There are a number of different types of solar panels on the market today such as monocrystalline, polycrystalline and thin film. However, the effectiveness of virtually all solar panels will impacted by the following four factors:
As you would imagine, the primary factor to enhance the effectiveness of your solar power system is the amount of sunshine the panels receives. This is called solar insolation which is simply a measure of the amount of sunlight that the solar cells receive. Obviously, the more the better so even if you live in a colder climate that is further north and receive ample amounts of sunlight, solar should work just fine for you. (If you want to learn more about how solar panels work, you can click here.)
Remember, Germany, is which is farther north than just about any state in the U.S., is the world leader in solar photovoltaic energy with over 9,000 Megawatts. That’s almost enough to cover the roofs of 2 million U.S. houses! So don’t worry if you live in a cold climate, just make sure that you receive plenty of sunshine. To see how many hours of sunshine, on average, you can expect to get over the course of a year, check out the National Renewable Energy Lab’s online Solar Radiation Data calculator.
(2) Roof Slope and Solar Panel Orientation
Assuming you mount your solar panel system on your roof, the slope of your roof will impact how much sunlight your system receives. In addition, the proper roof slope changes depending on the latitude of the location where you live. For example, the closer to the equator you live, the flatter your roof should be as the sun is more directly overhead. The more pole centric you live, the steeper your roof should be as the sun is shining at more of an angle as opposed to overhead. And if you live in the United State, in general, it is always best to make sure that you have plenty of sunshine coming in from the South due to the tilt of the Earth’s axis. Bottom line, if you live in the U.S. and have a solar system that is southern facing, sitting on a with a slope between 20 and 60 degrees, you should be in good shape.
As a corollary to factor #1 above, it your panels are stuck in the shade, they are not going to receive the proper amount of sunlight. So beware of finding a spot to mount your solar panels on your roof that is free from objects blocking this sun such as trees, buildings or power poles. Shading is commonly measured in 30-minute increments, throughout the course of the day. Furthermore, in general, if more than 10% of any one of your panels is shaded then that panel may shut down the whole system temporarily because most panels are wired in series and connected to a single power inverter so the performance on one panel affects the others. Don’t lose hope…often times you can trim trees to reduce shading. In addition, many solar energy installers will also customize your system such that the panels are either wired in parallel (where one panel won’t affect the operation of the other) or will connect each panel to its own small individual power inverter ensuring that each panel operates effectively on its own regardless of the shading on other panels.
(4) Dust and Dirt
Solar panels consist of a series of carefully manufactured, wafer thin photovoltaic cells which are very fragile. However, these cells are placed in and protected by a tempered glass case which is framed by non-corrosive aluminum. Because solar panels are exposed to the elements they are typically very sturdy and built to withstand rain, hail and other weather-related threats. In addition, the photovoltaic cells that make up the panel experience very little break down over time, similar to computer chips. As a result, most solar manufactures offer a full warranty over their solar panels for 20-25 years. However, the build of dust and dirt may impact the performance of your panels over time unless you are constantly cleaning them. Not to worry though as most solar manufacturers offer performance guarantees over 10-25 year period. Always make sure that the panels your solar installer uses come with a performance warranty.
Assuming you have quality solar panels, properly installed and oriented by a reputable solar installer, you should enjoy many years of ample electricity from your solar system. However, bear in mind, that since a solar power system is made up of electrical components, your system will experience electrical loss. For example, the wiring on your system will contribute to a certain amount of electricity loss which is due to the distance the electricity travels (among other things) and most solar installers will try to minimize the total wiring length needed. In addition, you may also experience power loss as the DC current from the solar system's panels passes through the power inverter and is converted to AC power. As a point of reference, good inverters are about 95% efficient. Finally, while plenty of direct sun is good for boosting total output, solar modules are not efficient at high temperatures.