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Frequently Asked Questions
What is district energy?
District
energy is not a new technology. It is not a technology we
have to wait to test or to research. It is here today, it
works today, and it holds great promise for our nation.
District
energy systems produce steam, hot water or chilled water at
a central plant and then pipe that energy out to buildings
in the district for space heating, domestic hot water heating
and air conditioning. Individual buildings don't need their
own boilers or furnaces, chillers or air conditioners. A district
energy system does that work for them.
Why district energy?
The
beauty of a district energy system is that since it serves
so many customers from one location, it can accomplish things
individual buildings usually cannot. For instance, district
energy systems can use a variety of conventional fuels such
as coal, oil and natural gas, whichever fuel is most competitive
at the time. And because of a district energy system’s
size, the district energy plant can also transition to use
renewable fuels such as biomass, geothermal, and combined
heat and power.
Buildings
connected to district energy systems also have lower capital
costs for their energy equipment because they don’t need
conventional boilers and chillers. They save valuable upfront
dollars they can invest elsewhere. Plus, they save building
space that can be used for other more valuable purposes.
Is district energy reliable?
Building
owners and managers can count on district energy systems since
energy professionals operate around-the-clock and have backup
systems readily available. Most district energy systems operate
at a reliability of "five nines" (99.999 percent).
To IDEA’s knowledge, there have been no rolling "heat-outs"
related to district energy systems!
Why haven’t I heard of district energy?
You
may not have heard of district energy, yet these systems operate
in nearly every major city in the United States, from Manhattan
to Seattle, and on most of our university campuses.
Many
people may not be familiar with district energy because it
quietly does its job – with rarely a crisis to report.
Plus, the pipes that deliver the steam, hot water and/or chilled
water are usually buried underneath the streets, so most people
don’t know they are there.
What is combined heat and power?
Combined
heat and power – also known as cogeneration – is
a way to increase the efficiency of power plants. Standard
power plants effectively use just 40 percent of the fuel they
burn to produce electricity. Sixty percent of the fuel used
in the electric production process ends up being rejected
or "wasted" up the smokestack.
Combined
heat and power uses this reject heat to heat buildings in
a surrounding area through a district energy system. Combined
heat and power is only possible when there is an area near
the plant that has a need for the heat – a downtown area,
a college campus or a industrial development.
If
one of our nation's energy challenges is lack of power, what
if we doubled the efficiency of as many power plants as possible
and got more energy for every gallon of oil or ton of coal
they burn? Combined heat and power can help us do just that
– and even help the environment in the process since
less heat and fewer emissions will be rejected into the atmosphere.
Why is district energy good for our cities?
District
cooling systems, in particular, displace peak electric power
demand with steam-based cooling, district cooling, and storage
using ice or chilled water. (Click
here to see a district cooling customer's electric
demand profile.) This benefits the local power grid by
reducing peak power demand and alleviating power congestion
due to power transmission limitations in cities. So district
energy not only helps heat and cool cities, it helps alleviate
the challenges posed by high electric consumption.
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