Tonga’s third solar farm is being constructed at Vaini on Tongatapu, at a cost of $14 million (USD) under Japanese aid funding. The project will introduce a special micro-grid system to coordinate electricity generated from a variety of renewable sources in the future.

The ground-breaking ceremony for the construction of the Vaini Solar Farm on Friday, 31 January 2014, was officiated by the Prime Minister, Lord Tu'ivakano and the Japanese Ambassador to Tonga HE Dr Kazuchika Hamuro.

Construction of the solar farm with 3000 solar panels, a concrete foundation and two buildings, will be carried out by two Japanese companies, the NPK Corporation Ltd and Fuji Electric Ltd.

NIkolasi Fonua and Carl Sanft, at the ground breaking for the Vaini Solar Farm, 31 January 2014.

Nikolasi Fonua, Strategic Development Manager of Tonga Power Ltd., said that the most impressive part of the Vaini Solar Farm project was its micro-grid system. It was a special piece of equipment that required the approval of the Japanese government to allow it to be used in Tonga.

The micro-grid system will be connected to Tonga Power’s new generator at Popua, and the Maama Mai Solar Farm by a 15km fiber optic cable, and in real time with the micro-grid system "the electricity generated can be coordinated in the most efficient manner possible."

Nikolasi said that the micro-grid system would also minimize the fluctuation of the electricity supply. It has the capacity to coordinate electricity generated from various sources in the future, such as wind.

2015

The Vaini Solar Farm was expected to be completed in early 2015.

Tonga already has two solar farms in operation as part of a long-term plan to reduce its reliance on electricity generated by imported fuel.

The Maama Mai Solar Farm at 'Anana, Nuku'alofa with a 1.32 megawatts capacity was the first to be in operation in July 2012, and was funded with  $7.9 million (NZD) development assistance from the New Zealand government.

The $4 million (USD) Vava'u Solar Farm, with a 500kwh capacity, went into operation in November 2013 and was funded by the United Arab Emirates.

Fossil fuels reduction

Nikolasi said that by March next year when the Vaini Solar Farm comes into operation, it would help Tonga Power to reduce its reliance on fossil fuel by 3%.

He said that with the success of the project to reduce losses of electricity during transmission, from 15% to 12% that Tonga will start to see reductions in its fuel imports for power generation.

"By March 2015 Tonga should be able to reduce its diesel imports by 13% or one million, six hundred thousand liters of diesel."

Fluctuating exchange rate

Carl Sanft, the chairman of Tonga Power’s board, expressed his frustration over what appeared to be an endless battle to bring down the cost of electricity. He said that despite the effort to reduce Tonga's reliance on fossil fuels, the price of electricity remained relatively high because of two things that we have no control over, "the high cost of diesel, and a fluctuating exchange rate."