For 75 days and counting, Costa Rica hasn’t produced any electricity through the use of fossil fuels such as coal or natural gas. Instead, the country has been running on renewable energy. Hydropower, or water power, has been the primary energy source, with wind and solar power also in use. Costa Rica has experienced heavy rains that have kept its hydroplants churning. Several factors make Costa Rica an ideal testbed for renewable energy. Its small area, population and lack of manufacturing make its energy needs lower than that of, say, the United States. And Costa Rica was forced to find new energy sources after being cut off from oil by Venezuela’s financial crisis. Nonetheless, this milestone represents a significant leap forward for renewable energy. Some people have doubted that renewable energy was reliable. But today it’s cheaper than ever. Other countries are making strides, too. Denmark gets 40 percent of its energy from wind. In Iceland, 85 percent of all energy comes from hydropower and geothermal technology. Costa Rica has a goal of carbon-neutrality by 2021. That means the country would remove as much carbon dioxide from the atmosphere as it puts in. It may already be well ahead of the curve.