This article discusses how Portugal generated electricity in March 2018 – 100% by renewable sources.
Portugal’s renewable electricity production exceeded monthly consumption for what is likely the first time, in March, according to the nation’s transmission system operator, REN. The average renewable generation for the month exceeded 103% of consumption, beating out the last record (99.2%), set in 2014.
It almost certainly won’t be the last time. The country is predicting that renewables will satisfy its mainland electricity needs by 2040, ultimately eliminating the electricity sector’s greenhouse gas emissions. Although most of last month’s electricity came from water and wind (link in Portuguese), the country relied on some fossil fuel and imported electricity. Water- and wind-generated power can be rather unpredictable, so even as total renewable generation exceeded Portugal’s electricity consumption for the month (as well as some exports), Portugal needed those sources to even out supply.