Designing Solar Mini-Grids for Rural India

In rural India, despite decades of electrification programs, about 400 million people making up half of all households still do not have access to electricity. SERC has recently joined a consortium of U.S.- and India-based energy experts to assess the feasibility of building solar photovoltaic mini-grids as a solution to the high cost of electrification in remote areas. These systems would each consist of a single solar generation station per village with a distribution network to provide power to all nearby homes and businesses. If successful, this model could be widely replicated at lower cost than providing each home with a stand-alone solar system.

SERC’s role in the project will include performing a literature survey of similar projects that have been installed in other developing countries, an assessment of how Indian energy policy and regulations affect the project, and field studies to estimate energy demand and willingness to pay for electricity in the participating villages. We will provide technical assistance to the rest of the team on several other project tasks.

The project is jointly funded by the U.S. Trade and Development Agency and Azure Power of India. San Francisco firm Energy and Environmental Economics (E3) is the lead consultant.

SERC Develops Mini-grid Interconnection Guidebook

SERC is collaborating with Chris Greacen of Palang Thai to develop a guidebook on the interconnection of mini-grids to national or regional electrical grids. Titled A Guidebook on Grid Interconnection and Islanded Operation of Mini-Grid Power Systems Up to 200 kW, the document addresses both technical and policy aspects of interconnection and is intended for energy policymakers, mini-grid operators, utility administrators and engineers, and community leaders. Worldwide, more than 50 million households get their electricity from renewable energy mini-grids powered by small hydroelectric generators, wind turbines, or solar photovoltaic arrays. These systems provide clean, reliable electricity to rural locations not yet served by national or regional electric grids. They may be developed by traditional utilities or, more commonly, by private-sector developers.

When a national grid reaches areas previously served by isolated mini-grids, operators are faced with several challenges. Will customers served by the mini-grid be connected to the main grid? If so, what happens to the mini-grid’s generator, power lines, and other equipment? Will these assets be abandoned, or will the generator become another power plant selling electricity to the grid? If the mini-grid system remains independent from the grid, how can the operator keep electricity prices competitive?

If there is no policy in place to address these issues, mini-grid developers may be reluctant to invest in new projects and may use substandard wiring and undersized equipment to reduce costs, knowing that their investment could be made worthless at any time if the national grid arrives. These problems plagued mini-grid systems in Cambodia until the government developed a policy to allow mini-grid operators to become small power distributors (SPDs) and resell electricity from the grid. Since these regulations were instituted, over 100 isolated mini-grids have been converted to SPDs. Other developing countries with interconnection policies include Thailand and Tanzania.

Renewable energy mini-grids, like this micro-hydroelectric system in Rukubji, Bhutan, provide electricity for millions of households worldwide.

Renewable energy mini-grids, like this micro-hydroelectric system in Rukubji, Bhutan, provide electricity for millions of households worldwide.

The interconnection guide discusses technical topics, including voltage and frequency control methods and protective relays, as well as mini-grid policies from developed and developing countries around the world. A draft version of the guidebook is currently being reviewed by outside experts, and final publication is tentatively slated for early February 2013. The guidebook is being developed for Lawrence Berkeley National Laboratories under the auspices of the US Department of Energy’s Global Lighting and Energy Access Partnership (Global LEAP). This program is associated with the Clean Energy Ministerial, a global forum promoting clean energy policies and programs.