Village-scale DC solar grids provide power for lighting and cell phones

Technology Review – Nearly 400 million Indians, mostly those living in rural communities, lack access to grid power. For many of them, simply charging a cell phone requires a long trip to a town with a recharging kiosk, and their homes are dimly lit by sooty kerosene-fueled lamps.

Nikhil Jaisinghani and Brian Shaad cofounded Mera Gao Power. Taking advantage of the falling cost of solar panels and LEDs, the company aims to build and operate low-cost solar-powered microgrids that can provide clean light and charge phones. Microgrids distribute electricity in a limited area from a relatively small generation point. While alternative solutions, such as individual solar-powered lanterns, can also provide light and charge phones, the advantage of a microgrid is that the installation cost can be spread across a village. The system can also use more efficient, larger-scale generation and storage systems, lowering operational costs.

For a cost of $2,500, a hundred households, in groups of up to 15, can be wired up to two generation hubs, each consisting of a set of solar panels and a battery pack. The grid uses 24-volt DC power throughout, which permits the use of aluminum wiring rather than the more expensive copper wiring required for higher-voltage AC distribution systems. The village is carefully mapped before installation to ensure the most efficient arrangement of distribution line.

Each household gets 0.2 amps for seven hours a night—enough to power two LED lights and a mobile-phone charging point—for a prepaid monthly fee of 100 rupees (a little less than US$2, current exchange 55 rupee to 1 US dollar); kerosene and phone charging generally cost 100 to 150 rupees a month.

A typical installation uses two banks of solar panels, located on different rooftops. Credit: Anna Da Costa

This business model and technology will enable everyone in the world to have basic electricity and along with low cost $10-20 smartphones, everyone will have a computer and mobile communication.

Mera Gao Power website

Quality, dependable light transforms lives; children are able to study at night, adults are able to earn additional income, and indoor air quality is improved. Our services benefit women who traditionally spend more time working indoors and children who accidentally drink kerosene and inhale its fumes. With a commercial model, MGP expects to scale up its services to reach 1,000,000 people by 2017.

Mera Gao’s first commercial microgrid was deployed last summer, and eight more villages have been added since; there are plans to expand to another 40 villages this year with the help of a $300,000 grant from the U.S. Agency for International Development. The company has also encouraged others to enter the Indian market for off-grid renewable energy, which the World Resources Institute, a think tank based in Washington, DC, estimates at $2 billion per year.

Jaisinghani says Mera Gao’s microgrid is not a replacement for grid power, but it’s what people want and can pay for right now. Currently the technology supports only lighting and phone charging, but the company is exploring ideas such as community entertainment centers where the costs of television, radio, cooling fans, and information services are spread across a group of homes rather than being paid by a single user.

Market

In India, the limited generation, transmission, and distribution infrastructure has left 400 million people across hundreds of thousands of villages without electric power. In a recent report[1], the World Resources Institute estimated that off-grid distributed energy (OGDE) in India is a $2 billion a year untapped market. Data varies by source, but the trends are consistent. As of 2010, it is estimate that 48% of rural households are unelectrified nationally; Bihar, Jharkand, and Orissa have electrified fewer than 35% of rural households[2]. Ministry of Power data put the percentage of villages in Uttar Pradesh with electricity at less than 42% in 2006 (and therefore household electrification likely even lower).

The IEA (International Energy Agency) estimated that for 2009 there were 1.3 billion without electricity (about 20% of the world population).

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