Complete beginner looking for some basic pointers

[johnb2713]

Hi - I am looking to create a PV system for my domestic property 3 bed semi. On checking with my smart meter it looks like I use around 12Kw a day with a peak of around 5Kwh in terms of load. I have a shade free roof facing due South and room for battery storage. My peak demand is early morning and early evening with little during sunshine hours so I am guessing storage is going to be key.

Quick initial research yields

Grid tie inverter to use PV/battery and take power from the grid when I need to top up ie battery is low or no sun? Also manage battery charging from PV when no load? Am I right with this - basically want to use as little mains as I can using PV and battery for close to all power but with grid for backup?

If this is correct could someone kind and knowledgeable point be to the best inverters, batteries and PV units.

Re batteries I have seen 7000 deep cycle bats for around £300 a KWH - might be optimistic on that!

On inverters looked at Sunny Boy storage 5K

Many thanks in advance

Kindest Tim

I have recently had a system fitted to my home. Growatt SPH6000 Inverter, Growatt 7 kWh battery, Hyundai panels 6.7kW, Myenergi Eddi / Harvi and Zappi.

I have done extensive monitoring of my electricity use before and after installation and so far the battery is key to money saving. The system wasnt the cheapest to install (£11k), I took out a loan to cover it, so far the saving have been sufficient to cover the monthly loan payment. I make full use of charging the battery on off peak which ends at 04:30, the immersion heater is operated from the battery until the panels come to life. We seem to use around 3kWh between 04:30 and 08:00. The battery then charges from the panels and we run other things too dishwasher, washing machine and charge the cars (2 x EV). As we go into the evening time we usually have 80% ish battery capacity following cooking the evening meal. Over the last 2 months we have used 5 kWh of peak rate electricity at 29.2p, all of rest has been on 7.5p or free from the Solar.

Our energy supplier raised our monthly payment from £178 per month to £465, I have now reduced this to £140 which easily covers the monthly bill which is now averaging £70.

Battery storage and energy diverter are key components in my view.

 

[Gian]

I have recently had a system fitted to my home. Growatt SPH6000 Inverter, Growatt 7 kWh battery, Hyundai panels 6.7kW, Myenergi Eddi / Harvi and Zappi.

I have done extensive monitoring of my electricity use before and after installation and so far the battery is key to money saving. The system wasnt the cheapest to install (£11k), I took out a loan to cover it, so far the saving have been sufficient to cover the monthly loan payment. I make full use of charging the battery on off peak which ends at 04:30, the immersion heater is operated from the battery until the panels come to life. We seem to use around 3kWh between 04:30 and 08:00. The battery then charges from the panels and we run other things too dishwasher, washing machine and charge the cars (2 x EV). As we go into the evening time we usually have 80% ish battery capacity following cooking the evening meal. Over the last 2 months we have used 5 kWh of peak rate electricity at 29.2p, all of rest has been on 7.5p or free from the Solar.

Our energy supplier raised our monthly payment from £178 per month to £465, I have now reduced this to £140 which easily covers the monthly bill which is now averaging £70.

Battery storage and energy diverter are key components in my view.

That has really got it down. But what is the pay back for your complete system . What is the total cost of this install.

 

[Gian]

After 6 years I have got another 2 years to go untill it's paid me back. If my battery goes bad now I will be out of pocket. On third battery and now our of warranty.

 

[johnb2713]

That has really got it down. But what is the pay back for your complete system . What is the total cost of this install.

The cost was a fraction under £11k

I have calculated via a spreadsheet based on last years consumption, todays prices and predicted solar generation based on each month, my payback will be less than 4 years. The predicted generation for this area so far has been slightly pessimistic too. When the prices go up again in October and January that will bring the time down further. I have not factored into calculations were not using gas for hot water at the moment all of that is done by the immersion heater.
I'm currently building a 16kWh battery that I'm going to AC couple into the system, charge on off peak rate so that we can use it throughout the day during winter to run heatpumps. This will bring the payback time down even more

 

[johnb2713]

After 6 years I have got another 2 years to go untill it's paid me back. If my battery goes bad now I will be out of pocket. On third battery and now our of warranty.

What make of battery? Do you limit the charge to 90% and cut off at 10%?

 

[glenns]

I have recently had a system fitted to my home. Growatt SPH6000 Inverter, Growatt 7 kWh battery, Hyundai panels 6.7kW, Myenergi Eddi / Harvi and Zappi.

I have done extensive monitoring of my electricity use before and after installation and so far the battery is key to money saving. The system wasnt the cheapest to install (£11k), I took out a loan to cover it, so far the saving have been sufficient to cover the monthly loan payment. I make full use of charging the battery on off peak which ends at 04:30, the immersion heater is operated from the battery until the panels come to life. We seem to use around 3kWh between 04:30 and 08:00. The battery then charges from the panels and we run other things too dishwasher, washing machine and charge the cars (2 x EV). As we go into the evening time we usually have 80% ish battery capacity following cooking the evening meal. Over the last 2 months we have used 5 kWh of peak rate electricity at 29.2p, all of rest has been on 7.5p or free from the Solar.

Our energy supplier raised our monthly payment from £178 per month to £465, I have now reduced this to £140 which easily covers the monthly bill which is now averaging £70.

Battery storage and energy diverter are key components in my view.

Great info....I've just completed the first part of my system (solar and inverter) the batteries (2x pylontech 5000) are arriving in a week or so....it's cost me less than 6k and ordered through my business so VAT can be claimed back, also solar counts as capital investment so there's the 130% deduction for that too

Was nice to see zero grid usage from when the system went live yesterday till 19:00!!! Hopefully when the batteries arrive it'll be even better.

 

[Gian]

The cost was a fraction under £11k

I have calculated via a spreadsheet based on last years consumption, todays prices and predicted solar generation based on each month, my payback will be less than 4 years. The predicted generation for this area so far has been slightly pessimistic too. When the prices go up again in October and January that will bring the time down further. I have not factored into calculations were not using gas for hot water at the moment all of that is done by the immersion heater.
I'm currently building a 16kWh battery that I'm going to AC couple into the system, charge on off peak rate so that we can use it throughout the day during winter to run heatpumps. This will bring the payback time down even more

What battery's are you using to make up your 16kw. I have a small hybrid system and I am only playing with it .I only have 4 x 12 130amph leasure battery's . However I have decided to buy a v2g ev charger and my intention is to use this, not bother with power walls or other battery's but utalise a second hand ev. My current set up uses one of my ev chargers as solar charge only. My madness is that a used ev has a huge battery already contained and mobile ,I do have a large drive way any way. So we have options to use car ,it's mobile, it still can charge using solar, it can still charge at cheap rate times so no expensive hybrid inverter needed. This is my way forward so I don't have to buy expensive kit and dedicated battery's with little warranty. I think that the second regulation due out next year for ev chargers will be about giving our electricity suppliers control, spenergy British gas octopos ect the right for them to offer a package but they will have the right to use it when they need it for grid supply. That's what I think is going to happen. I base this on the recent regulation just in for new ev chargers which now have restrictions built in to stop chargers from working imidiatly so they will be delayed because of the grid demand issue.

 

[carptench]

What battery's are you using to make up your 16kw. I have a small hybrid system and I am only playing with it .I only have 4 x 12 130amph leasure battery's . However I have decided to buy a v2g ev charger and my intention is to use this, not bother with power walls or other battery's but utalise a second hand ev. My current set up uses one of my ev chargers as solar charge only. My madness is that a used ev has a huge battery already contained and mobile ,I do have a large drive way any way. So we have options to use car ,it's mobile, it still can charge using solar, it can still charge at cheap rate times so no expensive hybrid inverter needed. This is my way forward so I don't have to buy expensive kit and dedicated battery's with little warranty. I think that the second regulation due out next year for ev chargers will be about giving our electricity suppliers control, spenergy British gas octopos ect the right for them to offer a package but they will have the right to use it when they need it for grid supply. That's what I think is going to happen. I base this on the recent regulation just in for new ev chargers which now have restrictions built in to stop chargers from working imidiatly so they will be delayed because of the grid demand issue.

Totally agree with using your EV as your battery storage. Are the V2G chargers now available in the UK? As I tried get to more information on this a few weeks ago and didn't get anywhere.

 

[King Arthur]

That's very interesting! The parents of one of my son's friends are heavily into solar power and have installed a very large PV ground array and also run two Teslas. They are currently planning a battery system and have concluded that second-hand Nissan Leaf's are the way to go as they are cheaper than any dedicated home battery systems, apparently.

I think I've previously mentioned my recent stay in an Airbnb property that was an old watermill and the owners had restored the wheel so that it now drives a 15kw gernerator, which supplies all their needs (and more!) and, of course, runs 24/7. So I was surprised when the owner explained that they were looking at a battery system but he said it was because he could charge them for free and then export (ie sell) during times of peak demand. I've read that such a scheme can be profitable even by charging during the cheap night-time rate and exporting at peak rate, so to have 'free' water powered electricity to sell must put them ahead of the curve!

Having said that, I'm wondering how long overnight cheap rates will be the norm because assuming more and more people convert to EVs then overnight demand will not be as low as historically normal. This, plus the ever-increasing numbers of smart meters could well mean that electricity pricing becomes more like a stock market operation with prices varying from minute to minute as demand changes.

We're definitely living in interesting times!

 

[johnb2713]

What battery's are you using to make up your 16kw. I have a small hybrid system and I am only playing with it .I only have 4 x 12 130amph leasure battery's . However I have decided to buy a v2g ev charger and my intention is to use this, not bother with power walls or other battery's but utalise a second hand ev. My current set up uses one of my ev chargers as solar charge only. My madness is that a used ev has a huge battery already contained and mobile ,I do have a large drive way any way. So we have options to use car ,it's mobile, it still can charge using solar, it can still charge at cheap rate times so no expensive hybrid inverter needed. This is my way forward so I don't have to buy expensive kit and dedicated battery's with little warranty. I think that the second regulation due out next year for ev chargers will be about giving our electricity suppliers control, spenergy British gas octopos ect the right for them to offer a package but they will have the right to use it when they need it for grid supply. That's what I think is going to happen. I base this on the recent regulation just in for new ev chargers which now have restrictions built in to stop chargers from working imidiatly so they will be delayed because of the grid demand issue.

I've ordered EVE LifeP04 280a/h x 16. Not many EV's can do the V2G connection, I know the Nissan Leaf can, I think the i-pace can and i would guess Tesla can but thats about it. Choose carefully!
The control of EV chargers is a user function that can be disabled, it will allow the DNO's to delay charging start or to interrupt charging if grid load becomes critical.
Octopus already offer V2G trial tariff if you have the relevant vehicle etc.

 

[johnb2713]

That's very interesting! The parents of one of my son's friends are heavily into solar power and have installed a very large PV ground array and also run two Teslas. They are currently planning a battery system and have concluded that second-hand Nissan Leaf's are the way to go as they are cheaper than any dedicated home battery systems, apparently.

Batteries can be expensive, my concern with vehicle batteries such as the Leaf, it has very poor thermal management, a lot of batteries on Leaf's are well down on capacity now.

I've managed to source some reasonably priced EVE cells at just under £2200 for the 16kWh battery im going to build.

 

[glenns]

Batteries can be expensive, my concern with vehicle batteries such as the Leaf, it has very poor thermal management, a lot of batteries on Leaf's are well down on capacity now.

I've managed to source some reasonably priced EVE cells at just under £2200 for the 16kWh battery im going to build.

Please keep us all informed on how you get on. I was originally thinking of using some EVE batteries for my setup as they are pretty easy to source and much cheaper than off the shelf systems.

Ultimately I went for the pylontech us5000 *2 as I can hook them straight to my inverter but even at a reasonable £1300 each they are much more expensive than EVE batteries.

 

[Andy1733]

Please keep us all informed on how you get on. I was originally thinking of using some EVE batteries for my setup as they are pretty easy to source and much cheaper than off the shelf systems.

Ultimately I went for the pylontech us5000 *2 as I can hook them straight to my inverter but even at a reasonable £1300 each they are much more expensive than EVE batteries.

Where did you get the us5000 from at £1300? I've ordered on of these at £1850 ( cheapest I could find)

 

[glenns]

Where did you get the us5000 from at £1300? I've ordered on of these at £1850 ( cheapest I could find)

ITS Technologies but this was back in April... gone up now to £1638 for pre-order.

 

[binky]

That's very interesting! The parents of one of my son's friends are heavily into solar power and have installed a very large PV ground array and also run two Teslas. They are currently planning a battery system and have concluded that second-hand Nissan Leaf's are the way to go as they are cheaper than any dedicated home battery systems, apparently.

I think I've previously mentioned my recent stay in an Airbnb property that was an old watermill and the owners had restored the wheel so that it now drives a 15kw gernerator, which supplies all their needs (and more!) and, of course, runs 24/7. So I was surprised when the owner explained that they were looking at a battery system but he said it was because he could charge them for free and then export (ie sell) during times of peak demand. I've read that such a scheme can be profitable even by charging during the cheap night-time rate and exporting at peak rate, so to have 'free' water powered electricity to sell must put them ahead of the curve!

Having said that, I'm wondering how long overnight cheap rates will be the norm because assuming more and more people convert to EVs then overnight demand will not be as low as historically normal. This, plus the ever-increasing numbers of smart meters could well mean that electricity pricing becomes more like a stock market operation with prices varying from minute to minute as demand changes.

We're definitely living in interesting times!

Smart meters are being used for half hour billing periods, you can get batteries compatible with Octopuss software which gives them control of the battery - not sure how beneficial that is to the battery owners. The off peak rates are unlikely to disappear as power stations need to tick over, overnight, and wind turbines work 24/7, and more of those are being erected all the time