On-Site Energy Installations Increase Nationwide
July 28, 2004
As power reliability becomes more and more important, the United States is turning to on-site energy systems more than ever before. Sales were up by 20 percent overall in 2003, and most purchases were fairly evenly distributed among the government, communications, and emergency response/healthcare sectors.
On-site systems generate power or heat for nearby use, and they can be connected to a building as well as to the electric grid. Energy generation thus appears to be following a "distributed" pathway similar to the one charted in the telecommunications industry by cellular technology.
Today, both established and new energy technologies are used for on-site electricity generation. Some of the major technologies include:
- advanced batteries and fuels cells;
- combined heat and power (CHP) systems;
- heat engines and smaller natural gas, propane, and diesel generators;
- micro-hydropower and small (less than 50-kilowatt) wind systems;
- modular biomass; and
- solar technologies (photovoltaics and solar thermal systems).
On-site systems can also provide thermal energy for space heating and cooling, water heating, and industrial process heat and preheating. In addition to CHP systems, these technologies include the following:
- concentrated solar systems,
- ground-source heat pumps,
- solar thermal water heaters, and
- transpired solar "walls" to preheat air for buildings.
There are several reasons for this increase in the use of on-site energy systems; one is cost. On-site systems save money in some applications, especially when the alternative involves installing new utility wires and transformers. In addition, both demand charges and peak power rates can often be offset by producing energy on site for use during times of peak demand.
Another reason for the increase in the use of on-site energy systems is regulatory. On-site renewable energy technologies help users meet green power requirements and renewable portfolio standards. They also provide ways to comply with procurement and environmental regulations established by federal, state, and local governments.
Some users want to ensure backup power with something other than diesel generator sets, not only because it might be hard to obtain diesel fuel, but also for environmental reasons. If the fuel must be transported a great distance, this can also be costly as well as risky. On-site solar, wind, or fuel cell generators are some of the technologies that can alleviate this problem.
Another reason for on-site generation is to increase power quality. In some applications, surges and transients on the electric grid can impede the performance of electrical equipment or even harm sensitive controls, computers, or communication systems. Dedicating sensitive systems to on-site generation, or adding distributed energy to the grid as backup, can be a good solution.
Finally, one increasingly important reason is to ensure reliability. Distributed, on-site energy systems are maturing to the point that it's easier than ever to use them to ensure reliable power, particularly for strategically-important functions such as national emergencies and homeland security.
In addition to installations described in earlier issues of FEMP Focus, there are numerous examples of effective, reliable on-site energy systems meeting the need for reliable power in critical applications. One is the 1-kilowatt ReliOn fuel cell unit installed at McCord Air Force Base in Tacoma, Washington. The unit runs on unpressurized, industrial-grade hydrogen to back up communications for a Federal Aviation Administration radar system. It has been running flawlessly, according to Mr. Howard Kernodle of the Federal Aviation Administration.
The FAA supported the San Francisco International Airport's installation of building-integrated photovoltaic (BIPV) roofing panels to produce 20-kilowatts of electricity. This system supplies a portion of the power needed at one of the airport's support buildings.
In New York City, Montefiore Medical Center was the only hospital that continued to operate with full power during the first night of the 2003 regional blackout, in large part because a Solar Turbines Taurus 60 generator set drives its CHP system. Montefiore operates its own 14-megawatt cogeneration plant, and all its critical loads are backed up by emergency power generators.
The United States Postal Service implemented an innovative combination of on-site renewable generation and demand control measures to reduce electrical demand and energy use at the Marina Mail Processing Center in Los Angeles. Their partnership with PowerLight and Viron Energy Services led to the installation of a 127 kWp solar electric system atop the Marina del Rey facility, and a state-wide energy information system for 27 USPS sites. This energy system allows USPS to automatically shed more than 4 megawatts of electrical load. The solar system covers more than 15,00 square feet of the facility's roof and can generate enough electricity during the day to power more than 120 homes. The combination of solar electric generation and demand control measures gives USPS maximum flexibility to respond to high electric demand charges and utility grid emergencies.
Utilities are also using on-site alternatives. Solargenix LLC recently installed a 30-ton solar absorption cooling system to cool the Austin Energy Sand Hill Power Plant control center in Texas. This power plant provides energy to many federal and state government facilities in and around the state capitol, so it's important to keep it up and running.
On-site systems are becoming more attractive options as cleaner, quieter, and even more reliable systems enter the market. They also come with warranties and are becoming more standardized.
To help cover costs, several innovative leasing and financing packages are available for federal, state, and local government groups. In the coming years, look for even better choices, system configurations, and financing methods that will help facility managers obtain the on-site energy systems that are best for their sites.