Do the Costs of Mesh-Grids Weigh Up? 18 Months Later for Steung Chrov

By Emma Best
July 06, 2022
Steung Chrov’s average revenue per user (ARPU) has exceeded expectations; the increase in revenue is due to appliance financing.

This 140 household project commissioned by the Cambodian Ministry of Mines and Energy and UNDP has surpassed the one-year mark! To honour this milestone, this blog will explore how the running costs of the Mesh-Grid compare to the forecasted cost, as well as looking into the shifts in energy demand, the project’s community impact, and the challenges faced along the way.

A birds-eye view of the lakeside houses in Steung Chrov

Why is One Year a Big Deal?

Off-grid electrification projects and energy access technologies are often criticised for lacking long-term planning. A 2017 study across 10 Sub-Saharan African Countries found that out of 29 mini-grid projects, 60% were abandoned within six months of installation. A lack of local maintenance expertise, and acceptance by the community, is a common cause of failure.

When designing the Mesh-Grid, we aimed to build a sustainable alternative, utilising remote monitoring and reducing the need for costly site visits by engineers. Using 50V extra low-voltage distribution lines, the Mesh-Grid is safe for those with basic engineering knowledge to maintain. For the entire project, a community member was hired and trained to maintain the site as an LMA (Local Maintenance Agent), following automated tailored instructions from Okra’s mobile app. The LMA also acts as a communication point between the households and energy developers – ensuring households’ concerns are addressed efficiently.

The Community

Located on the Tonle Sap lake; Steung Chrov village floods each rainy season, making the community unsuitable for connection to the national grid. Households are 10 kilometres from the national grid line and a 45-minute drive to the closest town with consistent energy access.

Before this project, households relied on expensive diesel generators, car batteries and wood-burning stoves that released harmful and carcinogenic fumes.

Before, the people here had a hard time due to lack of electricity. They [the households] are required to buy batteries and regularly take them 1-2 kilometres distance to recharge… after all, the batteries didn’t even last until 10 pm, putting us back in the darkness again.

– Ke Song, Steung Chrov village chief

Since November 2020, 140 households enjoy 24/7 clean energy access, with a system uptime of 99.5%. Nearly 19 months since project deployment, the site has generated 19.6MWh of clean energy. According to US Environmental Potential Agency, since deployment, this site has offset  13.9 metric tons of CO2. Thus, the project has the equivalent impact of 230 trees planted over ten years.

The Cost of Running a Mesh-Grid

The table below compares the forecasted costs vs the actual cost of running the Mesh-Grid. From February 2021 to February 2022, the project operation and maintenance costs were $2.59 per user per month – averaging higher than expected. The higher O&M costs were caused by the need to replace low-quality batteries, which we’ll look at further later in this blog. 

The project’s average revenue per user (ARPU) also exceeded expectations; the increase in revenue is due to the implementation of the Clean Cooking project, where households could pay off the cost of e-cooking appliances over time

With a system uptime of 99.5%; the low monthly cost to maintain the Mesh-Grid ensures problems can be addressed quickly on-site by the LMA. This is why the off-grid community members of Steung Chrov see clean energy, via the Mesh-Grid, as a reliable, efficient alternative to high pollutant fuels.

A breakdown of the expected and actual revenues and costs of the Steung Chrov project

Energy Demand

The site has seen a consistent gradual increase in energy demand. In February 2021, the total average daily load usage was 0.31kWh per household; one year later, in February 2022, the total average daily load increased to 0.41kWh per household per day. Energy demand across Cambodia has been growing rapidly since 2013, rising at an average of 6% per year until the Covid-19 crisis.

Energy demand in Steung Chrov has grown steadily over time

For this community, the growing energy demand highlights a greater reliance on clean energy access and enhanced purchasing power for electrical appliances. Most importantly, an increase in energy consumption validates that the tariff rates are affordable and rural households are capable of elevating themselves out of energy poverty if the right electrification technology is provided.

This is excellent news for the project, with Okra systems boasting 1.2kW of power per household. The system has a significant capacity for energy demand to continue to increase over the coming years – making Okra a long-term solution.

The Impact of Mesh-Grids

Since the launch of the project:

67.2% of households spent less money on fuel

Only 2.9% of households noted they spent more on fuel

23.7% of housholds used their savings to access healthcare

37.6% of households purchased additional food and water

Before receiving energy access, families spent up to three hours per day collecting wood for their fire stoves – a burden predominantly carried by women. With clean electricity and increased access to e-cooking appliances (such as rice cookers and blenders), 84.7% of households reported time savings.

..before this solar study, I had to wake up at 4 am to cook [for my children before school]. But after I’ve had this solar power, I don’t have to wake up early to cook anymore… then I have more time to prepare the stuff for sale and to do other things.

– Hem Sao, a Steung Chrov homeowner

In Okra’s Q2 2022 satisfaction survey, 79% of the energised community stated they were significantly satisfied with the energy access provided via Okra’s technology – great news all around!

Clean Cooking Access

The site also participated in the Modern Energy Cooking programme. 45 Cambodian households, across three different villages, were provided with e-cooking appliances to foster the transition to clean cooking. Families were able to pay off the cost of the appliances over time at a low daily fee (e.g. 10 cents a day for 340 days for a rice cooker). We’re proud to share that 100% of households have completed full payment of appliances in May 2022.

Read more about the project here.

The Challenges 

Despite the overall success, things haven’t been consistently smooth during this project, and several challenges have provided many lessons for this network and encouraged change for our future networks.

The intention of this project was to demonstrate to the Cambodian Government the versatility of the Okra Mesh-Grid Platform and its ability to truly provide a range of energy services, business models, capacity and solutions for all kinds of topographies, showcasing our technology can energise everybody at an affordable cost.

To do so, we combined several variables that had been laboratory tested but not sufficiently field-tested at this point to the demonstration:

  • High power output (24 V / 1200 W) – up until this point, Okra had only been used with 12 V systems in the Field.
  • Use of lithium batteries – Okra had before only used with Lead Acid Batteries
  • AC output – Up until this point Okra had only been used with DC Appliances and providing DC inverters. For this project, MSW Inverters were introduced. 
  • Community operator model – Prior to this Okra had only worked with a develop operator model

A major lesson learnt has been the importance of isolation of variables that are being tested. There needs to be sufficient baseline data so that the effect of the  addition of a new variable can be isolated. If you are interested in seeing some of our data and learning what we have learnt from each variable, contact us at support@okrasolar.com.

The main problem in retrospect was the decision to use an unvetted supply chain of batteries and inverters. As the Okra Pod can be used with any off-the-shelf battery, inverter and solar panel, a decision was made to purchase the new batteries locally with the aim of supporting the local economy whilst reducing equipment cost. 

But over time, battery problems began to multiply. Some batteries had low cell quality and had to be replaced as they had degraded after a short period. In other cases, there were issues with the over voltage protection and the cell balancing capabilities of the BMS (battery management systems) that were embedded into the locally sourced batteries.  

Fortunately, due to the decentralised nature of Mesh-Grids, this did not lead to a total collapse of the network and instead affected isolated households. Temporary solutions were put in place whilst the root cause was researched. The effect of these occurrences can be seen in the system uptime chart, however; it is important to note that even during the worst performance period, system uptime never fell below 97%

The biggest takeaways from this particular challenge have been two-fold:

  • We now offers fully bundled Kits of batteries, solar panels and inverters, as well as all the accompanying BOS (balance of system) components which have been thoroughly quality tested in our labs to ensure compatibility with Okra’s system, and we provide a competitive warranty on all of these items. 
  • We have also began extensive research into BMS and cell balancing. If you are interested in learning more about our Kits and about our experiences with cell balancing, email us at sales@okrasolar.com

What does the future hold for Steung Chrov?

The village has a bright and clean future ahead. Recently, the Steung Chrov project was equipped with solar-powered washing machines. This development has enabled households to wash their clothes hassle-free, for a mere 500 riel (12 cents) per wash. Before washing machines were installed, families had to wash their clothes in the lake, a strenuous process that required prolonged exposure to the sun.

Bringing energy access to this community has shown us first-hand the time saved and opportunities unlocked through working towards SDG7: Clean and affordable energy access for all.

A Special Thank You

As always, the Steung Chrov Mesh-grid would not have been possible without the continued support of our project implementation partners at UNDP, Ministry of Mines and Energy Cambodia and the Swedish International Development Cooperation Agency.

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Emma Best works in project development at Okra. She has worked with international institutions including the European Commission and African Development Bank to design and implement development projects globally. She holds a masters in Globalisation and Development from Maastricht University and is a published academic in the field of non-profit marketing.

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