Solsquare acted as general contractor on this project, collaborating closely with Conergy in the planning and engineering. The 62 kilowatt grid parity plant operates with 100% own consumption and does not have to rely on any help from state-backed feed-in tariffs. The 48 residents of the home and their 12 carers will cover around 70% of their electricity requirement from the plant in the summer and achieve a level of autonomy of 45% in the winter. The rooftop plants also represent one of the first projects with so-called “automated output power management”, which prevents solar power being fed into the grid in line with Cape Town city regulations. The majority of the funding for the project came from the “Energy and Environment Partnership” (EEP), a European development programme for South and East African countries.
Over 250 Conergy “P Series” modules on seven roofs of the welfare facility will produce around 97MW hours of clean solar power a year. One of the plants has been installed on a pitched roof using the Conergy SunTop mounting system; the others on flat roofs using SolarFamulus frames, which provide an incline of thirteen degrees. The solar experts thus achieve the best possible insolation while minimising vulnerability to the strong winds prevalent at the Cape, which can reach speeds of up to 125 kilometres an hour. The solar power plants will be preventing the emission of around 93 tonnes of damaging CO2 per year in the metropolis near Table Mountain, which corresponds roughly to the annual emissions of around 50 cars in the crowded city.
Besides excellent growth prospects, the South African market offers further advantages. For end consumers such as the home in Cape Town, solar energy is already cheaper than electricity from the grid today. One solar kilowatt hour from the plant on their own roof costs the home operators around 0.81 South African rand, while they pay an average 0.94 rand for each kilowatt hour from the grid. They will thus be saving around 13 South African cents or 16% of the cost with each solar kilowatt hour they consume. In addition to the electricity cost savings, the plant benefits from a scheme to encourage energy saving run by the state energy supplier Eskom. For each kilowatt hour of electricity saved during peak load time, the end consumer receives a so-called “Eskom rebate” of 1.20 rand for the first three years from the date of installation. As the plant does not feed power into the grid, the volume of electricity saved is calculated from the amount of electricity generated by the solar plant during peak load hours.
“The home is partly funded by the state and also to a large extent from donations,” said Niels von Hase, Managing Director of Solsquare. “Thanks to the solar plant, we shall be able to reduce the operating costs considerably. Although the plant is currently not permitted to feed power into the grid due to legal regulations, there is a large savings potential. In addition, the government has plans to introduce both a feed-in tariff as well as ‘net metering’ probably from the summer of 2014, which means that it will then be possible to offset the amounts of electricity fed into the grid, consumed on site and drawn from the grid against one another. Our plant can be converted accordingly at any time, offering both maximum flexibility and savings potential to the customer..."