Vodacom implements Solar PV to reduce carbon emissions

Submitted by: Jonathan Ramayia, Monday, September 30, 2013

<p>542 kWp Solar PV installation on the roof of Vodacom’s Cape Town head office at Century City (Image Source: Jonathan Ramayia)</p>

542 kWp Solar PV installation on the roof of Vodacom’s Cape Town head office at Century City (Image Source: Jonathan Ramayia)

Earlier this year Vodacom completed a 542 kWp Solar PV installation on the roof of its Cape Town head office at Century City.  “Combined with South Africa’s high levels of irradiance and the availability of a building with large roof space, the correct orientation and the slope of the roof, it was a no-brainer to implement a solar PV rooftop project of this scale”, said Suraya Hamdalay, Executive Head of Corporate Citizenship and Sustainability at Vodacom.

After implementing a number of energy efficient measures, and a few small stand-alone renewable energy projects, the telecommunications giant felt the time was right to pilot a larger renewable energy project says Hamdalay.  The project came in at a cost of R10.6 million with the system’s annual yield estimated at 894.9 MWh of electricity. The array, which consists of 2,127 panels is laid over 3,600 m2 of roof space and covers 75% of the building’s maximum electricity demand at peak power, generating surplus on weekends when the electricity demand of the building is lower. The building’s baseline demand stands at 520 kW and its annual electricity consumption is 3,000MWh, “on weekends, over low-load conditions we are discarding 250 kWh of electricity,” notes Hamdalay.

At present, there is no mechanism through which Vodacom is able to export electricity back to the grid, as it is not allowed by the City of Cape Town’s electricity department, much to the disappointment of Hamdalay and her team, “this would help improve the viability of renewable projects but we remain optimistic that this will change in the near future as there is greater demand from independent power producers.” The payback period, which includes the savings from the Eskom small renewables subsidy, has been worked out to 5.5 years, with a potential further reduction if excess electricity is sold to the grid. As they are currently unable to sell the excess electricity back onto the grid, Vodacom plans to make ice from the excess electricity which will be used for HVAC purposes during Cape Town’s summer months.

The Solar PV installation is just one of Vodacom’s strategies to reduce its carbon emissions.  As an organisation, the bulk of Vodacom’s electricity demand comes from its base stations, or cell phone towers, which holds together its large network across South Africa. In the 2012/2013 period, Vodacom had 9,405 base stations and its associated access network electricity consumption was 206.6 GWh. By contrast, its buildings only used 60.2 GWh of electricity. Realising this, Vodacom’s carbon reduction strategy has focused on making their base stations less dependent on electricity, and reducing the number of base stations required in the country.

Base stations house radio transmitters and receivers that pick up signals from phones, before transferring them to their respective network operators.  “One of the main reasons base stations consume a large amount of electricity is because the electronic equipment used for processing signals needs to be maintained at a certain temperature, to prevent overheating and equipment malfunction,” noted Hamdalay.

To reduce electricity consumption at base stations Vodacom has employed a technology called “free cooling” at a number of its base stations. “Traditionally our base stations, housed in a 2x2 square metre area, have used air-conditioning to keep temperatures cool, but free cooling has allowed us to make use of natural ventilation to ensure that the equipment does not over heat,” notes Hamdalay. In Tanzania, Vodacom’s base stations are not contained within a structure therefore are open and don’t depend on air-conditioning, in South Africa, base stations have to be housed for security reasons. A total of 1,000 sites have implemented free cooling technologies this year leading to savings of approximately 1,231,621kWh.

In addition, some base stations in rural areas that are located far away from grid connections make use of diesel generators, resulting in greater carbon emissions. “We’ve made an effort to reduce our dependence on diesel and have employed the use of small solar panels and batteries in areas like Canelands, located in rural KwaZulu-Natal,” says Hamdalay. The base station is remotely monitored which assists in theft prevention. In Lesotho, Vodacom’s base stations run entirely on solar panels and run-of-the-river energy solutions.

Energy efficiency remains an important strategy in reducing electricity consumption says Hamdalay, and as a result Vodacom has invested heavily in their radio access network (‘RAN’) renewal programme, which aims to replace their older, more energy-intensive network equipment with new, more efficient technology.

Combining its environmental strategy with its social responsibility, Vodacom launched the Community Power project in Emfihlweni community in Northern KwaZulu-Natal which provided electricity for a rural school while at the same time borrowing a local school’s roof space to power a nearby base station. Before the installation, the school was without electricity and the base station was powered by a diesel generator.

Vodacom aims to roll out more renewable energy initiatives on their various buildings as a result of the success of the Century City installation, but will continue to ensure investment in reducing their carbon emission from base stations. This is a challenge because of the amount of new base stations coming online as a result of customer growth says Hamdalay. Although the electricity consumed by its buildings decreased by 25.9% from 2013 to 2013, electricity demanded from base stations increased 9% in the same period, reflective of the 5.2% increase in the number of base stations.

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Jonathan Ramayia