Renewable energy projects saved South Africa 120 hours of load shedding in 2014

Submitted by: Brandon Nothling, Thursday, February 12, 2015

A recent study conducted by the Council for Scientific and Industrial Research (CSIR) has shown that in 2014 energy from wind and solar photovoltaic (PV) projects under the Renewable Energy Independent Power Producer Procurement Programme (REIPPPP) saved South Africa 120 hours of potential load shedding, which saved the economy R1,600 million. In addition a total of R3,690 million was saved on fuel costs for fuel that would have been used to power coal power stations and diesel fuelled generators. This resulted in a total net saving of R800 million for the country. “Our study shows that in 2014, renewable energy provided a net financial benefit to the country. Without the first solar and wind projects, we would have spent significant additional amounts on diesel, and energy would have had to be “unserved” during approximately 120 additional hours in 2014,” says Dr Tobias Bischof-Niemz, head of the CSIR’s Energy Centre.

Renewable energy projects in 2014

South Africa has set a target of 10,000 GWh of energy to be produced from renewable energy sources and has introduced the REIPPPP which involves the procurement of renewable energy from the private sector. By the end of 2014 the Department of Energy had commissioned a total of 1,600 MW of wind and solar PV projects, which are now feeding energy onto the grid. Of this 1,600 MW, 1,000 MW is from solar PV and 600 MW from wind sources.

Prevention of 120 hours of load shedding in 2014

In 2014 a total of 120 hours of load shedding was prevented due to the energy provided by the REIPPPP wind and solar PV projects, of which a savings of R1,600 millon was made to the economy. Without the energy from the solar PV and wind projects, and other countermeasures, the existing system would have had to reduce its supply. The country was therefore able to avoid 19 GWh of unserved energy, saving the economy R87 per kWh.

Saving of fuel costs

In addition to the prevention of load shedding hours, fuel savings were also made due to the renewable energy projects. Over the  2014 period, these renewable energy projects  generated a total of 2.2 Terra-Watt hours (TWh) of energy that would have been generated from expensive diesel fuelled generators (1.07 TWh) and coal power stations (1.12 TWh). The average savings per renewable energy unit worked out to R1.69 per kWh, resulting in a total savings of R3,690 million on fuel costs for the 2014 period. The tables below show the amount of energy replaced by wind and solar PV and the respective fuel savings for 2014. 

 

Coal/diesel replacement in TWh in 2014 due to electricity generated from wind and PV. Source: CSIR

In TWh

Electricity from coal

Electricity from diesel

Total

Wind replaced…

0.56 TWh

0.50 TWh

1.07 TWh

Solar PV replaced…

0.56 TWh

0.57 TWh

1.12 TWh

Total

1.12 TWh

1.07 TWh

2.19 TWh

 

Fuel savings in million Rand in 2014 due to electricity generated from wind and solar PV. Source: CSIR

In Million Rand

Money spent on coal

Money spent on diesel

Total

Wind saved…

R 170 million

R 1,570 million

R 1,740 million

Solar PV saved…

R 190 million

R 1,770 million

R 1,960 million

Total

R 360 million

R 3,340 million

R 3,700 million

The savings on both fuel costs and unserved energy costs have attributed to a total saving of R5,300 million. After payment to the independent power producers, which totalled R4,500 million, there was a total net saving of R800 million for the country.

Methodology

Bischof-Niemz explains how the study was conducted; “The study was based on actual hourly production data for the different supply categories of the South African power system (e.g. coal, diesel, wind, PV). We've developed a methodology at the CSIR Energy Centre to determine whether at any given hour of the year renewables have replaced coal or diesel generators, or whether they have even prevented so-called “unserved energy””.

The study assumed that the only power generators that changed their operations due to solar PV and wind were coal power stations and diesel fired open-cycled gas turbines. The study also assumed that for every hour in the year wind/solar PV could have one of the following three benefits:

  • For every hour that wind/solar PV replaced coal-fired power stations there was a saving of approximately R0.23-0.35 per kWh due to the coal fuel savings.
  • For every hour wind/solar PV replaced diesel-fired open-cycled gas turbines there was a saving of R3.11 per kWh due to fuel savings.
  • For every hour that wind/solar PV avoided “unserved energy”, macroeconomic losses were prevented. These were calculated at R87 per kWh. Unserved hours were counted as those where both the coal and diesel stations were running to their total capacities and still not reaching the amount required.

The study’s cost assumptions were taken from sources such as Eskom’s financial results for the 2014 period and the Department of Energy’s publications on average tariffs from renewables.

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Brandon Nothling