Smelter key to renewable energy strategy

Rio Tinto will ultimately determine the direction of Southland’s renewable energy strategy.

A Southland Murihiku Regional Energy Strategy 2022-2050 report released yesterday by Great South revealed that the direction of the province’s decarbonization trajectory depends primarily on whether Tiwai Smelter, part-owned by Rio Tinto, closes or remains open at the end of 2024 .

A closure would result in an oversupply of electricity from the Manapouri hydroelectric power station, which could be used locally for the proposed Southern Green Hydrogen (SGH) and ammonia plant, or diverted to northern centers on an aging and inadequate grid, causing large transmission is caused. to lose.

New industries near Tiwai may have the potential to repurpose the smelter’s power infrastructure.

But if both plants were operational, both hydro and wind would be needed to secure an adequate industrial electricity supply.

At the moment, “the power grid is vastly underpowered.”

The report says hydrogen production and storage should be explored regardless of the planned SGH facility.

The report, produced by Beca on behalf of Great South in conjunction with Murihiku Regeneration, revealed that the infrastructure network would need significant upgrades to handle the additional strains of new industries, including a data center and the world’s largest hydrogen plant.

The report noted that high-demand industries near Awarua or Makarewa would require a network upgrade, as well as substation upgrades that should be prioritized.

The province should ensure continued access to a reliable and uninterrupted power supply to attract new industry to the region.

In the event that Tiwai closed and the SGH plant was not built, many substations were inadequate to redistribute supply to new demand points, but upgrading the infrastructure would be challenging under current regulations.

“Most of the substations in the zone are unable to provide the end user with a guaranteed supply of electricity, which means that maintenance will cause a blackout or reduced supply. This poses a risk to industrial processes that require a constant supply and can cause a hinder decarbonization, or the creation of a new industry…”

Southland Murihiku could potentially become self-sufficient, or a net exporter of renewable energy, but investments in new generations were needed.

New power sources should be located close to a grid for easy connection.

Options considered were onshore wind farms, biogas, solar energy, methane gas recovery from the dairy sector, as well as waste energy, wave/tide generation and offshore wind.

Onshore wind farms, the cheapest form of new electricity, were a likely solution and more than 100 potential sites had been identified. Kaiwera Downs, Blackmount, Kuriwao Peak-Kaihiku Range and Venlaw Station were explored as possible sites.

The strategy prioritized wind farms, followed by a mix of Otago hydropower generation, large solar development north of Te Anau, Mossburn and possibly Fairlight, or offshore wind farms.

Southland had the highest per capita greenhouse gas emissions by region, but the county led the country in converting fossil fuel boiler systems to renewable energy and 89 of its 186 boilers had already been converted.

But a quadrupling of the demand for wood chips (biomass) would be necessary to ensure sufficient supplies.

– By Toni McDonald