How to Maximise the Efficiency of PV Panels: Should they Face South or West?

Despite what the Telegraph’s headlines suggest, south-facing solar panels generate more power than those facing west. But why are sections of the media and a small group of scientists rooting for west-facing panels?

Sensationalist Headlines

Telegraph managing editor Keith Perry says that according to energy experts, “thousands of people have spent vast sums of money installing eco-friendly solar panels but most will have probably had them fitted facing the wrong way.” As is often the case, probably is the key word here. Turns out that south-facing solar panels actually generate more electricity than west-facing solar panels, and whilst Perry probably knows this, his headline suggesting that the opposite is true is much more newsworthy, though also a little misleading.

The whole west is better than south argument first made waves back in November 2013 when a report from the Pecan Street Institute found that west-facing solar panels generated more electricity than south-facing solar panels for twenty four houses in Austin, Texas, but only over a three-month period. The same report concludes that over the course of a year south-facing solar panels provide “more total energy than other orientations.” Question marks have since been raised as to the report’s validity due to small sample size.

What’s the Argument for West?

West-facing solar panels don’t produce a higher energy yield than south-facing solar panels, but there is some credit to the idea that a mix of west-facing solar panels and south-facing solar panels might be better for the country in general. In Germany, the world leader for solar energy, so much energy is generated by solar panels at midday that the grid struggles to handle it. The German government is now advising people to build east and west-facing solar panels so that solar energy can be generated more evenly throughout the day

The same situation is occurring in Cornwall. Many people have built solar panels in the sunny Southwest and the grid is unable to handle any more energy. As such, they’ve had to reconsider construction for the time being. So whilst the individual homeowner gains more power from a south-facing solar panel, in places that already have a lot of solar panels it’s better for the grid to build east-facing or west-facing solar panels. It’s also worth considering that west-facing solar panels generate most of their energy in the afternoon, which is when demand for electricity generally peaks.

The government’s current feed-in-tariffs (FIT) pay out to homeowners based on the amount of electricity that they generate for the grid, with a typical system in the South of England generating an income of £330 plus savings annually. A homeowner with a south-facing panel will earn more through FIT than a homeowner with a west-facing panel. Unless the government changes the incentive system to reward west-facing solar panels, it’s unlikely that very many homeowners will opt for a less efficient, less financially rewarding placement of their solar panel.

What else to Watch out for?

In addition to to choosing a south-facing orientation, there are a number of other ways to maximise the efficiency of your PV solar panels:

  • Make sure that there are no shadows on your panels.
  • Make sure that there isn’t a layer of dust on your panels.
  • Keep your panels at the right temperature.
  • Although FITs are a nice source of income, it makes more financial sense to try and use the electricity that you generate, rather than sell it to the grid. If you have a south-facing grid, set your appliances to go to work at midday when you have plenty of solar energy available.

Of course, the most efficient way to use you PV panel is to get a fully automated solar tracking mount. This kind of mount follows the sun as it moves through the sky, so your panel is always facing the best possible angle. However, these kind of rigs can be expensive, so until the price comes down your best bet is probably sticking with a south-facing panel!

Are you interested to know how much money you could save with renewable energy? You can either keep reading our blog, or speak to a member of the team at 01621 827015.