Micro Combined Heat and Power (MCHP), for the most part, is an overlooked technology that can have significant impact on lowering costs and increasing efficiencies. Not to be confused with a Microturbine, MCHP is an extension of the cogeneration family. Applying the same principles of cogeneration, the smaller technology is best utilized in small commercial buildings, hotels or large homes as an efficient source of local power generation. MCHP can create on-site power for small buildings where CHP would not be a feasible solution.
The History of MCHP
The practical application of a MCHP unit is a question that had eluded scientists and inventors for almost 200 years. All variations of MCHP have been in existence since the 1800s with major breakthroughs changing the landscape of the industry fairly recently. The most common MCHP technologies are the Stirling Engine, Fuel Cell, and Reciprocating Engine. The original Stirling machine, for example, was developed in 1816 by Reverend Robert Stirling, and did not achieve significant technical or commercial success until the latter half of the 20th century.
Since inception, there have been numerous attempts to integrate MCHP a variety of applications, but the high cost of manufacturing and reliability issues prevented technologies like the Stirling Engine from gaining momentum. However, newer variants of MCHP units, specifically the FPSEs (Free Piston Stirling Engines), hold scalable benefits for growth.
How MCHP Works
Home heating systems remain the largest energy expense in U.S. households. The true benefits of MCHP are realized in the heat recovery from the exhaust. It captures heat that would otherwise be wasted by an internal combustion electrical generator. Using a heat exchanger to transfer the valuable waste heat from the internal combustion process can more than double the efficiency of electrical generation.
MCHP, like any technology that promises lower heating costs, is quickly gaining attention. During its process, MCHP burns natural gas to produce usable sources of heat and electricity. Using the recycled energy, MCHP can provide both stand-by electricity and heating at a lower cost than conventional residential or small commercial systems. Stand-by electricity is used to power designated circuits during an outage such as a refrigerator, lights or receptacles to charge phones and batteries.
The Benefits of MCHP
Beyond its advantages to small buildings or homeowners, local sources of micro combined heat and power are attractive at regional and national levels for its potential to help alleviate common inefficiencies associated with energy production and distribution by traditional power plants.
Typical power plants operate with efficiencies up to 30% for electrical generation, and vent the remaining energy up a chimney or smoke stack. MCHP units can capture that heat to bring the overall efficiency of the unit up to 90%, except on a smaller scale, by using a building to building approach.
Applying the MCHP unit effectively rests with the engineering. Having the ability to utilize the majority of the waste heat is crucial in determining if the unit will be cost effective for the end user. This waste heat is used to offset cooling, heating and hot water loads.
Finding the right balance between the cost to burn additional natural gas during the MCHP process and the cost to install the system is easier said than done. Doing your homework, and hiring a reputable firm to provide a single point of contact for the project, will provide you the best return on your MCHP investment.