POWER March 2023 - 18

COMBINED HEAT & POWER
A Complex Landscape for
the Future of Combined
Heat and Power
Few power-generating resources present the combination of workhouse abilities
that combined heat and power (CHP) does. But, powered predominantly by fossil
fuels, will CHP find its unique footing within the energy transition?
Sonal Patel
C
onsidering all its hefty attributes,
combined heat and power (CHP)
should thrive as the world races to
transition to an energy system characterized
by more efficiency and lower emissions.
The energy resource, sometimes
referred to as " cogeneration, " is a longproven
multitasker, generating on-site
power and useful thermal energy using
different technologies and various fuels.
Its production of two forms of energy
is highly efficient-at least when evaluated
against comparable separate heat
and power sources. Some systems can
achieve total system efficiencies of more
than 80%.
CHP can vary in size, satisfying distributed
or captive energy requirements for
a variety of end-users, providing heat and
power to hospitals, schools, university
campuses, hotels, nursing homes, office
buildings, and apartment complexes, as
well as for larger district energy systems,
microgrids, factories and other industry,
and even utilities. And perhaps uniquely
for a distributed resource, CHP is resilient
and can provide crucial reliability:
Capable of producing heat and power
24 hours a day, it can be designed to
operate independently from the grid or
implemented with black-start capability
to provide a reliable, cost-effective alternative
to installing backup generators.
Owing to these attributes, the technology
has enjoyed an expansion worldwide,
surging 30% between 2009 and 2019.
According to global industry group COGEN
World Coalition (CWC), the annual
output of CHP systems in 2019 amounted
to 11,200 TWh of heat and 4,159 TWh
of electricity, representing just over 15%
of total electricity generation. But that
share " has wobbled around, " varying by
region (see sidebar, " How CHP Is Evolving
Around the World " ), and overall, it
has diminished amid increasing demand,
18
noted Simon Minett, managing director
for Challoch Energy and a CHP expert.
Future growth of CHP at the same
rate over the next decade, meanwhile,
How CHP Is Evolving Around the World
According to the COGEN World Coalition
(CWC), which represents major
players in combined heat and power
(CHP), the world's most developed
markets for CHP technologies are centered
in Asia-Pacific, Europe, and the
Americas, and to a smaller extent, in
Africa and Australia. Each region has
its own characteristics in terms of CHP
capacity, market sector focus, and fuel
use (Figure 1), Simon Minett, managing
director of research and analysis
consultancy firm Challoch Energy, said
in November.
While Europe currently produces
700 TWh of CHP power-mostly
from steam turbines and combined
cycles gas turbines-its share of CHP
within the total electricity mix of 20%
has fallen, owing in part to the energy
price crisis. " There's not much
growth in that market. It's a mature
market, and Europe is focusing on a
lot of renewables and electrification,
so we can see some pressure on
cogeneration there. It has a decent
role to play, but it's an active policy
debate, " Minett said.
Europe's CHP plants, led by Germany,
are mostly powered by natural gas,
followed by renewable sources like
biofuels and biomass. However, coal
still makes up a large share of Eastern
Europe's CHP production.
North America's CHP market produces
about 330 TWh, representing about
6.8% of the total electricity mix. This
share has also fallen, even though the
market has mostly " remained flat over
the last decade, " Minett said. Natural
gas is CHP's dominant fuel in both the
U.S. and especially Canada, though
fuel mixes vary by region. Central and
www.powermag.com
1. The COGEN World Coalition estimated
that in 2019, more than half (59.39%) of
combined heat and power (CHP) systems
worldwide relied on coal and coal products,
and nearly a third (32.28%) relied on natural
gas. Less than 1% of the world's CHP
plants were powered by peat, oil shale and
sands, nuclear, geothermal, and renewables
like solar and wind. Source: COGEN
World Coalition
South American CHP markets, which
are much smaller, producing 87 TWh,
rely 70% on biofuels, including biomass,
biogas, and waste. Brazil makes
up to 90% of the region's total CHP capacity,
he noted.
The world's largest CHP market by
far is in the Asia-Pacific region, producing
nearly 3,000 TWh-a substantial
portion of CHP's global total of 4,000
TWh. " It's seen steady growth in terms
of heat output, " but 68% of that market
is dominated by China, which produces
" almost all " its CHP energy from coal,
mainly for district heating, said Minett.
In total, the regional market relies on
coal for 75% of its CHP production and
25% from natural gas.
POWER | March 2023
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POWER March 2023

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