Cape Town - A solar-powered generating plant on the roof of an office park in Observatory, Cape Town, has become the first of its kind to feed electricity into Cape Town’s distribution network.
The 1.2MW Black River Park Solar Project is also the largest roof-mounted integrated PV (photovoltaic) plant in Africa and one of the largest in the world, according to the developers, who say it’s able generate just under two million kilowatt hours per year from its 5 500 modules.
The initial 700kW installation has been operating above expectation since last August, feeding electricity into the city’s grid during off-peak demand periods by businesses at the park. Phase two, consisting of a further 500kW of solar power, was approved without any subsidies because of the performance of phase one.
Although the first electricity was fed into the city’s network in March, confirmation of the feed-in tariff is still subject to a legal agreement that will probably be completed within the next two months.
Acting mayoral committee member for utility services Brett Herron said the city was not yet compensating residents or businesses – other than three temporary residential pilot projects – for feeding power back into the grid.
“That said, the city is finalising the technical process and complex legal framework which will enable us to compensate (them). A number of residents and businesses, including Black River Park, have indicated their interest and the city is expecting to make an announcement in the near future.”
Chris Haw, managing director of the solar firm responsible for the design, construction and operation of the project, said the city’s approval marked “a considerable breakthrough in the pursuit of electricity users who invest in independent power production to sell energy back to the distributors during periods when it’s not needed on site”.
Haw, also spokesman for the SA PV Industry Association, said this was the practice in most parts of the world and they had been trying to implement it in South Africa “for years”.
The buy-back rate has been proposed at 49.72c/kWh, approximately that at which the city buys electricity from Eskom, but still lower than the rate at which the office park buys electricity from the municipality.
This encouraged most of the energy generated to be used on site, but catered for situations in which the local demand was less than what was produced by the solar system, he said.
The major obstacle preventing municipalities from encouraging more private generation and trade of electricity was the perceived threat to municipal revenues received from electricity sales, but sustainability experts advised otherwise, he added, and quoted Professor Mark Swilling, academic director of Stellenbosch University’s Sustainability Institute: “What municipalities are beginning to realise is the small amount of lost revenue from allowing solar generation is more than compensated for by the increased economic activity as a result of improved efficiencies and higher attractiveness of the location to do business.”
The 74 000m2 office park houses more than 100 businesses.
One of its tenants is the Green Building Council South Africa that has a “green lease” in the form of “a shared undertaking between landlord and tenant to ensure the effective running of the building along environmentally friendly principles such as energy efficiency”.