As of April 2023, around 1.2 million UK homes have installed solar panels, representing approximately 4.1% of the country's 29 million households. This data from MCS installations indicates potential for further growth in solar adoption as solar panel prices continue to fall.
If installed on every house in the UK (excluding flats). Solar panels could provide 60% of all domestic electricity consumption.
Cost 6.0p/kWh* at Leoht’s 2021 retail installation price including battery storage.
35% cheaper per kWh (with battery storage) than the wholesale price of new nuclear energy.
£92.50/MWh - Hickley point C. https://www.bbc.co.uk/news/business-24604218. £92.50 “at 2012 prices” means the cost could be £110.54 in 2021 prices.
47% cheaper than the current electricity wholesale price.
Year-Ahead electricity wholesale price - £112.41/MWh 8/09/2021 - Zenergi.co.uk - Market insights.
It would cost £133.565bn to install solar panels and battery storage on every house at Leoht’s current retail prices.
The equivalent of 3.59 track and trace systems.
Assumptions
This article will consider installing solar panels on houses only.
According to the EHS housing report, 2018.
https://assets.publishing.service.gov.uk/
22,260,856 houses in the UK. (27,837,320 x 80%).
Modelling an average solar array. This is quite a challenge.
Location: Coventry (central UK)
Azimuth: 139 degrees. South East. (41 degrees off due South
Roof pitch: 35 Degrees.
Array Size: 3.16 kW. 20.7% efficient premium all-black panels
5.12 kWh battery storage.
MCS Performance calculation.
Average domestic consumption = 3729 kWh.
103.8 TWh*/27,837,320 households, www.gov.uk, DUKES (https://assets.publishing.service.gov.uk...)
*Battery storage is included to maximise useful generation, smooth out intermittency of supply during the day, enable solar to be used at night and be able to store other forms of generation to supplement solar.
It’s a fairer comparison as renewable energy should always be coupled with energy storage.
System summary
There are 22,260,856 houses in the UK.
3.16kW solar capacity x 22,260,856 = 70,344,305kW = 70.34GW of installed solar capacity.
5.12kW battery storage x 22,260,856 = 113.97GW of storage capacity. (Which could be used for wind/nuclear in the autumn/winter).
2822kWh generation x 22,260,856 = 62,820,135,632kWh = 62.82 TWh of generation.
Total UK domestic electricity consumption = 103.8 TWh.
Installing solar panels on every house in the UK would provide 60.52% of our total domestic electricity consumption.
Between April and September, solar generation would exceed all domestic electricity consumption.
However, this only tells part of the story…
We need to consider how much of our electricity supply solar would provide under different circumstances/seasons/times of day.
Spring Energy Flows
Autumn Energy Flows
Summer Energy Flows
Winter Energy Flows
How to read the statistics
*Data for houses only.
Values are averages over the period. The eagle-eyed or those of us that live in the south of England will notice that a 3.16kW system only producing 1.5 kWh during the height of summer isn’t very good. Note that these are averaged figures over the .
Otherwise, the graph would be all over the place trying to predict the weather or when you switch the kettle on for example.
What the energy flow graphs can tell us.
Spring
Self-sufficient between: 7:45 am to 7 pm.
Importing from the grid: 7 pm to 7:45 pm.
Exporting to the grid: 7.30 am to 4.30 pm.
Generation required to cover shortfall: 8.9GWh
Duration: 12 hours. Additional electricity required: 106.8GWh.
Autumn
Self-sufficient between: 8.30 am to 5.30 pm.
Importing from the grid: 5.30 pm to 8.30 am.
Exporting to the grid: 8 am to 4 pm.
Generation required to cover shortfall: 8.9GWh
Duration: 13 hours. Additional electricity required: 115.7GWh
Summer
Self-sufficient between: 5 am to 9 pm. Almost completely self-sufficient 24 hours a day.
Importing from the grid: Very small amount. 9 pm to 5 am.
Exporting to the grid: 6 am to 5 pm.
Generation required to cover shortfall: 2 GWh
Duration: 8 hours. Additional electricity required: 16GWh
Winter
Self-sufficient between: 10 am to 3 pm.
Importing from the grid: 3 pm to 10 am.
Exporting to the grid: 9.30 am to 2 pm.
Generation required to cover shortfall: 12am-10am: 11.1GWh. 3pm to 12am: 20.0GWh
Duration: 19 hours. Additional electricity required: 291GWh.
Peak production/consumption
Peak production: 1.5 kWh x 22,260,856 = 33.39GWh.
Peak export (after charging the battery, available to the rest of the economy): 1.2kWh x 22,260,856 = 26.71GWh.
Peak unmet consumption: 24.49GWh.
Peak seasonal shortfall: 291GWh a day. (intermittency is a problem when relying on just one renewable energy source such as solar).
*Update: 21/09/2021: It could be argued that the reason we are seeing high gas prices in September 2021 is that we don’t have enough renewables to mitigate intermittency, we have a lot of wind capacity that currently is causing a shortfall, but not a lot of solar YET.
How do we cover the largest shortfall in the winter?
We would need to be able to supply 24.49GWh in the winter to cover the peak shortfall. 291GWh a day. This is where battery storage is important. 113.97GW at a maximum discharge rate of 1C could provide 113.97GWh for one hour or 1GWh for 113.97 hours.
We just need to charge the batteries over 24 hours.
Today’s installed capacity of Nuclear: 9GW. Load factor: 77% = 6.93GWh of constant power = 166.32GWh per day.
Today’s installed capacity of wind: 24.67GW. Load factor: 32% = 7.89GWh. = 189.36GWh average per day (intermittent).
Total renewable generation available today: 355.68GWh
Electricity required: 291GWh.
Today’s installed capacity of wind and nuclear would be able to provide enough electricity to houses to cover the shortfall from solar in the winter.
We’ll leave the adoption of heat pumps, electric vehicles and commercial consumption for another article!
How much would it cost to fit every house in the UK with solar panels and battery storage?
Leoht’s retail price including VAT for a 3.16kW system with 5.12kWh battery storage is currently £6000.
£6000 x 22,260,856 = £133.56bn. Or roughly 3.59 track and trace systems.
How would it affect the price of electricity in the UK?
The Levelized Cost of Electricity (LCOE) for this project is 6.0p/kWh at Leoht’s current retail price. Spread out over the lifetime of this system using a financial discount rate of 2.5%. Factoring in degrading performance of the solar panels (0.5% per year).
68% cheaper than today’s retail price of electricity. (19p. Ofgem).
47% cheaper than the current electricity wholesale price.
Year-Ahead electricity wholesale price - £112.41/MWh 8/09/2021 - Zenergi.co.uk - Market insights.
35% cheaper per kWh (with battery storage) than the wholesale price of new nuclear energy.
£92.50/MWh - Hickley point C. https://www.bbc.co.uk/news/business-24604218. £92.50 “at 2012 prices” means the cost could be £110.54 in 2021 prices.
Meeting a significant amount of our electricity needs with cheaper domestic energy production would reduce our reliance on international energy markets, which can be volatile and raise prices significantly for consumers.
Not having enough renewables or storage means you feel the effects of intermittency to a much greater degree. This intermittency means you have to go into the market and buy energy (usually fossil fuels) which can push the price up significantly.
Just look at the energy markets currently…
Electricity and gas prices in UK and Europe hit records. FT.com.
https://www.ft.com/content/bf84f4a9-4720-4655-801f-a40d57b634e6
Having an abundance of cheap renewable energy and storage to cover intermittency will lower the cost of energy.
It’s a paradox…
As we build renewable energy and storage capacity, expect intermittency to play a key role in pushing the cost of fossil fuels to new highs. Once we have achieved coverage of supply with renewables and storage, expect prices to fall rapidly.
Summary
Solar, wind and nuclear energy are enough to power our country at a lower cost than competing energy sources. Without exposure to volatile international energy markets, not only is this environmentally sound, it is an economic advantage for the whole economy, from the exporter with lower bills to the consumer with a higher disposable income.
* 6.0p/kWh is the Levelized cost of electricity (LCOE). Spread out over the systems lifetime, factoring in degrading performance (0.5% per year) with a financial discount rate of 2.5% per year. sciencedirect.com/.../levelized-cost-of-electricity
Hickley point C. https://www.bbc.co.uk/news/business-24604218
80% of people live in houses. According to the EHS housing report, 2018. assets.publishing.service.gov.uk/.../EHS_2017-18_Households_Report.pdf
Number of households in the UK. According to BRE group collating data from the 4 national survey reports https://files.bregroup.com/bretrust/The-Housing-Stock-of-the-United-Kingdom_Report_BRE-Trust.pdf
Average domestic consumption = 3729 kWh. 103.8 TWh*/27,837,320 households, www.gov.uk, DUKES gov.uk/.../DUKES_2020_MASTER.pdf
Electricity and gas prices in UK and Europe hit records. FT.com. https://www.ft.com/content/bf84f4a9-4720-4655-801f-a40d57b634e6
From 1 April… for a typical customer paying by direct debit will be 19p per kWh for electricity customers. OFGEM. https://www.ofgem.gov.uk/publications/energy-price-cap-increase-april-consumers-should-switch-save-money
