Costa Rica reached a major milestone in renewable energy: 75 straight days of electricity produced without fossil fuels. The country's power supply has been running without the burning of harmful fossil fuels, according to a March 16 release from the state-run Costa Rican Electricity Institute (ICE). Thanks to heavy rainfall, the country has been able to rely on its four hydroelectric plants for nearly all of its electricity -- with an added boost from geothermal, biomass, solar and wind power.

Beyond the positive environmental impact of not burning fossil fuels, which are linked to pollution and climate change, the use of renewable energy also prompted Costa Rica to lower its energy rates for consumers by 12 percent. And ICE predicts rates will continue to fall during the second quarter. "A total of 1.5 million households and businesses in the Central American country will receive discounts of between 7 and 15 percent in their power bills next quarter, depending on the company they use," Reuters reported last week.

Costa Rica has been able to reach this landmark moment in green energy due in part to its small size (a population of 4.9 million people), its lack of a large energy-consuming manufacturing industry, along with its substantial rainfall, and topographical features like volcanoes, which provide natural energy. (Costa Rica is also military-less, so it does not spend on defense.) In addition, Costa Rica is firmly committed to using renewable energy. In 2009 Costa Rica pledged to be carbon neutral by 2021, and in a 2014 report the World Wide Fund for Nature (WWF) ranked Costa Rica number one in Latin America for clean and renewable energy.

Costa Rica's reliance on rainfall and hydroelectric power does put it at risk. Drought or other changes to the amount of rainfall the country receives could negatively impact hydro power. Costa Rica is looking at other sources of green energy beyond hydroelectric. Last year the country approved a $958 million geothermal project, which is being funded by Japan and the European Investment Bank.