Biogas:
In village the cattle dug had been used to making dung cakes to be used as fuel for cooking purpose. Now a days this dung is dropped in a special type of pit and is covered from which biogas emits which is used as natural gas for cooking and lighting purposes and the residual dung is used as fertilizer in fields.
Solar Energy:
Special types of photo electric cells have been invented which convert the sunlight energy (Solar energy) into electricity. It source is sun in which FUSION reaction occurs and several lakh tons matter is converted into heat and electromagnetic waves. According to a estimate energy equivalent to 1800 MW strikes on every square Kilometer of earth.
If a small portion of it can be used as energy for useful Purpose then total requirement of energy on earth can be easily met. In Pakistan sunlight falls for 300 days year so lot of electricity can be generated but it would be costly electricity. However small units for this purpose have been set up at Kharkhera (Lasbela Baluchistan) Malman (Thatta Sindh), Watlal Khan Laghari (Tharparkar Sindh), Hut (Multan) Nasirabad (Gilsit).