The CHP concept in decentralized systems is a valuable way to transform energy inputs into highly efficient and very reliable systems, to meet both heating/cooling and power needs with low GHG and air pollution emissions. Fuel combustion always provides heat first, which is then converted into power and other energy services.

A challenge for the cogeneration sector is to have thermal energy (MWth) clearly recognized, with some consensus on quantifying the energy equivalence of high and low grade energy products. High value electricity should be viewed as a by-product of the energy system, where Heat-Power H:P ratios ranging from 0.5:1 to 10:1 are important design criteria for proper thermal sizing and low GHGs.
Danish CHP
However many environmental studies for CHP focus on euros or $ per tonne of CO2 reduction only – we need an improved Business Case for these systems, recognizing and balancing multiple environmental and reliability benefits to better deal with perceived 5-10 year paybacks. This can be done in at least two basic ways;

• Policies and regulations around air pollution could be improved to encourage prevention and system efficiency, and recognize waste heat recovery in a similar fashion to renewable energy. Decentralized gas-fired CHP and district energy facilities, at 200-300 kgCO2/MWhr, emit about half the GHGs of large gas power plants, and only 30-40 percent of coal power plants. But air pollution emissions are also minimized at the same time (some by 95% less than coal) including NOx/SO2, fine particulates, air toxics such as mercury, ammonia, arsenic, as well as CFCs from cooling, and local water impacts. That is why gas-fired CHP can be built so close to thermal loads for high efficiency.

• Recent floods, ice storms, grid failures and hurricanes have left millions of people without power and heat or cooling, reminding us how our societies are dependent on reliable and clean energy. Valuing energy security and process reliability, as well as lower power transmission losses, power/voltage support, and energy price stability can be very cost-effectiveness. The resilience of ‘islanded’ and interconnected local CHP provides the second part of a strong business case for sustaining long term clean energy infrastructure.

So in terms of integration of clean energy system objectives, education and training has always been a common theme to understand and break down conflicting issues and barriers. Can we help to improve Value Propositions to include comprehensive economic benefits of energy reliability, including balanced environmental advantages for our investments in cities & industries?

Ottawa-based Manfred Klein is an independent consultant on environment and energy issues for industries and cities. He spent 33 years in the Canadian government, most recently as Coordinator, Energy & Environment at the Gas Turbine Labs of the National Research Council, after a long stint with Environment Canada, involved in balancing industrial and energy-related solutions to emissions of air pollution and greenhouse gases. Contact Manfred through LinkedIn or email: