University of Canterbury designing hybrid power model for Tongan island group
January 12, 2015
A University of Canterbury postgraduate electrical and computer engineering student is designing a hybrid renewable
energy power system for the Ha’apai Island group in Tonga following a devastating cyclone last year.
Cyclone Ian, which struck the Ha’apai group last January, destroyed up to 70 percent of homes and buildings and affected
more than 80 percent of the infrastructure including the previous power system supplied by two 186kilowatt diesel
generators.
Numerous small islands around the world do not have electricity supply or mainly depend on fossil fuels for energy. This
means of electricity supply is typically uneconomical due to the cost of shipping of fossil fuels and routine diesel
generator maintenance.
The price of fossil fuels has kept increasing which has already caused a world-wide crisis. Constructing renewable
energy in the Ha’apai group is desirable in terms of environmental and economic considerations.
The Ha’apai island group is a flat island group with no available geothermal and hydro energy source nearby, and there
is insufficient land area for biomass development. Solar and wind energy will be the best options.
University of Canterbury student Hantt Cao is carrying out computer modelling research to completely rebuild the entire
power system after this disaster.
His supervising lecturer Dr Andrew Lapthorn says Cao is developing models to determine what a power system made up of
renewable energy sources such as wind and solar would look like and how it would perform.
“A lot of renewable energy sources are intermittent and their performance hard to predict due to the weather. A new
renewable power system will need to be quite smart in order to maintain a quality power supply to the island. As well as
the technical design, Cao is also looking at the economic side of things to determine the optimal combination of
generating resources and how that would compare with the diesel system that was in place before the cyclone.
“The outcome from this research will be used by Tonga Power, Tonga’s state owned electricity company, to determine
whether they proceed with a renewable energy option for Ha’apai. As part of Tonga’s energy roadmap the government is
committed to converting a portion of Tonga’s electricity generation to renewable energy sources.
“They already have some solar generation on Tongatapu and Vava’u. However as Tonga is quite a poor nation and they have
limited resources for such projects and rely heavily on external aid from other countries such as New Zealand and China.
Cao’s thesis could be used as a basis for some funding application to implement the power system.
“He has a strong passion for renewable energy having seen first-hand the effects of fossil fuel energy production on the
air quality in China and this was a major contributing factor for him to choose New Zealand to pursue his studies,” Dr
Lapthorn says.
The University of Canterbury has led a number projects in Tonga over the past few years including installing solar
systems onto five school rooftops. The university’s College of Engineering expects to send research students to Tonga
this year to continue helping Tonga Power.
About 170 international and domestic students studied electrical and computer engineering at the university last year.
ENDS