Direction and angle of solar panels: How to get the most out of them

The maximum power output of a solar panel system is determined, above all, by the direction that panels face. This direction depends primarily on the hemisphere you're in. In the southern hemisphere — in most countries of South America, South Africa and Australia - solar panels get the maximum amount of sunlight when facing north. In the northern hemisphere – Northern America, Europe, Asia and Northern Africa – the best possible direction for solar panels is south. At the equator solar panels system should be just facing the sky.

Some solar panel systems are equipped with solar trackers – special devices that turn panels so that they follow the sun all the time. While these systems produce around 25-30% more energy than fixed solar panel systems, their cost is significantly higher – in general, you would have to pay around 50% more for a similar-size system with solar trackers.

Not all the time it is possible to place your solar panels facing south – in the end it depends on configuration of your roof. In that case east or west sides are also fine choices, though studies show that overall energy output decreases by around 15% compared to panels facing south. To compensate for a loss of energy you can increase the number of panels for your home.

It is also possible to put panels vertically on the southern wall, but there are two problems: 1) it tends to cost more. 2) sunlight often gets blocked by trees, bushes or other buildings. Keep in mind, that if a part — for example 10% — of your solar panel system is constantly in shade, it doesn't produce energy, and the overall energy amount decreases by a comparable percent. You can put panels on the ground, but the system requires a substantial amount of free space in your yard.

There are situations where you would want your panels facing in another direction than the south (given that you are in the US or at least in the northern hemisphere). While a system gives maximum power output when it is turned to the south, sometimes solar energy is needed at a certain time of day. If you turn your panels slightly to the west, you get more energy in the evening, when people come back home from work and turn on lights and devices. If you turn your panels to the south-east, they absorb the light of the rising sun in the morning, which can be handy for reheating the house in the first hours of the day. In theory, by choosing southeast or southwest you lose around 7-8% of daily amount of energy but it's better used.

There are two other situations that are even more specific, but nevertheless seem interesting. The overall power output of solar panels drops slightly when it gets over 77 degrees Fahrenheit. In the hottest states of America, like Arizona or Nevada, it may be wise to turn panels slightly to the east so they would get more energy in the morning when it's still cold and panels function better. In some places certain times of day get cloudy — morning fog at San Francisco can be set as an example. Efficiency of solar panels drops by 15-25% in these conditions, so it would be smart to focus your panels on the time when they would have the most amount of sun. Of course, this last example differs from state to state. If you want to know more about solar panels efficiency in cloudy conditions, read our article on the effect of bad weather on solar energy production. " How solar panels perform on cloudy days and why electricity prices matter more than the weather ".

The right angle for solar panels is a tricky and a debatable thing. Generally, it is believed that you should tilt your panels towards the equator at the same angle as your latitude. For example, Los Angeles, the most popular town for solar panel systems is located at the latitude of 34 degrees, therefore an ideal angle for solar panels on a house in this town is 34 degrees towards the equator. It's important to note that panels with low-tilt generally accumulate debris faster and in winter snow doesn't slide off them, so they have to be cleaned more often.

If you are still not sure which direction and angle you should place your solar panel system, it's best to consult the professionals, who would be able to examine your particular situation and carry out the decision. Want to know more? Read our article "How to choose solar panels for home and commercial use".