Problem

Solar PV mini-grids are an increasingly popular way to supply small amounts of power to remote communities. Even though the price of solar PV has decreased significantly, few large mini-grids are powered by solar PV. In post-conflict countries like Afghanistan, where major electrical loads are likely to be outside the national grid, solar PV could be a cost-effective way to power whole towns.

Afghanistan generates limited amounts of energy, and more than half of its people lack access to electricity. The country’s energy framework and energy plans barely incorporate mini-grids. A few individuals operate mini-grids powered by diesel or renewable energy and sell electricity to neighborhood consumers. These grids operate apart from the national grid.

BREP sought to develop solar energy, the most abundant energy resource in the region. The mini-grid was funded by the New Zealand Ministry of Foreign Affairs and Trade and built by a joint venture of two New Zealand companies, Sustainable Energy Services International (SESI) and NetCon. After construction, project developers transferred the system to Da Afghanistan Breshna Sherkat (DABS), Afghanistan’s national utility that now owns and operates the system. SESI and NetCon helped DABS operate the system for the first year after installation.

Solution

Under BREP, four independent sites generate 1,050 kW of solar power. The mini-grids power loads during the day, using any excess energy to charge batteries for use at night. Diesel serves as a secondary energy source during periods of high demand, overnight and at times when solar insolation is low. The loads are primarily from residential homes and are single-phase. Larger consumers, including government offices and businesses, pay a higher tariff and have a three-phase supply and three-phase meters.

BREP uses a prepaid, pay-as-you-go model to collect revenue. Instead of the traditional analog electricity meter common in Afghanistan, each house is equipped with a digital meter. The customers take their charge cards to the utility where they pre-pay for their desired amount of electricity. The meter has a large backlit digital display that shows the customer how much credit they have left in kWh. If the customer does not add money to the charge card, the meter automatically disconnects the power when the balance reaches zero.

Innovation

BREP is one of the largest solar hybrid mini-grids in the world used to power an off-grid rural provincial center. The system’s size allows it to provide enough electricity to power institutional and commercial loads in addition to meeting household needs. Economies of scale and business consumers who can afford to pay more keep the tariff affordable for residential customers. Pre-paid metering and internet monitoring and control increase revenue collection and reduce theft. High-quality batteries and state-of-the-art inverters increase the lifespan of the system. These cutting-edge technologies enable DABS to manage and operate the mini-grid.

Challenges

Capacity Building and Ownership Transfer

The largest capacity-building need was educating staff of the national utility, DABS, on how to operate and maintain the plant. This included training DABS engineers to install the system and teaching clerical and management employees how to manage the electrical system, make customer connections, charge customer cards and maintain an accurate accounting system. For the first year, SESI and NetCon staff remained at the site to operate the system, allowing time to train DABS staff on long-term maintenance.

Tariffs

With its new tariff structure, BREP faced public resistance at first. Elsewhere in Afghanistan, power network subsidies result in low tariffs for electricity. Prior to BREP, smaller power networks in Bamiyan didn’t use meters, so customers didn’t know how much electricity they were using.

Power providers charged households on a “per-light-bulb” basis, using fixed prices for the number and types of appliances in a home. As a result, consumers didn’t understand the actual cost of power. When BREP introduced meters, the community compared its costs with those of cities (such as Kabul and Kandahar), where power tariffs are subsidized, and felt overcharged. In reality, BREP reduced household power costs from $1.95 per kWh to $0.25 per kWh. Eventually, customers accepted the new metered power and were willing to pay for it. In the first year of the project, consumer energy use and revenues increased. By 2017, BREP was earning $400,000 in revenue annually and consumer demand for electricity had increased to 15 MW.

Security and Logistics

Security and logistics are serious challenges in Afghanistan, where delivery vehicles are subject to ambush and attack. As a result, mini-grid operators in Bamiyan must focus on preventing component failure and anticipating system needs. Reducing the need for spare parts and ordering materials well in advance can keep mini-grids operating during periods of insecurity.

Lessons Learned

System Design

BREP relies on lead acid battery storage, an affordable and efficient technology at the time the BREP mini-grid was designed and implemented. However, given the considerable decrease in the cost of lithium-ion batteries in recent years, similar mini-grid projects instead could use lithium battery technology for higher performance.

Operations and Maintenance

Good design, operator training and proper household connections are vital to safely deliver electricity and build confidence in the system. Improper maintenance can jeopardize system performance and decrease public support. Proper financial management is also key to long-term viability. Operators need to set and maintain proper electricity tariffs and prevent theft, fraud and premature part failure.

Environmental, Health and Safety Considerations

Program staff members assessed environmental, health and safety (EHS) risks at the site and developed a health and safety plan and an environmental management and sustainability plan to manage those risks. The assessment identified the following as the greatest potential risks to health and safety:

• High direct current (DC) voltage from PV array strings (more dangerous than the lower voltage DC systems to which the community was accustomed)
• Battery acid from flooded lead-acid cells
• Flash burns from welding that could cause eye damage
• Electrocution from operators working on one part of the network while others are working on another part without communicating
• Dangers associated with heavy lifting and digging equipment

To address these issues, BREP raised awareness and built the capacity of on-site staff through hands-on training in hazards, safety equipment, first aid and other topics. Safety features, such as power system lock-outs, were integrated into the system, and workers were required to wear high-visibility clothing, hard hats and boots. The plans, in line with international standards, were designed to mitigate the greatest hazards initially and then build staff capacity over time to address additional risks.

The assessment identified waste management as the greatest environmental risk, so the environmental plan addressed waste from vehicles, sanitation services, organic waste and energy consumption, and planned for waste prevention, minimization, reuse, recycling and disposal. Used batteries are collected and exchanged for fresh ones periodically as a part of normal system maintenance.

Monitoring and Evaluation

Long-term monitoring and evaluation will be key to the program’s success. Each of the five BREP networks belong to a web-accessible monitoring system via the Bamiyan cellphone network. This allows online monitoring of error codes, power output, voltage and current, battery conditions and other core system parameters. This coordinated online system is key for troubleshooting and monitoring system needs.

Preparing for Long-term Viability

To ensure long-term viability, BREP must manage the following key risks:

• Potential lack of qualified support staff, both commercially and inside DABS
• Potential lack of support from Kabul DABS to respond to the needs of the Bamiyan DABS office
• Reduced consumer support if the system is not reliable
• Lack of adequate funds to perform scheduled maintenance, replace parts and/or upgrade the system
• Employee theft
• Theft of system components (as of 2017, theft of components has not been a problem for this program)
• Over-subscription of electricity services, inducing system failure
• Encroachment of the ongoing conflict in Afghanistan to the area