Normally energy falling on earth from sun is quite large so that theoretically it is possible to meet our needs from the annual energy derived from solar insolation. The potential of energy available in the State of Karnataka has been estimated by many persons.

Agrowastes provide an important energy source to rural poor in addition to other uses like fodder, manure etc. Table 11 gives a list of various agricultural crop residues in Karnataka as estimated for the year 1979-80. From this, we can see that about 54 billion thermal units of energy can be generated (which is more than twice our annual energy consumption); but only 20 billion units will be available for energy use - the remaining having other competing uses.

Wind energy potential has been estimated by Prof. R. Narasimha as about 40 billion units assuming an efficiency of 10% and available land area for installation of wind mills to be 0.4% of the unforested area. Similarly estimates of biogas energy have been computed to be 12.290 billion units. In addition to major hydroelectric projects, estimates of energy potential in canals for micro and mini plants has been estimated by K.P.C. A maximum power estimate is around

840 MW giving an equivalent energy of about 3.2 billion units. Microhydel potential on streams has not been surveyed so far. The Centre for Ecological Sciences is conducting a survey on this. Details on some of the identified streams as well as canals are given in Table 12. Similarly major hydroelectric potentials are identified in Table 13.

Solar energy can also be directly used by installation of solar water heaters (for heating bath water and for pre-heating water for boilers), solar cookers, solar driers, solar kilns and solar furnaces at end use points and by conversion of solar energy into electrical energy either by direct photovoltaic conversion process or by solar thermal route.