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6
Technology and Product Development
The basic technology for district heating and cooling is well
understood in the United States. In addition, the cases of Trenton,
St. Paul, and others cited throughout this report indicate a
potentially large market in both the United States and Europe for U.S.
manufacturers of district heating and cooling equipment. U.S.
manufacturers, however, suffer from several disadvantages.
Several U.S. manufacturers and trade associations claim that
European countries subsidize exports of district heating products,
particularly steel pipes. Thus, U.S. manufacturers say that Europeans
are able to submit bids on U.S. district heating and cooling projects
below the costs of their American counterparts. In addition, in
competing for European markets, U.S. manufacturers are confronted by
European companies with well-established technologies and products.
The committee has been unable to substantiate this charge, although
the Office of the U.S. Trade Representative recently found that
European countries were sending more than double the agreed-upon
amount (5.9 percent of U.S. consumption) of steel pipe into the United
States.
Nevertheless, U.S. manufacturers have several opportunities for
market penetration. District cooling, a technology developed in the
United States, exists only in a few cities in Europe (see Chapter 2~.
Innovative marketing could create inroads there. So, too, could
innovative products that either increase efficiency or reduce the
costs of systems. Research to improve the technology is needed to
take advantage of these opportunities.
RE SEARCH DIRECTIONS
There has been little research or market and product development for
district heating and cooling. The design and development of system
technology have advanced only marginally, with the exception of those
for district cooling. Product development has been very limited.
81
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Despite these facts, district heating and cooling is not inhibited by
technology or a lack of engineering skills. The case studies in
Chapter 3 and in Appendix A are replete with examples of innovative
applications.
Despite these and other innovative applications, there are some new
products that would help make the technology more efficient and U.S.
manufacturers more competitive. The Department of Energy (DOE) has
already proposed research or support for programs in 34 areas related
to district heating and cooling (U.S. Department of Energy,
unpublished information, 1984~. The committee has identified those
it believes to be the most important. These topics include meters,
nonmetallic piping, more effective insulation, low-temperature
systems, and combined district heating and cooling systems.
Because fuel flexibility and low-cost fuels are so important for
district heating and cooling, research on fuel alternatives and
combustion techniques should also be pursued. Environmental
restrictions on the use of certain low-cost fuels can be overcome only
by more effective combustion or stack cleaning devices. Combustion
appears to offer the best and least-cost opportunity.
Using municipal solid wastes as a fuel source offers the
opportunity to deal with two major urban problems simultaneously. As
discussed earlier, the disposal of municipal solid waste has become
increasingly more costly and problematic. At the same time, providing
constant, efficient, and inexpensive heating and cooling is an
essential urban development tool. Research is needed on the
technology for burning municipal solid wastes to cogenerate
electricity and thermal energy for district heating and cooling
systems.
Steam and hot water systems generally operate at temperatures well
above 150°F (65°C), but lower temperatures may prove economical
and effective. Geothermal heat and waste heat from power or
industrial sources represent significant low-temperature energy
resources of less than 150°F (65°C). The effective use of these
resources needs further research.
District heating and cooling systems are capital intensive,
particularly the distribution systems. Manufacturing and installing
pipes can represent about 70 percent of a project's capital costs (see
Figure 4-4~. The financial feasibility of a project is, of course,
markedly affected by these costs. Better standards and design methods
for pipes can reduce their cost significantly. Research can improve
pipe materials, insulation, installation methods, and fastening and
burial techniques. The use of low-temperature distribution systems
could lead to pipe insulation and installation changes that would
further reduce costs, as could the use of heat pumps or supplemental
firing, either at the plant or by the user.
Most U.S. systems can be switched between heating and cooling. The
operator must assess the weather and direct the system from heating to
cooling or vice versa. Most modern commercial buildings located in
moderate temperature zones are approaching the year-round use of
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daytime cooling. Many buildings are designed with windows that do not
open to increase energy efficiency by reducing heating and cooling
loss. Such buildings, however, may need cooling on days when others
whose windows open do not, unless they are equipped with
air-conditioning systems with natural cooling capability to compensate
for high internal loads and solar gains.
More responsive systems are needed to meet this change in use and
the differential and simultaneous heating and cooling requirements of
large buildings. Currently, separate heating and cooling distribution
systems are expensive. Using existing building equipment to heat and
cool simultaneously is possible, but is often inefficient or costly or
requires premium fuels. Research should be conducted on the use of
" two supply-one return" systems sized for heating and cooling or on
pulse systems using alternate pulses of hot and cooled liquids.
Storage systems required for the pulse method are another useful area
for research.
Retrofitting existing steam systems in the United States should be
considered in research and market development. Many steam systems are
50 years old or older. While many are supplied by conveniently
located cogenerating power stations that burn coal, others depend on
oil-fired, heat-only boilers for thermal energy, especially power
plants located outside downtown areas. System obsolescence, fuel
costs, and rising operating costs have contributed to the decline and
abandonment of such older systems. These systems are a unique asset
for district heating and cooling in central business districts, but
only if they can be rehabilitated economically.
Existing steam systems together with hybrid district heating and
cooling systems can significantly enhance equipment compatibility,
point-source pollution control, system backup, and demand
flexibility. Long-term recovery costs can be reduced by using
intermediate exchangers that convert steam to hot water and use steam
for chilled water production in either a networked or retrofitted
system.
More accurate and less costly customer meters are also needed.
European studies suggest a difference in consumption of 10 to 25
percent between metered and unmetered users (IEA, 19831. Current
flowmeters (supplemented by a differential temperature measure)
reflect Btu use rather than just water flow. Ingenious users can
achieve high heat input with low water consumption. Meters currently
cost from $200 to $400. Some sources suggest $100 is the greatest
justifiable cost. There is great market potential in both the United
States and Europe for such an inexpensive meter.
RE SEARCH DI S SEMINATION
Policy appears to have led to improved applications rather than new
technology development. The transfer of technical, product, and
market information is largely limited now to the efforts of several
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industry associations. Until recently, little information was
distributed to potential clients--mayors, county executives, system
designers, large developers, or those in the financial community.
Technical information is restricted primarily to communications
sponsored by industry assoc rations . The newest of these associations
has public programs to further the understanding of district heating
and cooling, but until recently the association appears to have
devoted more energy to lobbying than to disseminating general
information and developing the means for technology transfer. The
allocation of resources is now becoming more balanced.
Information on basic research and on applications can circulate
among trade, professional, and client groups. Each of these groups
maintains its own communication networks, so using these networks is a
cost-effective way to communicate information about district heating
and cooling nationwide. One focus of such an effort might be the
total energy systems committee of the American Society of Heating,
Refrigeration, and Air Conditioning Engineers (ASHRAE).
The government can also help ensure that such knowledge is
disseminated broadly. Technological advance and expansion of the
district heating and cooling industry serves a number of national
objectives, from export of U.S. technology and business to meeting the
goals of the National Energy Policy Plan (NEPP) for the use of
low-cost, abundant fuels that result in using energy more efficiently.
DOE has developed economic models and analytical techniques for
district heating and cooling. They have been used to help evaluate
the prospects for district heating and cooling in the 28-city
assessment program jointly run by DOE and HUD. Broad distribution of
these analytical methods and models, together with programs for data
exchange, would help reduce the planning barriers to district heating
and cooling in the United States, especially when combined with
technical help provided to local governments and the private sector.
Professional associations can support such technology transfer.
1
Representative terms from entire chapter:
municipal solid
