Ericsson is developing a wind-powered Tower Tube in cooperation with the University of Uppsala and Swedish Vertical Wind AB. A striking feature of the wind-powered RBS site solution is that it incorporates a turbine that revolves on a vertical axis (the tower being the “axis”) instead of spinning on a horizontal axis like a traditional wind mill-like turbine (Figure 1).
In September 2007, Ericsson released a radio base station (RBS) site solution called the Tower Tube. Ericsson Review briefly covered this in
Reducing CO2 emissions from mobile communications – BTS Power Savings and Tower Tube (Ericsson Review, Vol. 85(2008)1. Now, Ericsson has taken this concept one step further. Where telecom applications are concerned, a vertical-shafted wind turbine has several advantages compared with traditional wind turbin es:
 |
| Figure 1: Ericsson Tower Tube with wind-turbine |
- It is easier to fit on the tower without interfering with the antennas (a traditional wind turbine can only be placed at the top of a mast or tower).
- It will work without a control system regardless of wind direction.
- The design works with very few moving parts. The stator part is fitted directly on the tower, like a ring on a finger and the turbine is mounted directly on the rotating armature. This way there’s no need for a gearbox and the whole design requires a minimum of maintenance.
- Vertical-shafted turbines are very quiet compared with traditional propellers, because the wingtips, where most of the sound is generated, move much more slowly.
- Propeller blades often use mechanical adjustments to compensate for strong or weak wind, and the propeller has to be turned into the wind for optimized function. This functionality is redundant for a vertical-shafted wind turbine design.
Figure 2: Working prototype of the wind-powered Tower Tube in Uppsala, Sweden.
A prototype of a wind-powered Tower Tube is already in place in Uppsala, Sweden (Figure 2). When the product is ready for market, the 40-meter tower will contain a fully integrated RBS solution including batteries and a diesel generator for backup.
The solution is primarily intended for markets with little or no power grid. But the Tower Tube with an integrated wind turbine can also be deployed in markets with a good power grid, provided the feed-in tariffs are reasonable. In this case, the solution will be more or less self-sustained in terms of energy consumption.
There is huge interest in wind-powered telecom solutions. A main issue with wind power is the lack of reliable wind statistics, specifically in emerging markets. Therefore, a lot of data must still be collected and wind-mapping work done in order to make wind-power solutions a viable option.
Apart from the wind turbine, the innovative design of the Ericsson Tower Tube has several other positive environmental implications, such as shelter and tower in one unit, no need for fencing, and indoor housing of all equipment. What is more, the environmental impact of a concrete tower is lower than that of a traditional steel tower.
Finally, the Ericsson Tower Tube greatly simplifies civil works and installations.
