Lake Hargy Mini Hydropower Upgrade Study

Advancing

clean

energy

in

Papua

New

Guinea

SMEC, an SJ Group company, has been engaged by DT Global under the Australian Government’s Department of Foreign Affairs and Trade (DFAT)–funded Economic and Social Infrastructure Program (ESIP) to deliver a prefeasibility study (PFS) and desktop review for the Lake Hargy Mini Hydropower Project in West New Britain Province, Papua New Guinea.

Located approximately 13 kilometres northeast of Bialla township, the Lake Hargy scheme is a key component of the local mini-grid, supplying electricity to households, businesses and essential public services including hospitals, schools and government facilities. As the primary source of power for the Bialla system, the plant plays a critical role in supporting economic activity and community services across the region.

Unlocking additional hydropower potential

The existing scheme diverts water from the Lobo River through a 1.5 km open channel into dual penstock pipelines feeding a power station equipped with two 750 kW turbine-generator units, giving a total installed capacity of 1.5 MW. However, current generation has historically fallen short of this capacity, and a considerable volume of water is routinely spilled, highlighting untapped hydropower potential within the system.

The mini-grid currently serves a system demand of approximately 1 MW, with diesel generation providing backup capacity. However, ageing diesel equipment, combined with fuel and maintenance constraints, has limited its reliability and effective output. With demand expected to grow, increasing renewable generation capacity has become a priority for improving system resilience and reducing dependence on diesel power.

Location

Lake Hargy, West New Britain Province, Papua New Guinea

Client

DT Global

Funding Partner

Australian Government through the Department of Foreign Affairs and Trade (DFAT) – ESIP

Status

Ongoing (2026)

Expertise

Hydropower Energy & Renewables Water Resources Energy Efficiency

1.5

installed capacity across two 750 kW turbine-generator units

current demand served by the Bialla mini-grid

1.5

water conveyance system channeling flow from the Lobo River to the power station

Assessing practical upgrade solutions

SMEC’s PFS is focused on identifying practical solutions to optimise and expand generation. This includes a detailed assessment of available hydrological data, including rainfall, streamflow and historical plant discharge records, to quantify surplus flows and define upgrade potential. The study will evaluate multiple upgrade options, including refurbishment of existing systems, integration of a modular or containerised turbine unit and potential enhancements to intake, headrace and penstock infrastructure to accommodate increased flow.

In parallel, SMEC is undertaking a desktop review of a previously completed prefeasibility study for the proposed Lower Lake Hargy hydropower project, reassessing hydrological, technical and economic parameters to determine its viability under current conditions.

Lake Hargy presents a strong opportunity to unlock additional generation from existing infrastructure by making better use of available water resources. Through this study, we are identifying practical options to enhance reliability, improve efficiency and support growing energy demand in Bialla and Kimbe.

— Sujan Ghimire, SMEC Regional Lead, Dams & Hydropower, Papua New Guinea

A recent site visit by SMEC’s multidisciplinary team has provided valuable insights into the condition of existing infrastructure and available head and site constraints, supporting the refinement of upgrade concepts. The study will culminate in a comparative assessment of development options, identifying technically viable and economically sound pathways for future implementation.

Enabling future energy security

The Lake Hargy upgrade has the potential to maximise renewable energy generation from existing resources, improve system reliability and reduce reliance on diesel-powered generation.

Through this engagement, SMEC continues to support Papua New Guinea’s transition toward cleaner, more resilient energy systems, delivering tangible benefits for local communities and future growth.