The Cowessess First Nation High Wind and Storage Project comprises
a single 800-k W utility-scale wind turbine operating in combination
with a 400-k W ESS. Credit: Saft.
It is useful to consider the situation at a typical remote site.
Using standard power electronics a PV installation might contribute up to 20 to 30 percent of the power that would be generated by
the diesel genset during daytime hours. If we add dedicated software then the PV penetration could increase to 50 percent. For
example, a 1-MW microgrid might accept up to 300 k W, but this
could be raised up to 500 k W of PV in the best case. Since the PV
output is limited to sunlight hours, highly variable and does not
necessarily meet the required consumption profles, its contribution to the overall energy mix is naturally limited.
However, when an ESS is introduced, it is possible to maximize the contribution of renewables, increasing the penetration
and harvesting all of the PV power. Fuel savings of 50 to 75 percent then become a realistic possibility.
Three recent examples show how energy storage is now
making an important contribution for some very remote
Making the Most of the Arctic Circle’s Midnight Sun
The remote community of Colville Lake, 50 km north of the Arctic Circle, is home to about 160 people. It is only accessible by
air or by ice roads during a six-week window in February and
March. For some years, its electrical power requirements —
150 k W peak load and 30 k W base load — has been met by diesel generators. However, NTPC (Northwest Territories Power
Corporation) the power utility that serves 43,000 people spread
across 33 communities in northern Canada is now transforming
the region’s power supply to cheaper, cleaner and more reliable
In 2015 a microgrid was deployed at Colville Lake that combines solar panels with new diesel generators ( 2 x 100 k W and 1
x 150 k W) and an ESS. The 136-k W solar panels generate around
112 MWh a year. The solar output exceeds the community’s average electricity load. Therefore, the primary goal was to reduce
the runtime of the diesel generators, especially in the summer
when the sunlight is available for virtually 24 hours a day.
A key requirement for the ESS was to withstand the harsh
variations in local temperature from -50 ˚C to + 35 ˚C. NTPC also