Dr Leigh de Decker, founder of BrightHouse Energy, was the first private consumer to enter into an agreement with the City of Cape Town to sell electricity back into the grid.

Her decision to install a solar PV plant at her home was motivated primarily by a wish to live more sustainably and be more self-reliant and resilient.

Before state power utility Eskom’s loadshedding (rotational power cuts) escalated to 2023’s Level 6, she ran all her optional energy-intensive appliances, such as her swimming pool pump and irrigation system, off her solar system in the daytime and used grid power by night.

‘The real value of solar is not for what you can export, but the money you save by not having to import electricity (off the grid),’ she says.

Cape Town is one of a growing number of municipalities, especially in the Western Cape, that offer consumers the option of selling their surplus electricity back into the grid.

Crippling and sustained bouts of loadshedding over the past few years have led to a host of new options available for any South African keen to invest in renewable energy.

Aided by tax incentives, new financing options, a significantly more attractive regulatory environment and a boom in imports of solar panels and inverters, green energy is now within reach of an increasing number of households and businesses.

Pay as you sell

Setting up a household to sell power back to the grid still requires a substantial capital investment. Firstly there’s the solar panels, inverter, batteries and installation fees, and then, to take part in the buy-back scheme, households have to buy a bidirectional meter that measures incoming and outgoing current.

For households with single-phase power, the meters cost around R5,000, and older households with three-phase power typically found in industrial and commercial buildings the bidirectional meters cost R9,000.

The City of Cape Town paid households 87c/kWh for excess electricity they sold back into the grid at the beginning of 2024 (the rate was scheduled to increase by 11% from 1 July), along with a 25c/kWh incentive, for taking part in the scheme.

This amounts to only 42% of the price the city charges per kWh (308.58 c/kWh) for lower-consumption households, and only 30% of the 426.56 c/kWh charged to higher-consumption households.

The monthly electricity bill of households with bidirectional meters shows how much electricity was imported and exported, as well as the monthly electricity access fee, which is identical whether you have a solar system or not.

Choose wisely

Liam McGurk, owner of Cape Town Solar, one of the oldest rooftop solar installers in Cape Town, until a few years ago, says only a limited number of suppliers sold the specialised equipment necessary for a solar installation, but the booming demand brought about by loadshedding has flooded the market, bringing down the price of solar panels and inverters and spreading availability to just about every large supplier of electrical equipment in Cape Town.

Increasingly, solar installation is also no longer only done by specialised installers, but also by electricians who undergo additional training on solar systems. Not all training is equally comprehensive, and the required regulations are updated constantly – another reason to do your homework carefully before settling on a contractor.

It’s crucial not to shop on price alone, says McGurk. ‘You have to ask for references, and photos of jobs that the installers have done. It helps if an installer is a master installer with a reputable brand like Sunsynk, Luxpower or Deye’. Having master installer status gives the contractor 24-hour access to the manufacturer’s support team.

‘Does the installer have insurance, does he have the correct tools to connect the batteries, are they also going to do your certificate of compliance? Do they have backup batteries and inverters available should your system fail? The installer’s service doesn’t end when the system is installed, they should still be available afterwards to help you when things go wrong.’

McGurk says he maintains contact with all his clients and can also monitor and adjust their systems via the manufacturer’s app.

‘The technology is advancing so fast, I reckon that within a year you’ll be able to buy inverters that incorporate AI (artificial intelligence) to factor in the weather forecast when managing the system,’ says McGurk.

He has high praise for the way many of his clients take ownership of the technology. App controls allow both the owner and technician access to the real-time generation and usage data from the inverters, as well as making adjustments to what proportion of the home power comes from the solar panels, batteries or the grid.

‘This is a way for owners to learn how their system works and get the most out of it. The more efficiently you learn to use your system, the quicker it pays for itself,’ he says. And while an app makes for compelling viewing, it also records all data that may later be necessary to troubleshoot any faults should something go wrong.

‘You will certainly never get rich out of this scheme,’ says De Decker.

This past summer she accumulated the highest credit on her electricity bill since she started feeding electricity into the grid in 2014, but the line costs soon eradicated the credit.

‘You may find yourself with a nice big credit of R1,200 on your account, but then comes the VAT, and in the winter months when the sun is no longer shining as nicely or there is a week or two of pouring rain, that would have soaked up all your credits.

‘For me the value of this system is that without it, in summer, my electricity bill would probably run to R8,000 or R9,000 per month. Instead I’ve had one or two months where it was negative, and the highest it’ll get in winter is around R2,000 when we have heaters running.’