What matters now, and in the future, is that we find an intelligent way of combining solar, wind, geothermal energy, hydropower and biomass. The mix will vary depending on the region. Iceland, for instance, covers a large portion of its energy needs with geothermal energy and even uses it to produce electricity. But for a country like Spain, solar energy could make up the bulk of the mix. Sunny regions like North Africa could also benefit from systems that use reflectors to concentrate sunlight onto a liquid, which then produces steam that drives a turbine and generates electricity. These kinds of solar thermal power plants can store the heat from the sun and then even use it to keep the plant working for a few hours at night. Different regions also have varying degrees of potential for using wind energy, and many windy places are far from fully exploiting the power available to them.
This question was answered by Dr Antonia Rötger, science writer in the communication department of the Helmholtz-Zentrum Berlin für Materialien und Energie.