Reducing our energy use has the dual benefit of lowering costs and GHG emissions, and it is a central focus of both our EHS & SR strategy and our Lean approach to managing our business. We generate and purchase energy primarily for power, processing, heating and cooling. In 2020, energy consumption from Hess operated assets was approximately 28 million gigajoules, 2% lower than in 2019. Seventy-two percent of Hess’ energy use was directly generated from our operations, primarily at the Tioga Gas Plant and at our production facilities in North Dakota, the North Malay Basin, Denmark and the Gulf of Mexico. The remaining 28% was indirect energy (i.e., energy used by utilities to provide electricity) purchased for our North Dakota production operations and the Tioga Gas Plant.
In 2020, our U.S. operations accounted for all of our purchased electricity of approximately 840,000 megawatt hours (MWh), or a 20% increase from last year, primarily attributable to increased production in North Dakota and the conversion of new compressor stations from natural gas to electric compression. Based on U.S. electricity generation profiles, we estimate that approximately 27% of this electricity was generated from renewable sources, primarily wind power. We also support renewable energy through the purchase of renewable energy certificates (RECs) so that, in total, 100% of the net electricity used in our operations is attributable to renewable sources. To offset our purchased electricity that came from nonrenewable sources, we purchased 634,000 Green-e Energy certified RECs from Multiple Mix Products, including wind, solar, biomass, landfill, geothermal or hydroelectric, equivalent to 634,000 MWh or about 76% of the electricity purchased for our operated exploration and production assets in 2020. In total, including the RECs, 100% of our indirect energy use came from renewable sources.