Top 5 Things to Keep in Mind When Buying Solar Panels

Learn about the benefits of installing solar panel energy

Solar energy provides an alternative to the main grid power, helping create energy independence. Being renewable, it's a terrific way to reduce carbon footprint and contribute to sustainable living. Not only does solar energy have low maintenance costs and zero energy production costs, but it also helps power smart home appliances to reduce electricity bills. For a successful solar power installation project and when considering the pros and cons of solar panels, there are a few factors you need to think about. The major ones include your daily power load, the efficiency of the panels and the minimum warranted power. It's also recommended to check the PV USA test conditions (PTC) rating and the suitability of the installation location, as they will all have a significant impact on the panel's power output.

1. Match your load with the panel's power rating

Do some math and determine the total power consumption of your appliances to figure out which solar panels and batteries that satisfy your power needs. The first step is to calculate the watt-hour by multiplying the power rating of the gadgets with their running time.

For example, if the mean wattage of the appliances is 60W, and they run for an average of 6 hours a day, the total watt-hours (Wh) would be 60 x 6 = 360Wh. Supposing a loss of 20% of the energy in the system, then the aggregate power that you will work with becomes 360Wh x 1.2 = 432.

Since the sun is never in a constant position, you need to choose a solar panel that will absorb enough sunlight to convert to the energy you require. Assuming the panel gets 4 hours of straight sunlight exposure, you will need a panel that will produce 432Wh/4 = 108 watts. Rounding off the nearest standard wattage, a 120-watt, a 12-volt solar panel is enough to satisfy your power needs.

2. Consider the panels' efficiency

Efficiency refers to the rate of conversion of solar energy into electrical energy. For example, a panel capturing half of the sunlight energy would have a conversion efficiency of 50%, but in the real world, the efficiency rates range from 15% to about 21%. Why bother checking with the efficiency? It helps you decide if you really save money with solar panels. Higher efficiency means more electricity wattage per square meter which results in the need for fewer panels.

Solar panel technology determines the efficiency of a solar panel. Polycrystalline panels have cells with multiple silicon fragments, and they are recognizable with their blue color. Monocrystalline panels consist of cells that have a single silicon crystal and are popular for their improved efficiency.

3. Check for the minimum warranted power

Each solar panel has a minimum warranted power rating that reflects the maximum amount of output you should expect from it. Peak wattage on similar panels from different solar power kits can vary with a deviation of 5% to 12%, depending on the clarity and quality of the used materials. It means that for a 180-watt rated panel with a negative power rating of 10%, you would have a guaranteed power of 172.

High-quality brands try to keep the rating below 7% to ensure you get the maximum amount of power from the panel. The higher the percentage, the lesser the output, which might increase the need to get an extra solar panel to support your energy requirements.

4. Look for PTC rating

Unlike the standard testing conditions (STC) ratings provided by the manufacturer, the Photovoltaics for Utility Scale Applications (PVUSA) Test Conditions (PTC) rating comes from a third party, which provides the benefit of unbiasedness. It's a common requirement in the United States for panels entering the market to undergo this test.

The test’s goal is to protect you the consumer from inflated power ratings. For example, there are two panels that both have an STC rating of 150 watts. If the results show that the first panel has a PTC rating of 130W while the second one has a PTC rating of 150W, it would be prudent to go for the second as the discrepancies in the first panel implies rating inflation.

5. Location is crucial

Both the time and the amount of sunlight exposure influence the level of usable energy converted by the panel. To optimize your output, ensure the placement is not in the shadow of buildings and tall trees that might block the sun's rays.

When installing, align the panels facing the east or west position. This adjustment ensures they are parallel with the sun's path for maximum ray absorption. The panels will produce more power either in the morning or evening, depending on the installation location. The more hours the panels face exposure to the sun, the more efficiency and power you have. It's easy to move portable solar panels when camping to ensure they get the best exposure to the sun.

Final words

Now that you understand what solar panel energy is and how solar panels work for your home, the final piece of the puzzle is finding a dealer that will guarantee quality. Choose panels and other complementary solar devices, like batteries and inverters, that promise long-term reliability.