POWER October 2020 - 37

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to heat liquid salt to as much as 560C.
Virtual Heat and Power. A number
of technology providers today also already
offer a variety of " smart storage
heating " solutions, which allow electrical
heating to respond to network conditions
by storing energy during plentiful
supply. " These smart storage heaters
can be remotely controlled by aggregators
to both [optimize] heating costs for
consumers and provide grid-balancing
services to the national
grid, " IRENA
1. Types of heating systems that use electricity. Courtesy: International Renewable Energy
Agency, 2018
to utilize surplus power to address heating
needs. European countries provide
myriad cases. Swedish utility Vattenfall,
for example, in November 2018 began operating
an electric boiler in Hamburg that
uses excess wind power to generate heat
during peak-load periods. In September
2019, the company also connected a 120MW
P2H facility to the district heating
grid at its Reuter West power plant in Berlin.
The company said the three electrode
boilers at the plant, each with a capacity
of 22,000 liters, heat water to 130C using
electricity, and have allowed it to retire a
coal unit at the site.
Meanwhile, as part of the Heat Smart
Orkney project funded by the Scottish
government, a planned wind P2H
project will provide households with
energy-efficient heating devices that will
draw excess power generated from the
community-owned wind turbine. China,
which has grappled with solar and wind
surpluses, also has interesting projects.
The Inner Mongolia Autonomous Region,
which had installed about 22.3 GW
of wind power at the end of 2014, will
this year start operating a project to use
surpluses in electric boilers with a total
50 MWth capacity to provide heat for a
district heating system.
Introducing Flexibility for Load Shifting.
A handful of projects have also been
implemented to provide demand-side
flexibility using heat pumps. The EcoGrid
EU project, led by a consortium of energy
and technology companies from Nordic
countries, for example, in June 2019 ended
a three-year demonstration of an innovative
smart grid system that integrated
28,000 customers on Bornholm Island,
Denmark. The project showed time-ofOctober
2020 | POWER
use tariffs and real-time price signals are
useful in activating flexible consumption,
and that P2H may offer a significant potential
for peak load shaving.
Swedish firm EctoGrid, meanwhile,
has developed a technology to connect
the thermal flows of multiple buildings
that use heat pumps and cooling machines
to supply or withdraw heat energy
from the grid. The system uses a
cloud-based management system and
promises to reduce energy demand for
heating systems by 78%.
Providing Large-Scale Energy Storage.
The RHC notes that if coupled with
thermal energy storage, PTG's capability
to correct mismatches between heat supply
and demand could be enhanced. That
could allow for optimal usage of a combination
of different renewable sources over
a day, or even a year, it says. It suggests
several " state-of-the-art " technologies
could fulfill that potential, including sensible
heat storage (SHS) technologies, latent
heat storage (LHS) technologies, thermochemical
heat storage (TCS), and underground
thermal energy storage (UTES).
One interesting example is Drakes
Landing, a technical demonstration that
uses solar thermal energy and seasonal
UTES for a district heating scheme. The
project supplies a residential community
of 52 houses in Alberta, Canada, which
capture solar energy during the summer
and store it underground using borehole
thermal storage. During winter, heat is
extracted from the stores and distributed
to each home. German power company
RWE, meanwhile, is exploring building a
heat storage power plant at a coal plant
in the Rhenish lignite mining region,
where surplus wind power will be used
www.powermag.com
suggests. In the UK, for example, energy
provider OVO Energy and energy solutions
provider VCharge have developed a
solution to aggregate smart heating systems
used in nearly 1.5 million homes in
the country. The aggregation represents
a combined peak capacity of 12 GW. In
Switzerland, meanwhile, Tiko solutions
has connected more than 10,000 electric
heat pumps and hot water boilers. Those
components are continuously monitored,
and their electricity consumption
is controlled to provide flexibility services
to the national grid.
Distributed Power-to-Heat. In regions
that have no net energy metering or net
billing, self-production and consumption
of heat produced by surplus power, from
rooftop solar installations for example,
is starting to gain traction, says IRENA.
" Further, during hours of peak solar generation,
the distribution system operator
may not be able to absorb all generation
from distributed sources. In such cases,
heat pumps help maximise self-consumption
by converting the locally generated
electricity to heat or space cooling, "
it adds. One related example comes
from U.S.-based Kraft Foods, which
uses heat pumps at its plant in Iowa to
upgrade 2.1 MW of waste heat from its
refrigeration system to heat water. SolarChill,
a partnership between European
technical organizations and a number of
international development organizations,
is meanwhile working on a project to install
solar energy-powered refrigerators
for medical uses in regions with unreliable
power supplies.
IRENA suggests that more examples
like these will be introduced as renewable
power costs fall further, and the efficiencies
of P2H improve. However, it
also advocates for a " significant push "
from policymakers for these technologies
by urging them to consider limiting
the use of fossil fuel boilers, and to introduce
requirements for new buildings
to include renewable energy sources. ■
-Sonal Patel is a POWER senior
associate editor.
37

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POWER October 2020

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