Solar and battery microgrid project to return Tokelau to 100% renewables

In 2012, Tokelau took a major step towards energy independence by installing three large renewable energy systems capable of powering the atolls which comprise the nation politically; a step enabled by forward-thinking policies put in place by the government of Tokelau and the funding and support of the New Zealand Government.

The government’s National Energy Policy and Strategic Action Plan 2004 set a goal of achieving 100% renewable energy for the tiny nation in the heart of the Pacific.

This goal was maintained through to the Strategic National Plan (2010-2015), where the target date for achieving 100% RE was set to 2015.

It was under these policies that PowerSmart and ITP Renewables installed the original Tokelau Renewable Energy Project (TREP) – three island-scale PV and BESS systems (265-365kWP PV, 1.1-1.6 MWh [nominal] lead acid batteries) – were installed, bringing Tokelau’s renewable energy contribution to near 100%.

Figure 1: Fakaofo’s PV array and battery building.

For almost eight years Tokelau has enjoyed near 100% renewable energy; and while the TREP equipment is in excellent condition, increasing demand and the gradual decrease in battery capacity has left the systems unable to fulfil their initial role of contributing nearly all of Tokelau’s electrical energy needs.

As the battery capacity fades, maintenance requirements of the generators increase, and fuel consumption rises – increasing volumetric demand on the only cargo ship into the country.

Since the installation of the 2012 TREP, the Implementation Plan of the Integrated National Strategy for Enhancing the Resilience of Tokelau to Climate Change and Related Hazards 2017- 2030 has maintained a 100% RE target for Tokelau.

In order to meet this aim, the TREP equipment needed to be augmented and replaced as necessary to help achieve Tokelau’s policy goals through the period 2019-2029.

Not only would such a project contribute towards achieving policy goals, but also lower the cost of electrical generation and increase the nation’s energy independence and resiliency.

ITP Renewables was engaged by New Zealand Government Ministry of Foreign Affairs and Trade (MFAT) to conduct a technical review of existing data and proposals for increasing renewable energy in Tokelau, and to determine the appropriate RE system to achieve the Government of Tokelau’s goals of 100% RE on a least-cost basis.

Figure 2: The Nukunonu array

Based on available data, load growth was found to be increasing at a rate of 9% per year historically, which is expected to be maintained with a number of planned developments across the nation in the short and medium term.

A number of scenarios were developed based on future load growth, different targeted RE contributions as well as different technology options of PV, wind, lithium-ion batteries and diesel. Hybrid system designs for both 5-year and 10-year load growth were developed for each atoll.

Thanks to joint funding by the government of Tokelau and New Zealand, the Tokelau Renewable Energy Expansion Project (TREEP) is now underway; set to return Tokelau to approximately 100% renewable energy with installation set to commence in early 2020.

ITP visited each of Tokelau’s atolls to collect vital design information for the systems in mid-2019, and have since set about bringing the project into reality.

The project will deliver an additional 210kW of PV and close to 2MWh of li-ion battery capacity to Atafu, Fakaofo and Nukunonu, matching the even growth of demand across the nation.

Crucially, the systems are sized to ensure clean energy can be supplied over the next decade.

Preliminary design documentation has been prepared for the increased system size, and while the same amount of solar will be installed on each atoll, the systems are each constrained by different challenges due to the lack of usable land on the tiny atolls; each no higher than a couple of metres above sea level.

Figure 3: Nukunonu’s 295kWP array is seen at the centre of the image, with the Pacific ocean to the left and the atoll’s lagoon to the right.

As part of the project works, training will be delivered to DoE employees so that continued operation can be undertaken unassisted and maintenance of the system completed with only basic external support.

As part of the training, the DoE employees will take part in the installation works; learning the workings of the system as they install it.

Once the project is complete, this charming little nation, with the support of the New Zealand government, will both have taken steps to reach its policy commitments and will benefit from a new, reliable renewable energy system.

Additionally, energy supply on Tokelau will be more reliable, more resilient, less emissions intensive and have less maintenance commitments than the aging system it currently has.

Matthew O’Reagan is from IT Renewables