Ultra high voltage (UHV) transmission - Power transmission lines with voltages of 1,000 kV or higher for alternating current or 800 kV or higher for direct current. It allows power to be transmitted at greater distances with lower losses than lower voltage transmission lines.

Ultra supercritical power generation (USPG) - Coal-fired power plants that operate at very high temperatures and use advanced steam cycles in order to achieve higher heat efficiencies and less emission than conventional coal power plants.

Underground coal gasification combined cycle (UCGCC) - Process by which coal is converted into a product gas underground and then combusted aboveground to generate electricity in combustion systems that capture and utilize waste heat.