/ 27 November 2009

Only the big need apply

Electricity users in South Africa who are hoping to offset their electricity bills by installing a few photovoltaic (PV) panels on their roofs and selling electricity to Eskom are in for a long wait.

Not only does the latest set of renewable energy feed-in tariffs (Refits) set a minimum contribution of 1MW, but the infrastructure connecting individual households to the electricity distribution grid has not been designed to conduct or meter electricity flowing in more than one direction.

For ordinary consumers the most logical way to generate their own electricity would be to include the installation of PV panels, allowing them to use the sun’s power to generate electricity to power homes.

One of the problems facing consumers is that the majority of electricity generated by these systems happens at a time — during the day — when electricity consumption is at its lowest point.

To properly harness this power generation, consumers would need a storage device. This would require the installation of expensive battery-based storage facilities or the ability to sell that power to the national grid.

The power could then be bought back from Eskom during times when the PV panels are not generating sufficient electricity.

Cornelis van der Waal, programme manager for energy and power systems at Frost and Sullivan, says that in countries such as Germany and Spain systems are in place to allow individual consumers to contribute back to the grid.

He said that even though it would be difficult under the current regulations for individuals to sell power back to the grid, there are still opportunities for communities to leverage their combined purchasing power to find ways to integrate renewable energy on a local level.

‘Although legally you cannot transmit electricity across roads, it is possible for communities to band together and install some electricity generation capacity that can be shared by community members,” he says.

Van der Waal points out that another stumbling block in the path of the integration of renewable energy into the national electricity system is that Eskom has still to sign a single power purchasing agreement for the supply of renewable energy into the national grid.

‘There also remains some uncertainty about how much electricity Eskom will be required to purchase from independent power producers,” he says.

The smallest level of power production permitted at resent by the Refit is a PV system generating 1MW of electricity. This is beyond the reach of normal consumers.

National Energy Regulator of South Africa spokesperson Charles Hlebela says that the regulator has decided on a minimum of 1MW to participate in the Refit programme for the moment and that the minimum term that a potential power producer must commit to is 15 years.

Van der Waal says the reason potential electricity producers have to commit is to ensure the stability of the national grid.

He says the tariffs that have been stipulated by Nersa for the introduction of renewable energy will have to be funded by the regular tariffs that consumers of electricity pay.

The tariffs range from R0.96 /kWh for biogas systems to R3.94/kWh for large-scale grid-connected PV systems generating more than 1MW. This is in contrast to the R0.33/kWh that Eskom charges.