In its first year of operation, the
ESIF achieved an EUI of 168.3
kBtu/ft2. Electricity consumption accounted for 138.6 kBtu/ft2,
and district heating and cooling
accounted for 28. 6 kBtu/ft2, while
natural gas consumption for process
heat accounted for 1. 1 kBtu/ft2. The
breakdown of energy consumption
in the ESIF during its first year of
operation is detailed in Figure 2.
Note that over 40% of district heat
on NREL’s campus comes from a
wood chip fueled boiler in NREL’s
Renewable Fuel Heat Plant. Also, the
natural gas consumption in the ESIF
only goes to support process loads in
the high bay laboratories, not to heat
As previously mentioned, waste
heat energy recovery is a key energy
reduction strategy in the ESIF.
Figure 1 shows the measured performance of the ESIF heating system
during its first year of operation
compared to the energy model predictions. The overall heating energy
consumption from the model to the
measured performance is very close.
However, the waste heat recovery performed below expectations
(output was 84% lower than modeled from October 2013 through
February 2014). With control
improvements made in March of
2014, which included heat recovery
during 40°F – 60°F outdoor air temperatures, performance improved.
The HPCDC successfully achieved
its goal of a PUE of 1.06 or less since
it became fully operational in April of
2014. This is dramatically lower than
the data center industry average PUE
of 1. 8. Figure 3 shows the monthly
average PUE from April through
December of 2014. The average PUE
during this time span was exactly 1.06.
Achieving such a low PUE without
the use of mechanical cooling is a
major success of the ESIF.
NREL’s ESIF is successfully pursuing its objective of meet the nation’s
crucial research objectives for integrating clean and sustainable energy
technologies into the grid, but it is
doing so in an energy-efficient and
The building was procured using
design-build process. As a result,
the building achieved an EUI of
168.3 kBtu/ft2 and a PUE of 1.06 in
its first year of operation while supporting energy-intensive, megawatt-scale research activities.•
ABOUT THE AUTHORS
Michael Sheppy, P.E., Associate Member
ASHRAE, is an energy engineer in the
NREL Sustainability Group in Golden, Colo.
Otto VanGeet, P.E., Member ASHRAE, is a
principal engineer in the NREL Integrated
Applications Center in Golden, Colo.
Shanti Pless, Member ASHRAE, is a
senior engineer in the NREL Buildings and
Thermal Systems Group in Golden, Colo.
Chris Gaul, P.E., is an energy engineer
in the NREL Sustainability Group in
FIGURE 3 HPCDC PUE
CONSUMPTION OF THE ESIF
Natural Gas (research only)
Daylighting in the new high bay laboratories
minimizes lighting loads through the use of
effective daylighting strategies.