Since 2015, $1 billion has been invested in renewable energy projects in Ukraine, Serhiy Savchuk, State Department of Energy Efficiency, told Kyiv’s International Sustainable Energy Forum on Tuesday. One fast growing segment – often overlooked, he said – is rooftop solar. So far, $100 million has been invested in 4,660 of these household and factory projects. He called on the Rada to approve a government bill to replace the ‘green tariff’ in 2020 with auctions for electricity produced by solar farms larger than 10 MW and by wind farms larger than 20 MW.