Institutional applications are seen as potential growth markets for CHP in the U.S. The U.S. Department of Energy and developers have both invested in technology improvements for these applications, focusing on increasing efficiency, incorporating new thermally activated technologies to provide both heating and cooling services, and integrating components and controls into cost effective packages. Approximately 60% of existing commercial CHP capacity is used in colleges, hospitals, government facilities such as prisons, campuses and military bases, and in downtown district energy systems.
Waste Water Treatment Plants
CHP has been successfully implemented in many different sectors, including WWTFs. CHP at WWTFs can take several forms, including anaerobic digester gas-fueled CHP; non-biogas fueled CHP (e.g., natural gas); heat recovery from a sludge incinerator that can drive an organic rankine cycle system; and a combined heat and mechanical power system (e.g., an engine-driven pump or blower with heat recovery).
Solar is also a long-term, safe, and low cost electricity alternative. Solar can provide electricity during day-light hours to off-set electric consumption and reduce utility costs. Some states and utilities permit excess generation to be credit toward times of day when the solar system isn’t generating electricity. Typically, flat land or rooftop space is needed, and needs to be as close as possible to the tie-in point.
Healthcare + Hospitals
Hospitals are ideal candidates for combined heat and power (CHP) systems. Because hospitals function 365 days a year, 24/7, they require round-the-clock energy. Combined systems enable hospitals to reduce energy costs, improve environmental performance, and increase energy reliability.
The number of hospitals using CHP systems has grown steadily in recent years. Hospitals using cogeneration are taking advantage of favorable utility rate structures and hedging against rising electricity prices. Because cogeneration uses waste heat to produce thermal energy for heating and cooling, hospitals that use CHP systems are more energy efficient. Reduced emissions lessen their impact on the environment as well.
Hospitals must perform critical, lifesaving functions even when a widespread disaster interrupts their supply of natural gas and electricity from the utility grid. CHP systems can be designed to maintain critical life-support systems, operate independently of the grid during emergencies, and be capable of black start (the ability to come online without relying on external energy sources). Because they are already up and running, CHP systems can offer a more seamless, reliable power alternative than traditional emergency generators.
Colleges + Universities
Many colleges and universities supply energy to dozens or even hundreds of buildings from central power and heating plants. This is an exceptional opportunity for CHP. The central heating plant usually supplies medium- and high-pressure steam for space heating, laundry and sometimes food service and laboratory operations. In some cases, the university is also affiliated with healthcare facilities, which have additional requirements for steam and hot water. The college/university often also supplies chilled water for chillers and other purposes.
In most cases, the demand for electric power, heat and chilled water is year-round, 24 hours a day. Thus, the heat captured from power generation can be fully utilized. A supplementary steam system may sometimes used for peak winter heating periods.
Due to the surplus of available rooftop structures in combination with the heating and cooling loads previously described, university and college campuses are often great applications for hybrid systems incorporating solar and combined heat and power. Energy storage is added in order to reduce demand charges and provide voltage regulation support.