The construction of the Rowallan Microgrid, an off-grid renewable power system, supplying customers on Southland’s south coast is a first for electricity network management company PowerNet. The solution has been commissioned on The Power Company Ltd (TPCL) distribution network as a reliable solution good both environmentally and economically in such a remote location.

PowerNet has installed the microgrid to supply power to a lodge and house owned by the Rowallan Alton Incorporation located on its1330ha property near the start of the Hump Ridge Track on the edge of Fiordland National Park.

The customers were historically supplied via overhead power lines that ran along the coast, but these have been damaged by gradual coastal erosion, resulting in occasional power outages.

The Rowallan Microgrid was commissioned in March 2020 and has been performing reliably. It comprises 12kW renewable solar generation, 27kWh energy storage and a back-up diesel generator. A lithium-ion battery stores and supplies energy to accommodate any variability in renewable solar generation and load, while the back-up diesel generator can be used if sunlight is low for days or load is higher than normal. The storage, inverters and control infrastructure is secured in an 8ft container, protected from coastal weather conditions. The system and site design enables upscaling if needed in the future.

Without the need for overhead lines, the visual impact on the natural environment of supplying electricity to the remote site is removed.

“Installing this microgrid system is a first on the TPCL network. We see this as a very good solution for remote areas where traditional infrastructure may be more costly to install and maintain,” says TPCL chair, Doug Fraser.

Rowallan Alton Incorporation are also pleased with what the microgrid solution provides. Chairman, Harold Thomas says the site looks quite impressive as you approach the site on the access road where you get a good view from a hill above.
“The Rowallan Alton Incorporation shareholders were generally pleased about the supply arrangement especially given the history of coastal erosion affecting power supply to the site,” says Mr Thomas.

For PowerNet, the Rowallan Microgrid meets their goal of providing a safe, reliable, and efficient power supply to customers on PowerNet-managed networks, and delivering a supply and service that is consistent with an electricity supply delivered via more traditional infrastructure.

PowerNet’s general manager New Energy Development and Strategy, Kavi Singh says “This project was the obvious choice to pilot this new approach to providing electricity supply to customers in a region that had significant challenges. The lessons we have learnt on this project equip us well to implement similar non-traditional solutions for our customers across the region where this makes sense for both the customer and the electricity network.”