There’s a new box about the size of a book appearing on towers and at rural sites across Africa
Look at it more carefully and you’ll see that it’s a wind meter and is being used to measure wind speeds in the area so that operators can identify the most viable sites for wind power.
Wind power technology has improved a lot over the last few years and wind is now a reliable, sustainable and cost-effective energy source. We are starting to see commercial base stations in Africa being powered by either wind-alone or hybrid wind-solar solutions.
The first generation of wind turbines for powering base stations weren’t really mature enough for deployment on a mass-scale. They were too expensive, required a lot of maintenance and the turbines were large, heavy, difficult to install – and most importantly required high wind speeds.
All these problems have been solved with a new generation of small wind turbines which are lightweight, can be installed on existing towers and can generate energy at much lower wind speeds than previously of around 3 metres per second. With correct installation maintenance can be reduced to zero as today’s turbines can be controlled and checked remotely.
Solar drawbacks
Of course, there’s no lack of sun in Africa and when we’ve discussed alternative power in the region in the past we have usually been talking about solar. All the big vendors have solar-powered base stations in their portfolios. But solar does have its drawbacks: firstly it is not suited to areas prone to fog and clouds. Secondly the panels require a large space and are relatively easy to steal. And so they are usually surrounded by a fence with constant security on-site that, of course, adds to the cost of deployment.
Many people also don’t think of Africa as a windy continent but as the African Wind Energy Association’s slogan tells us: there is wind in Africa. https://afriwea.org/ And indeed there are wind farms operational in a number of countries including South Africa, Malawi, Zimbabwe, Mozambique, Kenya and Tanzania.
Commercial deployments of wind turbines
We are now starting to see commercial base stations in Africa being powered by wind in both off-grid and on-grid areas, at new sites and retrofitting existing sites.
In off-grid situations wind power is, of course, being used to reduce the reliance on diesel generators. Operators who have implemented wind power are saving around 50% of the diesel consumption for existing remote rural sites, sometimes up to 100% of diesel (at repeater sites). Plus, of course, the costs of transporting the diesel and the associated risks need to be factored in.
Wind is also being used by some operators to compliment solar-generated power. Solar is used during the day and then wind is used day and night to both power the network and charge up batteries.
Cost and ROI of wind power
The Business Case for an existing site depends on a number of factors:
Average wind speed in the area/site
Height of the tower and capability to locate more windload
Site power load, maximum load during the day
Site design, the number of TRX, base station type, transmission
Battery capacity & quality
Wind as a backup, or primary source, Solar elements
Accessibility of site
Obviously costs depend on the vendor chosen but as an estimate the cost of buying and installing two turbines which can power a typical rural GSM Base station requiring 600 watts on an existing tower with 6-7 m/s of wind is around ZAR 114,000 – 152,000.
Certainly wind power is now ready for commercial deployments. This time next year wind turbines will be deployed across Africa in off-grid rural areas.
Our trade organisation, the GSMA, estimates that nearly 639,000 off-grid base stations will be rolled out across emerging markets by 2012 and is aiming for 118,000 of these to be powered with renewable energy.
“Renewable energy base stations are the best way for mobile operators to extend their networks off-grid while minimising energy costs and their impact on the environment”, says David Taverner, Senior Programme Manager for the GSMA’s GPM.
The old way of using diesel as the primary energy source or backup will result in higher costs over time while wind has the opposite effect.
Zephyr Corporation’s small wind turbines are being used to power the base stations of operators in Africa – and across the world. www.zephyrcorporation.com
By Mats Vilander, GM for EMEA, Zephyr Corporation
