Vodafone in South Africa plans to avoid the recent problems it has had with South African power outages with more hydrogen-powered fuel cell base stations.
To support remote mobile cell sites, Vodafone puts in on-site generation and microwave backhaul. The sites can be dedicated to 2G, 3G, 4G or use multiple technologies.
Most mobile phone base stations which are too remote for mains power run with a diesel generator, but with an eye to CO2 emissions Vodafone is keen to reduce the use of diesel. It’s also noisy and smelly – which limits where it can be use – and significantly, it is valuable.
Thefts of fuel lead to regular outages, and in some parts of Africa it’s not unknown for people charged with running the base stations to sell the fuel and then charge people to climb the tower to get a signal.
Replacing the fuel with something which is harder to re-sell doesn’t eliminate the problem of theft, but does significantly reduce it.
Ideally, Vodafone will power sites using the mains supply but this is often unavailable or unreliable in South Africa, which means supplementing what’s available. Vodafone will sometimes supplement diesel with solar, but that doesn’t work too well in urban situations which might not have a good view of the sky.
The hydrogen is stored in compressed cylinders and does not need cooling, and leakage has not been an issue. There are various makes of cells being used and tested, typically producing 2.5-5kW. Delivery to sites is also quicker than pumping diesel.
Vodafone told us: “For sites where we use hydrogen fuel cells, we swap out empty cylinders with full ones as required. Frequency of refills depends on how much the fuel cell runs, i.e. the worse the grid quality, the more frequent the refills. Some sites are connected to our remote monitoring solution, which gives live status of the unit and its fuel levels.”
Sites are kept secure, meaning there have been no problems thus far. All the fuel is externally located within the site's open-air compound, so there is no access for anyone who might want to use the generation process as a source of clean water, as that would breach site security. Moreover, fuel cells do not produce enough water to justify a drinking fountain. ®