Cape Town - Eskom Group executive for Transmission and Sustainability, Thava Govender, says Eskom’s membership to a global body of 19 of the largest global grid operators will help the power utility access knowledge of how to integrate renewables into its power grid.
Govender said this when Eskom briefed the media following a meeting of the GO15 Steering Board members at the Radison Blu Hotel at the Waterfront, in Cape Town, on Tuesday.
GO15, which was founded in November 2004, is a joint initiative between 19 of the largest Power Grid Operators in the world.
“As grid operators, we have to manage the diverse mix of energy sources at it comes in, whether it is renewable, coal, nuclear, hydro - all those energy sources - the grid operator has to manage it seamlessly so that it flows and goes into the transmission network and ultimately to the consumers.
“One of the challenges we sit with now is the integration of renewables, where we get photovoltaic that comes on in the morning – photovoltaic – and obviously goes off, and then you get the variability of wind.
“What the GO15 Committees and the sub-working group look at, is how to manage this variability of renewable generation,” he said.
Govender, who was also voted as the new Vice President of GO15's 2017 Steering Board at the meeting, said while it is easy to manage stable generation, challenges arise when a grid operator has to deal with variable generation, which comes with frequency fluctuations.
“So we have seen a lot of renewables being deployed in Europe and the USA.
“For example, in the USA in California, they have what we term the ‘test bed’ for renewables, where the generation is made up of renewables but when the photovoltaic falls away, they have like 15 000 to 16 000 Megawatts.
“When night falls away, you need flexible generation to pick it up because it is a given exactly when it falls away. Cloudy conditions comes, so they use issues like piped gas, they use hydro. So I think those are the lessons that we need to learn…” he said.
Climate change
Govender said the second big issue that Eskom could draw lessons from is on climate change.
“We need to see how we meet our obligations for COP21 in terms of CO2 emissions, which means we have to look at our coal-fired power stations and the age they actually retire.
“When you do that, you actually remove your base load. So what is happening here is we are looking at how other countries have managed their coal-fired power stations, how they manage their grid. So we are trying to learn those issues from them.”
Access to global expertise
Eskom Board chairperson, Dr Baldwin Ngubane, said being part of the GO15 brings the power utility in touch with the best and most modern trends in electricity generation transmission and distribution, as well as developing new markets for electricity products.
“Our partnership enhances access to global expertise in transmission and systems operation and secondly allows for the optimisation of mutual opportunities,” he said.
He said today Eskom, which has not had load shedding for the past 15 months, has a safe and reliable power grid compared to a few years ago.
“We are actually exporting the surplus to the surrounding countries in Southern Africa, and we hope in the future, to Sub-Saharan Africa. So there are opportunities for investment and growth. While we are managing the largest capacity expansion project in South Africa, Eskom has since 2014 to the end of September 2016 invested approximately R12 billion in transmission infrastructure and the strengthening of transmission projects. More than 6 000 kilometres of transmission lines and 32 000 of MVA in terms of substation transformer capacity has been developed.”
He said Eskom currently has supply agreements with neighbouring SADC countries through which it exports 0.5% of its electricity via the country’s transmission lines to countries in the Southern African region.
Renewables programme
“In just over four years, South Africa has developed and implemented a renewables programme which is seen as an example for other African countries and further afield.
“More than 6 000 megawatts of generation capacity has been allocated to bidders across the variety of technologies – principally wind and solar. Some 2000 megawatts is already connected to the grid in the past financial year alone.
“Eskom has spent approximately R9.5 billion in IPP renewable energy,” he said.
Dr Ngubane said, however, that the world wide introduction of renewable energy has created significant complexities for system grid operators as most of the technologies exclude the necessary storage.
“Under these conditions, as a member of G015, we call for grid operators to be afforded the necessary instruments such as demand response and renewable storage to accommodate the variability of the new energy sources.
“It is important that regulatory frameworks and technology solutions take into account the changing roles of the grid operator of the future,” he said. – SAnews.gov.za
