Right now the key to a significant niche energy storage market is probably sitting in your pocket. The mobile phone industry is an important battery consumer, and not just for the cells that power shiny handsets. Base station power is a critical issue for mobile operators, and one where energy storage plays a serious role.
Whenever you make a call your phone’s signal has to be picked up by a base station which needs a constant power supply to work. If a power outage puts the base station out of commission then calls won’t connect and the mobile operator starts losing money.
Base station outages are less of an issue in built-up areas because grid connections tend to be good and neighbouring base stations can field signals not picked up by an inactive mast. But in remote areas, or where grid power is irregular, energy storage, usually in the form of batteries, is a must. Plus it makes economic sense.
The traditional way of delivering power to off-grid base stations is through diesel generators or gensets, but these need to be refilled regularly and can leave the mobile operator with a useless mast if they break down.
Carrying batteries for backup
Hence most off-grid base station generators carry batteries for backup. Judicious use of battery power can significantly reduce the operational expenditure (opex) on maintenance, says Amir Yerucham of Ascot, a power module developer. With traditional gensets, maintenance is required every couple of weeks, but “with batteries you can cut the opex costs by 65%,” he says.
If you add photovoltaic panels into the equation, so the base station mainly draws solar or battery power, the genset may only cut in a couple of times a year and maintenance costs can fall by nearly 99%, he adds. The benefit of having almost fully autonomous base stations cannot be underestimated in many remote locations and emerging markets.
Some masts can be virtually inaccessible at certain times of year, for example because of snow or floods. Elsewhere, the threat of operations crews being subject to theft or extortion can add to the cost and risk of maintenance.
As mobile phone companies increasingly extend their reach into far-flung territories, batteries have become an ever more important part of the base station power equation.
Companies jostling for attention
No surprise, then, to find a range of battery makers present at this year’s GSMA Mobile World Congress in Barcelona. Ballard Power Systems, GE Energy Storage and Saft were among the companies jostling for attention. Their promotional efforts seem justified given the likely growth of the market.
Frank Dai, vice president of Shenzhen Megmeet Electrical Co, which has installed power equipment at around 26,000 mobile sites worldwide, says around 6,000 new off-grid base stations are going up every year in China alone.
Part of this activity is due to network expansion but further growth is due to the introduction of a new mobile standard, 4G, which has sparked something of a base-station bonanza worldwide.
Shenzhen Megmeet Electrical relies on lead-acid batteries from manufacturers such as BSB Power Company. Lead-acid holds sway in the base station market because of its low cost, but the technology is facing competition. For example, says Arthur Sams, president of Polar Power: “Right now we can sell lithium-ion for nearly the same as lead-acid, so why would we sell lead-acid?
“Lithium-ion is smaller, lighter, and we can provide [the batteries] at a comparable cost.”
Important considerations in the tropics
Lithium-ion is also theoretically more heat-tolerant than lead-acid, which is an important consideration in many tropical and sub-tropical countries. Lead-acid battery makers are not standing still, though. BSB Power is commercialising products designed to work at up to 45ºC. “Lead-acid is still 95% of the market for mobile base stations,” says Stanley Lou, vice president of marketing and sales.
“With our new products, now it goes to higher temperatures, plus it’s cheaper and can be recycled.”
Last but not least, GE Energy Storage is clearly beginning to establish a presence in the base station market with its sodium nickel-based battery system. Base station power unit providers such as 3Tech are beginning to select GE’s Durathon batteries but others grumble about the cost.
GE Transportation sales director Kimani Tharao acknowledges this is an issue for system integrators that are trying to make a margin on integrated systems. The company is responding by trying to get mobile operators to specify Durathon in the first place. “We are introducing the technology to operators,” says Tharao.
“A lot of efforts are around making sure the end user knows which benefits they will receive from this.”
Written by Jason Deign
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