Telecommunications (telecoms) group MTN would increasingly use renewable energy technologies to assist in bridging the digital divide and provide voice services and wireless broadband to communities far from urban centres.
On a site visit to the off-grid base transceiver (BTS) station near Riemvasmaak in the Northern Cape, MTN executives said that following the success of this BTS, there were plans to roll out a further 150 ‘green' base stations in 2011.
The R2,6-million BTS is situated more than 120 km west of Upington and makes use of the region's abundant solar irradiation, with a 3 kW installed capacity solar array.
In addition to solar power, at the top of the 56-m high BTS is a Bergey wind turbine, which has the capacity to generate about 7,5 kW of clean power at the site.
MTN South Africa core implementation manager Willem Weber explains to Engineering News Online that the solar photovoltaic (PV) array consists of fifteen 220 W panels, manufactured by Tenesol - a France-based company, which has a manufacturing facility in Cape Town.
Sealed, maintenance-free gel batteries have capacity to store enough power for the BTS site to operate for two days in the event of no solar or wind power being generated.
The complete generation capacity exceeds the current needs at the BTS, which has been designed to draw a 1,5 kW DC load. This means that there is room for expansion at the BTS should more equipment be required to increase the telecoms capacity.
Air conditioning for the equipment is one of the major power requirements at the BTS, and at this site normal AC air conditioners are not used. Two DC extraction fans keep the equipment cool, and only 150 W on 220V is available in AC for a laptop from a DC/AC inverter.
There is no secondary energy source at the station, which has been operating for some four months, without any problems reported, notes MTN SA network group green BTS site build project manager Christene Jonker.
MTN SA central region BTS implementation head Hendré Kruger notes that previously, if there was no option to extend utility power to a BTS site, the company would not be able to provide services in the area, particularly since renewable energy solutions were prohibitively expensive. "But the costs are coming down fast," he says, thus making such sites viable.
Turnkey telecoms infrastructure company Plessey was the project manager for this site, with civil work subcontracted to Towcon Civils, while the electricity and reticulation portion of the contract was awarded to Energy Insight.
Of the total BTS project cost of about R2,6-million, some R1-million was dedicated to the renewable energy portion of the project. This was still considered less than the cost of extending the Eskom grid to power the BTS, which would likely have cost in the region of R1,5-million.
The bonus with renewable energy is that after the one-off capital expenditure (capex) cost, there are no more utility bills.
Weber also said that the site expected to be a money-maker, despite the low volumes of traffic, because once the capex is recouped, there is no running cost and only minimal maintenance.
The BTS site covers a 35-km radius, and is the second off-grid BTS site in the area, where previously, low-income communities had little contact with the outside world, as the fixed line operator declared that access to the sites was not viable. For the last two years, farmers in the area used two-way radios to communicate and bedand breakfast operators had to travel to town to use the telephone and manage bookings, as fixed line services were not upgraded.
The base station employs universal mobile telecoms system (UMTS) 900 technology, and makes use of the 900 MHz network spectrum, which is usually used to provide voice (second generation or 2G) services, to provide third generation (3G), or wireless broadband services.
MTN SA radio planning and optimisation GM Thaigan Govender explains that using this technology allows coverage over vast distances, and provides the benefits of both voice and the Internet, as well as the affordable roll-out of 3G services.
Sitting on a rock surrounded by sparse shrubbery and not much else under the blazing Northern Cape sun, Govender tested the Internet connection bandwidth using his mobile phone. The speed test showed a 1,3 Mb download ability, with 1 Mb for uploads, and the device streamed music videos without buffering.
MTN SA said that it aimed to continue re-farming a portion of its new 900 MHz spectrum to extend its wireless broadband coverage into rural South Africa.
The company's data services currently cover almost 50% of South Africa's geographical area, and with the phased roll-out of the new network, MTN is initially looking at communities close to outlying cities to enhance its 3G footprint, with the second phase expected to extend to more remote areas.
"Wireless broadband is the most effective mechanism to bring data services to rural South Africa - it makes business and economic sense. We believe much of our future data market will come from these previously under-serviced areas that are desperate for the full end-to-end connectivity services MTN can provide," said MTN SA MD Karel Pienaar.
On the two-hour journey to reach the green BTS station from the nearest town at Augrabies, Pienaar and the MTN executives stopped in at the Riemvasmaak Primary School, and provided the headmistress with a cellular phone for the school, as well as T-shirts, caps, bottles and pens for the school children.
When asked if there was anything in particular that the school needed, the headmistress said that the school needed the Internet, which of course would require computers.
MTN was considering further investment into the rural community, and the school in particular, through its social investment arm, the MTN Foundation, and the schools connectivity programme.