Solar panels and battery - any real world reccomendations?

[dimension99]

How much are you paying for that system if you don't mind me asking? What area and who is installing it as well? It seems a decent system. Is the solis inverter a hybrid one?

I'm paying £8500 the company is TCLSolar in Lincolnshire it is a small family business but they have independent insurance/warranty. the larger companies seemed to only want to push products they wanted to sell, not what I wanted.

the inverter is a standard non hybrid 4G inverter as the givenergy charger/inverter handles the BMS/battery side side, they suggested the Solis as it is more proven and oversized so should be under less stress than the current 5KWh GE Inverter.

I should be able to get all the generation stats from the GiveEnergy charger/inverter, and they are developing a local access API for HomeAssistant so I can use this to monitor everything along with my current 6 channel CT clamp power monitor that monitors most circuits in the house

 

[dimension99]

Thanks for that. I had a company ring today and all they offer is the Tesla Powerwall so I politely told them that it uses up most of my budget so thanks but no thanks.

Is there any reason why you aren't going to just install the batteries all at once? You will only pay 5% vat on installation with the solar but then pay full Vat if you then install more at a later date.

They wanted £3300 to install a second battery but I can buy it for £2500 and install it myself, seems simple, power connection to other battery and coms to the charger then a call to GE to configure it from their side. Plus the larger batteries are not available yet and I didnt want to wait as the prices will probably be higher by Q2 this year.
Tesla powerwall is nice as it has automatic failover to the battery, I can add this with the GE battery but the Automatic changeover switches are over £1000 so not worth it for where I live as the powercuts are usually minutes in length, I will use a manual changeover sw for circuits, lights and Aircon.

The one thing I would like to find how to do is find a way to allow Solar PV power generation during a powercut, as the inverters will shut down when the grid goes down to protect anyone working on the grid. Im sure there is way to configure a double pole switch that can ensure we are isolated and then feed 240v from the battery to the inverter allowing it to power up.. this would be great for situations like they had in Scotland recently with several days of power loss.

 

[GinG]

They wanted £3300 to install a second battery but I can buy it for £2500 and install it myself, seems simple, power connection to other battery and coms to the charger then a call to GE to configure it from their side. Plus the larger batteries are not available yet and I didnt want to wait as the prices will probably be higher by Q2 this year.
Tesla powerwall is nice as it has automatic failover to the battery, I can add this with the GE battery but the Automatic changeover switches are over £1000 so not worth it for where I live as the powercuts are usually minutes in length, I will use a manual changeover sw for circuits, lights and Aircon.

The one thing I would like to find how to do is find a way to allow Solar PV power generation during a powercut, as the inverters will shut down when the grid goes down to protect anyone working on the grid. Im sure there is way to configure a double pole switch that can ensure we are isolated and then feed 240v from the battery to the inverter allowing it to power up.. this would be great for situations like they had in Scotland recently with several days of power loss.

Makes complete sense doing it that way...I did also wonder how easy it is to add one yourself later down the line.

In relation to the solar PV during a powercut...is this what 'Islanding' does?

 

[casper_uk]

I'm paying £8500 the company is TCLSolar in Lincolnshire it is a small family business but they have independent insurance/warranty. the larger companies seemed to only want to push products they wanted to sell, not what I wanted.

the inverter is a standard non hybrid 4G inverter as the givenergy charger/inverter handles the BMS/battery side side, they suggested the Solis as it is more proven and oversized so should be under less stress than the current 5KWh GE Inverter.

I should be able to get all the generation stats from the GiveEnergy charger/inverter, and they are developing a local access API for HomeAssistant so I can use this to monitor everything along with my current 6 channel CT clamp power monitor that monitors most circuits in the house

Thanks for the info, just a shame they don't cover Birmingham. It seems you are correct, it is very difficult to find a decent solar company that works in your area, and doesn't want to just push what ever they can get that's the cheapest.

 

[Nikumba]

I'm paying £8500 the company is TCLSolar in Lincolnshire it is a small family business but they have independent insurance/warranty. the larger companies seemed to only want to push products they wanted to sell, not what I wanted.

the inverter is a standard non hybrid 4G inverter as the givenergy charger/inverter handles the BMS/battery side side, they suggested the Solis as it is more proven and oversized so should be under less stress than the current 5KWh GE Inverter.

I should be able to get all the generation stats from the GiveEnergy charger/inverter, and they are developing a local access API for HomeAssistant so I can use this to monitor everything along with my current 6 channel CT clamp power monitor that monitors most circuits in the house

Just on the TCL part my friend had a system fitted by them just before Christmas and was happy, they quoted me £7500 for a 8kw system with no battery storage.

What sized system were you quoted for dimension99?

Also agree were nice people to deal with, listened to what I wanted to achieve and speced it similarly

 

[SoliD]

Thanks for that.

I think I will go for the larger battery...I have also asked them to pride me for 2x5.2kwh batteries as a comparison.

So far price is £9522 for 6,370kwh system, 5kwh GivEnergy inverter and 8.2kwh battery.

£8755 with a 5.2kwh battery.

Just been quoted 23.2k for a 7.5Kwh system with a Tesla Powerwall Will get phoning around some more based on the above!

 

[GinG]

Just been quoted 23.2k for a 7.5Kwh system with a Tesla Powerwall Will get phoning around some more based on the above!

It's the Powerwall which ups the price loads and in the UK is a little overspec'd really...unless you have regular power cuts?

So most companies are saying I can only really fit a maximum or 14 panels at 390W but then I've had another company come back with 16x 455w.

With 5kw inverter and 8.2kw battery quotes are coming in at around £8200 - £8800 for just over 4kw in solar panels. £9800 ish for the 6kwh system.

Payback quotes are not dissimilar to the 4 or 6kwh systems so I am wondering if it's worth the extra solar panels due to the payback time...around £70-£100 per year is being quoted for avings with the bigger solar system which increases the payback period somewhat.

 

[SoliD]

It's the Powerwall which ups the price loads and in the UK is a little overspec'd really...unless you have regular power cuts?

So most companies are saying I can only really fit a maximum or 14 panels at 390W but then I've had another company come back with 16x 455w.

With 5kw inverter and 8.2kw battery quotes are coming in at around £8200 - £8800 for just over 4kw in solar panels. £9800 ish for the 6kwh system.

Payback quotes are not dissimilar to the 4 or 6kwh systems so I am wondering if it's worth the extra solar panels due to the payback time...around £70-£100 per year is being quoted for avings with the bigger solar system which increases the payback period somewhat.

Yeah the Tesla was 8.7k quoted price. The quote was for 18 Sunpower 415w panels and all the rest at £14.5k.

I will get a few more quotes. I got AC installed at the back end of last year, so i'm looking at something that can power this and be my primary heating source for the winter, which may be the biggest issue with battery, although if I put it on to heat upstairs or the lounge its only pulling 2.5-3kwh, so think a battery should be fine with that.

 

[Journey]

So most companies are saying I can only really fit a maximum or 14 panels at 390W but then I've had another company come back with 16x 455w.

It may seem odd but as the 455w panels will be 2.11m x 1.05m panel (2.215m2) vs the smaller ~390w which will be 1.77mx 1.05m (1.86m2) so each panel of the 455w is 12% more surface area. You might have a very tall roof, meanings the large panels are somewhat a better fit as it wastes less roof space. Do you know the height and width of your roof sides?

With 5kw inverter and 8.2kw battery quotes are coming in at around £8200 - £8800 for just over 4kw in solar panels. £9800 ish for the 6kwh system.

Payback quotes are not dissimilar to the 4 or 6kwh systems so I am wondering if it's worth the extra solar panels due to the payback time...around £70-£100 per year is being quoted for avings with the bigger solar system which increases the payback period somewhat.

The extra cost should only be panels, plus the uprated inverter costs. It is worth getting as many panels as possible installed as the vast majority of the cost is in the labour and scaffolding etc. Adding 2KW or for £1k based on your numbers makes total sense, that is 50% ore generation potential for an uplift of less than 15% costs. Same would apply to going to a relatively huge 7.2kW system, it it is adding a little on top but will allow you to generate more in the darker months, and export more in the summer months, then you'll soon pay the extra back. The only caveat is that with the much larger system you'd probably want to go with a dual/split inverter system 3kW each so you can charge the battery(ies) faster, and or a car at max rate if not wanting to export at low value, it's also worth exploring the dual 5.2kW battery cost vs a single 8.2kW, as you can then also discharge at 6kW if you want to run more items in your house at peak times from the pack(S)

 

[GinG]

It may seem odd but as the 455w panels will be 2.11m x 1.05m panel (2.215m2) vs the smaller ~390w which will be 1.77mx 1.05m (1.86m2) so each panel of the 455w is 12% more surface area. You might have a very tall roof, meanings the large panels are somewhat a better fit as it wastes less roof space. Do you know the height and width of your roof sides?



The extra cost should only be panels, plus the uprated inverter costs. It is worth getting as many panels as possible installed as the vast majority of the cost is in the labour and scaffolding etc. Adding 2KW or for £1k based on your numbers makes total sense, that is 50% ore generation potential for an uplift of less than 15% costs. Same would apply to going to a relatively huge 7.2kW system, it it is adding a little on top but will allow you to generate more in the darker months, and export more in the summer months, then you'll soon pay the extra back. The only caveat is that with the much larger system you'd probably want to go with a dual/split inverter system 3kW each so you can charge the battery(ies) faster, and or a car at max rate if not wanting to export at low value, it's also worth exploring the dual 5.2kW battery cost vs a single 8.2kW, as you can then also discharge at 6kW if you want to run more items in your house at peak times from the pack(S)

Thanks for the info.

I'm not sure on the size of room unfortunately I can try and find out what the companies are basing the sizes on.

I see what you mean in regards the actual cost of panels Vs the generation.

I am finding that depending on the companies that they will say that they can only fit certain amounts of panels as that is what they only supply. The one company offering the biggest system is a large multinational energy system (supplies boilers etc) and offers a variety of brands and panels.

I've been advised a 5kw inverter is best with the 8.2. I have also asked for a price based on the 2x 5.2 batteries however not sure on the efficiency Vs the 8.2 which is the actual storage with it being a 10kw battery compared to the 5.2 which has a DOD of 90% I believe?

 

[Journey]

I am finding that depending on the companies that they will say that they can only fit certain amounts of panels as that is what they only supply. The one company offering the biggest system is a large multinational energy system (supplies boilers etc) and offers a variety of brands and panels.

Yes, I think a lot of the time they have their own interests being put first, and selling what they make money on or have lots of in stock/easily available. I'd much rather wait for a fully bespoke system that just whacking up whatever they suggest, after all it is a very long term commitment you are making.

When I designed my system, I did it with a view of changing the panels after 10-12 years depending on how much the technology changes, so I chose panels that offered a good £/w/area, rather than Solar Edge/LG etc. as you were paying a for a warranty and a slightly higher % efficeincy loss over 25 years, it made no sense to spend up to 50% more for and extra 30w per panel. I'd imagine once they scale up making PV with perovskite panels we'll see cheap 550w+ panels and my energy use is only going one way once everything is electric in my home, so going from ~6kW to ~9kW will make a huge difference.

I've been advised a 5kw inverter is best with the 8.2. I have also asked for a price based on the 2x 5.2 batteries however not sure on the efficiency Vs the 8.2 which is the actual storage with it being a 10kw battery compared to the 5.2 which has a DOD of 90% I believe?

Check the stats on the two inverters, you'll see the are the same with 2600w max out put from the battery, but when using both solar+battery it changes, as the 3kW inverter only allows 3600w vs 5000w on the 5kW version, so if running 2x 3kW you get a max battery output of 5200w, or 7200w using both at once. Those figures are for the backup output.The DoD of 90% is standard now across all there batteries I believe, as they have gone with a 10 year or 26MWh warranty now, but I'd say they last at least 2x as long as that.

 

[GinG]

Yes, I think a lot of the time they have their own interests being put first, and selling what they make money on or have lots of in stock/easily available. I'd much rather wait for a fully bespoke system that just whacking up whatever they suggest, after all it is a very long term commitment you are making.

When I designed my system, I did it with a view of changing the panels after 10-12 years depending on how much the technology changes, so I chose panels that offered a good £/w/area, rather than Solar Edge/LG etc. as you were paying a for a warranty and a slightly higher % efficeincy loss over 25 years, it made no sense to spend up to 50% more for and extra 30w per panel. I'd imagine once they scale up making PV with perovskite panels we'll see cheap 550w+ panels and my energy use is only going one way once everything is electric in my home, so going from ~6kW to ~9kW will make a huge difference.



Check the stats on the two inverters, you'll see the are the same with 2600w max out put from the battery, but when using both solar+battery it changes, as the 3kW inverter only allows 3600w vs 5000w on the 5kW version, so if running 2x 3kW you get a max battery output of 5200w, or 7200w using both at once. Those figures are for the backup output.The DoD of 90% is standard now across all there batteries I believe, as they have gone with a 10 year or 26MWh warranty now, but I'd say they last at least 2x as long as that.

Thanks mate...once I get a couple of other quotes in would you mind if I sent you a trust message and get your opinion please?

 

[Journey]

Thanks mate...once I get a couple of other quotes in would you mind if I sent you a trust message and get your opinion please?

Sure thing happy to cast a glance over them, I'm not an expert mind you, just a well informed novice.

 

[GinG]

Sure thing happy to cast a glance over them, I'm not an expert mind you, just a well informed novice.

That'll do for me!

 

[SoliD]

Thanks for that.

I think I will go for the larger battery...I have also asked them to pride me for 2x5.2kwh batteries as a comparison.

So far price is £9522 for 6,370kwh system, 5kwh GivEnergy inverter and 8.2kwh battery.

£8755 with a 5.2kwh battery.

Pretty much just had the same quote today c. £9k for 6kwh system system, 5kwh inverter and 8.2kwh battery givenergy too. coming round in a couple of weeks to give a formal price as that was just over the phone. @Journey would I be right to assume that going for another battery on top of this would be beneficial?

Currently use about 20-25kwh a day, but no electric car in the house, but plug in hybrid coming in May and as said earlier i'd ideally like to use the AC as my primary heat source. - All cooking is electric.

 

[GinG]

Pretty much just had the same quote today c. £9k for 6kwh system system, 5kwh inverter and 8.2kwh battery givenergy too. coming round in a couple of weeks to give a formal price as that was just over the phone. @Journey would I be right to assume that going for another battery on top of this would be beneficial?

Currently use about 20-25kwh a day, but no electric car in the house, but plug in hybrid coming in May and as said earlier i'd ideally like to use the AC as my primary heat source. - All cooking is electric.

Who was that with out of interest?

I haven't gone back to any for any discounts as yet...£9k would be a sweet spot for me for that system.

 

[SoliD]

Who was that with out of interest?

I haven't gone back to any for any discounts as yet...£9k would be a sweet spot for me for that system.

Small Company just up the road from me solarpowerful.

 

[GinG]

Small Company just up the road from me solarpowerful.

Ah ok thanks, I think 9kish is a sensible cost for that sort of setup.

 

[Journey]

Pretty much just had the same quote today c. £9k for 6kwh system system, 5kwh inverter and 8.2kwh battery givenergy too. coming round in a couple of weeks to give a formal price as that was just over the phone. @Journey would I be right to assume that going for another battery on top of this would be beneficial?

Depending on your generation predictions figures, then an extra battery could help you make more use of the energy you produce from the solar. You have to consider your charge/discharge as if you aren't using the battery then you paid for it for no reason. So if you were to have a 16.4kWh setup with 90% DoD, that will give you 14.76kWh of energy storage for use after the sun sets, or before it rises again, and means less will be going back to the grid in summer at the ~5.5p per kWh rate you get paid. You need to consider the deliverable kW from the inverter/pack as you are limited to not much more than 2.6kW from a single battery/inverter setup if using high drain appliances for long periods together.

I am trying to target grid use minimisation, so my battery will also be used during daytime hours not just peak hours, if I can't power the house purely from the solar generation and the battery has some charge, up to a set cut off point to leave some free before my off-peak rate kicks in at 20:30 again, so I can charge it cheaply to use during the night and then again in the early hours when there is little/no solar generation. Obviously this is a seasonal thing, as in the summer months the sun comes up much earlier and you can possible get what you need even from early morning solar + a little battery power to top it off. Sorry that is a bit of a mouthful to read.

I think the 9k figure is pretty good tbh, and you'll be hard pressed to do better than that, if you can get another battery at the lower 5% VAT rate then it is certainly worth looking at, if its not possible get 2x 5.2kW packs which will give you a little more storage, but a lot more power delivery potential 2x 2600w

 

[SoliD]

Nice one thank you. Makes sense. (sort of)

I'm not on the cheaper off peak tariffs currently, obviously will be moving when I get the install done, but roof is south facing and should only be in the shade for first 1 or 2 hours of the day in summer when Tree in my back garden is in bloom. Not had a summer with the ac yet so not sure on what sort of power it'll be pulling but can't imagine it'll be much different to when it's acting as heat pump.

I'll ask the questions when the guy comes around, seems to be very highly rated locally too which is another benefit.

I presume with the way you're talking you can set all your power usage up via an app and tell it when to use what power source etc?