If you are planning the purchase of a complete solar panel system or if you are shopping for parts to assemble your own solar panels you want to make sure to purchase the best solar panels for your individual purpose. This article puts up some basic information on solar panels to help you make the right decision.

One thing right at the beginning, there is nothing like “the world’s best solar panels for everyone.” It makes a big difference whether you want to generate electricity for your home and even feed surplus capacity in the power grid or if you want to charge a car battery now and then. And producing hot water from a solar installation needs actually a complete different technology. In narrower sense those so called “thermal solar collectors” or “solar collectors” are not even proper solar panels. So what’s the difference?

solar power in nashville tn (photovoltaic panels, photovoltaic modules) convert shortwave radiation, e.g. parts of the sunlight, into electrical power. They consist of interconnected solar cells which are protected by a range of different materials. The surface is transparent and the solar panel is framed, mostly in an aluminum frame.

Solar collectors on the other hand, are a system of liquid filled tubes. Sunlight heats up the tubes and the liquid. A heat exchanger now transfers the heat to the facility water circuit for warm water and heating. Since this article discusses “best solar panels” let’s get back to generating electricity out of sunlight and save solar collectors for another article.

Solar module efficiency

Always look at the efficiency of the total solar module, not only of the individual solar cell and be aware that high efficiency degrees are nothing without a high minimum warranted power rating. (see next paragraph)

Solar module power rating

It tells you about the wattage of the particular solar electric module. Make sure to check the (warranted) minimum power since the maximum power, stated in Peak Watt (Wp), is always measured under standard test conditions (STC). As you know, nature is not a laboratory. It provides real live conditions and they can differ surprisingly in many ways.

Operation voltage

Open circuit voltage, stated in Volts (V), is the maximum voltage a solar cell produces when illuminated and not connected to a load. The hotter the Solar Panels get, the lower the open circuit voltage gets.

Temperature operating range (TOR)

As mentioned above, operation voltage decreases with increasing temperatures. Make sure the TOR suits your local climate conditions.


Consider that you are purchasing a fragile high tech product that may be installed on your rooftop and should be be able to withstand roasting sun as well as wind, hail and heavy snow loads. Choose the right mounting system. Medium duty is good, heavy duty is better. The best solar panels are useless when blown down the roof and crashed on the ground.


Compare the panel dimensions to the active area to avoid a waste of space.