Harnessing the power of the sun to meet our daily energy needs is a sustainable and increasingly popular approach worldwide.
As more and more homeowners turn towards the sun for their electricity requirements, a question that frequently arises is, “How many solar panels do I need to power my house?“
In this post, we will delve into the core factors that determine the number of solar panels necessary for a house, based on energy consumption, sun exposure, and panel efficiency. Let’s get into it.
How many solar panels to power a house?
For a one-bedroom house, a general estimate suggests the need for around six solar panels. For a three-bedroom house, this figure increases to approximately 10 panels, and a larger five-bedroom house would require around 14 panels.
The energy generated from this number of panels accounts for roughly 46% of the average energy consumption of a household over the year. This percentage could be higher if you’re often away from home and don’t use much electricity.
Annual electricity usage is measured in kilowatt-hours (kWh).
To give you an idea, 1 kWh is the amount of electricity that a 1,000 watt (1 kW) appliance would consume if it runs for an hour. For instance, if you have a 500-watt washing machine, it would utilise 0.5 kWh within an hour.
Without a solar battery, you could end up not utilising about half of the electricity that your panels generate, especially if you’re not home when the energy is produced. Instead, this surplus energy will be sent back to the grid.
But don’t fret – this excess electricity can be sold back to the National Grid via the Smart Export Guarantee (SEG).
The combination of the savings from the SEG and reduced reliance on costly electricity from the National Grid means that you would typically recoup your initial investment in about 14.1 years, based on our calculations.
How to work out how many solar panels you need
To work out how many solar panels you need for your home, you need to consider three factors:
- Your roof size and orientation
- The sun hours in your area
- The average daily energy consumption of your property
Let’s briefly explore each factor.
1) Roof size and orientation
It’s crucial to understand your roof’s dimensions as it determines how many solar panels it could possibly accommodate.
On average, a typical solar panel measures approximately 1.6 square metres, and an average solar power system consists of between 10 to 12 of these panels.
Even with a smaller roof, you still have options – deploying fewer solar panels with a higher power capacity can provide an adequate solution.
However, to get the most out of your solar panels you must also consider the best position for your solar panels – depending on your roof’s orientation.
For optimal power generation in the UK, solar panels should face south. This positioning allows them to capture the maximum amount of sunlight throughout the day, thus generating more electricity compared to panels facing other directions.
In comparison, panels placed on east- or west-facing roofs tend to generate 20% to 30% less power than their south-facing counterparts.
However, it’s always advisable to consult with a solar energy professional for an accurate estimate of the number of panels required for your home, as these are general guidelines.
2) Sun hours
Undeniably, some regions in the UK experience more sunlight hours on average than others (for instance, England averages 4.1 hours, while Northern Ireland averages 3.2 hours).
Nevertheless, these sunlight hours are enough to power a conventional solar panel system efficiently.
As mentioned in the last point, your roof’s orientation significantly impacts the effectiveness of your solar system.
Roofs facing south are considered ideal as they receive more direct sunlight and for extended periods throughout the day.
Therefore, assessing your roof’s orientation and the average sunlight hours it gets is crucial in determining the number of solar panels you need.
3) Daily energy consumption
To accurately determine the number of solar panels required, it’s essential to understand the annual electricity consumption of your dwelling. Your energy bills are a reliable source for this information, showing how much power your property utilises on a daily basis.
Let’s say, for instance, your household consumed 155 kWh in the month of May. This means your daily power usage is around 5 kWh. This information is pivotal in determining the capacity of the solar PV system you would need.
Here’s a basic reference for a solar PV system comprising 250 W panels:
- 1 kWp system: 3 panels
- 2 kWp system: 6 panels
- 3 kWp system: 12 panels
- 4 kWp system: 16 panels
- 5 kWp system: 20 panels
- 6 kWp system: 24 panels
To put it into perspective, an average UK home consumes around 3,731 kWh per year. This implies that a 3kWp system (which includes 12 panels) would typically be sufficient.
How to install solar panels at a reduced cost
Did you know through the Energy Company Obligation (ECO) scheme, you may be eligible for free or discounted solar panel installation?
Currently in its fourth phase, ECO4, the energy saving grant designed to ensure low-income households are able to reduce their energy bills and improve the energy efficiency of their dwellings.
Thus, if you meet certain criteria for the ECO scheme you would be entitled to receive either partial or full funding from the government to cover your solar installation costs.
To learn more, contact So Eco today or complete our free online eligibility checker and a member of our experienced team will be more than happy to provide you with further information.