-tidal energy and wave energy if a dam or barrage is built acoross a river mouth or inlet,electricity can be obtrained by the flow of water though turbines in the dam as the tide rises and falls. the movement of waves can also drive air turbines to make electricity although tidal and wave energy don't produce pollution they can cause other environmental problem.
wind energy moving air turns the blades of large windmills or generators to make electricity, or to pump water out of the ground.A high wind speed is needed to power wind generators effectively.while wind generators effectively. while wind generators don't produce any greenhouse gas emissions they may cause vibrations,noise and visual pollution
solar energy solar energy is light and heat energy from the sun. solar cells convert sunlight into electrical energy.Thermal collectors convert sunlight into heat energy. Solar technologies are used in watches,calculators,water pumps,space satellites,for heating water,and supplying clean electicity to the power grid.
renewable energy is a source of energy that can never be exhausted. we can obtrain renewable energy from the sun(solor energy),from the water(hydropower),from the wind(windmills),from hot dry rocks,magma, hot water springs (geothermal) and even from firewood,animal manure, crop residues and waste (Biomass)
if a dam or barrage is built acoross a river mouth or inlet,electricity can be obtrained by the flow of water though turbines in the dam as the tide rises and falls. the movement of waves can also drive air turbines to make electricity although tidal and wave energy don't produce pollution they can cause other environmental problem.