DER Basics http://www.eren.doe.gov/der/
resources (DER) refers to a variety of small, modular power-generating
technologies that can be combined with energy management and storage systems and
used to improve the operation of the electricity delivery system, whether or not
those technologies are connected to an electricity grid.
Implementing DER can be as
simple as installing a small electricity generator to provide backup power at an
electricity consumer's site. Or it can be a more complex system, highly
integrated with the electricity grid and consisting of electricity generation,
energy storage, and power management systems.
DER systems range in size
and capacity from a few kilowatts up to 50 MW. They comprise a portfolio of
technologies, both supply-side and demand-side, that can be located at or near
the location where the energy is used.
DER devices provide
opportunities for greater local control of electricity delivery and consumption.
They also enable more efficient utilization of waste heat in combined heat and
applications — boosting efficiency and lowering emissions. CHP systems provide
electricity, hot water, heat for industrial processes, space heating and
cooling, refrigeration, and humidity control to improve indoor air quality and
DER technologies are
playing an increasingly important role in the nation's energy portfolio. They
can be used to meet baseload power, peaking power, backup power, remote power,
power quality, as well as cooling and heating needs.
Customers usually own the
small-scale, on-site power generators, or they may be owned and operated by a
third party. If the distributed generator doesn't provide 100% of the customer's
energy needs at all times, it can be used in conjunction with a distributed
energy storage device or a connection to the local grid for backup power.
resources support and strengthen the central-station model of electricity
generation, transmission, and distribution. The diagram below shows how the grid
looks after the addition of distributed resources to the power grid. While the
central generating plant continues to provide most of the power to the grid, the
distributed resources meet the peak demands of local distribution feeder lines
or major customers. Computerized control systems, typically operating over
telephone lines, make it possible to operate the distributed generators as
dispatchable resources, generating electricity as needed.
In grid-connected applications, DER involves using small electricity generators throughout the distribution grid (at points indicated by arrows) to augment the electricity supplied by a large, central-station power plant. This is often referred to as "distributed power" (DP) or "distributed generation" (DG). Energy storage devices and load reduction measures are sometimes also used in combination with generators. "Distributed energy" is the collective term for all of these approaches to reducing demands on the power grid.
From Mainframes to Networks
The growing popularity of
DER is analogous to the historical evolution of computer systems. Whereas we
once relied solely on mainframe computers with outlying workstations that had no
processing power of their own, we now rely primarily on a small number of
powerful servers networked with a larger number of desktop personal computers,
all of which help to meet the information processing demands of the end users.
And just as the smaller
size and lower cost of computers has enabled individuals to buy and run their
own computing power, so the same trend in generating technologies is enabling
individual business and residential consumers to purchase and run their own
electrical power systems.
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Financing & Partnering
This part of the DER Web
site is still in development. When completed, it will provide information on the
& Local Information
This part of the DER Web
site is still in development. When completed, it will consolidate geographically
related information from other parts of the DER Web site, including information
The Office of Distributed
Energy Resources (DER), created in October 2000, had its origins in an earlier
DER Taskforce. Formed in March 2000, the Taskforce combined DER-related programs
of the Office of Energy Efficiency and Renewable Energy (EERE) into one office
to enhance the effectiveness of research, development, demonstration, education,
and implementation activities.
The DER Office has a
vision — that by 2020, the United States will have a flexible, secure,
efficient, and reliable energy infrastructure by optimizing the use of
distributed energy resources. At the heart of this vision is the goal of meeting
20% of the nation's generating capacity additions with DER by the year 2010.
Relationship to National
Energy Policy (NEP)
The Distributed Energy
Resources Program directly supports the Administration's Reliable,
Affordable, and Environmentally Sound Energy For America's Future: Report of the
National Energy Policy (NEP) Development Group in the areas of Transmission, Combined Heat and
Power, and Alternative Energy. The program supports regional efforts as
recognized in Chapter Two: "The NEPD Group recommends the President
recognize unique regional energy concerns by working with the National Governor
associations to determine how to better serve the needs of diverse areas of the
country". In the area of Transmission, the program is supporting a National
Grid Study as recommended in Chapter Seven: "Direct the Secretary of
Energy, by December 31, 2001, to examine the benefits of establishing a national
grid, identifying transmission bottlenecks, and identify measures to remove
transmission bottlenecks". Under Combined Heat and Power (CHP), the Program
is supporting EPA in the elimination of barriers to installing CHP and
developing advanced integrated energy systems that provide power, heating,
cooling and improves indoor air quality as discussed in Chapter Six. Distributed
Energy Resources is referred to as Alternative Energy in Chapter Six, and the
Program is responding to the recommendation "that the Secretary of Energy
develop the next-generation technology — including hydrogen and fusion".
Under this recommendation, the Program is developing advanced microturbines,
reciprocating engines and fuel cells with a vision towards the integrated energy
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