Renewables are viable today
Technology designed to capture renewable energy resources is available and ready for use today, and is already supply power to millions of people around the world.
The technology will always be improving--in terms of both efficiency in capturing renewable resources, and in cost--so we can plan now to increase the amounts of energy we plan on sourcing from renewables. Prices will continue to come down due to technological advances and experience with technology, education programs, and installation increase.