Generate power and sell extra to city

Cape Town – A Constantia, Cape Town, couple has found a way to beat electricity price blues. They generate their own electricity – and sell their excess power to the city council.

Leigh de Decker and her partner Mark Blelochk, of Nova Constantia Road, are one of the first households to sign a contract with the City of Cape Town to be electricity generators. Although the city has similar contracts with businesses, the domestic market is still in its infancy.

“It’s all signed off and legal, and we were told we were the first domestic house to do it. It’s been done all over the world for many years, in Germany, the US and UK, but somehow in sunny South Africa we’ve been very slow on the uptake of generating solar power on rooftops,” De Decker said.

Leigh de Decker has installed solar panels at her home in Constantia, and feeds excess current into the Escom grid. Picture Jeffrey Abrahams

The couple have installed several photovoltaic (PV) panels on the roof of the garage, and a PV inverter inside. This converts the direct current from the panels into alternating current that can be fed into a commercial electrical grid. When the sun is shining and the household has more electricity than it can use, it “sells” this back to the city via their bi-directional metre.

“Money doesn’t change hands, as the city purchases by credit. As my metre ticks over from the power the PV panels generates, I’m building up credits at a rate of 56c a kilowatt hour. That is the price the city buys power from Eskom.

“And when we need power at night, then we import electricity from the city and we get it at a 42 percent discount. From a business point of view it is a remarkable win-win situation.”

A modem allows her to monitor the electricity generation on her computer, including how much CO2 she has avoided.

The cost of installing the panels and inverter varies depending on the quality of the equipment and the number and panels installed.

De Decker said the total cost of their set-up was around R160 000.

“We’ve worked out that the pay-back time at current electricity prices – and they’re going up all the time – will be four and a half years. This is not a system for small electricity users with bills of R800 or less, it is for big users.”

Mayoral committee member for utility services, Ernest Sonnenberg, said any domestic consumers could become part of the project.

However, he said householders who generated electricity did not get a special discount on tariffs.

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By Melanie Gosling
Cape Times