Tokelau is located north of Samoa, and consists of three small atolls – Atafu, Nukunonu and Fakaofo – accessible only by boat. Its land area covers approximately 11 km², and the country has a population of around 1,500 people.
In the past, all three atolls relied almost exclusively on diesel generators to produce electricity, but can now look forward to a future without fossil fuel following the installation of ground-mounted solar arrays and battery storage on each atoll, featuring 4,032 solar panels and 1 megawatt of capacity.
The establishment of solar power for Tokelau was funded by the New Zealand Ministry of Foreign Affairs and Trade’s Aid Program and supported by the Tokelau Government. New Zealand-based solar system designer and installer PowerSmart was the lead contractor for the project, working in conjunction with project manager IT Power Australia, while Sunny Island solar products from SMA were used to create the systems.
Each system includes a solar array of 300 kilowatts (kW) and battery inverter capacity of 150 kW, using approximately 700 SMA inverters and chargers.Article continues below…
Each atoll has an electricity grid, to which all households are connected. Previously, power was typically only provided during peak demand periods and for between 15–18 hours a day, with 24 hours of electricity reserved for special occasions. With solar power installed, electricity will be available for 24 hours every day. Tokelau’s electricity system has undergone upgrades to improve the reliability of service and increase supply efficiency.
The discontinued diesel generators in Tokelau previously burned approximately 200 litres of fuel daily, and as the atolls are surrounded by reefs with no ports or harbours, access was both difficult and expensive. Fuel cargo was offloaded out to sea and ferried to the shore in smaller boats.
Solar energy will not only eliminate the pollution created by the diesel generators, but will help to reduce the risk of the surrounding waters being polluted by the petrol and kerosene that was shipped in drums to the island, or the diesel that was transferred to the islands from tanks on the M.V. Tokelau, the islands’ ferry. Noise levels on the islands will be significantly reduced.
SMA says that rainfall on the atolls is heavy but irregular, so the diesel generators will still be maintained for the purpose of providing electricity during the rare prolonged periods of inclement weather. Outside of these times, the generators will be run at a minimum level in order to maintain the parts and keep the batteries at a high state of charge.
PowerSmart developed weather-proof touch screens for each system so that their performance can be observed locally. Remote monitoring is also possible via the Internet through the use of SMA Sunny Webboxes and SMA Sunny Portal software.
PowerSmart undertook a trial installation at its New Zealand headquarters to ensure all of the necessary components for the systems were factored in before commencing work at Tokelau. Due to the remote location of the islands, the company wanted to ensure that its engineers and electricians had correct equipment on site when necessary during the install. The project team arrived Tokelau at the end of April 2012 and work on the systems commenced in May.
The system was designed with regard to the high ambient temperatures of the location, its salt-laden air, and its risk of cyclones and flooding, according to PowerSmart.
Local labourers were employed for the project, and SMA conducted SMA Solar Academy training in Tokelau in July 2012 to provide local residents with the knowledge required to manage the systems.
According to SMA, local residents were initially concerned about introducing full solar power to the islands, as they had previously experienced difficulties with a small solar system installed in Tokelau that could not be adequately repaired if it malfunctioned, due to a lack of training on the use of the small system.
“This is the first time that locals will be equipped with the knowledge to maintain their system, and ongoing support will be provided by SMA and PowerSmart,” SMA says.
“Because the atolls are particularly susceptible to the risks of rising sea levels, it is particularly significant that they are leading by example.”
Two of the three systems in Tokelau are now complete, after PowerSmart switched on the system on Nukunonu.
“We are happy with how the installation has gone here on Nukunonu, and are now looking forward to starting on the third and final system on Atafu,” PowerSmart Director and Mechanical Engineer Dean Parchomchuk says.
PowerSmart says that the original tender specification called for the solar systems to supply 90 per cent of Tokelau’s electricity demand, but through creative design, project management methodology, and sheer scale, the project team was able to implement systems that will supply 150 per cent of current electricity demand, allowing Tokelauans to expand electricity use without increasing diesel use.
The three solar systems have a total cost of $NZ7.5 million and will be fully completed by November 2012.