Gaining ground across the globe - Kloben

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District heating system for 54 individual
homes: EnerWorks added collectors to the
solar powered subdivision in the town of
Okotoks in the province of Alberta.
Photo: EnerWorks
The collectors of an entire solar
powered subdivision shimmer in
blue violet as the sun rises in the
small town of Okotoks, Canada. The
Canadian company EnerWorks constructed
a solar district heating system
for 54 individual homes here towards the
end of 2007. The residents are provided
with heat energy from the 2,300 m 2 of solar
collectors installed in this system.
Some homeowners have even installed
small rooftop systems to meet their water
heating needs.
SUN & WIND ENERGY surveyed solar
thermal companies around the world regarding
their experiences with largescale
solar thermal systems. In the survey
we made a distinction between systems
that have 50 to 500 m 2 of solar col­
lectors and systems with over 500 m 2 of
collectors. The EnerWorks system is in
the smaller segment of solar district heating
systems. Of the 35 companies who
participated in the survey, only three
have implemented systems with more
than 500 m 2 of solar collectors. The two
other district heating networks were built
in Germany with the help of federal funding.
The Austrian company Tisun GmbH
supplied collectors for a solar powered
community in Munich, which also includes
a seasonal storage tank with a capacity
of 5,700 m 3 . In the third project,
solar collectors were supplied by the German
company Wagner & Co. and are now
used to provide solar heat to a school, a
sports hall and an indoor swimming pool
in the southern German community of
Eggenstein­Leopoldshafen. In contrast to
the two other systems, which involved
the construction of new buildings, this
solar heating system replaced the heating
systems found in old buildings from
the 1960s that were specifically renovated
for energy efficiency.
Solar thermal systems that have more
than 500 m 2 of collectors are relatively few
and far between. Only about half of the
companies surveyed have implemented
systems of that size, most of them between
10 and 50. Only three companies have
completed more than 100 projects: The
Chinese company Jiangsu Sunrain Solar
Energy Co., Ltd., indicated that it has implemented
around 9,000 of these projects
and therefore has the most experience with
large­scale systems. Following far behind
are the Turkish company Ezinç Metal A.S.
and the Indian company Emmvee Solar,
which have installed about 320 and 200 of
these systems, respectively.
Hotel projects dominate
When asked about what types of systems
they install, most of the companies (13)
mentioned hotel systems. An extremely
large system with more than 1,500 m 2 of
solar collectors was recently built in Cuba
by the Israeli company Chromagen Solar
Energy Solutions. The hotel La Estrella
has 1,308 beds distributed over 38 buildings.
“La Estrella is one of the most prestigious
hotels in the Caribbean region”,
says International Sales Manager Dorit
Cohen. A storage tank with a capacity of
more than 120,000 litres ensures that the
hotel guests have access to hot water
whenever they need it, especially in the
evening and morning hours.
Sun & Wind Energy 5/2009 67