Smart grids to reduce costs and improve service

September 27th, 2017, Published in Articles: Energize

In his opening address at the SAIEE’s Smart Grid Conference recently, the president of the South African Institute of Electrical Engineers (SAIEE), Jacob Machinjike, said that a smart grid infrastructure would provide unique opportunities for improved electricity services which would benefit people in Africa.

Jacob Machinjike

 

The conference, which was held at the Eskom Convention Centre in Midrand recently, heard that since the continent has wonderful wind and solar energy resources, these should be harnessed and fed into a smart grid which would efficiently control and regulate the inherently varying supply of electricity.

Machinjike said that the development of a smart grid, which will enable the integration of renewable energy sources into micro- and mini-grids, will also require new skills which industry will have to provide and which may require some changes at tertiary education level.

In his presentation, Nico de Jager, a councillor from the Johannesburg City Council, said that a smart grid would be of benefit to City Power as the utility focuses on the growth and extension of its electrification programme. Johannesburg, he said, which covers an area of over 1600 km2, contributes 16% of South Africa’s gross domestic product (GDP) and 40% of Gauteng’s economic activity. There are 181 informal settlements within the city’s limits, he said, many of which still lack electrical power and other basic infrastructure.

Currently, the city’s peak demand of 4 GW is met by electricity generated by the Kelvin Power Station, Eskom, and some diesel and methane powered generators. Diesel, together with some methane from the city’s refuse sites, is used to generate 170 MW, he said.

Nico de Jager

The city has a growth and development strategy, de Jager said, to make energy reliable and affordable by 2040. Part of the programme is the reduction of harmful greenhouse gases which come from energy generation and vehicular transport. To achieve this, the city will make use of more renewable energy. By making use of a mix of generating technologies, the city plans to reduce the cost of electricity to consumers.

Eskom is, and will remain, the city’s largest supplier of electricity, he said. However, some residents, who have installed – or will install – rooftop PV systems, are likely to generate more electricity than they need. A smart grid would enable them to  supply the surplus to the city, de Jager said.

City power’s smart grid programme will allow the network to change from having a hierarchical structure to a more interconnected one, where energy and data moves bi-directionally. The objective of the programme is to improve customer satisfaction by improved billing, condition monitoring, demand-side management and outage management, he said. According to de Jager, the city is highly reliant on accurate billing because 60% of the city’s income comes from electricity sales, along with water and refuse removal services.

Reji Kumar Pillai, the president of the Indian Smartgrid Forum, said in his keynote address, that just as progress in technology over the last 25 years has changed the way people do things, so too we must expect things to change in the energy sector.

Reji Kumar Pillai

He said that smart metering, which is a vital component in a smart grid network, is difficult and expensive for a municipal utility to manage and should be outsourced to a specialist company which is paid a fixed fee per meter it manages.

Energy storage, another important part of any renewable energy-based network, has developed significantly in recent years and will continue to do so, Pillai said. Citing an example of a flywheel storage system which provides power for four hours in California, and the dramatic decrease in the price of Li-ion batteries, he said that recent developments in various mechanical and chemical storage systems have extended storage capacities and reduced the cost per MW stored.

These developments make the variable output from wind- and solar-powered generators more useful in off-grid applications, and less disruptive to grid-based networks.

Solid state distribution transformers and other technological advances in electrical equipment, will continue to improve power quality while reducing capital and maintenance expenditure – resulting in more reliable and less expensive electricity to power homes and businesses across the city, he said.

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