There is no requirement on the number of solar panels required for an installation on your home. Typically, the higher the number of solar panels installed the more electricity you generate and the more you will be able to save on your electric bills. Coupled with solar battery storage, you could save further money on your electric bills by storing excess energy for use whenever required.

The most common solar PV system size in the UK is a 3kW system comprising 12 panels or a 4kW system compromising of 16 panels. Annual electricity bill savings of these systems will vary between £150 - £300, however, there are several variables that affect this figure including export tariffs as well as the type and quality of solar panel system.

Despite this, the most efficient solar system typically is based on your energy usage, ensuring that electricity generation from the system matches that of the household usage. To do this, finding out your annual energy usage is a vital step to understanding how many panels are optimum for your home and circumstance.

Annual Energy Usage

Average annual electricity usage is usually the main factor when determining the number of solar panels required for your home. Reputable solar panel installers will typically ask for information such as energy usage from your energy bills, to ensure that any solar panel installation can meet the demands of the household or business. Installing too many panels can have a determinantal impact on the financial feasibility of solar panels, as any unutilised energy from the panels can go to waste which will not help offset the savings from the initial investment.

Another determining factor is the amount of space available either on your roof or in the garden. With these two areas being the main spaces where solar panels are typically installed, the number of solar panels that can be installed can on occasion be restricted by the amount of space available to install the panels.

Average Household Energy Usage

Once you’ve discovered how much energy is used by your household or business you can start to calculate how many solar panels are required to offset household usage. Solar panel output can vary depending on the brand and type of solar panels installed, varying anywhere between 200-400W.

In homes with a smaller space to install panels but a higher energy usage, installing panels with a larger output is beneficial as it’ll allow more electricity to be generated within the space available. Based on 300W solar panels being installed, the number of panels installed on typical property types are below:

Household TypeAnnual Energy UsageTotal Panels InstalledTotal System Output
Detached4,153 kWh144,200 kWh
Semi-detached3,847 kWh133,900 kWh
Bungalow3,866 kWh133,900 kWh
Micro business5000 – 15,000 kWh175,100 kWh
Small business15,000 – 25,000 kWh5015,000 kWh
Medium business25,000 – 50,000 kWh8425,200 kWh
Large businessOver 50,000 kWh16750,100 kWh


If you’re looking at installing solar panels for a larger business, suppliers will typically handle energy suppliers slightly differently. To find out more about solar panels for larger businesses, enquire or call us today.

Energy Production Day/Night

A consideration when installing solar panels is when the energy is used within the household or business. Household peak energy usage is in the morning and evening, typically when energy output for the panels is at its lowest. Ensuring that energy from your panels can be used during these times is critical if you’re to maximise the energy output from the solar system. To get around this issue, many homeowners consider installing a solar home energy battery which stores any unused power from the solar panels for whenever it may be required.

If you’re a business owner, typically energy usage is highest during the day when solar panels are at their most efficient at peak output. This is the ideal set-up allowing for the most efficient set-up from the solar panel system. In this situation, a solar battery is less beneficial, as only power during the evenings would be stored, typically when output is lower anyway, so the battery may never reach full charge.

Solar Panel Installer

At SolarTherm UK, our team of renewable energy experts can offer advice based on the latest information to ensure you’re maximising your investment. On all installations, our team will conduct a feasibility study so owners can understand the amount of time it’ll take to break even from the initial investment, as well as potential earnings that can be made above and beyond that.

Our expert installers have installed thousands of renewable energy products across the country, with customer service and quality always being at the forefront of any installation.

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