Using Mesh-Grids to Energize Rural Cambodia

A Case Study

The Cambodian Government is piloting innovative approaches to sustainably electrify last-mile areas

By Kisa Giebink
May 14, 2021

Cambodia’s last-mile electrification challenge

It was the goal of the Cambodian government to achieve 100% countrywide electrification by the end of 2020. Whilst the government has reduced the number of off grid villages from over 14,000 to less than 500 by extending the national grid, using this approach to connect extremely remote villages with low-density populations is not practical, nor viable. Other conventional last-mile electrification methods – such as diesel and solar-diesel hybrid mini grids – have struggled to demonstrate commercial viability, so a new approach was needed.

Electrifying the remaining off-grid villages in Cambodia is characterized by two key challenges:

1. Households are arranged in sparse clusters in areas with harsh and ever-changing environments

2. The remoteness of these villages makes it costly to conduct operations and maintenance and revenue collection on an ongoing basis.

Electricité du Cambodge – the arm of the Cambodian Government responsible for providing energy services – has therefore begun evaluating alternative solutions that will enable provision of equitable and commercially sustainable energy access for the remaining unelectrified areas of Cambodia.

“My work with EDC started with a commitment to equity. All Cambodians should have access to the same rights including the same quality and cost for services such as power access. This commitment is a professional but also a personal one from myself to the Cambodian people.”

ㅡ H.E. Keo Rottanak, Minister attached to the Prime Minister, and Managing Director of Electricité du Cambodge

The Steung Chrov project

In search of innovation

The Ministry of Mines and Energy (MME), with support from the Electricity Authority of Cambodia (EAC) and the United Nations Development Program (UNDP), recently energized the remote villages of Steung Chrov, Ta Daok and Prek Spean using Okra Solar’s mesh grid hardware (Pod) and software (Harvest). Neighbouring households were connected together into energy sharing clusters whilst further-away households were equipped with standalone high-power solar home systems that can join larger clusters in the future. This flexible approach aims to demonstrate the potential of mesh grids as a solution that can be scaled to other hard-to-reach areas.

Steung Chrov village map on the Okra Harvest platform

Capital expenditure

In less than 8 weeks, MME connected all 140 households within the 3 villages and provided the community with 2 fridges, 49 rice cookers, 7 kettles and 8 blenders. They are paying for these appliances through mobile money financing with energy access being used as their collateral. Since, families have been able to generate income through productive use of these appliances and can also purchase additional appliances in combination with their basic energy payments through the micro-financing options available in Harvest. The total project cost amounted to $118,234, including the costs of shipping, installation and two years SaaS fees to manage the project remotely using the Okra Harvest platform.

 

A traditional mini-grid installed in this context would have been 40% more expensive. This is due in large part to Okra’s technology reducing transmission and distribution costs by around $70,000 as compared to a traditional AC mini-grid.

 

The two major reasons for increased transmission and distribution is that:

a) in a traditional mini-grid with a centralized powerhouse, 25mm^2 or greater cables are required which leads to transmission and distribution amounting to ~50% of the CapEx cost. These cables are ~10x thicker than what was used in the node-node distributing mesh network which used 2.5mm^2 cables.

b) transmission poles carrying larger conductors have to be thicker and taller.

Operations and maintenance

The remote and distributed nature of these communities can also impact the quality of energy access, leading to power cuts or abandoned systems. To address this challenge, MME is exploring a way to monitor these communities remotely using the data from the field, collected by the Okra Pod and available in a digestible format on the Okra ‘Harvest’ software platform.

To ensure reliable power distribution and keep operation and maintenance costs low, MME uses Okra Harvest to assign suggested maintenance actions to a field agent or the local maintenance agent. MME also uses Okra Harvest for mobile money payments and appliance financing, keeping track of what households have paid and enabling the local maintenance agent to ‘top up’ household payments remotely.

The local maintenance agent is a community member who is responsible for conducting basic maintenance on the Okra system and processing mobile money payments. In Steung Chrov, the local maintenance agent is Mrs. Thai Vimean Rothana. She received training by the Okra Solar team and is hired by the Committee composed of the village chief, the MME, the UNDP and Okra Solar.

Mrs. Thai Vimean Rothana, Local Maintenance Agent in Steung Chrov

Through the combination of remote monitoring and local maintenance, the system ensures a minimization of blackout amounts and blackout time. In March 2021 for example, the 3 villages electrified in the region under the same project, had an average of 99.73% system uptime.

Business Model

The Steung Chrov Okra Meshgrid was given by MME to the community and is currently overseen by a village committee that is responsible for setting the tariff and paying for maintenance. In this community houses are paying the subsidized tariff: an average of 640 Riel/kWh ($0.16/kWh).

Detailed package distribution

The levelized cost of energy (LCOE) based on the upfront and ongoing costs is calculated at $0.45/kWh (on a 7 year basis). However, given the upfront costs were provided by grant funding from the UNDP and the community is responsible for the Okra Meshgrid on an ongoing basis, the key business model sustainability metric is the breakeven point on collected revenues and ongoing costs. Under full utilization, the grid is sustainable on ongoing operations and maintenance costs.

 

In different utilization scenarios, the necessary kWh subsidy is as follows:

Calculated subsidy need per utilization scenario

These subsidies will enable the community to have 24/7 access to power for 7 years until such a point as battery replacement is necessary – where further investment will be required.

 

Conclusion

Building on their experience with Okra, MME is currently evaluating the potential for a scale out of the Okra technology as an effective solution for energizing hard to reach communities throughout Cambodia.

“We want to extend the grid as much as possible but in areas that will take us too long to extend the national grid to, or it is not cost-efficient to do so then the SHS and mini-grids will be the alternative.”

ㅡ H.E. Keo Rottanak, Minister attached to the Prime Minister, and Managing Director of Electricité du Cambodge

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Kisa works in project development at Okra, helping our partners to leverage finance and innovative business models to scale up their reach. Her background is in renewable energy investment in North America and the Mekong region. She holds a Masters of Management in Finance from McGill University.

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