When a sweeping power failure blacked out 700 million people in India last July, the cell sites that connect nearly one billion mobile phone users in the country were largely unaffected.
The vast majority of Indian cell-phone base stations, which each include a tower and radio equipment attached to it, had backup diesel power because the electricity goes out frequently, and many run on diesel entirely if there is no power grid in the area at all. Now dirty diesel generators in India are being challenged by clean, renewable energy, and the movement has implications for other developing nations that also have incomplete or unreliable electric networks. Even in developed nations with reliable electricity, changes in the structure of mobile networks could open the door for alternative energy.
In India, which has about 400,000 base stations, the government has mandated that 50 percent of rural sites be powered by renewables by 2015. The decision comes as the Indian government, which heavily subsidizes diesel, looks to lessen the country’s reliance on foreign oil and reduce greenhouse gas emissions. By 2020 75 percent of rural and 33 percent of urban stations will need to run on alternative energy.
The move by the world’s second-largest mobile market after China will likely drive down the price of renewable-powered base stations for other regions with low electrification rates, such as sub-Saharan Africa, according to Mrinmoy Chattaraj, a campaigner with Greenpeace India’s Climate and Energy Unit.
“It’s been a slow rate of adoption,” Eric Woods, research director with Pike Research, says of the telecom industry’s uptake of renewables to date. “But India’s deployment will have an impact across the developing world. It’s moving the market away from the default position of using diesel.”
There are about five million cell phone towers worldwide, 640,000 of which aren’t connected to an electrical grid and largely run on diesel power. One study estimated that 75,000 new off-grid towers would be established in 2012 alone.
The Indian telecom industry consumed an estimated 3.2 billion liters of diesel in 2011, and the amount could rise to six billion liters by 2020, according to Greenpeace India. Enforcement of new regulation would save more than 540 million liters of diesel annually and cut about nine million tons of carbon emissions by 2015.
Diesel prices have nearly tripled in the past twelve years in India, to about 80 cents per liter in July 2012. The price is expected to increase further with diesel deregulation, according to Chattaraj, as solar technologies become cheaper. Today, solar installations with battery backups are more expensive to install upfront, but the yearly operational expenditure is far lower, recouping the investment in about two to four years. The current annual cost to run a diesel generator for a base station is about $14,510 in India, compared with $8,215 for solar with battery backup. By 2020 the annual cost of using diesel is expected to be more than $20,000 whereas the cost of solar and batteries will likely fall to less than $5,500.
Renewable options also become much more viable as the amount of energy needed to power base stations is reduced. The average cellular base station, which comprises the tower and the radio equipment attached to it, can use anywhere from about one to five kilowatts (kW), depending on whether the radio equipment is housed in an air-conditioned building, how old the tower is and how many transceivers are in the base station. Most of the energy is used by the radio to transmit and receive cell-phone signals. On the low end, a tower that runs all the time uses about the same energy annually as an average U.S. household. Many of the off-grid stations, however, use closer to five kW, according to Pike Research, a market research firm that covers global clean-tech markets.