Renewable energy sources and have always been available on the planet, but until recently, humans have not had the technology necessary to harness them. Since solar and wind energy are limitless, it clearly makes sense to invest the necessary amounts of money to build one-time infrastructure capable of powering all human activity without depleting natural resources.
The condition that is a prerequisite already being fulfilled is that technology be developed to make alternative energy solutions <em>economically viable and profitable </em>enough to be able to compete with traditional non-renewable sources.
