In the context of carbon neutrality, it has become a global consensus to vigorously develop clean energy. In order to promote the large-scale application of solar photovoltaic power generation, we need to have a breakthrough in the technology of solar photovoltaic itself.

A solar module's efficiency is stated in a % (percentage) of how much energy is captured per square meter of solar panel.

Solar modules are tested (in a lab) at an irradiance of 1000 watts per square meter meaning a solar module that is one square meter in area would produce 1000 watts if it was 100% efficient.

If a solar module was one square meter in size and 50% efficient, it would produce 500 watts.

If it was one square meter and 75% efficient it would produce 750 watts.

The high efficiency Sanyo module in the photo on the right would produce 202 watts if it was one square meter in area.

Does this mean you should spend more money to get the 20% efficiency?

Not really unless you have a limited space to install the panels. The truth is a 100 watt solar module will produce up to 100 watts whether it is 12% or 20% efficient. The difference will be the size of the module.

http://www.flagsunsolarpanel.com/