POWER February 2016 - 21

COMBINED HEAT AND POWER
2. Pocket tri-gen. This containerized solution combines biogas generation, power, and
waste heat recovery into a single modular system. Courtesy: Entrade
4. Full steam ahead. This Cat CG26012
gas-fired generator set was installed at
Markham District Energy's Birchmount Energy
Centre in Markham, Ontario. It supplies
both power to the local grid and steam for the
district heating system. Courtesy: Caterpillar
Barrett said that while incentives are nice,
the economics of CHP in many cases are
such that incentive money is just a bonus.
" Financially, the project makes sense even
without it. "
Siemens' Dresser-Rand unit recently inbining
the turbine and heat exchanger in
a single self-contained module allows for
higher efficiency because less heat is lost
outside the unit, especially when it is situated
outdoors. Demaret said the units will
be able to achieve up to 92% efficiency.
For those looking for completely self-contained
CHP, German firm Entrade announced
in December that it would begin offering a
containerized system that can take raw biomass
and waste materials, turn them into syngas
in an onboard reformer, and use that to
generate power, heat, and cooling (Figure 2).
Though relatively small compared to other
options discussed in this article-the E3 system
generates up to 25 kW of electricity, 60
kW of thermal energy, and 30 kW of cooling-Entrade
says the system is completely
turnkey and can be installed and commissioned
in a single day.
An even more unusual CHP system is
being marketed by Israeli firm AORA Solar.
The Tulip is a modular hybrid concentrating
solar power-microturbine system
that is able to generate both electricity and
hot air. The Tulip's solar tower, instead
of generating steam, heats air to drive the
microturbine, which can also run on a variety
of fuels, including biogas (Figure 3).
Each module can generate up to 100 kW
of electricity and 170 kW of heat. Two Tulip
systems are currently in operation, one
in Israel and the other in Spain. Another is
under development in Ethiopia.
Engines Power Up
Existing technologies are also being reoriented
more and more toward CHP, in particular
reciprocating engines, which are seeing
February 2016 | POWER
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increased use as natural gas prices remain
low and diesel and fuel oil fall out of favor
for environmental reasons. Patrick Barrett,
an account manager for Caterpillar, who has
worked extensively on CHP deployments,
told POWER that his company is seeing
substantial growth for reciprocating engine-
based CHP in the commercial and institutional
fields because the abundance of shale
gas has resulted in lower costs and less pricing
volatility in the marketplace (Figure 4).
" The biggest driver for us is spark spread, "
he said, referring to the margin between gas
costs and electricity prices. " There is a pretty
favorable spark spread in the Northeast, and
while universities are always looking to be
green and efficient, they are also looking to
reduce their operating costs, which makes
CHP a win-win for them all around. We are
seeing a lot of university and hospital CHP
projects right now, and again, it is an economic
driver. "
3. Flower power. The Tulip is a hybrid
CHP system that combines concentrating solar
power with a microturbine to produce electricity
and heat around the clock. Courtesy:
AORA Solar
stalled a CHP-powered microgrid at a Northeastern
university, Wesleyan in Connecticut.
The campus lost power for nearly a week after
a nasty 2011 storm, and in the aftermath,
the university opted to upgrade its existing
cogeneration system to better prepare for future
outages. Powered by a 676-kW Guascor
SFGLD 360 gas engine, the new system can
supply about 90% of the campus's electrical
load in island mode if necessary. The project
was supported by a state program designed
to strength the grid through deployment of
advanced microgrids.
GE is also pushing its reciprocating engines
on the CHP market, having delivered
its eighth J920 Flextra gas engine to a 10MW
CHP plant (shown on the cover of this
issue) owned by CHP firm HanseWerk in
northern Germany in November. The plant
will provide grid support while supplying the
local district heating system.
Reliability and Efficiency
Cogeneration has come a long way from
the days of simple diesel engines and boilers.
Between the environmental benefits of
greater efficiency and the reliability provided
by CHP and advanced microgrid technology,
the sector's future appears bright.
" What we're concentrating on is reliability, "
Connecticut Gov. Dannel Malloy said at
the inauguration of the Wesleyan microgrid,
" the ability to recover, to keep our citizens
warm, to keep their phones charged, the ability
to have a hot meal. So if we can build this
system out around the entire state, we're going
to be able to respond better to those kinds
of emergencies. " ■
-Thomas W. Overton, JD is a POWER
associate editor.
21
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POWER February 2016

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