We support renewable energy and
partner with our customers to ensure safe and reliable interconnection of
renewable energy into the electric grid.
Combined Heat and Power (CHP), or cogeneration, provides
both an on-site source of electric power and useful energy from a single fuel
source. These systems capture thermal energy that would normally be lost in
traditional power generation and use it to serve on-site heating and cooling
A form of distributed generation, CHP systems typically
are located at or near the energy-consuming facility. Recovering the heat
normally lost in power generation or transmission processes to provide on-site
heating or cooling results in increased energy-efficiency and reduced
greenhouse gas emissions.
CHP systems are configured with either a topping or
bottoming cycle. In a typical topping cycle system, fuel is combusted in a
prime mover -- such as a gas turbine or reciprocating engine -- to generate
electricity. Most energy lost from the prime mover’s hot exhaust and cooling
systems is recovered and provides valuable and usable heated air or
water. The heated air is generally used for industrial processes such as
petroleum refining or food processing, and the hot water is typically used for
laundry, dishwashing, space heating, cooling, and dehumidification. In a
bottoming cycle system, also referred to as “waste heat recovery,” fuel is
combusted to provide thermal input to a furnace or other industrial process.
Any heat rejected from this process is then used for electricity production.
Maryland, the energy generated by CHP systems must be consumed by the facility
and no excess generation can be fed back onto the grid. Thus, no DC-to-AC
inverter is required and Pepco does not install a net-capable meter.
Based on the standard Maryland Level 2, 3, & 4 Interconnection
Application and Agreement, the Maryland Combined Heat and
Power Interconnection Application and Agreement facilitates these special circumstances
and provides CHP-specific directions for completing the application form
and review process.
CHP systems in Maryland may be eligible for rebates under
the EmPOWER Maryland Energy Savings Program for Commercial & Industrial
customers. This requires a separate application. For more information, see the
EmPOWER Maryland CHP Program website.