DoCoMo tests blackout-proof hydrogen cell base station in Japan
Ready for the next tsunami
Nokia Siemens Networks, working with Ballard Power Systems, has delivered a cellular base station with an integrated hydrogen cell that replaces battery- or generator-based backup during a power outage.
The base station has been installed at DoCoMo's research site in Japan’s Yokosuka Research Park and can operate for 40 hours in the absence of mains electricity, with the hydrogen fuel cell delivering 4.5KW of electricity. The idea is to provide backup power, without needing the regular maintenance of a generator or taking up the space of lead-acid batteries.
In the UK, most base stations only have batteries to keep them operational for an hour or two, and there's no obligation on the operators to keep infrastructure operational, but the Japanese tsunami focused attention on the question. Meanwhile, in the US, legislators are starting to wonder if battery backups shouldn't be mandated for cell sites.
US Senator Charles Schumer has written an open letter to the FCC chair asking that the regulator create a proper plan for keeping network infrastructure running in an emergency. His letter points out that a third of New York households rely exclusively on cellular networks, and that Hurricane Sandy knocked out a quarter of the cell sites it passed, mostly by cutting off their power.
Fuel cells can run base stations for a lot longer than batteries, though they'll still need somewhere to connect to. Both the Japanese tsunami and the US storm knocked out control centres, leaving base stations with nowhere to go even if they had been supplied with power, but recovery might have been faster if there had been a little more hydrogen in the mix. ®
Molten salt batteries
Molton salt batteries are the way to go. They're rechargeable and you can store them for a long time when they're cold with no self discharge and start them again with a detonator. Used in missile guidance systems, and more recently as the batteries for newer diesel electric locomotives with regenerative rather than just rheostatic braking.
Re: Lack of maintenance??
In an emergency I'd rather have the water available to drink instead of being slowly pissed away due to hydrogen leaks.
storing hydrogen somewhat tricky
If you keep it under pressure it has a nasty habit of embrittling whatever's being used to store it (including rubberised bladders, etc). if you don't, then you need LARGE storage tanks.
Hydrides are nice, but too expensive.
There are already fuel cells available which run on methane or propane, both of which are readily available and a small (or not so small) diesel donkey generator keep the batteries floating has been the standard backup method for critical services in Telecoms for decades.
Decent deep-discharge traction cells aren't cheap either (nor small), which is why a lot of cellular sites don't bother with them. Current thinking is that losing cell density is acceptable, but beancounters tend to take this model too far.