Steam-gas plants are the ones generating electricity twice: first with a gas turbine and then with a steam turbine. This solution allows for more efficient conversion of heat energy into electricity, as well as saving water and greenhouse gas emissions. As the International Panel on Climate Change (IPCC) estimates, greenhouse gas emissions from gas turbine power generation are 490 kilograms per MW*h of generation, compared to 410 kilograms per MW*h for combined cycle plants. In the US., gas turbines are used mainly to cover seasonal peaks in demand. For example, in 2023, the average utilization of gas turbines was 12.9%, while for combined cycle power plants it reached 59.7% (the average utilization indirectly indicates duration of operation of power generators during the year).
Gas-fired power plants play a key role in balancing the US energy system in the context of coal phase-out and slowing down the pace of nuclear reactor commissioning. Thus, within 2021-2023, In the United States, 20.7 GW of gas-fired thermal power plant (TPP) capacity was commissioned, while the total capacity of coal-fired TPPs decreased by 36.9 GW, and nuclear power plants (NPPs) – by 0.8 GW (including due to decommissioning of the third power unit of the Indian Point NPP in April 2021). The share of gas in the US power generation mix increases from 40.2% in 2020 to 42.5% in 2023, while the share of coal decreased from 19.1% to 15.9% and the share of NPPs decreased from 19.5% to 18.2%.
Wind and solar generators have been the leaders in recent years in terms of generating capacity additions in the US. The total installed capacity of these power plants in the US between 2020-2023 increased by 73.3 GW (excluding a residential sector). At the end of last year, the share of wind and solar installations in the national power generation mix reached 15.5%. The RES boom is associated, among other things, with the spread of technological solutions facilitating the generation of clean energy. These include heterojunction solar panels being resistant to high temperatures and solar trackers allowing the angle of the panels to vary depending on the time of the day. According to S&P Global Platts, the introduction of solar trackers in the United States in 2023 reached 36.5 GW (in terms of the capacity of the panels installed), and in the world as a whole – 94 GW.