24 District Energy | Spring/Summer 2019 © 2019 International District Energy Association. ALL RIGHTS RESERVED.
different impacts by region in the U.S.
according to the National Climate Assessment issued in 2014.
According to that 2014 assessment,
average annual temperatures in all U.S.
regions will continue to rise. In the
Northeast, Midwest, Southwest and
Northwest, this will contribute to the
increased frequency, intensity and duration of heat waves and may intensify
drought conditions in the summer and
fall months, due to higher evapotranspiration rates and changes in seasonal
snowmelt patterns. (Evapotranspiration
is how water is transferred to the atmosphere; it is the sum of evaporation from
land and water plus transpiration from
Seasonal precipitation amounts are
predicted to increase in certain areas,
but regions such as the Southwest could
have much less winter and spring precipitation, impacting water supply. Both the
temperature and precipitation patterns
are expected to lead to serious drought
conditions throughout the region. In the
Northwest and Hawaii, heavy precipitation events are projected to increase in
intensity and frequency.
The intensity of severe storms, such
as winter storms and hurricanes, is
expected to strengthen in all regions,
except the Southwest. Sea levels are
projected to rise throughout the coastal
regions, causing higher and more damaging storm surges and high tides. In the
Northeast, this is likely to happen at a
higher rate than the global average due
to subsidence in the region.
DISRUPTING ENERGY DISTRIBUTION
Climate change and extreme weather
have cascading effects on infrastructure,
economies and public health – all of
which depend on energy. In regions with
more extreme high temperatures, electric-
ity demand is expected to surge due to
the increased use of and need for air con-
ditioning. In some locations, peak demand
may also occur at a time of lower water
availability or drought conditions, while
water is necessary for energy production
from traditional sources such as fossil fuel
or nuclear power plants. To help offset the
stress on the electric utility infrastructure,
distributed energy producers could pro-
vide the additional capacity necessary to
meet the energy demands during these
peak usage periods.
CLIMATE CHANGE AND EXTREME WEATHER
HAVE CASCADING EFFECTS ON INFRASTRUCTURE, ECONOMIES AND PUBLIC HEALTH –
ALL OF WHICH DEPEND ON ENERGY.
High winds are another consequence
of extreme storm events such as hurricanes or blizzards. With an increase in
intensity and frequency of such events in
many regions, high winds may disrupt
power transmission and distribution lines,
which can take time to repair, especially
during a widespread outage.
Increases in precipitation patterns
or sea level rise (with associated storm
surges) may also cause flooding of power
plants or energy sources, creating an outage. If electricity demand cannot be met
or power distributed, brownouts and
blackouts occur, putting public health at
risk and disrupting the economy.
To provide resiliency against these
consequences of climate change and
extreme weather, some campuses and
facilities are looking into pooling their
distributed generation facilities together
to form a microgrid. The microgrid allows
the community to offset energy costs during normal operations by providing power
to the utility grid during peaking events or
continuously via cogeneration and renewable energy-producing facilities. In the
event of a widespread power outage, the
microgrid can island itself from the power
grid and utilize the community’s distributed generation facilities connected to
the microgrid to provide power to their
PREPARING INFRASTRUCTURE FOR
The first step in ensuring that a given
energy facility or infrastructure network
is well-prepared for threats of climate
change is to conduct a review, or audit, of
that asset. This identifies specific problem
areas over the useful life of a facility. The
level of risk is determined by the severity
of the climate change impact in the particular location and the facility conditions.
It is important to understand how
critical that particular infrastructure is.
This may be assessed by asking basic
questions about the asset function: What
purpose does it serve? What are the consequences if it fails? What climate impact
might cause it to fail, and how likely is
that to occur in this location? Next, consider the useful life of the asset: If it is
nearing retirement, it likely does not
make practical sense to upgrade to a
more resilient design.
As an alternative or supplement to
grid-derived utilities, district energy systems play a valuable and critical role
in meeting end-user/customer energy
needs and requirements. Distributed
energy models are an increasingly important part of our energy future. Systems
can be designed to operate in conjunction with the grid and island, should an
issue occur. They can also incorporate
additional redundancies, and equipment
can be designed to operate within specified climatic events or conditions, which
might prove otherwise difficult for larger
utility-scale systems. District energy system design factors to consider based
on potential climate change impacts are
listed in Table 1.
MANHATTAN HOSPITAL PLANS FOR
The potential for district systems
to offer resilience is often noted only
after a damaging event has occurred.
When owners and operators rebuild after
a disaster, they frequently choose to
design district energy systems to withstand potential future extreme weather.
A case in point was the design of a new
boiler plant to serve a public hospital in
In 2012, Hurricane Sandy had
severely impacted areas along the East
Coast, including zones surrounding metropolitan New York City. One such area
was Roosevelt Island in Manhattan.
According to the Roosevelt Island Operating Corp., the island succumbed to a
3- to 5-ft storm surge that caused a
500-year flood event, with power outages, steam tunnel flooding and damage
to the island’s seawall.
Following the event, a public hospital located within the affected area was