if you're on a flat rate tariff. If you are on an overnight cheap-rate, at typically 1:4 (or 1:5 even) cost ratio then the sun must shine for at least 75% (or 80%) of the time. This is rare, even on a typical summer's day. Cloud free days - maybe, but I've lots of experience trying this and frequently I get clouds coming over and it really does depend on keeping an eye on it ready to disconnect. For most people, I'd guess that the savings are just a nice warm eco-satisfying illusion.

Batteries are a different kettle of fish, and will help a lot (just because it enables short-term averaging) but as for a guaranteed payback, I'm not sure. I've ordered mine at a time when my payback would have been 6 to 7 years, but recent changes in tariffs and government subsidies announced may undermine that calculation and I've no idea what the situation will be in 1, 2 or 3 years time.