Page 33 - Energize August 2021

Repurposing coal stations –

a circular economy energy solution

by Wayne Glossop and Tord Johnsson, Wärtsilä We envisage that some of those power
generation sites could become gas power
ll over the world, utilities are facing the plants, possibly combined with BESS, as we
problem of what to do with obsolete and have demonstrated at Barker Inlet. Some of
Ainefficient power stations. the renewable energy developers could be Wayne Glossop
In South Africa, most of our power interested in co-locating their solar PV or wind
stations were built in the 1960s and 1970s, plants near to these plants to utilise some of the be considered include environmental impact
when the predominant technology was coal. infrastructure, particularly the grid connection. assessments and generation licences per site
In the 21st century, with the focus on a low- Beyond power generation, the sites could which would need to be reviewed and updated.
carbon economy, coal-fired plants cannot be also become smart technology hubs. They could These issues can be resolved relatively quickly,
rejuvenated, but could be adapted to become become training centres which would pass on with the support of government departments
modern, multi-use facilities. the operational and maintenance skills required including Environment, Forestry and Fisheries,
Shutting old coal-fired power stations, for these new technologies. They could also Trade and Industry, Mineral Resources and
demolishing them and sterilising the site has incorporate testing and research facilities into Energy and Public Enterprises, all of which have
a number of undesirable effects, including future fuel sources. The green power from an interest in finding a solution. The full backing
significant environmental liabilities, socio- this facility could be used to fuel a hydrogen of Eskom is also needed to make these projects
economic hardship and the stranding of production plant, and the hydrogen could be a success, and to date Eskom has given positive
transmission infrastructure which still has value (initially) combined with natural gas to generate signals in this regard.
but is impracticable to move. greener energy until such time as the technology Eskom is understood to be preparing the first
A far better solution to decommissioning is a is mature enough to rely solely on hydrogen. Request for Proposals (RFPs) for decommissioned
coal-fired plant is to “repurpose” it – which aligns These sites could benefit from co-location, co- power plants and these should be released in
with the principles of re-use and recycle in the creation and sharing assets among private and the next few months. An important outstanding
circular economy. public companies and academia. aspect of repurposing an old coal-fired plant
According to the US Energy Information Sourcing the gas for these power plants is determining which party will assume
Administration, 121 coal-fired power plants is naturally a critical element to consider but responsibility for setting aside the necessary
in the US were repurposed to burn different thankfully, there are positive developments funding guarantees for remediation of legacy
fuels, usually gas, between 2011 and 2019 ongoing in this regard. Most of Eskom’s power environmental damage. An overly complex
(https://www.eia.gov/todayinenergy/detail. stations earmarked for repurposing are located approach to these liabilities is likely to deter
php?id=44636). The most appropriate power near, or within reach of, existing gas pipelines from investors and cause unnecessary delays. We
stations for conversion are those with smaller the Pande and Temane fields in Mozambique. expect this will be made clear in the RFPs.
capacity, which are over 50 years old. While these gas fields may be nearing end Our experience in Australia has shown that
A good example of how this can be done of life, there are plans under way to supplement converting a thermal power station to flexible
was Wärtsilä’s recent project for AGL Energy at that gas through LNG imports into Maputo or gas and/or BESS can ensure the reliability of
Barker Inlet power station in South Australia. This Richards Bay. The final solution should emerge renewable power in the grid, provide cost
involved taking an old and inefficient 480 MW in the near future as either Mozambique starts savings, and reduce CO₂ emissions.
thermal power plant and replacing its obsolete to execute its LNG importation project or
equipment with new dual-fuel reciprocating when South Africa’s gas-to-power programme Contact Wayne Glossop, Wärtsilä,
engines, capable of running on either natural accelerates. Tel 021 511-1230, wayne.glossop@wartsila.com,
gas, synthetic gas or liquid fuel. The repurposed Some of the issues which would need to www.wartsila.com
power station is able to generate 211 MW of fast-
start and high-efficiency gas power to balance
variable generation from renewable energy
sources. AGL Energy has also selected Wärtsilä
as a preferred supplier for up to 1 GW of battery
energy storage systems (BESS).
As South Africa moves towards a greater
reliance on renewable energy sources, and starts
to close its older power stations, its need for
dispatchable power to balance the grid could be
linked to the repurposing of those sites. Their
special attraction is that they already have some
of the necessary environmental permits in place
and are well-situated for access to transport links
and transmission infrastructure. Barker Inlet power station

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