Thinking of buying a battery to help power your home? Here’s what you need to know

Batteries are undoubtedly part of our energy future. Should you put one in your home now to store solar output, manage your energy use and cut costs? It really depends on what you want to achieve.

Studies in 2017 and 2021 identified key motivations for installing home batteries:

  • using your own solar energy
  • good for environment
  • independence from the grid
  • saving money

With these goals in mind, our research suggests it’s hard to justify buying a battery right now on cost savings alone. If other reasons also matter to you, it might be justified.

Using your own solar

One way you can avoid curtailment is by shifting some of your energy use to the middle of the day. Significant loads that could be shifted include:

  • water heating
  • pool pumps
  • air conditioning
  • appliances such as dishwashers, clothes washers and dryers
  • electric vehicle charging.

If you still have surplus generation, it can be stored in a battery and used later to reduce the energy you import from the grid to cover loads you can’t shift. The energy you could transfer via a battery each day will be whichever is the minimum of your excess generation and the amount you normally import. For example, if you have 3 kilowatt-hours (kWh) of excess generation in a day but import only 2kWh to meet your overnight loads, the maximimum energy you can transfer via a battery is 2kWh.

The battery itself will limit rates of charging and discharging. If you are generating more power than it can handle, some of the surplus will be exported or the solar output could be curtailed. If your load is more than it can handle, you will need extra power from the grid.

Environmental benefits

Storing surplus solar energy and using it instead of fossil-fuel energy from the grid will have environmental benefits.

Most home batteries are lithium-ion batteries. Despite concerns about the environmental impacts of a lithium-ion-led energy revolution, efforts are being made to reduce these impacts.

Other ways to reduce environmental impacts without a battery include:


2017 study found nearly 70% of respondents wanted to eventually disconnect from the grid. Remote households have done it for decades, but need large solar systems and large batteries backed up by diesel generators and gas for heating and cooking.

Being connected to a grid has significant benefits. When not generating enough solar power you can get energy from somewhere else. And when generating more than you need, you can send the surplus somewhere else that needs it. Connecting many loads to many generators increases flexibility and efficiency.

A home battery can let you run your home when the grid fails, but you may need extra equipment to isolate it from the grid at such times. Being off-grid means you may also need to manage your battery differently to keep enough energy in reserve to meet your needs during outages.

Saving money

You could use a battery to reduce costs in two ways:

  • store surplus solar energy during periods of a low feed-in tariff (the money you receive for exporting energy to the grid), then use it later instead of importing energy when the price is high
  • join a virtual power plant (VPP).

Let us explain further.

The cost of electricity varies throughout each day, depending on demand and on available generation. If you have a meter that records when energy is used, time-of-use and dynamic tariffs will allow you to make the most of price fluctuations.

The payback period is better for smaller batteries, which cost less, and for houses with larger annual export.

The other way of reducing the payback period, and supporting the grid, is to join a virtual power plant (VPP). A VPP is a network of home solar batteries from which the electricity grid can draw energy in times of need.

Other options might be a better bet at this stage

Understand why you want a battery before you start looking. There are other options for making better use of your solar generation, getting clean energy and reducing your costs.

If you have a large solar system, high grid imports and can get a good subsidy, or if you just want cutting-edge energy technology, then you might be able to justify a battery.

If you don’t have solar already, the economics of a solar system with a battery can look attractive. But the solar panels will provide most of the savings.

Article courtesy The Conversation


  1. Peter Pudney Associate Professor of Industrial and Applied Mathematics, University of South Australia
  2. Adrian Grantham Adjunct Research Associate, University of South Australia
  3. Heather Smith PhD Candidate, Industrial AI Research Centre, University of South Australia
  4. John Boland Professor of Environmental Mathematics, University of South Australia
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December is a time to recharge but what about the planet?

By Lance Dickerson, co-founder and MD of REVOV

Those of us who are lucky enough to be traveling this December are looking forward to a well-earned break. It may be somewhere along our staggeringly beautiful coast, in our majestic mountain ranges, or to one of our many game and nature reserves. Mother Nature’s breathtaking beauty will, hopefully, recharge our batteries for what promises to be an action-packed 2023.

But what about Mother Nature herself? Does the planet not need time to breathe and recharge? With the rate at which oil, coal, and diesel is being burnt to keep the lights on around the planet, we can be sure of only one thing – there’s no timeout for planet earth, even though there should be. To our credit, we have become efficient in our energy usage, but there’s also another billion of us.

Isn’t it ironic that when we are exhausted or burnt out that we use the idiom: “recharge our batteries”? It is ironic because one sure way we can start to put our money where our mouths are is by investing in better batteries. Why batteries, you may ask? Good question, and here’s the answer.

You will know there has been a massive drive globally to invest in renewable energy precisely because burning fossil fuels is finite but also deadly to our planet. South Africa took a circuitous route to cotton on to this reality – with highly influential politicians still not sold – but now there are many new wind and solar projects in the pipeline on these shores, either as independent power producers or in large industries that have been given leeway to generate their own power.

Fossil fuel advocates point to the fact that renewable energy is dependent on nature. If there is no wind or sun, you won’t generate power. This power dearth when you need power timeously is managed through batteries. Simply put, we refer to installations of batteries that store the power being generated so that there is constant supply. In other words, when the wind blows and the sun shines, the installations generate power that is then stored in battery installations which ensure that at night, or when the wind stops, there is still a supply of power, and so the cycle continues.

It is evident then that unfailing, consistent, renewable energy there must be batteries. This large-scale market is set to explode to levels unimaginable. To give one a taste of the sheer magnitude of this market, a few months ago BlackRock invested $700-million (that’s about R12-billion) into about 1 gigawatt Australian battery storage, and then said they are ready to look into other Asia-Pacific markets for further investment, precisely because large-scale battery storage systems are becoming increasingly important as renewable energy investment and capacity expands.

So, what does any of this have to do with us mere people? To date, the most suitable battery storage for renewable energy, from utility scale down to industrial scale down to office parks and private homes, is lithium iron phosphate, which the world refers to as LiFePO4. All good and well, except that it triggers an ecological conflict of conscience.

As the electric vehicle (EV) and renewable sectors clamour for batteries and push up demand, it’s the planet that pays the price. Efforts to invest in sustainable mobility and renewable energy result in escalating mining demand and massive carbon emissions to meet that demand. Is this yet again, the seeds of another tragedy? Rare earth metals nickel and lithium are mined, transported to docks, shipped across the oceans, beneficiated, then shipped back to whomever has paid for the product at a colossal carbon cost. It would appear that this is an inescapable price that earth must pay, but it’s not.

There is another solution, and it is called 2nd LiFe, where the good cells of replaced EV batteries are repurposed for storage solution. In the life of every EV, there comes a time when the weight of the battery no longer justifies the output, and it is replaced. In these batteries are perfectly good cells that still have many years’ life and thousands of potential charge and discharge cycles. The best part is that these cells were produced for a mobile environment meaning they have a greater tolerance for extreme temperatures and harsher operating cycles than first life LiFePO4 ESS cells.

These cells are repurposed, repackaged and built into fit-for-purpose storage batteries. If this doesn’t happen, they are stowed in dilapidated warehouses as a sustainable recycling process does not yet exist, and so again, there’s another point of friction in the sustainable economy – it is all good and well to e-drive around without creating emissions, but why then poison the planet when you are (only half) done with the cells?

2nd LiFe batteries tick all the boxes, they are as good as and, in many cases, superior, to first-life batteries. There’s a misconceived argument that they are second hand, which is simply not the case as it is like taking a BMW sedan, stripping it, using the parts, and building a boat. They are repurposed batteries using only the perfectly good cells, with a bunch of new computerised parts.

2nd LiFe batteries can be used in all sizes of installations, and they give us, the consumer, the power to decide that enough is enough, and to do our bit to reduce carbon emissions which are scarring our planet. As you sit at the beach or watch a sunset over a mountain, let this be food for thought when you recharge your batteries: what about the planet’s batteries?

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BASF and G-Philos power up on stationary storage systems for renewable energy projects

Partners offer NAS® batteries for long-duration, high-energy stationary storage coupled with a suitable power conversion system for power-to-gas, power grid and microgrid applications. Through their cooperation agreement, both companies strengthen their commitment to the renewable energy market in South Korea.

BASF Stationary Energy Storage GmbH (BSES), a wholly owned subsidiary of BASF SE, and G-Philos, Korea’s leader in power-to-gas (P2G) technology, signed a sales and marketing agreement for NAS batteries (sodium-sulfur stationary batteries) for P2G projects, power grid and microgrid applications. The companies will work together to develop and market energy storage systems based on NAS batteries from BASF and power conversion systems (PCS) from G-Philos. G-Philos will also purchase NAS batteries from BSES with a total capacity of 12 MWh.

BASF and G-Philos started to work together in 2020 when an NAS battery system and a PCS developed by G-Philos were deployed in a demonstration P2G project implemented by G-Philos in collaboration with Korea Midland Power (KOMIPO) at Sangmyung Wind Farm, Jeju Island, South Korea. In this project, the NAS battery serves as an energy buffer between wind turbines and electrolysers to ensure stable hydrogen production from surplus wind power despite the fluctuating nature of wind. NAS batteries were selected for this application due to their enhanced safety, which is required due to their proximity to hydrogen production. Now that the concept has been proven by the successful operation of the system for more than a year, the partners are looking forward to expanding their cooperation further.

Based on their agreements, BASF and G-Philos plan to strengthen their commitment to the market for long-duration energy storage and climate-friendly hydrogen in South Korea and the Asia region. G-Philos also intends to offer preconfigured package solutions consisting of a combination of NAS batteries with its power convertors through its own distribution network. G-Philos can supply PCS products suitable for NAS battery systems ranging from 250 kW up to 1 MW.

Gawoo Park, CEO of G-Philos, says: “With the increasing use of renewable energies, NAS batteries will be one of the most important solutions for storing electricity from renewable sources and, in particular, for CO2-free hydrogen production. With this agreement, we look forward to making an important contribution to establishing NAS batteries in this application together with BASF and intend to purchase further NAS batteries from BASF in the future.”

“We are pleased to see that the benefits of NAS batteries have been proven once again, now in this challenging application. With G-Philos as a partner, our NAS battery business in South Korea is expected to grow steadily. The new agreement is the starting point to expand the distribution of NAS batteries to other business areas beyond power-to-gas projects,” comments Frank Prechtl, Managing Director of BSES.

For more information on NAS batteries in South Africa, contact Lloyd Macfarlane, Altum Energy:

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Going green with sustainable, responsible lead-acid battery recycling

Have you ever wondered what happens to your old vehicle battery once you replace it? If you recycle it with authorised recyclers, it will be recycled and reused to make new batteries. If, however, your old battery gets disposed of with other household items, it may end up in a landfill, where the battery components such as lead, plastic, and acid can leak into the soil, causing environmental damage and harm to people and animals.1

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Plugging into the reality of 2nd LiFe batteries: second life is not second-hand

“A 2nd LiFe Battery is not second-hand. A 2nd LiFe battery has been repurposed and the cells have had their life extended by being applied to less strenuous operating conditions.”

A pioneer in the sector, REVOV, has been developing and supplying 2nd LiFe storage battery systems in South Africa and neighbouring countries for four and a half years. Not only is an investment in second life technology the environmentally prudent thing to do, but it makes sense from a performance and price perspective and international players have discovered this.

After a few years electric (EV) batteries are replaced with new ones because the weight of the battery in the car no longer justifies its performance. However, when the cells are repurposed for storage batteries, there is a compelling solution to preventing huge numbers of batteries being dumped into landfills.

The concept and application is gaining traction around the globe, and bolster’s REVOV’s resolve. The Australian Renewable Energy Agency (ARENA) said Relectrify, which has been working with American Electric Power and Nissan North America on a pilot project, will now finalise development and undertake certifications ahead of the deployment of 20 ReVolve battery units across C&I applications throughout Australia.

In order to understand what it is that REVOV and its international counterparts are seeing in 2nd LiFe, we delve a little deeper to understand the science behind these batteries particularly now that load shedding is once again on every South African’s agenda.

We asked REVOV MD Lance Dickerson to plug us into the reality of 2nd LiFE batteries and what they are:

Please go into a little detail of why automotive grade batteries are so transferable to storage?

Automotive grade cells are manufactured specifically for use in the very harsh environment of a motor vehicle. This includes being mobile, subjected to vibrations continuously, high temperatures and to high charge and discharge currents in the effort to optimise charge time vs distance vs speed.

Stationary storage applications change this high throughput requirement, and optimise the requirement to provide a lower throughput over a longer period of time, significantly enhancing the life expectancy of the once automotive battery.

In which circumstances in daily use will this come in handy, or will the owner notice these benefits?

Typically a backup storage battery is dimensioned to provide power throughout the night, around 10 hours or more, or at worst for at least the four hours of load shedding we all have come to love.  The battery, dimensioned to provide 10 hours of backup, is only typically running at 1/10th of its maximum output which lends itself to an extended life, and an optimal cost per kWh.

Effectively, an automotive grade cell running at less than 1/10th of its design potential can obviously be expected to last longer than originally planned

Let’s compare 2nd LiFe Lithium-iron to other types of batteries. What are you prepared to say, if anything?

Firstly, Any Lithium Iron Phosphate cell is superior in terms of safety, over any other Lithium Ion battery chemistry, and typically has a higher life expectancy and a higher specific power. It loses some distance in terms of specific energy per kg, however, this is not important in a stationary application where weight is less important.

Secondly, an automotive grade 2nd LiFe Lithium Iron Phosphate battery, used in a stationary storage application, is subjected to charge and discharge currents that are significantly lower than its design capability. This reduced stress translates into a non-linear improvement in terms of cycle life, easily providing the same lifespan as a new battery specifically designed to provide stationary storage only, at a much-reduced cost.

When we say a battery is repurposed (2nd LiFe). What does this specifically mean?

A 2nd LiFe battery can take on a number of different shapes and sizes. If the battery is removed from the vehicle and found to be in exceptional condition it can be used as is, in a mostly 12v configuration, at medium-to-low charge and discharge rates. The only addition would be an external battery management system which would ensure the battery cells are protected from excessive charge and discharge currents and voltages and ensure the cells inside the battery remain balanced.

Most often the capacities and voltage combinations used in modern EVs are not suitable for the modern 48VDC renewable energy system. Most 2nd LiFe battery cells are unpacked from the vehicle battery casings and packed into formats that suit their usage in the environments they are being destined to. This requires new components in every part of the battery except the battery cell itself.

As an example, a very popular format is the 19-inch rack-mountable size, allowing them to be mounted easily in cheap IT-type cabinets. 2nd LiFe can be packaged into almost any shape, size, capacity and for any application, you can imagine. Easily packaged into tubular shapes for mounting around poles at height, into thin wide arrangements to fit behind 4×4 seats for auxiliary power whilst camping, into small cubes to fit into UPSs created for rectangular Lead Acid batteries, and almost any other use you can think of.

In your words, what is the difference between 2nd LiFe and second hand (if there is more to it than above)?

A 2nd LiFe battery has been used in a motor vehicle, or mobile application specifically as a primary source of power to drive the vehicle. Its 2nd LiFe is engaged when the battery has lost approximately 20% of its original capacity, and due to weight being an issue in a mobile application, its purpose is changed to become mostly a secondary power source, storing energy generated by renewable sources or Eskom Grid power. This energy is stored and then used at a reasonably mediocre rate to provide power when renewables such as wind and sun are not available or to provide backup power for periods longer than two hours.

This process effectively extends the life of the battery giving it what we term a 2nd LiFe.

In contrast, a second-hand battery would be a storage battery used to provide storage for a time, uninstalled and re-installed to perform the same function in another location. Nothing in this process extends its life or changes the conditions under which it operates and it will simply last as long as originally planned.

What is the lifespan of 2nd LiFe in cycles and years?

Due to the reduced stress, and the history provided with a 2nd LiFe battery, by the vehicle BMS, lifespan is easily predicted forward.

Most 2nd LiFe batteries were originally designed with a life expectancy of 6 000 to 7 000 cycles in an automotive primary power source application and applied into 2nd LiFe applications once they have endured 1 500 to 2 000 cycles in a vehicle.

This means they still have a life expectancy of another 4 to 5 000 cycles under the same conditions as in the vehicle. But stationary storage reduces the stresses on the battery cells enormously from their design capability and hence the life span of the 5 to 6000 additional cycles is easily met.

In REVOV batteries – which components are brand new in the 2nd LiFe batteries – electronics, cases, display etc?

The only component inside a REVOV battery which is not new is the actual battery cell. From the busbars interconnecting cells, to the monitoring harnesses, cables, and sensors, casing, connectors, screws, and bolts, all are new. The Battery Management System used is specifically designed for the 2nd LiFe cells and is not the same system used in the vehicle either.

What are some of the biggest REVOV 2nd LiFe installations you are aware of, and were they used for UPS or renewable setups?

We currently have a number of REVOV 2nd LiFe installations exceeding 320kWh, these are in total off-grid applications where the customer has disconnected Eskom or doesn’t have reliable access to Eskom, to similar size units which provide UPS functionality in case of Eskom failure. These are typically in the 48V nominal range, and 300-350 kWh is really the limit that a low voltage (48VDC) installation should be built at. Larger than that the requirement for larger conductors becomes critical, and installation becomes impractical.

The vast majority of our installations and applications are between 10kWh and 100kwh. We are currently working on some much larger applications, but these will ultimately use a High Voltage setup and design, where the batteries are connected in series to reach voltages up to the 800VDC range, this, in turn, has a significant effect in terms of ease of installation and cable sizes and costs.

Watch this space carefully as REVOV launches the first 2nd LiFe HVDC battery product in Africa in the next few months.

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Lithium-ion batteries offers an electrifying opportunity for South Africa

The global move to low-carbon transportation options, such as electrical vehicles (EVs), brings battery technologies to the fore. This provides unique opportunities for policy makers and local producers to explore South Africa’s competitive advantage in the lithium-ion batteries (LIBs) value chain.

This emerged as a key theme from a study on opportunities to develop the lithium-ion battery value chain in South Africa, initiated by the United Nations Industrial Development Organisation (UNIDO) and the Department of Trade, Industry and Competition (dtic) as one of the deliverables of the Low Carbon Transport project in South Africa. A report on the study, which was conducted by Trade and Investment Policies (TIPS) on behalf of the project, was launched today during a side event of the Africa Energy Indaba.

According to Gerhard Fourie, the dtic’s Chief Director of Green Industries, the report is intended to “feed into the broader debate around low-carbon transport, green industrial development and policy shifts in terms of the development of the EV value chain. The increased prominence of EVs entering the market is mentioned in the report, highlighting battery technologies as an important component of sustainable development. In view of the commitment of government and industry to ensure the country retains the position of the local automotive manufacturing value chain as a key player in the mobility of the future, the study investigated the potential for a South African lithium-ion battery (LIB) value chain.”

Fourie adds that “every stage of the LIB value chain was therefore investigated with the aim of identifying the country’s existing and potential competitive advantage. In addition, the TIPS research team sought to answer a number of questions, such as: can the country develop new capabilities relevant to the battery value chain? Should the country focus on specific segments of the value chain or work to build a complete value chain domestically? And finally, acknowledging that the country has the minerals required for the production of batteries, does South Africa and other African countries have the potential to build on their natural resources to support mining and beneficiation?”

What emerged is that there is a “vibrant value chain”, but not all stages are at the same level of development. The report points out that “mining of multiple LIB-relevant minerals, such as manganese, iron ore, nickel and titanium, is already underway in the country and the region. Mineral beneficiation for battery production, while limited, is also present in the country, with existing pockets of excellence in manganese and aluminium and interesting developments in lithium, nickel and titanium. Importantly, battery manufacturing (off imported cells) and battery refurbishing (second-life batteries) is a booming opportunity with many firms operating in this space, leveraging unique expertise and intellectual property, notably in the development of battery management systems. By contrast, cell manufacturing, while explored at the R&D level, is yet to be proven commercially viable in the country. Similarly, the development of recycling is still early days in the country.”

Identifying where in the value chain South Africa is competitive is critical, so as to channel support and resources into the most sustainable activities. Based on the research, four possible technical pathways are proposed to support the development of the LIB value chain: 1) battery manufacturing 2) mineral refining; 3) cell manufacturing; and 4) battery recycling.

The study noted that developing battery manufacturing and mineral refining are ready for scale-up whilst cell manufacturing and recycling could be explored in the medium to long term, provided they prove to be economically sustainable. The report notes that where there are “key pockets of excellence” (battery manufacturing, mineral beneficiation and mining), efforts and resources should be focused on these activities. TIPS research leader Gaylor Montmasson-Clair stresses that “indeed, the development of the LIB value chain is a fantastic opportunity for South Africa, provided the country invests in its strengths and competitive advantages, rather than unsubstantiated aspirations.” 

The study pointed out that “an established LIB industry is instrumental to the local development of both the (renewable) energy and (electric) transport industries.” Hence, ensuring high levels of local content in renewable energy and automotive manufacturing will be dependent on localising the battery value chain as much as possible. In turn, strong partnerships and collaboration between public and private institutions as well as between local and international players is critical in growing the LIB value chain.

According to Dr Blanche Ting, Energy and Low Carbon Coordinator for UNIDO, it was noteworthy that the study also mentions the minerals beyond South Africa, particularly on the African continent.  Among SADC are graphite (Mozambique and Tanzania), nickel (Botswana, and Zimbabwe), titanium (Mozambique, Madagascar) amongst others.  Potential for regional industrial integration of these minerals notably though the implementation of the Southern African Development Community Industrialization Strategy and Roadmap 2015-2063, and the recent implementation of the African Continental Free Trade Agreement (AfCFTA) should be explored. 

In moving forward, the report highlights that aside from identifying where in the entire LIB value chain South African industries are (or could be) competitive, a number of key components, such local testing and certification as well as access to funding for commercialisation of innovations, are required to establish an enabling policy framework for the development of the LIB value chain. In addition, facilitating access to markets, both domestically and globally, and shaping R&D and skills development in line with South Africa’s competitive advantage would play a large part in South Africa succeeding in developing the value chain.

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How to choose a storage battery: Think of an onion

South Africa’s stretched energy grid has led to a rapid uptake of uninterrupted power supply (UPS) systems and a marked increase in renewable energy investments.

Freedom from the grid needs reliable storage batteries – where the energy created by turbines or solar panels is stored for continuous power, or in the case of a UPS system in a home or business, the power from the grid is stored for use when the power trips. “When you understand what makes a high-quality storage battery, it makes choosing the right battery system a lot easier. I always tell people to see it as they would an onion with its multiple layers,” Felix von Bormann, co-founder of REVOV says.

There are four layers that make a good battery, says Von Bormann. They are:

First layer: The chemistry

“This is perhaps one of the most crucial elements,” says Von Bormann. “If the chemistry inside the battery is not right, it will not only be ineffective, but dangerous as well. Different chemistries are better suited for specific environments. For instance, automotive-grade battery cells deliver extreme temperature resilience and high energy density, which makes them well-suited to environments that rely on these characteristics.”

Second layer: Charging capacity

Once you are satisfied with the chemistry, you need to ensure that the battery chosen has the right capacity insurance. “This is to provide the ability to support the charging required and remain within the 48-volt paradigm critical for renewable energy.”

Third layer: Well-designed box

The battery cells must obviously be of the highest grade. Von Bormann says: “The chemistry means little if the battery is not constructed correctly. The physical box must be rugged while the connections to the cells for monitoring and power delivery must be solid. The battery must have a well-designed box that can take shocks.”

Fourth layer: Safety

“The final part is ensuring the battery does not leak or explode,” says Von Bormann. “The safety specification of the battery you choose is an important consideration. Chemical devices need to be designed and stored correctly as this speaks directly to their safety.” 

A lithium battery, for instance, features a battery management system (BMS) that monitors and shuts down the battery if something goes wrong. “There are also physical signs to check out as well such as whether the battery is misshapen or has watermarks on it,” says Von Bormann.

Interestingly, says Von Bormann, repurposed, or second life, batteries from electric vehicles (EVs) are tailor-made to deliver the performance and safety required to be quality, robust storage batteries. “Of course, it is not a case of simply removing them from a car and plugging them into a solar solution. Care must be taken to select the right kind of battery that can deliver this second life and that is equipped to deal with the demands of long-term storage.

“If you consider that these carefully chosen and repurposed second life batteries have 10 to 15 years of use once we have repurposed them from EV into storage batteries, the value is two-fold: first, you pay less for high-grade batteries and second, by repurposing EV batteries that would have ended up in landfills by their tons, we can move off the grid in a carbon-sensitive and sustainable manner.”

He adds that quality batteries should be put through rigorous testing so that by the time they are built into commercial or residential systems, the end-user knows they have bought quality. “Ongoing testing really is non-negotiable. When you are choosing a battery, ask about the testing. Our 2nd LiFe lithium-ion phosphate batteries, for instance, have been quality checked and have gone through rigorous testing to ensure they are fit for purpose, that is long-term energy storage.”

READ MORE | Repurposed EV batteries a boon for stational energy storage

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Out of the coal age and into the stor-age

Seydou Kane, managing director for South Africa at Eaton, considers the shift away from coal towards renewables – and the potential for a future microgrid energy market in South Africa

South Africa’s energy generation capacity is dominated by fossil fuels, with this source accounting for 91.2% of the country’s energy, according to the 2019 Integrated Resource Plan. While the country is likely to continue turning to coal as its main source for generating electricity, plans are well underway to diversify South Africa’s energy mix. With multiple solar projects already operational, along with numerous wind farms producing energy too, it’s clearer than ever before that South Africa is well on its way to sourcing as much as 25% of its energy mix from renewables by 2030.

If the future of South African energy is going to depend increasingly on renewables, effective storage will be vital to better connect these energy sources to the grid. Energy storage will also be key to making our national energy infrastructure more resilient and, importantly, enabling it to increasingly rely on clean energy sources.

Learning to rely on renewables

Renewable energy has long been treated with skepticism. Some policymakers argue against renewable energy sources as unreliable, and this has resulted in a roller-coaster market for renewables as policies sometimes shift rapidly – seemingly without consideration for the impact to benefits such as jobs and energy independence. Yet, the ever-decreasing cost of renewables as technology advances has kept the South African market growing, albeit more slowly than is required to meet stated commitments for carbon reduction.

One major argument against renewables is that they do not produce a consistent baseload power like fossil fuels. The common refrain is that the wind does not always blow, and the sun does not shine at night. Of course, these are true, but it must be remembered that we are in a transition to a cleaner future – it is not an overnight change. It will take time, but the day will come when we run completely on renewable and clean power. 

This is being accelerated by the falling cost of battery storage which helps optimise the use of intermittent renewable energy on the grid – further opening up the possibility of powering South Africa with clean, renewable energy while shifting further away from our reliance on fossil fuels.

When renewable energy sources generate more energy than businesses or homes require, the excess can be stored securely. This energy can then be released during times of peak demand, which means less need for conventional fuel generation. This reduces the carbon footprint of South Africa’s energy supply. Even better, this energy can be located anywhere on the grid or in private consumer homes, so that businesses and houses can help eliminate harmful emissions and save costs.

To meet global emissions reduction targets and drive forward a nationwide low carbon economy, we will need to learn to rely on renewables.

The deployment of pioneering energy storage solutions will be crucial in this process as we attempt to embed sustainability within the national energy grid.

Creating a more resilient grid with a ‘behind the meter economy’

Another increasingly interesting application of storage is in microgrids which can efficiently and economically plan for local energy generation and distribution, while increasing reliability. The implementation of local, distributed power generation and storage can be designed to allow portions of the grid and critical facilities to operate independently of the larger national grid when necessary, helping reduce the potential for unforeseen blackouts. The storage systems that are part of these microgrids – whether large or small – can also provide ancillary services to the grid, again strengthening performance and reducing the use of carbon generation.  

Energy storage gives businesses and consumers the power of choice to optimise their energy costs and provides them with flexibility for the future. We are already seeing advanced aggregators working with businesses to educate and inform them on the extra money to be made while supporting the transition to a smarter, environmentally-friendly energy grid.

The investment opportunity

Investment in storage still needs to increase to ensure renewable energy sources can fully step into the breach created by the decline in coal use.

The ever-falling price of energy storage technology today is creating an increasingly viable and attractive investment opportunity – but many South African businesses are still not aware of this potential.

Energy storage technology can be complicated to understand from a commercial perspective when it comes to exactly how it will save money for a particular site. However, the option to sell surplus energy back to the grid through ancillary services opens up new revenue streams that help offset the cost of electricity and dramatically strengthen the business use case. Adapting the South African regulatory framework to remove barriers to entry in the ancillary services market will facilitate this option and better support the development of a healthy energy grid.

The shift to a cleaner future is already taking place as South Africa moves away from coal and towards renewables. Eskom CEO Andre de Ruyter affirming that renewable energy will have to have a place in the country’s energy portfolio if the utility is ever to provide reliable energy, along with recognising that the company cannot continue to violate environmental laws.  Energy storage will accelerate this trend and help ensure a clean, stable, and cost-effective supply of electricity for the country.

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VIDEO | Storage: The missing link to renewable energy


What’s the key to using alternative energy, like solar and wind? Storage — so we can have power on tap even when the sun’s not out and the wind’s not blowing. In this accessible, inspiring talk, Donald Sadoway takes to the blackboard to show us the future of large-scale batteries that store renewable energy. As he says: “We need to think about the problem differently. We need to think big. We need to think cheap.”

Donald Sadoway is working on a battery miracle – an inexpensive, incredibly efficient, three-layered battery using liquid metal.

This talk was presented at an official TED conference, and was featured by our editors on the home page.

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What’s on the Energy Storage Market Besides Lithium-ion Batteries, Asks IDTechEx Research

In this first part of a series of articles from IDTechEx, an overview of the flow batteries characteristics is provided, extrapolated from IDTechEx’s recent report “Redox Flow Battery 2020-2030: Forecast, Challenges, Opportunities“. 

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