Renewable energies are sustainable and do not cause any pollution for the environment while fossil fuels are not sustainable and cause an extensive pollution that damages the environment. Renewable energies are solar energy, wind energy, bio energy, geothermal energy, tidal energy, and hydropower. Approximately all these forms of energy are hampered by their high costs. Moreover, solar energy, wind energy and tidal energy are characterized by their intermittent nature, as they are not available all the time. This intermittent problem can be solved by energy storage. Renewable energy plays an important role from the political point of view. Countries with no or minor energy resources from fossil fuels found the renewable energy as a very prestigious opportunity for a new era of dependency on their own renewable resources for energy instead of importing their energy needs from other countries. The thermal performance of a single pass solar air heater with five fins attached was investigated experimentally. A comparison of the results of the mass flow rates by solar collector with and without fins shows a substantial enhancement in the thermal efficiency.