Solar panel sizes: Find solar panels in the right size and wattage for your home

Solar panel size is one of the secrets to getting the best return on your solar investment. It’s not as obvious a factor as the overall size of your solar PV system, but the size of each individual solar panel helps to determine whether they fit your roof safely, stand up to the elements and look the way you want them to.

Solar panels come in a surprising range of sizes that make them suitable for lots of different locations, from houseboats to warehouses. Standard house roof panels have a 350W output and measure about 2 metres by 1 metre, but not all roofs are standard, and nor is your personal taste. You may prefer one huge panel, or your delicate roof may be crying out for smaller, lighter panels.

In this article we’ll look at the different solar panel sizes and shapes available, and help you choose the right size to maximise your energy capture from the sun.

READ NEXT: How many solar panels do I need?

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How big are solar panels?

The UK’s average 350W solar panel is 2 metres long and 1 metre wide, about 3-5cm thick and weighs in at 20-25kg. That means a typical 10-panel solar PV system requires 20m² of roof space and weighs 200kg or more.

Luckily for small and delicate roofs, it’s now pretty easy to get more petite solar panels that provide nearly as much energy as the standard 20kg-plus panel. For example, the Panasonic HIT N340 (pictured below), which we named best solar panel for old roofs in our roundup of the best solar panels you can buy, weighs 18.5kg and measures just 1 x 1.6m.

The solar panels you get in solar kits for DIY, caravans and other off-grid projects can be even smaller, measuring about half a metre at their shortest and generating around 50W to 150W.

At the either end of the spectrum, you can now get solar panels that measure more than 3.5 metres and provide 700W of power – twice as much as standard-sized panels.

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Why does solar panel size matter?

In our article “How many solar panels do you need?”, we talked about why it’s important to get the right size solar PV system for your needs. A system that’s too small won’t cover your energy usage, and a system that’s too big will have an unnecessarily high upfront cost and capture more electricity than you can use.

The size of each individual panel is less important. An average 3kW solar PV system can be made out of 10 standard 350W solar panels, seven larger 500W panels, or 35 sleek, small 100W panels. Overall, each system would produce a similar amount of electricity in similar conditions.

Panel size is partly a matter of taste. It’s a bit like having your roof retiled. The overall roof size is the main factor, but choosing larger or smaller tiles depends on how you would like your roof to look. But there are a few more factors.

Your roof: If your roof is particularly delicate, steep or unusually shaped, then standard panels may not be a good or safe fit for it. Slim, small, lightweight solar panels may cost you more but prove to be a wiser investment.

Durability: Some sizes of solar panel are a better fit than others for certain weather conditions. For example, you can now get heat-resistant ’tile’ panels that are more efficient in summer if your roof gets a lot of direct sunlight.

Budget: Standard size solar panels tend to be the most affordable, but again it’s a bit like roof tiles: you pay more for more specialist products that aren’t produced on a mass scale.

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Are bigger solar panels better?

Generally speaking, the bigger a solar panel is, the more electricity it can generate. An array of 500W 3.5m panels would meet high energy demands and look fabulous on a large house. And with fewer gaps between panels, an array of large panels is easier to keep clean.

But as well as being more expensive per panel, these powerful panels are individually very heavy (32kg or more) and much more challenging to install. That will all push up the price of your installation quote, making it higher than an installation of similar overall size made up of standard panels.

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Can I get small panels that generate high power?

There’s an increasing choice of high-efficiency solar panels that are small in dimensions but big on power. These panels have particularly high conversion rates (the percentage of solar energy that’s converted to electricity), often around 23% compared with the industry average of 18%.

High-efficiency panels are an excellent choice if your roof space is limited but your energy demands are high; for example, if you run an electric vehicle and have an EV-compatible solar storage battery.

Small, slim solar panels are also preferred by many people for their more unobtrusive appearance. The Marley SolarTile range of panels measure around 1.1 x 1.8m each and are designed to fit flush with your roof, rather than sit on a frame on top of it. Installation is more tricky and expensive, because you need to have an area of your roof tiles removed.

Despite their name, Marley SolarTile panels are not actually solar tiles. Solar tiles are roof tiles with a solar PV coating that generates electricity from the sun. As with standard roof tiles, solar tiles come in a range of sizes including plain tiles (270 x 170 x 12mm), up to around double that size.

The main downside of small solar panels is their higher cost, because they are produced in lower numbers than standard panels. Solar tiles are particularly expensive, costing around three times as much as an equivalent panel array. But with solar technology advancing fast, panels of all kinds are becoming more affordable.

READ NEXT: Our guide to solar roof tile installation

What solar panel size is right for me?

Your taste, budget and roof will all be key factors when choosing the ideal size of solar panel for creating your solar PV system, but we recommend chatting to a qualified installer before you get too attached to particularly big or small panels.

Our free quote-finder tool above will help you find a solar panel installer near you, and reveal how much money you could save over a lifetime of slashed electricity bills.