The US produces energy from oil, natural gas, coal, nuclear, hydro, wind, and solar. Each carries a different mix of cost, reliability, emissions, land use, and security implications, and the grid must balance supply and demand continuously.
Electricity must be generated at the moment it is consumed. Sources that produce on demand are described as dispatchable; wind and solar are not, which makes storage, transmission, and backup capacity central to any high-renewable system.
Nuclear power generates large amounts of carbon-free electricity continuously but faces high capital costs, long construction timelines, and unresolved long-term waste storage. It divides both environmental and business constituencies.
Permitting and transmission constraints affect all sources. Projects of every type, including renewables, pipelines, and transmission lines, face multi-year approval processes and local opposition.