South Africa is one of the largest power producers in Africa and one of the largest consumers. We may be providing over 80% of the population with energy, but it is no longer as cheap as it was nor is it clean.
It will be some time before our dependence on coal will shift to renewables or alternatives. But the process of choosing the better future option may be favouring the use of stored energy rather than baseload generation. Could batteries work as well as a coal plant in ensuring there is enough power? It can't right now, but that is changing.
A battery is a store of power; we typically imagine electrical energy, but it could be heat or chemical too. The name was coined by Benjamin Franklin in the 1700s when he compared the battery’s operation like a battery of guns firing in unison.
Lead-acid batteries are the most common, and most vehicles use them. They made up almost 50% of all batteries until recently. They are heavy and contain dangerous chemicals, but are very reliable, long lasting and can store and deliver a significant charge. Early electric vehicles used lead-acid batteries; most electric golf carts use them too.
Modern electric cars use lithium-ion batteries as do all electrical devices like phones and laptops. Lithium has a high storage ratio to weight and can deliver the charge quickly and consistently. Charging speeds and recharging cycles are drawbacks, but there have been improvements to both with the technology now reaching its peak.
This is the reason Apple recently admitted to limiting the performance of older iPhones to place less demand on the ageing lithium batteries. They have since opted to provide a lower cost battery replacement.
The Tesla battery built in Australia for $50 million was built in record time (Elon Musk bet that he could build it in less than 100 days or supply it free). It was completed by the deadline of 1 December and was able to fill in the gap in supply only weeks later when a baseload coal power plant tripped. The 128 MWh capacity makes it currently the largest lithium battery in the world.
The bulk of the world lithium deposits are in South America and are recovered from the salt flats of Chile and Argentina.
As good as it is, the man who developed it, John Goodenough, in 2017 announced he had created a solid state battery that had better capacity, charging speed and number of charging cycles. The catch is that it's currently very expensive to produce.
A battery-powered bell has been ringing non-stop since 1840
There are dozens of battery types, and some research includes the development of biochemical batteries which will use the similar process of getting energy from molecules like glucose.
The other potentially exciting development in bulk grid energy storage is the Vanadium Redox Flow batteries (VRFB), capable of significant capacity storage, long-term use, rapid discharge and full use (lithium-ion batteries typically only use 80% of their capacity to avoid damage).
The potential and demand for these vanadium based units have seen prices for the metal increase with outlooks for sustained or higher prices. That is good news as South Africa has significant deposits of vanadium.
The opportunity would be to develop its use both for use in South Africa in connection with the growing renewable energy capacity and to roll out its use to our neighbours and throughout Africa, making the most of the significant wind and solar power rather than betting on coal or nuclear.
While the Australian Tesla battery is impressive with 128 MWh, there is an 800 MWh Vanadium flow battery under construction in China that is due to come online at the end of 2018.
The most significant challenge with electricity management is keeping the grid stable by balancing the electricity generated with the electricity needed. During peak times the demand may exceed supply and cause a blackout. Baseload options such as coal or nuclear can’t easily increase and decrease their generated supply which means they need to operate to handle the peaks resulting in over capacity for the rest of the time.
The VRFB’s can provide their maximum capacity almost instantly and are built to be able to sustain that level for about four hours, long enough for the peak to pass. It means traditional power plants, as well as renewables, can be used to charge the batteries and not need to run at full capacity, cutting down on excess supply and added pollution.
The most surprising element is that South Africa is no stranger to cutting-edge battery technology. South Africa pioneered the commercial development of the molten salt batteries in the early 80s thanks to contributions by Johan Coetzer. Michael Thackeray was one of the first to create what would become the first lithium-ion battery based on John Goodenough’s research and findings.
The first VRFB outside of Japan was built in Stellenbosch in 2001 and, currently, SA companies are working with Eskom to determine what the best type and configuration would be for energy storage.
There is still a long way to go. But, considering the contributions of the South Africans mentioned above and the contributions by Elon Musk and Lyndon Rive, it is arguable that South Africa has one of the best renewable energy and energy storage pedigrees of any country on the globe. Hopefully, we will be able to use that to the advantage of South Africans and fellow Africans.
This article first appeared on 702 : A big battery may work better than a power plant