Tonga exploring cheaper and sustainable electricity

Tonga exploring cheaper and sustainable electricity through biogas generation

24 September 2018

Nuku’alofa, Tonga – Biogas generation using agriculture and animal products has promising potential for Tonga and the Pacific Islands, if pursued through a well-defined circular economy strategy. This was the conclusion of a 4 day visit jointly organised by the Pacific Community’s Centre for Renewable Energy and Energy Efficiency (PCREEE) and the Institute for Applied Material Flow Management (IfaS) of the Trier University of Applied Sciences, Germany earlier in September.

The Circular Economy system alludes to the ecological cycles of nature with a constant stock of matter and influx of sun energy. In this natural economy waste does not exist. All matters are recycled with the help of sun energy as the needed additional energy source for 100% recycling. More practically explained Circular Economy means reducing resource use and reducing the load on our natural sinks.

Most of the renewable energy developments in Tonga and the Pacific Islands are currently based on solar and wind energy. They are however available on an intermittent basis such that a sudden drop in solar radiance due to cloud covers or a drop in the wind speed during calm days, etc would be a sudden drop in the power network’s ability to meet demand. Power Utilities in the Pacific are looking at battery storage systems to address this challenge.

Hon. Poasi Tei, Minister for Meteorology, Energy, Information, Disaster Management, Climate Change and Communications led a delegation from Tonga and the Pacific Community (SPC) to witness how biogas is used in Germany as community-owned investments that generate affordable and highly efficient electricity and heat (or cooling) to the community.

“We are looking for a technology that would immediately lower the costs of power generation and have immediate impacts on the tariff to consumers, a power source that is also sustainable in the long term”, said the Hon. Minister.

Biogas production is a mature technology that relies on the decomposition of bio matter. Farmers in Germany plant, harvest and use maze as substrate for the biogas plants. Maze plants are only harvested once a year during summer. In Tonga, the “saafa grass” grows wild everywhere and can be harvested year round.

“SPC is providing the necessary support to PICTs to increase their renewable energy mix and usage and we are happy to support the Government of Tonga to witness a number of operating biogas plants and technologies in Germany,” said Dr Andrew Jones the Director of the Geoscience, Energy and Maritime Division of SPC.

Biogas has been successfully used in Tonga at the household level. In Germany, it is used on an industrial scale with capacity of up to 5MW. There are close to 10,000 commercial biogas plants in Germany and it is a proven technology.

Biogas produces energy on a 24 hours basis. It is a base load energy source that can replace diesel power generation and have an immediate impact on reducing the power generation costs. The efficiency of the power generation is above 90% and it will generate organic fertilisers that are much needed for the declining soil fertility on the Kingdom.

A team from the Institute for Applied Material Flow Management (IfaS) of the Trier University of Applied Sciences, Germany will visit Tonga in November to hold further discussions with stakeholders and government on advancing Tonga’s desire to embrace biogas generation using a circular economy strategy.

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