Telecommunications company Telkom completed Phase 1 of a three-phase, 3 MW solar photovoltaic (PV) installa- tion as part of a new parking lot for staff mem- bers at its Centurion headquarters, Telkom Park campus, last month. The project uses solar PV panels mounted on the roofs of new parking bays.

Phase 1 of the project will introduce 1 MW into Telkom’s integrated electricity distribution network for consumption by the Centurion-based office park. Each subsequent phase will introduce another 1 MW into the system, thereby representing about half of Telkom’s daytime electricity demand. Total peak consumption on the campus is about 7.2 MW. Power demand at night stems solely from two data centres, thereby dropping to about 4.2 MW.

All 3 MW is expected to be fully commissioned by the end of this month.

The solar gains achieved using the solar panels are enhanced through the cantilever and angled design of the new parking bays, with various sections of the bays being specifically angled towards the sun’s rays throughout the day.

Telkom corporate real estate services head Praven Naidoo says useful solar gain is from about 8 am to 4 pm – a good spread of energy throughout the most productive hours of the day.

The panels are connected in a parallel format, ensuring that, if one becomes dysfunctional, the remaining panels can continue functioning.

Construction of the car park and solar PV project began in January, with the concept having been conceptualised and discussed in April 2015. Naidoo tells Engineering News the solar PV project is “proving highly commercially viable” for Telkom, with a predicted return on investment, linked to the current exchange rate, in about eight years.

The 3 MW generated by the solar panels will help Telkom decrease its carbon-linked emissions by about 15 000 t a year.

Meanwhile, the cantilever design not only “looks great” but also reduces the risk of damage by vehicles, as there are fewer posts to collide with, notes Naidoo.

However, the solar panels are angled towards the sun, which results in the carport having a higher degree of wind resistance. This is problematic because it creates the danger of solar panels being torn from the carport. The wind resis- tance is also exacerbated in the high winds area, as a result of the car park’s low-lying geography.

Telkom addressed the issue by engineering the carport framework and by using larger foundations to increase the anchorage and stability of the carports to ensure they are unaffected by strong gusts.

In an addition, the carports have an extra layer of metal covering under the solar panels to mitigate the potential of solar panels being separated by their mountings in strong winds.

As a bonus, Telkom staff will be able to charge electric vehicles using electricity generated by the solar panels.

Extending Energy Savings
Telkom is planning to explore other energy- saving concepts and ideas at its Centurion campus, thereby diversifying its energy composition.

Naidoo tells Engineering News that discussions are ongoing to install another 3 MW of trigeneration infrastructure at the campus in the form of a gas-piped network, and three or four gas generator sets.

These generators will be adapted to offer Telkom trigeneration energy potential, with heating and cooling components, thereby further reducing the company’s energy consumption.

“On the back of the gas generators, there is potential to gain 1.5 MW of heating and cooling power as part of the trigeneration package,” he says. Telkom plans to start the gas portion of its energy plane once the solar PV section is fully commissioned. “If all goes according to plan, in about 18 months to two years, we could be completely off-grid,” Naidoo states. Telkom is also considering plans to centralise its major backup systems at its Centurion campus and install uninterrupted power supply infrastructure to enhance its service offering and resilience. Further, a system to diversify its planned energy use is also being installed. It will serve to balance energy use – evening out peaks and troughs of energy use – and enable Telkom to use electricity from the grid during times when it is the cheapest, thereby significantly reducing its electricity bill. Telkom is working with other companies and providing its adoption of renewable-energy systems and ecofriendly initiatives as a proof of concept that going green is beneficial