Electricity and Control June 2024

ENERGY MANAGEMENT + THE INDUSTRIAL ENVIRONMENT

Understanding the value of battery energy storage Lance Dickerson, co-founder and MD of REVOV, points out that in investing in solar energy generation – government institutions, corporate organisations, other investors, households too – need to recognise the importance of battery energy storage, which is essential to avoid losing a significant share of that investment.

Lance Dickerson, MD of REVOV.

A lthough South Africans have witnessed a welcome stretch of stable electricity supply – more than 50 days without loadshedding at the time of writing – Eskom has stated that it is not yet in the position it wants to be with regard to energy availability and the performance of its fleet, and Minister in the Presidency for Electricity, Dr Kgosientsho Ramokgopa has consistently said that the country needs to build more generation capacity. Investment in new solar (and wind) energy generation capacity continues and here Dickerson emphasises that a concomitant investment in battery energy storage systems (BESS) is critical to addressing energy security in South Africa, no matter the size of the generation investment. He notes that the national electricity regulator, NERSA, has recognised this, but understanding its importance is not yet widespread in the marketplace. Referring to NERSA’s warning, he says the regulator highlighted the R7.8 billion investment in solar power generation facilities, including three commercial solar generation facilities, at a value of R1.7 billion, in the last quarter of 2023. And by comparison, NERSA said only R4 million – or 1 MW – was invested in battery energy storage. This is a problem, even though it is only half the problem, Dickerson says. “Solar panels work to convert solar energy into electricity when the sun is shining – but that is for only half the day, at best. More likely for about six hours, if the sunrise and sunsetting hours are excluded. If there are no batteries, none of the electricity being pro duced is saved. When the grid needs the electricity gener ated, it can be fed into the grid, but when the grid does not need the supplementary power, it is lost.” The three commercial solar generation facilities regis tered by NERSA in the last quarter of 2023, have a total capacity of 77 MW. If one of those is a 50 MW solar plant, it is not simply producing 50 MW and feeding it into the grid. (Apart from the issue of grid access, which in this example we assume to be in place) that solar plant will produce only what is demanded of it, which may be 1 MW. The other 49 MW is merely hypothetical, Dickerson says. This is where batteries are critical. A bank of batteries and an inverter configured for a 50 MW facility could feed say 25 MW into the grid if the grid demanded that, and 25 MW would be stored in the batteries, instead of being wasted. This also means that, especially during peak de mand periods, 6am to 9am and 5pm to 9pm, the energy stored in the batteries could serve to cover a potential

shortfall in the national utility’s generation capacity. Dickerson says in many cases, at smaller and larger scale, batteries and inverters are not considered and the focus is only on the solar panel installation or developing the solar farms. He emphasises that it is in the engineering of batteries and inverters that the real value lies and says the billions of rand invested in solar generation projects without bat teries represents an inordinate waste of money. In his view, one third of the amount could have been invested, with an equivalent investment in battery energy storage, to achieve the same impact and provide a fully backed up buffer to cover peak demand periods and limit load shedding. He says installing solar panels without installing batter ies represents an eyewatering waste or money and energy – every day. Although the panels may serve well in supply ing the energy demand during the daylight hours, the plant could better serve to bridge the gaps in Eskom’s capac ity when they occur, and provide a backup when Eskom needs to replenish its energy reserves. □

High voltage battery energy storage technology is applicable and scalable across various sectors.

For more information visit: www.revov.co.za

JUNE 2024 Electricity + Control

13