What are the advantages and disadvantages of other ‘green energy’ sources?

'Green' energy sources	Advantages	Disadvantages
Wind	•         Free •         Renewable •         No dangerous emissions •         Can be used in remote areas •         Can be used with other renewable energy sources	•         Needs a reliable source of wind •         Wind speed can change •         Noisy and visually unappealing •         Turbines expensive to maintain •         Energy storage devices (batteries) are necessary
Hydro-electric	•         Renewable •         One of the most efficient energy sources (kinetic energy of water converted to electrical energy) •         No dangerous emissions •         No fuel is needed •         Less expensive to run compared to other sources •         Energy can be gathered straight away (other generation stations take hours to start) •         Electricity can be stored for later use •         Hydroelectric plants only need a turbine and generator	•         Construction is expensive •         Site specific ( you can’t build wherever you want) •         Hydroelectric plants have a negative effect on environment (areas are flooded, habitats are lost, people lose their land)
Solar	•         Sunlight is free •         Renewable •         Climate suitable for solar energy •         No dangerous emissions •         Converts sunlight directly to electrical energy •         Can provide energy to remote areas	•         Solar cells can impact on the environment •         Energy must be stored in batteries •         Thermal solar systems are expensive •         Takes up a large area •         Dust, smoke and weather conditions affect performance of energy collectors
Tidal	•         No dangerous emissions •         Renewable •         Provides secondary benefits (bridges and roads built over tidal generators)	•         Facilities are expensive to construct •         Can raise tidal levels •         Changes the sedimentation and turbidity (how clear it is) of the water system •         Can flood shoreline (affects marine population)
Geothermal	•         renewable •         produces no greenhouse gases •         limited land necessary for mining structures •         limited impact on landscape	•         sites can run out of heat for significant periods of time •         difficult to safely dispose of hazardous minerals that are produced •         difficult to find and use suitable reserves of geothermal energy