July 24, 2023

CHP. RNG. H₂. CH₄. CO₂. Speaking about new energy solutions can sometimes seem like a swirl of alphabet soup. We hope our "Emerging Energies Explained" articles will help you explore energy technologies already shaping our future.

In this first edition, discover how CHP captures energy that traditional generators do not utilize (and thus lose) to provide greater efficiency and lower costs.

The U.S. Environmental Protection Agency (EPA)^* estimates that nearly two-thirds of the energy used for electricity production, transmission and delivery is lost before it reaches a customer’s doorstep. While emerging technologies may enhance efficient electricity production, other technologies can be applied to further improve efficiency and thus maximize the amount of energy that can be productively used.

Combined heat and power (CHP), or cogeneration, refers to solutions that generate onsite electricity and produce thermal energy. Thermal energy is a captured byproduct of electric generation which, at conventional power plants, is generally a lost or “wasted” energy resource that is discharged to the atmosphere. Capturing this thermal energy reduces the fuel needed for conventional heating systems that would otherwise rely on electricity, natural gas or oil.

While conventional electricity generation occurs at central power plants, CHP systems are often located onsite or near facilities with high, 24-hour energy needs: manufacturing plants, hospitals, universities and other locations. They might also appear as large-area, supplemental solutions such as microgrids, which are networks of distributed energy resources that can be connected to larger utility grids. Micro-CHP have recently entered the market and can be productively used in other settings, including multi-family housing and hotels.

CHP systems may include equipment such as reciprocating engines, microturbines, fuel cells, steam turbines and gas turbines. CHP systems are highly efficient in recapturing produced heat that goes unused during power generation, maximizing the energy output to generate additional onsite electricity, heating or cooling.

The EPA offers the following striking example of the efficiency gains provided by a typical CHP system. To produce 80 units of electricity and useful thermal energy, a conventional system uses 155 units of energy inputs for an overall efficiency of 52%. However, the CHP system needs only 100 units of energy inputs to produce the same 80 units of electricity and useful thermal energy—a total system efficiency of 80%.

Flexible and efficient, CHP can run on various fuel sources: traditional natural gas and biogas, propane, diesel, methanol and hydrogen. In case you were wondering, biogas describes the sometimes-pungent byproducts that result when organic matter decomposes—think backyard mulch piles, landfills and wastewater treatment plants. These gaseous byproducts can be captured and converted into useful fuel.

CHP in Action: Say Cheese

Are you wondering if you might already be benefitting from CHP technology? The answer could be as close as the cream in your coffee or the milk in your cereal.

HP Hood LLC, the operator of several well-known dairy brands in the United States, relied on Washington Gas to implement a 15-megawatt CHP system and energy management system to support cost reduction at their facility in Winchester, Virginia. Installed within a single day, HP Hood LLC reported that this solution has reduced energy intensity, the amount of fuel per unit of energy used, by 24% and resulted in a 30% reduction in carbon dioxide emissions.

"Using natural gas to fuel our combined heat and power system was essential for this project,” explains Dennis McNutt, Sustainability and Energy Manager. “Natural gas is cost competitive, dependable and an efficient fuel source. Washington Gas was a trusted partner in developing our CHP system [and] enhancing our existing natural gas service necessary for CHP while remaining operational.”

Why CHP Matters to You

Through high system efficiency, CHP technology can reduce emissions when compared to conventional systems that don’t recover heat. Recapturing rogue or underutilized heat produced during electricity generation means that less fuel can produce the same amount of energy. Lowering fuel needs per unit of energy produced also makes CHP a helpful factor in managing energy costs because the systems (located on-site) often use natural gas.

Perhaps the most significant benefit of CHP is its contribution to overall energy resiliency. The U.S. Department of Energy’s Office of Electricity describes the U.S. electric grid as a multi-operator ecosystem spanning over 9,200 electric generating units and at least 600,000 miles of transmission lines. Increasing demands on the aging power grid place it under periods of high stress that can potentially result in more frequent downtimes. CHP technology can help ensure uninterrupted operation for critical facilities even during large-scale power outages.

To learn more about CHP click here. 

Thank you for reading. Stay tuned for future articles that will provide an in-depth look at other emerging energies, including renewable natural gas (RNG).

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