Renewable Energy Mini-Grids

Over the past year, SERC has been collaborating on the Renewable Energy Mini-Grids for Improved Energy Access project with researchers from Lawrence Berkeley National Laboratory (LBNL), Energy and Resources Group (ERG) at University of California at Berkeley, Prayas Energy Group and Palang Thai. These efforts are in support of the Global Lighting and Energy Access Partnership (Global LEAP) initiative associated with the Clean Energy Ministerial.

Renewable energy-based mini-grids offer a significant opportunity to increase access to reliable electricity services for rural populations throughout the developing world. A mini-grid is a village-scale electrical distribution system served by an isolated generator of up to a few hundred kW in capacity. Power on these grids is often provided by diesel generators, but can be supplied by local, renewable resources such as microhydro, solar, biomass or wind. Mini-grids offer an intermediate solution between stand-alone individual home power systems and main grid connection, and often prove to be more cost-effective and beneficial to the community than either of those alternatives.

Our team recently produced three documents to help inform delegates participating in the Mini-Grid Development roundtable discussion at the fourth Clean Energy Ministerial (CEM4) in New Delhi in April. CEM4 brought together energy ministers from 23 of the world’s leading economies, along with business leaders, NGOs and academia to discuss policies, technologies, investment, and skills needed to achieve the CEM’s goal of “accelerating the transition to a global clean energy economy.” Our team’s contributions included:

A biomass mini-grid in India.

A biomass mini-grid in India.

 

SolarMiniGridJP

A solar mini-grid in India.

  • Sustainable Development of Renewable Energy Mini-Grids for Energy Access: A Framework for Policy Design, which provides a review and critique of mini-grid policies from several countries and offers recommendations for national policy design to support the development of mini-grids.
  • A Guidebook on Grid Interconnection and Islanded Operation of Mini-Grid Power Systems Up to 200 kW, which is intended to help meet the widespread need for guidance, standards, and procedures for interconnecting mini-grids with the central electric grid as rural electrification advances in developing countries.
  • Review of Strategies and Technologies for Demand-Side Management on Isolated Mini-Grids, which discusses different measures available to help with load management on isolated mini-grids.

These documents are available on the SERC website at www.schatzlab.org/projects/developingworld/minigrids.html.

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.