Solar energy and other types of energy require large tracks of land for construction and servicing of sites. One known solution may be to use different types of renewable devices on the same land or sea site. As an example, an area in the dessert could utilize both solar, geothermal(along with solar thermal) and wind all within the same land area thus recurring the eco foot print. Another example is wind, tidal and wave energy all in the "ideal" location. We may need a Energy per Hectare measurement for renewables to determine if the the amount of energy produced is actually worth the footprint on the environment. Another solution could be to utilize existing hydo dam sites where the damage has already been done to build wind and solar plants that feed into an existing grid from the hydro electric dam. There are several sites around the world (ie northern Quebec and Labrador come to mind) where wind turbines could compliment the existing hydro dams without destroying new etiologies. i understand that governments would have to get involved and provide an incentive for private industry to build these sites either a direct subsidy or tax breaks for existing land or sea sites