Are you considering harnessing the sun’s power and wondering how much you can save on your average monthly electric bill with solar panels?
Investing in solar panels allows you to generate free, renewable electricity, reducing your reliance on the grid and cutting electricity bills.
According to the Energy Savings Trust, solar panels can save London residents from £510 to £690 annually depending on whether they sign up for export payments like the Smart Export Guarantee (SEG) and how much solar electricity they use.
But what changes can you expect on your average monthly electric bill with solar panels, and what factors affect how much you can save?
Quick Takeaways:
- You can reduce your average monthly electric bill with solar panels by 50% to 70% or up to 80% if you incorporate a battery
- Reducing an average UK energy bill of £145 a month by 50% can save £72.5 a month. If you save 80%, you’ll reduce the monthly electric bill by £116 a month
- You can save around 14p for every unit of electricity you store in a battery and use at night
- Factors influencing how much you save include system size, efficiency, geographical location, electricity use habits, seasonal and weather variations
What is the Average Monthly Electric Bill in the UK?
The Energy Price Cap controls what most households pay for each gas and electricity unit in the UK.
As of January 2025, the average annual energy bill for households in Great Britain is £1,738, equating to approximately £145 per month. This figure encompasses both electricity and gas expenses for a typical household.
The average annual cost is £772.74, or about £64.40 per month when you focus solely on electricity. Energy prices have experienced fluctuations in recent years due to various factors, including changes in wholesale energy costs and regulatory adjustments.
Ofgem periodically updates the energy price cap to reflect market conditions. In January 2025, the price cap increased by 1.2%, adding approximately £21 to the average annual energy bill.
What is the Average Monthly Electric Bill with Solar Panels?
Solar panels can help reduce your monthly electric bill and offer impressive savings. A typical solar customer with high-quality panels can see their electricity bill drop by around 50% to 70%.
It can go up to 80% when you add battery storage and reduce the need to import and pay for electricity when the panels aren’t generating electricity. The Energy Savings Trust notes that you can save around 14p for every unit of electricity you store in a battery and use at night.
Savings and the average monthly bill will vary from person to person. You can work out how much panels can save you through a few steps:
- First, determine how much electricity you use daily from a recent energy bill.
- Now you know what size solar system you need to cover your usage. For example, if you use 3.9kW daily, you’ll need a 4kW system.
- Your savings will vary throughout the year due to the longer and shorter days of the year. The average UK energy bill is £145 a month. Let’s use a conservative estimate and say you generate 50% of your energy with your solar panels. That means you’ll reduce your energy bills by 50%, so simply halve your bill. In this case, you’ll be saving £72.5 a month. If you save 80%, you’ll reduce the monthly electric bill by £116 a month.
- You’ll save more money using panels in the best possible way, like using appliances when the solar is working and switching appliances on one after the other instead of all simultaneously.
What Factors Affect the Average Monthly Electric Bill with Solar Panels?
Size of the Solar System
The size and efficiency of a solar panel system are critical determinants of energy production and cost savings. Solar panel systems are measured in kilowatts (kW).
A typical UK household may install a 4kW system, which generates around 3,700 kWh annually, enough to cover most energy needs for an average family and reduce the monthly electric bill.
Larger systems can generate more electricity, reduce reliance on the national grid, lower monthly bills, and generate surplus energy that you can export to the grid and get paid for.
Solar Panel Efficiency
Efficiency refers to how effectively solar panels convert sunlight into electricity. High-efficiency panels produce more energy in limited space, making them ideal for homes with smaller roofs.
For example, a system with 20% efficiency will generate more electricity than one with 15% efficiency, given the same conditions.
They may cost more initially but often provide better long-term savings by generating more energy per square meter.
Geographical Location
Geographical factors play a significant role in determining solar panel performance. Areas with more sunlight hours allow panels to generate more electricity.
Southern England regions in the UK experience higher solar potential and have more daylight hours than northern regions like Scotland.
Households in sunnier regions see more significant savings on monthly bills due to increased energy production.
Seasonal and Weather Variations
Solar panels produce more electricity in summer when sunlight hours are longer. This seasonal disparity affects monthly savings. During the summer months from May to August, energy generation often covers most or all household needs, reducing bills to minimal levels.
During winter months like November to February, shorter daylight hours and lower sunlight intensity reduce energy output, increasing reliance on grid electricity.
Weather conditions also impact how much you can save monthly. While solar panels work even on cloudy days, their output decreases with reduced sunlight. Prolonged overcast weather may result in slightly higher monthly bills.
Electricity Use Habits
Your electricity use habits directly impact the monthly electric bill by influencing how much solar energy offsets grid usage. Solar panels generate electricity during the day.
A family home with members present during the day may consume more solar energy directly, lowering grid dependence. Households with no one home during the day may rely more on stored or grid energy, reducing savings.
You can make the most of the electricity generated by your panels by adjusting energy-intensive activities to daylight hours. For example, running washing machines, dishwashers, or charging devices.
You can also implement energy-saving habits and smart technologies to optimise energy usage in your home.
These can include smart meters, energy management systems, programmable appliances, LED lighting, energy-efficient appliances, and turning off unused devices to amplify the cost benefits of solar panels by reducing overall consumption.
Incorporating Battery Storage
Battery storage systems significantly influence the effectiveness of solar panels in reducing electric bills.
Battery storage allows you to store surplus energy produced during the day for use during evenings or cloudy periods. This reduces reliance on grid electricity when solar panels are not generating electricity.
For example, a 5kWh battery can store enough energy to power a home for several hours, lowering grid usage and associated costs.
Although batteries add to installation costs, they improve energy independence and maximise solar energy usage. Homes with battery storage often achieve lower monthly bills, especially during non-peak sunlight periods.
Roof Suitability
The physical characteristics of your roof will influence solar panel performance. Factors to consider include:
- Roof Orientation – South-facing roofs receive the most sunlight, maximising energy production. East- and west-facing roofs are less efficient but still viable options. Proper mounting and orientation are essential to capture the most sunlight.
- Shading – Obstructions such as trees, chimneys, or neighbouring buildings can reduce the amount of sunlight reaching the panels, lowering their output.
- Roof Space – Larger roofs accommodate more panels, enabling higher energy generation. Smaller roofs may limit the system size, reducing potential savings.
Regular Maintenance and Inspections
Regularly maintaining and inspecting your solar panels ensures optimal performance. They only require minimal maintenance to ensure they operate at maximum efficiency.
Dust, dirt and debris can reduce efficiency, but the rain can clean your panels if tilted at 15 degrees or more.
The main thing is to ensure nearby trees are well-trimmed to minimise shading. Occasional cleaning may be necessary if you have ground-mounted panels where debris will likely build up or live in an area with more dust.
Regular inspections can help identify issues early and ensure the system continues to operate efficiently.
Your installer will provide written details of any maintenance checks you should perform to ensure everything works correctly.
Case Study on Savings with Solar Panels
A case study at Energy Savings Trust illustrates how solar panels can help reduce monthly electric bills. A retired couple living in their detached bungalow near Coventry installed a 4kW solar panel system consisting of 16 panels and added a diverter and battery, helping to make them self-sufficient while saving lots of money.
Installers had predicted that the couple would see around a 10% reduction in electric bills and a seven-year payback. However, they did it in five and a half. After 10 years, the solar panels had paid for themselves more than twice over.
Key outcomes include:
Electricity Generation
Solar generation gives the couple 1,800 kWhs annually either directly or through the battery, and they import around 950 kWhs annually during the winter at a cheap overnight rate. This covers their annual electricity consumption needs of 2,750 KWhs per year.
Electric Bill Savings
The couple notes that solar panels have made an enormous difference. From mid-March to mid-October, they hardly purchase electricity from the grid, achieving near self-sufficiency.
Their monthly bills during this period are close to zero. For example, in August, they get a bill of £0.79.
Savings from the Battery
The couple is on a tariff with a cheaper electricity rate at night than during the day. In winter, they charge the battery, then run the dishwasher and heat the water tank at night when it’s cheap. The energy cost from the grid is more expensive during the day, so they rely on the battery during this time to minimise costs.
Final Thoughts on Average Monthly Electric Bill with Solar Panels
Installing solar panels on your property can help reduce your average monthly electric bill.
Factors influencing how much you save include system size, efficiency, geographical location, electricity use habits, seasonal and weather variations, and whether you incorporate a battery.
While the upfront costs of solar installations may seem high, long-term savings and environmental benefits make them an attractive option for many UK households.
By understanding and optimising these factors, you can maximise your investment in solar energy and achieve greater energy independence.
Sources and References
- https://energysavingtrust.org.uk/advice/solar-panels/
- https://www.ofgem.gov.uk/energy-price-cap
- https://energysavingtrust.org.uk/case-study/installing-solar-and-saving-energy/