The efficiency of solar panels can decrease over time. There are several factors that can cause this degradation, mainly weather conditions. Temperature and cold can cause microcracks, which place constant strain on panels. Apart from the weather, solar panels can also be affected by the slope and elevation of roofs.
Loss of efficiency of solar panels due to weather
When the ambient temperature is high, a solar panel's efficiency decreases. Each degree that the temperature rises, the panel loses 1% of its peak output. To find out the temperature coefficient's impact on your solar panels, click here. High summer temperatures, like those in California, can lead to lower efficiency.
Also, solar panels' efficiency can be affected by snow or ice. Solar panels are not ice-resistant but can take some time to warm up after a night of freezing temperatures. In addition, the snow will block some of the sun's rays, which reduces efficiency. In winter, solar panels produce less power because they get less sunlight than in warmer months.
Color has an effect
Solar panels that use light from the sun are more efficient than those that do not. Only a small part of the electromagnetic radiation is suitable for photovoltaic generation. This is because the higher the wavelength, the less efficient the solar cell becomes. The second law governing thermodynamics states energy absorbed must equal energy released.
You can choose from a variety of colors for your solar panels. It is important to choose the right color as it will affect the amount light that panels reflect. A light-colored panel, however, will only reflect a tiny fraction of the sunlight. The panel's power and current will be decreased due to the reduced light transmission. It will vary depending on what color you choose. However, the more dark the color, the better the performance. Interference coatings can be used to minimize the effects of this phenomenon. This will decrease reflections and improve performance.
Chemical buildup can have adverse effects
Solar panels will eventually lose some of its efficiency. This process is called degradation. This natural process can cause a significant drop in panels' production. According to a National Renewable Energy Laboratory report, solar panels lose anywhere between 0.5 to 0.8% of their annual capacity. Although it isn't usually significant enough for most home-owners, this is something to keep in mind.
Many chemicals are used in the manufacture of solar panels. These chemicals can cause harm to the environment. Manufacturers of solar panels might decide to dump the chemicals instead of recycling them. Other solar panel manufacturers may try to cut costs by using non-recyclable materials or byproducts that may degrade the panels.
Roof slope effects
The slope of your roof might not be as crucial as you think. Actually, the slope is less important than the direction for solar panel efficiency. For steep roofs, solar panels looking east at a 45-degree angle will generate the highest amount energy. The energy production can be decreased by approximately ten per cent by lowering the tilt to 5 degrees. Flat roofs however will be covered with leaves, windborne dust, and other debris. They can't be kept clean by themselves.
Depending on the latitude of the home, the orientation and placement of the solar panels will play a significant role. The panels should be facing the true South. According to Aurora Solar's study, they will lose approximately eight percent of the energy that they produce if they are oriented north or southwest. In addition, solar panels installed on a north-facing roof may be partially obscured in the morning and evening.
Temperature and its effects
Solar panels' efficiency is greatly affected by their temperature. The temperature at which the most efficient panels perform is around 25 degrees Celsius, or 77 degrees Fahrenheit. This is the industry standard for optimal performance. Manufacturers assign panels energy ratings based on how much they produce at each temperature. The temperature coefficient is a measure of how much energy can be reduced for each temperature higher than the standard. This number can be found on the specification sheet of a panel.
Solar panels' temperature effects are evident. In summer solar panels can generate more energy than in winter. This effect will be balanced in most climates. To achieve optimal performance, it is essential to keep an eye on the temperature in your locale.