Heating and Cooling Energy - Hydrogen and Fuel Cells: Advances in Transportation and Power - page 240

The distribution system of an ICES is the same as that of a conven-
tional district heating system. Each ICES has warm water supply and cool
water return mains. Systems that supply both heating and cooling at the
same time may have independent distribution systems for hot and cold
water. Distributed systems using groundwater as a heat source may have
only a distribution water supply line. Cascaded and distributed ICESs
have separate heating distribution systems for each building.
Depending on the winter climate, the heat source can be a lake, res-
ervoir, underground storage tank, aquifer (underground river or lake), so-
lar-heated water, sewage or waste water, geothermal energy or waste heat
from industrial or commercial facilities.
In an ICES that serves both small and large buildings, the surplus
internal heat from the large buildings can be used to provide source heat
to smaller ones. An ICES in areas with moderate winter temperatures may
use air as a heat source. Systems that use lakes or reservoirs rely on the
natural collection of heat by these water sources throughout the year.
The operation of an ICES depends upon the nature of the heat source
and if the system is centralized, distributed or cascaded.
Solar energy can be used to warm heat pump source water. In this
system solar collectors are mounted on a large, insulated water tank where
the warmed water is stored. Most of the heat is collected in the summer for
use during the winter. In the winter, the hot water can be used directly for
space heating until it cools to about 85 to 90°F. The remaining heat can be
removed and concentrated by a centralized heat pump.
An ICES using a large fabricated tank of water can operate as a com-
munity-scale ACES. The water in the tank is slightly higher than 32°F.
During the winter a centralized heat pump removes heat from the tank,
causing the formation of ice. This ice is then used for summertime air con-
ditioning or for winter cooling of large buildings.
Sewage and wastewater heat sources are usually not much colder
than the buildings from which they come. A cascaded ICES can remove
heat from waste water and transfer it to the distribution system which
then acts as a secondary heat source for heat pumps in individual build-
ings. Waste heat is often lost into the environment by industrial facilities
in the form of hot water. This hot water can be used directly by the heat
pumps in a centralized ICES.
ICES have several advantages over conventional district heating
systems or individual building heating systems. An ICES will often serve
business, commercial and residential districts. Since the peak heating and