We'd like to remind Forumites to please avoid political debate on the Forum... Read More »
We're aware that some users are experiencing technical issues which the team are working to resolve. See the Community Noticeboard for more info. Thank you for your patience.
📨 Have you signed up to the Forum's new Email Digest yet? Get a selection of trending threads sent straight to your inbox daily, weekly or monthly!
Is Solar PV still worth it?
Options

Therooster100
Posts: 42 Forumite

I am seriously considering Solar PV but I am not sure if it is still worth it?
Having received a quote for 12 panels (5KW output) with a sofar 6.0 inverter & 10KWH battery at £9,000. I use roughly 10,000 KWH of electricity a year (fully electric house)
It would make a big dint into that but £9,000 is 8 years worth of electricity!
Having received a quote for 12 panels (5KW output) with a sofar 6.0 inverter & 10KWH battery at £9,000. I use roughly 10,000 KWH of electricity a year (fully electric house)
It would make a big dint into that but £9,000 is 8 years worth of electricity!
0
Comments
-
Rough estimate: your 5kWp system will generate 5000kWh pa, but will only meet your full demand on 10% of all days. You will at most use around 4000kWh (80%) of what you generate and export 1000kWh. You will still need to import 6000kWh. Savings total around £550, so > 16 years ROI. If you can shift a significant portion of your usage to overnight then maybe a time of use tariff could slightly lessen that.
In all liklihood, your usage will be high in winter (when your generation is low) and low in summer so you will probably only use 50% of your total generation. That puts annual savings down to £450 and the ROI up to 20 years.0 -
I am using about 15kW a day but even at this time of year on Octopus "GO" my daily cost is usually under £1 including standing charge. I do all the usual stuff in the "GO" tariff period, dishwasher, washing, if only I could persuade my partner to get up to put the washing in the dryer at 3 am !ROI was not really a consideration as almost everyone agrees the addition of Batteries is not a sound financial investment, but with interest rates as they are not much risk free investment is either. I do actually "like" having a system there is in my case some satisfaction watching the batteries filling up when the sun is shining. Almost a full year since install of batteries but impossible / difficult to calculate savings... Solar produced 4061 kW, battery delivered 2075 kW.... I still exported 874 kW this will be lower this year as I have AC installed so when the panels are pouring power into the grid I will be cooling our bedroom3.995kWP SSW facing. Commissioned 7 July 2011. 24 degree pitch (£3.36 /W).
17 Yingli 235 panels
Sunnyboy 4000TL inverter
Sunny Webox
Solar Immersion installed May 2013, after two Solar Immersion lasting just over the guarantee period replaced with Solic 200... no problems since.
13 Feb 2020 LUX AC 3600 and 3 X Pylon Tech 3.5 kW batteries added...
20 January 2024 Daikin ASHP installed4 -
mickyduck55 said:I am using about 15kW a day but even at this time of year on Octopus "GO" my daily cost is usually under £1 including standing charge. I do all the usual stuff in the "GO" tariff period, dishwasher, washing, if only I could persuade my partner to get up to put the washing in the dryer at 3 am !16 Sanyo Hit 250s.4kWp SMA 3.8kWp inverter. SW roof. 28° pitch. Minimal shade. Nov 2011 install. Hybrid car. Ripple Kirk Hill. N.E Lincs Coast.0
-
legoman62 said:mickyduck55 said:I am using about 15kW a day but even at this time of year on Octopus "GO" my daily cost is usually under £1 including standing charge. I do all the usual stuff in the "GO" tariff period, dishwasher, washing, if only I could persuade my partner to get up to put the washing in the dryer at 3 am !The issue is getting her to move it from the washing machine to the dryerMaybe I could use an alarm clock!
3.995kWP SSW facing. Commissioned 7 July 2011. 24 degree pitch (£3.36 /W).
17 Yingli 235 panels
Sunnyboy 4000TL inverter
Sunny Webox
Solar Immersion installed May 2013, after two Solar Immersion lasting just over the guarantee period replaced with Solic 200... no problems since.
13 Feb 2020 LUX AC 3600 and 3 X Pylon Tech 3.5 kW batteries added...
20 January 2024 Daikin ASHP installed4 -
When I moved to my current house, I was full of enthusiasm for 'going green' (solar PV & thermal, GSHP etc) but the more I investigated the options the less financially viable they seemed to be. A 15-20 year payback time seemed just too speculative, especially with PV panels being rated for around 25 years.
So I invested in having mains gas connected to the house instead, which cost about £500 in total. Having mains gas then immediately kicked out any form of heat pump being financially viable as it would need to be around 400% efficient just to have the same running cost as a condensing gas boiler.
I expect to revisit things in about 5-6 years time when my car might need replacement and I'll throw and EV into the mix, which might change the financial viability of solar PV, plus mains gas prices might also have increased relative to electricity. So, I'm certainly not against PV but I just can't see it as a sensible financial option at the present time.
I'm still thinking about solar thermal though and deliberately specified a spare coil in my thermal store to make it an easy addition if necessary. But mains gas is a tough competitor when it comes to cheap energy.
0 -
Petriix said:Rough estimate: your 5kWp system will generate 5000kWh pa, but will only meet your full demand on 10% of all days. You will at most use around 4000kWh (80%) of what you generate and export 1000kWh. You will still need to import 6000kWh. Savings total around £550, so > 16 years ROI. If you can shift a significant portion of your usage to overnight then maybe a time of use tariff could slightly lessen that.
In all liklihood, your usage will be high in winter (when your generation is low) and low in summer so you will probably only use 50% of your total generation. That puts annual savings down to £450 and the ROI up to 20 years.0 -
Mickey666 said:When I moved to my current house, I was full of enthusiasm for 'going green' (solar PV & thermal, GSHP etc) but the more I investigated the options the less financially viable they seemed to be. A 15-20 year payback time seemed just too speculative, especially with PV panels being rated for around 25 years.
So I invested in having mains gas connected to the house instead, which cost about £500 in total. Having mains gas then immediately kicked out any form of heat pump being financially viable as it would need to be around 400% efficient just to have the same running cost as a condensing gas boiler.
I expect to revisit things in about 5-6 years time when my car might need replacement and I'll throw and EV into the mix, which might change the financial viability of solar PV, plus mains gas prices might also have increased relative to electricity. So, I'm certainly not against PV but I just can't see it as a sensible financial option at the present time.
I'm still thinking about solar thermal though and deliberately specified a spare coil in my thermal store to make it an easy addition if necessary. But mains gas is a tough competitor when it comes to cheap energy.0 -
I'd suggest you would get a better return with more panels, as this will serve you better in the winter months when you will use more electricity for heating.
10Mwh is alot, and so I'd say you have a good chance of using all of your electric.
Assuming you have a hot water tank, then a solar diverter would be advantageous to use the excess solar once the batteries are filled.
And moving to octopus go would also help use your battery and heat the hot water for 5ppkwh instead of 15ppkwh in the winterWest central Scotland
4kw sse since 2014 and 6.6kw wsw / ene split since 2019
24kwh leaf, 75Kwh Tesla and Lux 3600 with 60Kwh storage2 -
Solarchaser said:I'd suggest you would get a better return with more panels, as this will serve you better in the winter months when you will use more electricity for heating.
10Mwh is alot, and so I'd say you have a good chance of using all of your electric.
Assuming you have a hot water tank, then a solar diverter would be advantageous to use the excess solar once the batteries are filled.
And moving to octopus go would also help use your battery and heat the hot water for 5ppkwh instead of 15ppkwh in the winter0 -
Therooster100 said:Solarchaser said:I'd suggest you would get a better return with more panels, as this will serve you better in the winter months when you will use more electricity for heating.
10Mwh is alot, and so I'd say you have a good chance of using all of your electric.
Assuming you have a hot water tank, then a solar diverter would be advantageous to use the excess solar once the batteries are filled.
And moving to octopus go would also help use your battery and heat the hot water for 5ppkwh instead of 15ppkwh in the winter
It won't give you as good a return as south facing, but is very good for later summer sun and some winter sun when it's low in the skyWest central Scotland
4kw sse since 2014 and 6.6kw wsw / ene split since 2019
24kwh leaf, 75Kwh Tesla and Lux 3600 with 60Kwh storage0
Confirm your email address to Create Threads and Reply

Categories
- All Categories
- 350.9K Banking & Borrowing
- 253.1K Reduce Debt & Boost Income
- 453.5K Spending & Discounts
- 243.9K Work, Benefits & Business
- 598.8K Mortgages, Homes & Bills
- 176.9K Life & Family
- 257.2K Travel & Transport
- 1.5M Hobbies & Leisure
- 16.1K Discuss & Feedback
- 37.6K Read-Only Boards