How efficient are solar panels?

Whether you’re looking to cut down on your energy bills or become independent from the rising costs of the national grid, more people are choosing solar panel installations as a clean and sustainable energy solution to their home heating. But how efficient are solar panels?

Well, there’s a lot to consider when it comes to solar panel efficiency – from the type of panel to the size of your roof – so let’s just get right into it, shall we?

• What does solar panel efficiency mean?
• Why is solar panel efficiency important?
• What are the most efficient types of solar panels?
• Why are solar panels only 20% efficient?
• What factors affect the functioning of a solar panel?

What does solar panel efficiency mean?

Solar panel efficiency is how well a solar panel can convert daylight into usable electricity to power and heat your home.

Why is solar panel efficiency important?

Solar panel efficiency is important because higher efficiency will generate more electricity from the same amount of sunlight than less efficient panels. This means you’ll need to invest in fewer panels for the same amount of electricity.

Due to their better performance, highly efficient panels are generally more cost-effective in the long run. They’re also ideal for homes with smaller roofs as they maximise energy production without the larger installation area.

What are the most efficient types of solar panels?

There are many different types of solar panels, each with its own advantages and drawbacks. The type of solar cell you choose will determine the efficiency of your panel.

Monocrystalline solar panels

These are made from a single crystal structure and, while they are more expensive, usually have higher efficiency rates.

Polycrystalline solar panels

These panels are made up of multiple silicone crystals with space in between. While this results in slightly less efficiency, they’re often a more cost-effective option for many.

Why are solar panels only 20% efficient?

Sunlight is made of a spectrum of light energy particles. Solar panels are designed to absorb only specific light particles because others along the spectrum are too high or low energy to be effectively absorbed.

At the same time, some light energy is reflected back from the panels’ surface, and some is lost as heat within the panel itself. At the end of the day, solar panels – especially at a domestic level – are a balance between efficiency and cost-effectiveness.

While more efficient panels exist, they are typically not affordable for homeowners; this 20% efficiency offers the best balance between performance and affordability.

Will solar panels ever be 100% efficient?

Unfortunately, we’re unlikely to see 100% efficient solar panels due to current limitations in solar technology. In fact, the Shockley-Queisser Limit states that anything above 33.7% efficiency would be theoretically impossible with current technology.

What factors affect the functioning of a solar panel?

A few factors can influence your panels’ efficiency, including shading, panel placement, and outdoor temperature, so be sure you know each before investing in solar power.

Shading

Even a small amount of shade can affect a solar panel’s efficiency, especially if your solar array is made up of “strings” that rely on each other for their overall output.

To get around the shade problem, consider micro inverters or power optimisers to allow each panel to operate independently.

Panel placement

If you’ve heard people talking about their “south-facing” garden, it’s because they capture the most sunlight during peak hours when the sun is highest in the sky.

It’s the same for south-facing roofs and solar panels. If your roof faces the south, it will capture the highest possible sunlight during peak hours.

Temperature

We all know things don’t work the same when they’re too hot, whether it’s your phone, laptop or car. Well, it’s the same for solar panels.

While they are designed to convert sunlight into electricity, they won’t work as effectively if their temperature rises too much. However, this shouldn’t be a problem in the UK as our summers tend to stay relatively mild.

Roof pitch

The angle at which you install your solar panels can affect the sunlight they receive daily.

Maintenance

Don’t be fooled into thinking the rain will keep your solar panels spotless. Occasionally, you will have to give them a deeper clean to remove bird droppings, dirt, or leaves that may have collected over time. The cleaner they are, the better they work.

Do you think a solar panel installation would be perfect for your home but aren’t sure how much you’d save? Our handy solar savings calculator will do all the hard work for you, showing you the potential savings of a solar PV system on your home.

Unlock the power of solar with Grant Store today

So, now you’ve done the research, you just need to decide which type of solar panel you want and get it installed.

That’s where Grant Store comes in. With a range of Solar PV packages available, our experts are available to help. Get in touch today to start your solar panel journey.