To help some who might be trying to get their heads around how to save on fuel bills, I thought this might be helpful, if you were considering alternatives.

Firstly you need to consider that natural gas will rise in cost more than electric, at least for the next few years. Also if green power is really moved to by 2030 in the UK then electricity should at least stabilise in cost but is not likely to come down in price (someone has to pay for the wind turbines and nuclear power stations). Unfortunately oil based fuels will increase in price over the next 5 years, so we are talking heating oil, kerosene for planes, petrol, diesel and LPG and anything else produced from Oil or Coal.

We bit the bullet in November 2021 and installed 22 PV panels, 390w each, 10 on East facing roof and 12 on West facing, both at 30% slope which is near optimum for solar, but about 15% loss in generation as East/West and not due South. We have 2 Batteries, 9.7kw each and a Hybrid DC/AC inverter, so far we have maxed at 5.8kw generation but should be more in the summer, I would expect just above 7Kw at peak. This lot I admit was not cheap, but we are all electric(no gas) with an Air source heat pump. We are still getting used to how it works and how much we generate on a day to day basis depending on cloud cover. 

Yesterday on a bright sunny day we generated 40.08 kWh, Self-consumption: 11.9 kWh, Export:28.18 kWh, Import from Grid:0.42 kWh (there is always a small grid input). Batteries were at 100% from 11:30 to 20:30, and depleted to 80.4% by 6:30am next day. 

Previously we had a different make of batteries and inverters that were replaced due to constant faulting in April, the January to March consumption below is from from electric bill, and Solar is from my recollection, April onwards is actual system data as now installed.

Jan 2022 - 

From grid 895kwh, from solar approx 180kwh, we averaged 34.6kwh

Feb 2022 - 

From grid 741kwh, from solar approx 200kwh, we averaged 30kwh

March 2022 -

From grid 334KwH, from Solar  approx 400kwh, we average around 25kw used a day

April 2022
System Production:726.47 kWh
66%  Self-consumption:481.66 kWh, 34% Export:244.81 kWh

Total Consumption:544.72 kWh,
88% Self-consumption:481.66 kWh - 351.16 kWh from batteries (72.9%)

12% Imported:63.06 kWh

Total Electrical cost 63.06 * 0.22 * 1.05(VAT) = £14.56 (plus £15.60 standing charging) Average Daily electric cost £0.49, +£0.52 standing charge.

May to date (8 days)

System Production:241.1 kWh
60% Self-consumption: 144.96 kWh, 40% Export:96.13 kWh
Total Consumption:160.08 kWh 
Self-consumption: 144.96 kWh - 104.56 kWh from batteries (72.1%), Import:15.12 kWh

Average Daily electric cost £0.44, +£0.52 standing charge.

Based on Solar data for our part of the country I would anticipate that from mid October through to end of March we will use from the grid in the order of 4320Kw of electric(from previous bills), £995.92 including VAT, over the year we should export in the order of 8000-10000kw which in terms of revenue at present would be about £280-350, so for a year our total power costs for the house would be in the order of £650-720 the year. If we were paying for the total electric at our current fixed rate(£0.21/kw) the total bill would be £1764(including vat) , but at the current flat rate of £0.35/kw it would be £2940. In October electric prices are expected to rise to around £0.52/kw which would make the same yearly bill around £4368.

So based on the above I would anticipate the our systems cost will pay for itself in 5-6 years, although if electric prices come back down to around £0.25/kw then it will take 10-12 years to break even, based on around 8000kw usage annually.

Something I would emphasise is that the key to getting the most from Solar is to generate as much as you possibly can and store it in batteries for night and morning time usage. You need to understand your peak electricity usage times and how much power you need to store to meet this. Toget the benefit for as much of the year as you can you need a bigger system. A lot of Solar installers will tell you that you are only allowed to generate around 3.8kw of power, this is rubbish it just makes their life easy, if you have the roof space you can generate more as long as you do not exceed what is agreed with the Electricity Grid supplier (not the Electric company), in my area it is Western Power that run the grid, to do so you just need an inverter that can limit the output to the grid or is designed not to exceed what is agreed with the Electricity Grid supplier.

There is one thing that I have not mentioned which is we charge up our Tesla primarily for free from the solar, this averages about 200kw per month or 800 miles, for about 3-4 months we expect having to pay for charging it, so around 3200 miles or 800kw which is £200. So to do 10K miles a year it will cost about 2p/mile, if that was in a 40mpg petrol car at current average prices it would be £1875 for the year or 18.75p/mile.

So if you add the savings on car fuel per year to the house savings, then with electric staying at 0.25p/kw and petrol at around £7.50/gallon, the yearly saving is in the region of £3000/year, so the system is paid for in 6 years, if electric and petrol/diesel costs rise then the payback is even sooner. 

We are also considering a small vertical Tessup wind-turbine that can produce up to 5kw, and will generate power from as little as 7mph of wind, this is the most efficient way to generate power, it would feed into our inverter as well as the solar. Our area averages over 10mph through Nov-Feb, so it could provide most of our electricity needs through the winter months. The one we are looking at is £1100, is 1.2m tall, 420mm diameter, and when spinning is very quiet at less than 50dB, we could mount it on our flat roof garage. You do not need planning permission unless you already have an air source heat pump, there are some rules such as it has to be at least 5m from your boundaries and should protrude more than 3 metres above the highest part of the chimney, and the overall height of the house + wind turbine should not exceed 15m, there are some other requirements.

Your welcome Steve, it was a bit of a leap of faith for us. Starting with the Air Source heat pump, driven by future gas issues, and we were doing up a neglected bungalow that we moved to in Jan 21. I also did not mention we have solar thermal for water, we managed to get a grant for this but in retrospect a bit costly in relation to the return and unnecesary if you have sufficient PV/wind generation.

I tried to do lots of investigation and spoke to as many ECO ‘professionals’ as possible to get a realistic view, tbh it was a bit of a minefield.

We have an EcoDan air source heat pump which is very good with a dual coil stainless water tank, this came with the solar thermal. Originally we had a GivEnergy system two batteries and two hybrid inverters, on paper they looked good and vfm, however one battery kept either not discharging or charging, also one inverter kept loosing connection and faulting, we spent a month trying get them to resolve issues and inaccurate power reports and in the end gave them back. I think the issue was a relatively new company developing what should be good products but not giving enough time to test and expanding to quickly. We moved to Solaredge, single hydrid inverter connected to two batteries, the batteries have be around for about a year from them, we have had a couple of drop outs with one, which was firmware, sorted out within 12 hours. Solaredge have been around since about 2008, so are well established with large customer base worldwide.

I would only go Heat source pump and full PV/battery supported by wind turbine if you know you will be staying in the house at least 8 years. But I would definitely get away from gas/oil asap so solar PV may be a necessity to keep yearly costs in check.

Cheers

I have looked at solar panels a couple of times, but still too expensive.

Turning 60 this year, and luckily now mortgage free.
But most spare money going towards retirement (teachers' wages are not high).

Have a wood burner as main heating source.
Bought a more expensive one (I usually go for the cheapest).

An engineer was tasked with building the most efficient woodburner he could (NZ Department of Scientific and industrial Research).
It has a double burning chamber. Very efficient, and low emission.
I order 8m3 of pine each spring and chop/dry/stack it over summer, which has been around £270/year.

In an old cottage built 1929 (lived here since 1994). Managed to get sash windows fixed and installed double glazing. What a difference.
Had insulation blown into the walls. Not the best system, but better than nothing.
And have just replaced the ceiling insulation. Recommended R2.9. Put in R4.1 batts.

Turned a cold drafty house to one that is much warmer.

Solar panels getting better. Soon hopefully for cost benefit

Wood burners are not good for you

Cancer warnings about log burners plus

www.newscientist.com/article/2119595-wood-burners-london-air-pollution-is-just-tip-of-the-iceberg/

woodsmokepollution.org/climate.html

www.theguardian.com/environment/2021/dec/17/wood-burners-urban-air-pollution-cancer-risk-study

Burning wood in any way produces large amounts of co2 no matter how you dress it up. Modern wood burners are efficient at producing heat but they still release co2 and other nasty gases and soot particles. I understand why people like them, we have had several and enjoyed that type of warmth, but they really are not good in comparison to producing energy from other means.

Points noted guys

We've had the rads on for a while.
Insulation fitted underfloor in the kitchen diner and honeycomb blinds eventually
Think a few of the windows in the house need new seals