• Photovoltaic systems also make it possible to generate and use electrical energy independently of existing power grids, dispensing with high cost of constructing power grids over long distances.

• Transformers or substations may be required depending on the size of the wind farm and the voltage of the electrical line.

• Fuel cells are an emerging technology that can provide heat and electricity for buildings and electrical power for vehicles.

• The electricity generated from solar PV systems can be used to power residential electrical devices or can be fed back into the grid.

• The simplest method of using them is to directly use the direct current generated by the solar energy to operate electrical equipment.

• They have the potential to be fueled with coal-derived fuel gases or natural gas and can be used for electrical utility, industrial, and military applications.