Wind power base station energy

Wind power may be part of the answer to Africa’s base station energy supply problems
Mobile operator’s margins are coming down from the heady days ten years ago and the growth left in the voice market is largely among low ARPU customers. Data may help rescue ARPUs in some countries but not those with low literacy levels. All this plus higher levels of competition amongst more operators must focus minds on the costs side of the equation. Providing energy to base stations is a huge element of any operator’s costs. Shared energy transmission supply options are being developed but not with any great speed. So looking at other energy options is a must if costs are to come down. Russell Southwood talks to Zephyr’s Europe, Middle East and Africa General Manager Mats Vilander.
Africa is famous for its sunny climate but if you ask where has the wind to support energy generating turbines, the answers are perhaps not so obvious. Wind strength maps show that the following countries have enough wind on a regular basis to power turbines: South Africa (particularly in the Eastern Cape and Cape Town), Namibia, Kenya, Nigeria, Madagascar, most of North Africa (particularly Libya) and Ethiopia. The US space agency NASA has wind maps for the entire globe at 40 metres above the earth’s surface and this with historic weather data is used to identify whether a site might be used for wind power. For as Vilander told us:”When 60 metre towers are erected, vendors look for evidence of what wind they will need to withstand.”
The cost for a wind power turbine from Zephyr (including construction) for a site using 10 KW a day is US$25,000. This costing is based on putting the turbine on an existing tower. Mats Vilander says:” The concept is modular so that it can be scaled up based on load and the wind turbine and its battery work independently of existing systems. It will work intelligently with a generator and identify when there’s no wind and therefore no power left in the batteries.” It can also work as a back-up system for existing sites reliant on diesel generators.
One pan-continental operator estimated that 10% of its sites were operating solely on diesel generator supplied power costing them US$146 million a year. It has been estimated that 65% of mobile operators’ energy consumption is for base stations but few companies have systems for tracking these costs in ways that will reduce them.
Given the costs, the pitch for wind turbines is two-fold: firstly, it can be used as a way of reducing diesel costs on existing base station sites (50% OPEX reductions claimed on rural sites) and for new sites (100% CAPEX savings where wind conditions are right). For as Vilander concedes:”It’s unlikely to be the primary source of energy for an existing site but it will be for new sites.” So with all the usual caveats about total energy requirements, wind speed, battery size and total cost of investment, the payback is likely to be around three years.
But whilst Vilander can point to plentiful wind turbine deployments by Zephyr, work with mobile companies is in its early stages. The company has a base station with Turkcell that has been in place for two years and according to Vilander the experience has been positive. There’s also sites in Japan but these have been used to feed energy back into the grid, something which should be happening in Africa but isn’t yet. There’s also a site in the Maldives that has been operating for six months. The company is currently talking to a range of African operators.
In terms of maintenance, Vilander claims zero cost provided the installation is done properly:”Any failures have been due to bad installing. Otherwise it doesn’t need maintenance. Everything is built in. It’s a low mass per watt output and comes with a 5 year warranty but will actually last 25 years. It can be controlled and checked remotely. If it exceeds 20 metres per second, the rotors will go down.”
The GSM Association’s Green Power for Mobile programme estimates that there have been 1,500 deployments of green power solutions in the developing world. The programme involves 25 global operators and from Africa’s viewpoint Vodafone and Bharti are on the list.