Cogeneration is a process that simultaneously produces electricity and useful heat from a single fuel source, typically natural gas or diesel. Also called combined heat and power (CHP), cogeneration captures waste heat from electric generation for space heating, hot water, or industrial processes, achieving overall efficiencies of 60 to 80 percent.
Technical Details
Cogeneration systems use gas turbines, reciprocating engines, or fuel cells to generate electricity while recovering exhaust heat through heat exchangers. Typical installations range from 50 kilowatts to 50 megawatts. Systems maintain electrical efficiency of 25 to 45 percent while capturing 40 to 50 percent of input energy as thermal energy. Total facility efficiency can exceed 80 percent compared to 45 to 55 percent for separate electricity and heating sources.
Economic and Environmental Benefits
Cogeneration reduces energy costs and carbon emissions for commercial buildings, universities, hospitals, and industrial plants. Facilities experience 20 to 40 percent reductions in operating energy costs through heat recovery and improved overall efficiency. Systems qualify for federal investment tax credits and state renewable energy incentives. Proper system sizing, maintenance, and controls are essential for maximizing payback periods of 5 to 10 years.