Advances in small-scale generation technology coupled with growing environmental concerns, a changing energy market, evolving public policy and customer need for reliable and economical electric power supplies will provide a new growth market for electrical contractors. Economical on-site electric power generation that was once practical only for large institutional facilities, process plants and heavy industrial installations is rapidly becoming economically viable for any size building. Commercial and residential buildings, along with smaller institutional, manufacturing and light industrial facilities can all potentially benefit from integrating alternative power sources with traditional utility service.

Distributed generation

Locating small-scale electric generating units at or nearby the load served is referred to as distributed generation (DG). DG is not a new concept; Edison championed it more than a century ago.

But the ability to locate generating stations in remote areas and move large blocks of power into urban areas via high-voltage transmission lines resulted in the central plant concept, which allows economies of scale and has dominated utility planning ever since. However, environmental concerns and legislation restrict the size, location and economics of large power plants as well as the ability to build new transmission lines to provide needed power to urban load centers and interconnections to increase the reliability of the power supply. In order to ensure an adequate, economical and reliable power supply to their facility, owners are increasingly considering the use of on-site generation to protect their business, reduce operating costs and avoid losses resulting from brownouts and blackouts.

Alternative power sources

Most electrical contractors have been involved in the DG market for years and haven’t realized it. An emergency generator or an uninterruptible power supply (UPS) are examples of DG. Even though these systems are very reliable and important to your customer’s business, neither offers an economically or operationally viable alternative to the utility power supply. However, they do provide you with a good foundation for dealing with the emerging small-scale generation technologies.

Alternative power sources such as microturbines, fuels cells and photovoltaics have operating characteristics that will make them very attractive to your customer. All three are compact, environmentally friendly, quiet and very reliable. As a result, these alternative sources can easily be integrated into the customer’s facility and, with the proper relaying, be operated in parallel with the utility supply. In addition, the cost of these alternative power sources makes them an economically viable alternative to your customer’s existing utility power supply.

Choices, choices

Microturbines generate electricity with only one moving part, which makes them very reliable. The high-frequency AC generated by the microturbine is transformed into usable 60Hz power using a solid-state power converter.

Microturbines can operate on a variety of readily available fuels including natural gas and have efficiencies between 25 and 30 percent when generating electricity alone. However, capturing waste exhaust heat and using it to displace energy that would otherwise have to be purchased can increase the efficiency of the overall system considerably.

Fuel cells have been around for years and found their first real application in the space program. Continuing research and development is increasing fuel-cell efficiency and lowering first costs, which has resulted in fuel cells being experimented with by utilities, automobile manufacturers and others. Fuel cells generate DC power through a chemical reaction between oxygen and either hydrogen or a hydrocarbon fuel. Water and carbon dioxide are typically the only byproducts of the reaction, so fuel cells are very environmentally friendly.

Photovoltaic (PV) cells are semiconductors that convert sunlight to DC power. Like fuel cells, photovoltaics have been around for a long time and are just now beginning to become economically viable for the building industry. In addition to generating electricity, when integrated into a commercial building’s curtain wall, photovoltaics can reduce the building’s cooling load and increase the efficiency of the building as a whole.

Your customers need help evaluating their power supply needs, identifying alternative ways of meeting those needs, and selecting the power supply option that best meets those needs. When the selected power supply option includes on-site generation using alternative power sources, you can assist your customers in the selection, installation and maintenance of the needed alternative power source. This market will grow as better technology results in higher efficiency and lower costs. EC

GLAVINICH is an associate professor in the Department of Civil, Environmental and Architectural Engineering at The University of Kansas and is a frequent instructor for NECA’s Management Education Institute. He can be reached at 785.864.3435 or tglavinich@ku.edu