According to the World Bank, 100% of registered homes in the United States have access to the electricity grid, so it is unusual for a cell tower to be “off-grid,” and thus require a distributed source of energy in order to operate. However, in many parts of the world, mobile service has outstripped existing electricity grid infrastructure. In India, for example, only 40% of the energy requirement of the telecommunications sector is met by grid electricity, because nearly 70% of existing cell towers are located in rural areas. The distribution is similarly askew in developing countries all over the world, where rural communities have received mobile phone service before receiving reliable grid electricity.
Off-grid cell towers number in the hundreds of thousands, and one report suggests that as many as 75,000 new off-grid cell towers are being built in developing countries each year. Companies who own and operate these off-grid cell towers must typically rely on diesel generators for electricity. As a result of their explosive growth over the last decade, diesel powered – or supplemented – cell towers have quickly become a major global consumer of fossil fuels. In India, the telecommunications industry is now the country’s second largest consumer of petroleum (Ahmed, 2015).
The use of diesel generators at these sites is far from ideal. Telecom providers incur high maintenance and energy costs, consumers are subjected to noise pollution, and the world suffers the climate impacts of inefficient fossil fuel burning. However, off-grid cell tower infrastructure also presents an enormous opportunity for improved regional sustainability.
The 7th Sustainable Development Goal states that, by 2030, we will “ensure access to affordable, reliable, sustainable and modern energy for all.” Energy poverty is a powerful impediment to global equity; however, expanding national electricity grids is an extremely slow and expensive undertaking, requiring stable financing and refined political coordination; both of which are often out of reach for countries most in need of expanded energy development. Given these barriers, there is a strong argument to be made for putting a greater emphasis on distributed renewable resource development in off-grid regions. It is in this pursuit that existing off-grid cell towers could have a dramatic impact. Off-grid cell towers provide an industry platform around which to build distributed and renewable energy resources, providing an abundance of co-benefits.
Reduced maintenance and energy costs
Purchasing the necessary diesel for these cell towers contributes 25% of the towers total operating cost. There are also the indirect costs of fuel transportation and generator maintenance which in some cases can match or even exceed the cost of fuel. Having a portion of energy demand supplied by renewables, reduces the need for fuel delivery, cuts the cost of energy, and can provide a back-up for the fossil fuel generator. Even for grid connected towers, on-site solar or wind power can significantly reduce energy costs.
One of the greatest challenges facing cell towers with an unreliable grid connection is service reliability. If the grid losses power, or if the generator stops operating, customers will lose service, which can interrupt work productivity and essential services. By integrating regionally appropriate renewables and a battery storage system, service reliability can be ensured.
Energy for the community
Excess electricity from off-grid cell towers can be used by the community to store vaccines and medicine or charge appliances, thereby reducing local energy poverty. Even a small amount of electricity can have an enormous impact on the lives and health of rural communities, and providing the surrounding community with electricity can increase telecommunication revenue. Excess electricity can be sold, and the supply of electricity will promote nearby development and increased appliance usage. This will in turn increase service density and reduce operation costs. As tower efficiency continues to improve, and generation investments continue, the share of electricity sold to the public will grow, creating a network of distributed energy resources.
Global environmental benefits
It is estimated that the global carbon footprint of cell towers is approximately 230 million tons, and raising every year. Cell towers that rely on diesel generators are especially inefficient and polluting so replacing some of their energy demand with clean renewables would significantly improve the industries environmental impact.
These co-benefits are not strictly theoretical. India has already mandated that 75% or rural towers and 33% of urban towers operate off of hybrid power by 2020 rather than attempting to extend grid access to the sites. Although some progress towards this goal has been made, by December 2016 only 20% of India’s 450,000 cell towers were diesel free. It is now estimated that India’s cell towers alone contribute more than 64 million tons of CO2 each year.