POWER May 2021 - 27

GEOTHERMAL ENERGY
Commercial, Industrial, and
Residential Applications
Geothermal has been used as part of
district energy systems; for example, it
heats much of the downtown business
district of Boise, Idaho. Darcy Solutions,
a Minnesota-based company, has developed
a geothermal system to heat and
cool commercial and residential buildings.
Brian Larson, Darcy's CEO, told
POWER his company has a philosophy
of " putting groundwater to work, " using
the thermal properties of groundwater
to facilitate heating and cooling. " Darcy
Solutions addresses the two biggest
challenges for geothermal ground
source heating and cooling: cost and
footprint, " said Larson. " Our patentpending
approach harnesses the thermal
advantages of water and consistent
temperature of shallow Earth to make
sustainable heating and cooling practical
and financially attractive for commercial
and residential buildings. "
Said Larson: " Our technology dramatically
improves system efficiency,
lowering energy use and reducing site
footprint requirements up to 95%. By
offering project paybacks under 10 years
and the greatest reduction in carbon
emissions, Darcy makes its environmentally
friendly heating and cooling
solution viable for new construction and
retrofit projects. "
Larson said a current project in Minneapolis,
Minnesota,
is
focused
on
" cooling
only. They've got a different
system for their heating. [We give them]
a 78% reduction in the cost for cooling, "
which he said provides a return on investment
" in five to seven years instead
of 10 to 15. That's part of the appeal, and
of course more and more people are interested
in reducing their carbon footprint,
and you're getting away from any
source of emissions. "
Deep Drilling
The Iceland Deep Drilling Project (IDDP)
is ongoing, more than two decades after
a consortium of three Icelandic energy
companies founded the project.
It began with the objective of drilling a
4- to 5-kilometer (2.5- to 3.1-mile) deep
hole into a high-temperature hydrothermal
system in order to reach 400C to
600C supercritical hydrous fluid at a rifted
plate margin on a mid-ocean ridge.
The feasibility report was completed in
2003, leading to a decision to drill the
first IDDP candidate well at Reykjanes.
That well was abandoned three years
later due to a blockage, but other well
May 2021 | POWER
sites have been identified and drilled.
Baker Hughes, a longtime leading
global oilfield services company, has
developed and deployed a directional
drilling system for high-temperature
applications, including for the IDDP-2
well (Figure 2). IDDP officials have said
results from that well could be presented
at this year's World Geothermal
Congress event, which began online
sessions in late March and will culminate
with a scheduled in-person event
in Reykjavik, Iceland, in October.
Taylor Mattie, geothermal innovations
leader for Baker Hughes, told POWER
the company " has applicable technology
for every active geothermal region
globally, and geothermal experts familiar
with the unique challenges of operating
in high-pressure, high-temperature
applications. We have developed geothermal-specific
technology and services
designed to handle the extreme
reservoir conditions of geothermal systems
to lower costs, maximize production
efficiency, and reduce risk. "
Baker Hughes operates " several testing
facilities around the world where
we simulate actual geothermal conditions,
mimic well fluid compositions,
and can deploy our advanced design
and additive manufacturing capabilities
to create and build 3D-printed prototypes
and end-use parts optimized for
form, fit, and function, " said Mattie. " An
example is our research and technology
center in Celle, Germany, where
we can emulate the conditions of geothermal
wells to test everything from
high-temperature materials and components
to full drilling assemblies and
submersible pumps. "
Mattie told POWER that " as an energy
technology company, Baker Hughes
is working on multiple fronts to make
geothermal more cost-effective and
efficient. As the geothermal industry
pushes the operational envelope, we
are focused on technology advances
that allow for deeper and faster drilling
in increasingly hotter and harsher well
conditions. Technologies that reduce
risk and minimize upfront project costs
are particularly important to geothermal
operations. "
Key Areas for Innovation
Walsh said he sees geothermal innovation
focused on three key areas:
■ Drilling Technology. To reduce the cost
of drilling, making geothermal less expensive
to harness.
www.powermag.com
2. The drilling rig Thor is being used at the
IDDP-2 well, part of the Iceland Deep Drilling
Project. The rig, operated by Iceland Drilling,
has been used in other geothermal projects
in the Reykjanes peninsula. Courtesy: Iceland
Drilling
■ Heat Exchanger Technology. To increase
the efficiency
or heat required,
which potentially reduces the
amount of drilling required for some
applications.
■ Process. To add revenue opportunities
beyond " heat " to a geothermal plan,
such as lithium production from directuse
geothermal.
Walsh said his group is " looking at
geothermal technology startups that are
applicable to Latin America. There are
other cleantech venture capital firms
that are also looking at geothermal and
placing some bets to help them succeed.
Should the resurgence of geothermal
materialize, then I predict that
we will see more ESG-related capital
come into the sector to scale the new
versions of geothermal into real powerproducing
projects. "
Larson said another benefit of a geothermal
heating or cooling system for a
commercial building is the opportunities
it opens for other energy sources to provide
power. " The complementary nature
of the technology with something
like solar, " said Larson. " This building in
St. Paul [with a Darcy system] had 36
rooftop units on it, related to its legacy
HVAC system. It now has four. In terms
of the real estate it opened up for rooftop
solar, now it's wide open. There's
also an aesthetic benefit. The architects
like not having a bunch of equipment sitting
outside or on the roof. "
Larson noted the trend of microgrids
to power entire communities. " Creating
these microgrids, now a building will
have its own solar array on the rooftop,
and then have our [geothermal] system,
and it can function as a microgrid and
support that neighborhood. " ■
-Darrell Proctor is POWER's
associate editor.
27
http://www.powermag.com
POWER May 2021

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