Distributed Generation: Who Benefits?

Distributed Generation

In the first of three articles, experts at Oak Ridge National Laboratory examine the technical obstacles, deployment, and economic issues surrounding distributed generation.

The existing electric power delivery system is a critical part of this country's economic and societal infrastructure, and proposals to increase the role of distributed energy resources (DER) within this system are welcomed by few in the utility industry. Such resistance to change in our electrical power system is not new.

Utilities view DER as a potential threat because it tends to reduce utility revenues. More important, many utilities view DER as a source of safety and protection problems, especially as the amount of DER connected to the circuit grows. For example, an energized DER system can continue to feed short-circuit faults, such as a tree shorting a distribution circuit, and can therefore pose a safety problem for utility crews. In addition, DER can feed back into the distribution circuit, offsetting the circuit current feed during a fault and possibly fooling existing protection schemes. In spite of these issues, the potential societal benefits of widespread DER, especially cogeneration, which includes cooling applications, are beginning to be recognized. These include:

Improved generation efficiency due to local use of waste heat;

Reduced transmission and distribution losses;

Increased energy security;

Localized voltage and reactive power support; and