ENERGY TIP: USE THE POWER MANAGEMENT SETTINGS ON OFFICE COMPUTERS TO SAVE $10-50 PER COMPUTER EVERY YEAR.
Are you looking for new solutions to squeeze efficiency for
GSA’s Green Proving Ground (GPG)
program allows the agency to test emerging technologies at federal buildings to
overcome barriers to adoption. These
trial sites shield commercial properties
from having to take on the risk of new
solutions and yield evidence-based data
that will accelerate a product’s energy
Two of the latest evaluations look at
technologies that productively harness
the sun’s power.
Photovoltaic-Thermal (PV-T) Hybrid
Solar Systems: In order to convert solar
radiation into electricity, standard photovoltaic systems need plentiful sunlight
but shed excess heat in warmer climates.
Photovoltaic-thermal (PV-T) hybrid solar
systems address this problem by using a
solar-thermal collector to capture that
Advances for Solar Hot Water and Window Films
THIS SOLAR-THERMAL COLLECTOR captures
excess heat shed by the PV panels and uses it
for domestic water heating.
While choosing renewable
energy for your facility is a great
option, you may be tempted to
save on capital costs and lease a system
instead. New research, however, shows
that the levelized cost of energy for
buying a PV system could be up to 30%
lower than the option of leasing solar
The NREL report To Own or Lease
Solar: Understanding Commercial Retailers Decisions to Use Alternative Financing
Models compares the strategies used by
IKEA and Staples, two retail companies
that have a large PV presence in the U.S.
IKEA typically elects to own its solar
equipment, while Staples uses the lease
or PPA (power purchase agreement)
As long as the PV lifetime reaches 30
years, self-financing is optimal in the
long term. For an organization like IKEA,
owning a system that involves fewer
parties in the financial transaction and
requires less expensive electric meters
Should You Own or Lease Solar?
has advantages over PPAs.
Leasing panels, however, works to
Staples’ advantage as it can readily deploy
solar and has more positive cash flow
available. Unlike purchasing a PV system,
PPAs are off-balance sheet transactions,
which might suit companies unwilling or
unable to add the liability of a PV loan.
Leasing might also reduce exposure to
risks related to PV underperformance,
unanticipated O&M costs, and delays in
receiving incentives and grid-intercon-
Deciding whether to own or lease
comes down to your company’s ability to
balance these rewards and risks.
“The attractiveness of the financing
methods varies due to different assumptions for capital costs, perceptions of
PV investment risk, and sensitivities to
the risk of using a particular financing
method,” note the authors. B
wasted heat in a way that is useful for
heating domestic water.
GPG commissioned NREL to assess the
performance of the nation’s first large-
scale PV-T system installed at the Thomas
P. O’Neill, Jr. Federal Building in Boston,
MA in 2011. The evaluation found numer-
ous lessons in system design, as well as
Modeling found that PV-T should target buildings in locations with high utility
costs and electric hot water backup, such
Applied Solar-Control Retrofit Films:
Heat gain through windows accounts for
30% of cooling energy demand in U.S.
commercial buildings. Applied solar-control films can reduce that demand
by reflecting or absorbing solar energy
before it reaches interior spaces.
GPG commissioned Lawrence Berkeley
National Laboratories to assess the performance of a liquid-applied, spectrally
selective absorbing film at the Goodfellow
Federal Center in St. Louis, MO in 2012.
Using collected results, LBNL modeled
the energy performance of both spectrally
selective absorbing and reflective films in
a range of climates and found potential
combined heating and cooling savings of
up to 29% with reflective films.
OWNING OR LEASING a PV array largely comes down to your company’s tolerance for risk.
Investing in a system is better in the long term, but a PPA can also free up cash flow and