One of the following is not a problem involved in harnessing solar energy?

Unreliability is not a problem involved in harnessing solar energy. Solar energy is considered a renewable energy source, which means it is sustainable and will never run out. The energy is harnessed from the sun, which means it is abundant and widely available. Therefore, unreliability is not a problem with solar energy. On the other hand, poor technological know-how, adequacy of capital, and fear of competition with established energy sources are some of the challenges involved in harnessing solar energy. Poor technological know-how can lead to inefficient use of solar panels or other solar energy technologies. Adequacy of capital can be a problem since solar energy systems can be expensive to install and maintain. Fear of competition with established energy sources can discourage investment in solar energy and limit its growth.