SEPTEMBER 2015 \ BUILDING DIALOGUE \
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I
n any building project, there are a number of
choices to make. One of the most critical deci-
sions is how the building will source and use en-
ergy. With an increase in sustainability practices,
alternative energy systems are being given greater
consideration. Project economics, installation capa-
bilities and design are all factors in determining the
most optimal solution. One of the greatest assets a
building partner can bring is the ability to provide
a variety of options for renewable energy integration
and energy conservation.
Our firm designed the recently completed Gilpin
project, located in a dense residential neighborhood in
Denver, which presents a case study in selecting an inte-
grated, 100 percent renewable energy system. In this case,
geothermal and solar energy were selected to supply the full energy
source. Solar panels installed on the south-facing roof captures power
to charge internal heat pumps, artificial lighting and plug loads. As a
complementary system, geothermal energy most efficiently heats and
cools a large volume of space.
Comparing the cost and installation of solar photovoltaic and geo-
thermal, these two systems vary widely. In the case of Gilpin, 20 kWh
solar panels cost the client (after rebates and federal tax credits) ap-
proximately half of what the geothermal system cost, which requires
a trained installation team. Additional considerations associated with
geothermal installation include: drilling the wells, compression, mon-
itoring computer and in-floor distribution. There is a common mis-
conception that geothermal is not accessible because of the drilling rig
height requirements. However, there are many instances where cre-
ative problem solving and integrated energy planning can open great-
er possibilities to geothermal. On the Gilpin project, a central atrium
was planned ahead of time to increase passive solar energy and make
a connection to the outdoors from inside. Since the atrium required a
hole to be cut in the ceiling, this made it possible to use a compact rig
to drill the wells.
In order to ensure 100 percent renewable energy reliance, the gas
line for the Gilpin project was cut off at the source. Without gas avail-
able, there is a clear demonstration of the building’s energy efficiency.
Each month, the utility bill reveals a simple view of the energy gener-
ated and consumed. Taken together, these systems will generate more
energy than the building consumes. The result is an E-positive situa-
tion, which supplies surplus resources directly to the power grid for
cost savings and a monthly rebate.
While the renewable energy system is the core of the building’s effi-
ciency profile, energy conservation measures further enhance energy
Melissa
Belongea
Commu-
nications
Manager,
tres birds
workshop
