Global investment in renewable energy increased 17% last year to $270 billion, and installed capacity exceeded 100 gigawatts, according to a report from the United Nations Environment Programme. Renewable energy sources, including solar, wind, and geothermal, now account for 10% of kilowatt hours of electricity generated worldwide, says UNEP Executive Director Achim Steiner. “The underlying logic of our energy future is that fossil fuels will grow more expensive,” he says. As more renewables are built, they will become cheaper, he adds. About half of 2014 investment in renewables took place in developing or emerging economies. The growth of renewables is considered “disruptive” because energy infrastructure no longer needs to be centralized and local entities can more easily make generation and distribution decisions, Steiner says. Some 49% of total global energy investment in 2014 went to renewables, he continues, with China becoming a major player both in the construction of photovoltaic solar panels for export and in the rate of domestic installation.