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Winning the case for small hydro

Stortemelk Hydropower Project, An Aurecon Project

Stortemelk Hydropower Project

16 March 2017 - Can South Africa’s highly successful Renewable Energy Independent Power Producer Procurement Programme (REIPPPP) be made even better? One man certainly felt it could be if changes were made to the network requirements for small hydro.

REIPPPP has stimulated an investment commitment by the private sector in excess of US$14 billion, and the award of 64 projects predominantly in wind and solar. But small hydro, a valuable source of renewable energy for countless millennia was at risk of losing out!

Jimmy Goulding, a Technical Director and Electrical Technologist with the Cape Town based Energy Unit of global engineering and infrastructure advisory company Aurecon, championed the cause of small hydro in a determined effort to ensure its rightful place in South Africa’s energy future.

“In 2014, I considered that if improvements were made to the newly introduced Version 2.8 Grid Code for Renewable Power Plants (RPPs) to make the Code more compatible with viable small hydro technology, it would open the door to small hydro development in our country,” says Goulding. “The necessary changes, as I saw them, specifically related to the Grid Connection Code for RPPs connected to South Africa’s electricity transmission or distribution system, as well as the clauses in the Code relating to Meteorological Data requirements and Forecast Data.”

“Everybody in the industry understood that changes to the Code were required to ensure small hydro was a viable option under the REIPPPP. With years of experience in both hydro and Grid Code compliance, Jimmy stepped forward and set out to develop recommended changes to the Code for discussion with the National Energy Regulator of South Africa (NERSA) and the South African power utility, Eskom,” comments Paul Nel, Aurecon’s Unit Manager – Energy & Resources, Cape Town.

The introduction of the REIPPPP Code was achieved with admirable speed, and reflected the fact that wind and solar power would be the major renewable contributors to the electricity grid.  Consequently, the drafting of the Code was based on inverter type technologies, whereas, unlike wind and solar, hydro generators are synchronous machines. This fundamental technical issue, among others, was at odds with the requirements of the Code and effectively constrained the development of small hydro.

“Once wind and solar were successfully on track, it was a case of drawing the attention of the authorities to the fact that although of lesser potential, small hydro could have a worthwhile future, especially considering that, unlike wind and solar, hydro has very high levels of availability. This could be unlocked if certain changes were made to the Code,” says Goulding.

The key issue with the Code was that it required a hydro facility to stay connected to the grid under some specific network disturbances, which would have been extremely complicated given the different nature of these types of machines.

“To comply with the Code, small hydro units would have had to be designed with massive flywheels to ensure they had enough momentum to ‘ride through’ the faults. Ultimately, this would have made the designs exorbitantly expensive and unfeasible,” explains Goulding. “Other issues that I felt needed to be raised included the way energy forecasts had to be done based on meteorology that was incompatible with the characteristics of small hydro generators.”

After pursuing a lone campaign for a considerable time, the value of Goulding’s expertise began to be appreciated and he was asked to Chair a small hydro work group to discuss his proposals with the system operator Eskom. The engagement process started in November 2014 and presentations of proposed amendments for the Code were made to the Grid Code Advisory Committee and an industrial expert team in October 2015.

Once these two bodies accepted the proposals, they were drafted by Eskom into a new Code for presentation to NERSA for their approval. This led to a proud day for Goulding, when the Version 2.9 revision of the Grid Code was published in November 2016.

“I believe a key lesson learned is that too often problems, such as the issues I had with the Grid Code for small hydro facilities, are dismissed as the government’s problem,” concludes Goulding. “Eskom and NERSA are to be commended for their willingness to work with industry experts to develop regulatory Codes that facilitate beneficial technological development. It is tremendously important for the private sector to be actively engaged in helping to define this country’s energy future.”

“We congratulate Jimmy Goulding on a remarkable achievement. He has established himself as an industry leader in this field and his individual services are being sought by Aurecon’s clients,” says Nel. “There are currently four small hydro projects in South Africa that have either been developed or are being developed and will benefit directly from the ‘Goulding’ changes to the Code, saving developers millions of Rands in engineering design, and compliance mitigations. Most importantly, small hydro has come in from the cold and future development is now realistically possible and financially viable.”

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