What is Combined Heat and Power?
Combined Heat and Power (CHP), also known as Cogeneration (Cogen), is the most fuel efficient and environmentally friendly process of using a single fuel to simultaneously produce electricity and heat at the point of use.
Combined Heat and Power offers significant advantages to all sectors which have a simultaneous thermal and electrical load. When the CHP plant is correctly sized and installed, these advantages include:
- Substantial financial savings on utility costs
- Large carbon reduction
- Increased security of electrical supply
Natural gas is typically used as a fuel source during combustion and releases mechanical energy which converts into electricity via the alternator. Heat recovered from the engine exhaust heat exchanger provides hot water and space heating to local infrastructure.
Cogeneration uses natural gas at extremely high efficiencies in the order of 85% – 90% when compared to conventional means of taking electrical energy from the grid and thermal energy from on-site boilers, which may be up to 40% less efficient.
Industry sectors and CHP
Combined Heat and Power can benefit a wide range of industry sectors including; hospitals, universities, data centres, farming, agriculture, food and drink processing, sewage and wastewater treatment facilities, industrial and commercial building.
Facilities with 24hr/7day load profiles can maximise savings as longer run hours produce more savings and improve payback times. However, CHP is also suitable for applications with lower operational hours, typical 15 hours per day for 5-7 days a week.
When to consider Combined Heat and Power?
Existing buildings can benefit from the retrofit of cogeneration application. However and most importantly, consideration at the start of a project will maximise the full benefits and payback. For instance, CHP is best considered when:
- Designing a new building or energy centre
- Installing new boiler plant
- Replacing existing plant
- Managing electricity supply and security
- Reviewing standby electrical generation capacity
- Considering energy efficiency
Benefits of a gas engine CHP plant
Above all, Combined heat and power provides a number of substantial benefits, including:
- High electrical efficiency
- High thermal efficiency
- Low operation costs
- Simple electricity production
- Fast project set up and installation
- Flexible power opportunities
- Reduced energy bills – CHP typically saving a minimum of 10% on previous energy expenditure
- Typical return on your investment payback in 3-4 years
- Significant reductions in carbon emissions
- Greater site resilience – maintains security of power supply
- Future proofing sites from uncontrollable external energy factors – improves financial forecasting (energy spend) and business competitiveness
- Enhances corporate ethics
To summarise, combined heat and power enables the fastest return on investment as the energy generated from the process can displace grid purchased or supplied power along with on-site generated thermal energy, which includes the cost of fuel, boiler efficiencies, maintenance and replacement equipment.