Chevron and BP's venture capital funds just announced investments in one Canada-based geothermal company. : Canada-based geothermal company Eavor Technologies on Tuesday announced a $40 million funding round that included participation from BP Ventures and Chevron Technology Ventures as big oil companies increase investments in renewable energy. Geothermal power is renewable energy produced from underground heat. The U.S. Department of Energy calls geothermal a "vital clean energy resource," noting that it emits little to zero greenhouse gases. While adoption rates differ from country to country, on the whole geothermal remains a nascent energy source.