Solar Panel Water Heating Efficiency

The efficiency and effectiveness of a solar water heating system will depend on the size and type of panels used and on positioning them to maximise absorption of solar radiation.

Solar panel water heating efficiency. How much you can save depends on the type of water heating system you are replacing. Photovoltaic modules are tested at a temperature of 25 degrees c stc about 77 degrees f and depending on their installed location heat can reduce output efficiency by 10 25. Don t choose a solar water heating system based solely on its energy efficiency. The two types of solar panel commonly available are.

It may seem counter intuitive but solar panel efficiency is affected negatively by temperature increases. Positioning to maximise solar heat absorption. Using air as a coolant was found to decrease the solar cells temperature by 4 7 c and increases the solar panel efficiency by 2 6 while using water as a coolant was found to decrease the solar cells temperature by 8 c and the panel efficiency by 3. Typical solar factors are 0 5 0 75.

The solar fraction varies from 0 to 1 0. The values range from 1 to 11 with most residential systems having a water heater efficiency of 2 or 3. Therefore cooling by water was found to be more effective than cooling by air. As the temperature of the solar panel increases its output current increases exponentially while the voltage output is reduced linearly.

Savings with a solar water heating system are moderate.