Energy cost, constraints and supply interruptions risk mining companies’ productivity, output and profits. While mines are better prepared to operate on reduced power than they were during the 2008 electricity crisis, the sweeping blackouts at the end of 2019 impacted the industry severely, prompting the Minerals Council of South Africa (MCSA) to call on the government to address the regulatory constraints on how mines are able to source power and allow them to develop more extensive self-generation facilities.
Since the 2008 energy crisis, mines have responded by implementing energy reduction tactics such as shifting loads to off peak periods, switching to more efficient equipment and having better maintenance programmes to improve energy efficiency and reduce energy wastage. Some have been trying to limit their reliance on utilities by generating their own power.
However, according to Nick Oosthuizen, Managing Director at Inframid, there is an opportunity for mines to turn their energy liabilities into assets.
“Strategic decisions on energy management can’t happen in silos. Mining companies have massive potential to reduce costs and limit their reliance on national utilities by getting their energy mixes right. For this to be achieved, it is important to take a holistic, engineering approach to energy mixes and look at the total load, how different loads are supplied, and what can be done to apply the flow of energy in the most feasible way.”
Mines have numerous loads that require various sources including utility, back-up supplies, renewable energy and seamless (UPS) changeover supplies. There must be a feasible combination of these energy sources to ensure that they are used efficiently. For instance, by providing the most appropriate backup, viable renewable energy and UPS power where it is needed, without overcompensating. Over-sizing UPS’s to provide backup for example is an expensive and inefficient use of stored energy which unnecessarily drives up costs.
“A comprehensive analysis will show how different types of electrical loads can be satisfied and optimised in such a way that energy savings turn into bottom line profits. Instead of being a liability, these high loads can be transformed into assets,” says Oosthuizen.
Analysing the total load will also reveal opportunities to save on costs by managing different loads optimally. Power factor correction, changing utility connections to the correct tariff scales and insertion of renewable energy are just some of the opportunities to drive efficiencies that are often overlooked.
“The bottom line is that the detail of the total load must be interrogated before deciding on energy supplies or investing in energy efficiency technologies, including renewable and backup energy. It is only once you understand the loads, both day and night, that you can intelligently determine how your energy sources can be economically applied.
“For example, you can supplement your ‘base load’ with solar power to provide renewable energy during the day, so that the energy sources that peak during day time can be brought down,” explains Oosthuizen, adding that mines normally have vast unused areas that can be utilized to develop renewable energy stations to supply large scale energy.
“The adoption of renewable energy sources in the mining sector has been low, mainly due to high costs of establishing it and storing the power that is generated. However, technologies have advanced and prices started to drop, making renewable energy more attractive for mines.
He concludes: “A comprehensive feasibility study is where it should begin as this helps decision makers to determine their energy efficiency concept, based on realistic and actual feasibleness. This includes procuring high quality systems independently from the best suppliers at reasonable prices. All cost elements must be considered, such as total lifecycle management. For equipment to be feasible and offer high returns on investment, it must work for at least 25 years.”
With electricity price hikes on the cards and load reduction being implemented, more people are thinking about gaining independence from the national grid with alternative energy sources, like solar, to power their lives. Switching to solar makes sense if applied for the correct reasons. South Africa has an ideal climate with around seven hours of sunlight a day. Using the sun’s energy which is clean, unlimited and quiet, solar power systems that are planned aesthetically have very little impact on the environment, so it suits companies and people who have green goals. Though the sun’s energy is free, the photovoltaic panels and associated systems that collect it, and especially those meant to store it, require a considerable investment.
This is why Nick Oosthuizen, Managing Director at Inframid, advises companies and homeowners thinking of making the switch to first plan and then buy.
“Don’t just jump in. First, understand your reasons for wanting solar power. Is it to save on overall energy costs, is it to provide backup power during load shedding, or is it a bit of both? You also need to know what your energy demand profile is and what type of system you would need to meet your needs. Solar power systems are a serious investment, and the worst thing you can do is overcapitalise. You will not see a return on your investment if you do.”
He explains that as a backup in the event of power failures, solar systems will normally be connected as a typical uninterrupted power supply. This needs storage capacity to supply enough energy to cover the load for the planned back-up period.
“If your reason for installing solar is to provide backup power, you will need to buy large enough batteries to provide capacity for the average load reduction outage of three to four hours. For this purpose, it is important to compare the cost of different backup technologies, such as petrol, diesel, gas and battery. There could be cheaper backup power options for you.”
To save on electricity costs, both grid-tied and off-grid systems are options. Off-grid systems work entirely independent from the national electricity grid, which means they need ample battery storage to provide backup during low solar irradiation. The idea of being “off-the-grid” is enticing for frustrated South Africans being hit with regular load reductions and power outages. However, Oosthuizen says these systems must be planned carefully, especially in terms of cost, and keep in mind that it will take some time to see returns.
If your need is to save on electricity costs, grid-tied solar systems are the most common because they are cost-effective, the easiest to install and need the least amount of equipment which means they have fewer points of failure. They are connected parallel to the grid and the load, thus being exposed to the total load, meaning that the solar system has the best chance of applying its total capacity to the load, therefore used in a feasible manner.
“To save on energy costs, a grid-tied system is a good option. Depending on the size of the system, the installation and how you use it, you could see impressive savings on your monthly electricity bill. A grid-tied system won’t help you if your reason for wanting solar power is for backup, unless you have another backup system to carry your load demand during power outages,” explains Oosthuizen. He adds that hybrids of grid-tied and off-grid systems are also available. These must, without doubt, be planned and configured correctly.
The feasibility of a solar generator that is intended as an investment, based on cost savings, strongly relies on the following aspects:
Aside from helping to reduce energy costs and reliance on the national grid, grid-tied systems also offer the potential to provide passive income for businesses that feed excess solar power they generate with their photovoltaic systems to the utility. Utility supply in South Africa is progressing with the process of setting up the legal, technical, metering and tariff framework for the connection of small-scale generation to the low voltage network.
Oosthuizen says it is preferred to allow between six and 12 months of metering time, across all seasons, to measure electricity usage and determine a feasible solar system size needed to tend to the energy demand. A feasibility study is worth the effort to get an accurate picture of how much energy is used and what it costs over these periods.
“Other things to consider include practical considerations such as the type of roof on the building or house. Is it strong enough to accommodate the solar panels? And, does it face the right direction to capture sufficient sunlight? If not, you need to plan for providing more solar capacity,” adds Oosthuizen.
With this in mind, he says that developers should allow for future solar infrastructure when planning new builds.
“Certainly, achieving some independence from the national grid is becoming critical for an increasing number of South Africans. Many of us are also concerned about the environment and choosing renewable energy sources like solar is healthier for it.
“Advances in solar technologies mean that the sun’s energy is a reliable source of power, especially in South Africa, where we are blessed with sunlight, even in winter. Nevertheless, a solar investment must be carefully considered to ensure that it addresses the reason for the installation feasibly. Rather be conservative. Take the time to do the metering to ensure that you invest in the most appropriate system architecture for your needs,” concludes Oosthuizen.
With more companies getting ready to operate again and empowering their employees to work from home, reliable electricity is essential. But, reliable power is not a given. It can come with a threat to business continuity for remote workers trying to operate from home offices as well as businesses starting to run again.
Aside from the threat to business continuity when the lights go out, there is a risk of damage to computers, other electronic equipment, machinery and manufacturing processes.
“South Africans need to become more energy independent. Not necessarily off the grid, but independent,” says Nick Oosthuizen, Managing Director at Inframid, which provides Electrical Energy Efficiency Consulting and Program Management Services.
He advises companies, institutions and individuals to be careful about buying solar combined with battery backup systems before first weighing up the costs of backup power versus only Uninterrupted Power Supply (UPS) systems versus UPS systems connected with renewable energy such as solar.
“Don’t confuse your UPS requirements with your backup needs. Backup power ensures that your total energy pool is covered in the event of a power failure. This means that you will have electricity to source power to all the energy-using systems your business needs to keep operating. However, within that pool, there is a load which cannot be lost for even a few seconds; otherwise, there is a significant risk of losing critical systems and information. This critical load is where UPS systems are needed to provide a seamless transition during the changeover to the backup power supply.
Certainly, a UPS can be used as backup power if the essential installation is small. But UPS systems can be costly and they only last as long as their batteries last. If your total essential load is minimal, as in the case of a small house or small office, a UPS could be used as a backup energy source. However, you would need a bigger battery to run it for more extended periods.
“Likewise, for bigger installations and when more extended periods of uninterrupted power supply are required, a large battery will be needed, and it becomes costly. This is when a UPS with an alternative backup power source makes more sense.”
When considering UPS systems, Oosthuizen says it is vital to understand which part of the energy load would require a seamless transfer of power. In other words, know the total demand and how much of that requires an uninterrupted power supply to avoid the risk of damage or loss of valuable data.
A UPS will be needed in the following scenarios as seamless transfer and bridging the gap between the electricity mains going down and the backup power source taking over:
Oosthuizen gives an example of a school that needs backup and uninterrupted power for the IT classroom only.
“For backup in the IT classroom, they would implement a UPS because they require backup only for the classroom. In the event of a power outage, the UPS takes over seamlessly and lasts for say 30 minutes. So, if the outage is less than 30 minutes, the UPS can also be considered as a backup. However, during exams the school needs to hire a generator to cater for possible longer power cuts. In this case of the school, a backup generator with a local UPS is the most cost-effective way to support their energy needs, both during exams and normal tutoring.”
He says that localising UPS systems in this scenario is more sensible than centralising a UPS on the main power supply but should be considered on a case by case basis. UPS systems can be localised on every office or classroom where uninterrupted power is essential. Less costly backup power can then be implemented more centrally to provide electricity for longer periods.
Cost-effective backup power solutions include diesel, petrol, steam and gas of which the refilling can be controlled. Sun-powered energy such as solar panels is an option, but alone it is not a reliable source to use as backup power for essential loads since it is reliant on sunshine. And, the addition of batteries is costly.
A feasibility study is recommended to understand all aspects of the total energy demand, identify which parts require uninterrupted supply, determine the most cost-effective options for backup power and consider renewable energy sources to lower energy costs.
Oosthuizen concludes: “Don’t confuse UPS and renewable energy with backup power as it could cost you dearly. UPS systems are necessary, but they can be expensive if they are called to provide backup power for your entire load. The golden rule is to localise your UPS and centralise your backup power and grid tied renewable energy as much as possible.”
South Africa has enjoyed a reprieve from load shedding since the nationwide lockdown began on 27 March 2020. Although the demand for power has dropped by 7500MW during the lockdown period, demand will increase as industries start to ramp-up, and load shedding is likely to resume. Power outages will cost businesses that have already lost valuable time during the lockdown.
“The predicament for businesses is that load shedding will stop them in their tracks just as they are trying to get going again. Downtime costs money. After weeks of partial or total shutdown, no business wants or can afford it. With the load shedding stint averaging two to four hours at a time, it equates to two to four hours of productivity lost during the workday. Having reliable backup power can help businesses to keep the cogs turning.
“It is not only about business continuity. It is also about preventing damage to equipment due to power surges and dips, which are common when electricity switches back on after an outage. Damage to manufacturing processes due to power cuts can become very costly, for example if there is disruption in injection moulding processes where the time taken to restart can damage the moulds and cause hardening,” says Nick Oosthuizen, Managing Director at Inframid, which provides specialist Energy Efficiency Consulting and Program Management Services to the education, manufacturing, and commercial sectors.
He explains that backup power is an energy source that companies can rely on, control and regulate themselves. Backup power can include energy sources such as diesel, petrol, steam and gas, which lowers dependence on utility power supply. Sun-powered energy, such as solar panels, should not be considered as backup power since it is reliant on sunshine—the same counts for batteries as they rely on electricity to recharge. They can however be applied as backup power to small loads, but is more applicable as part of UPS systems providing a seamless transfer for mains fail to backup power. Renewable energy has its place in energy saving, but cannot be relied on when backup for essential loads is needed and becomes very costly when sized sufficiently to provide backup.
With load shedding a reality for the foreseeable future, companies that want to ensure business continuity should weigh up the costs of the resulting downtime against the investment in backup power. Not all companies, especially smaller businesses, have the capital to invest in grand scale backup power systems. However, Oosthuizen says there are options for companies with small essential loads, such as localised UPS (uninterruptible power supply) systems, small off-the-shelf backup generators and small solar powered UPS systems. The latter being rather suitable for day time loads where mounting space for PV panels is available. Companies should first understand their load. For some businesses, it might suffice to only have backup power for essential loads. Organisations should analyse four segments of their electrical load before considering backup power:
“A feasibility study will assist companies in calculating the cost of downtime, determine the need for backup power and confirm an acceptable return on investment. A tremendous amount of time and effort is put into understanding client backup power needs before installing any systems. As loads, needs and budgets vary, there is no one size fits all approach for every business.
“Some of our recent projects included feasibility studies with backup power that reached break-even points within one year. With the rate of load shedding it becomes very possible for businesses to recoup all cash invested in new energy supply elements within a year,” says Oosthuizen, adding that once a company has done a feasibility study, continuous measuring is crucial to monitor return on investment.
He concludes saying that power outages result in considerable productivity and financial losses for businesses.
“Load shedding will be back for an encore. When everyone is chomping at the bit to get back up and running after the lockdown, the last thing you want is to be stopped in your tracks. Be prepared with reliable backup power. Now is a great time to do a feasibility study that will showcase overall energy needs and cost saving opportunities. Once companies are up and running this will already be in place.”
While many businesses, homeowners and public establishments look to save electricity usage and increase their security of power supply, it is critical that they consider their unique needs before deciding on new elements of power supply. This is according to Nick Oosthuizen, Managing Director at Inframid and consultant in energy efficiency, who highlights the importance of understanding your electrical load before investing in new power supply systems.
“Schools are a clear example of why you cannot take a one-size-fits-all approach in efforts to secure your power and save energy. School loads are not only seasonal but also vary throughout the weeks and days,” says Oosthuizen. He recommends that you undertake an in-depth financial feasibility study that weighs up all elements of power supply in relation to the prevention of downtime and assuring return on investment. “The first step is to conduct an ‘electrical audit’ and understand your current electrical load, which will help to identify the real needs for special supply systems and avoid fruitless expenditure. It is thus important to know your electrical demand, load content, and electrical distribution architecture.”
To assist in understanding your electrical load needs, Oosthuizen explains that there are at least five different segments to consider: essential loads, critical no-break loads, non-essential loads, energy inefficient loads, and your total load profile over time. It is fundamental to determine these different load categories you are dealing with, firstly so that the different types of power supply systems can be applied appropriately, secondly to avoid over-sized and therefore over-priced systems, and thirdly so that the potential for load reduction and renewable energy can be considered all with the view to achieve acceptable return on investment (ROI).
The essential load is made up of electrical systems that are fundamental to help the school remain operational, and to keep safety and security systems going. These essential loads require reliable backup power supply sources in order to maintain the electricity supply under mains fail conditions for as long as needed. For schools, these normally include classroom lighting, educational sports facilities, power points for educational systems, offices, learning and admin computer systems, printers, projectors, essential water pumps, etcetera.
Critical no-break loads
No-break loads are those elements of the essential load that need seamless power transfer and cannot tolerate even a split-second unplanned break in power supply when switching from utility supply to backup power. In a school, seamless transfer is needed in areas such as administration and classroom computing systems where valuable information will be lost if power supply is interrupted. “These no-break loads require uninterrupted power supply, UPS, systems when the main power supply fails,” says Oosthuizen. As these UPS systems are normally battery and sometimes solar supported and very costly, it is important to know exactly what size the no-break loads are and how long they will need to be supplied by the UPS systems.
“Non-essential loads include those systems for which you don’t need backup in any form. It is the part of your load that the school can do without while remaining operational during mains fail conditions. An example of this might be geysers, heaters, air-conditioners, pool heating, and pool pumps, which are not essential for running a school.” However, if you lose your utility supply for long periods, the situation might change, as will the definitions of the non-essential loads.
Inefficient energy loads
According to Oosthuizen, inefficient energy loads include electrical elements which can be replaced by energy-efficient alternatives to make the load less bearing. “This lends itself to energy saving in day-to-day operations. For example, all new geysers must comply with the new minimum standard as set by the Department of Energy, namely Class B, as specified in SANS 151, to ensure less pressure on your electrical load,” he explains. In schools, the replacement of air conditioners and electric heaters with the latest state-of-the-art low energy and unity power factor technology will have quite an impact on energy consumption. Changing older light fittings to the newest technology LED fittings will also have a significant impact on energy usage. Water and sewage pumps are other considerations. In general, pumps have a very low power factor, which means they draw higher current than necessary. “Where schools have many pumping systems, it is worth considering power factor correction to these loads to increase the power factor, which will decrease the reactive power with various cost benefits, such as lower demand charges, avoiding reactive power penalties and freeing up distribution system capacity” advises Oosthuizen.
“When determining your school’s power supply needs, some forethought can go a long way in ensuring appropriate systems,” says Oosthuizen. “You should determine your total load profile for at least a year, bearing in mind that school loads are seasonal and are changing from day to day. When determining your load, don’t only use utility account information – this normally only provides monthly maximum demand where applicable and energy usage. Additionally, it is important to understand which parts of your load can be moved to non-operational times, such as after 15h00, when total consumption is less. There are many timer and automation technologies on the market that can help with load shifting in order to spread the usage curve,” says Oosthuizen.
“Investing in an alternative power supply system for your school is a good idea, but for it to be a feasible investment you must clearly understand your load requirements before making any decisions. Knowing what you have is the critical first step to knowing what you need next. Analysing this resultant need for alternative power supply solutions against your potential loss of business, loss of information and energy savings forms the essence of your business case for investment” concludes Oosthuizen.
As South Africans settle into the routine and inconvenience of load shedding and planning their activities around shifting electricity supply, it is businesses that are taking the biggest hit through the loss of operational capabilities, productivity, and profitability. While individuals deal with maneuvering their household times and sitting in gridlock traffic, local businesses, hospitals, schools, and industrial sites must find ways to remain operational despite limited generating capacity.
The electricity shortfall makes it crucial for organisations to reconsider their power supply systems. According to Nick Oosthuizen, Managing Director at Inframid and consultant in energy efficiency, there is no silver bullet to solving this challenge. “Businesses need to take a holistic approach when looking at securing their power supply. There is no one-size-fits-all solution. A tailored system, based on a feasibility study that considers unique power supply elements for your organisation, will ensure the highest return on investment (ROI),” he advises. According to Oosthuizen, there are at least five essential aspects to consider.
1. Know your load
To ensure an optimal energy supply system, you first need to understand what it is you are currently dealing with. It is important to know your electrical demand, load content, and architecture. “Businesses should conduct an electrical audit before considering other energy sources. This will help avoid fruitless expenditure and help plan a low energy load. A good place to start is by considering the energy efficiency of the load elements,” says Oosthuizen.
“For instance, the Coefficient of performance (COP) is the efficiency of refrigeration, aircon, and water heating systems and is highly dependent on product quality. A higher COP equates to lower operating costs, so businesses should continuously consider the technology they are using, especially as part of maintenance replacement plans. The same considerations are relevant to light fitting technologies.”
2. Check your utility connection
“Although utility-supplied power is highly unreliable at the moment, it is still the cheapest. As your main source of energy, you should validate that you have utility connections at the most cost-effective tariff scale. Acquiring and operating backup power can be rather expensive if not part of an overall plan, and all energy-saving initiatives should be considered.”
3. Consider your backup options
Popular backup power solutions include diesel generators, gas generators, and batteries. The chosen solution will largely depend on cost and usage requirements. “While backup power reduces your dependence on utility power – a feature in high demand at the moment – it comes at a price. Electrical teams need to motivate this investment to the decision-makers, and the best way to do this is through a financial feasibility study that weighs up all elements of power supply in relation to each other and the prevention of downtime,” says Oosthuizen.
According to Oosthuizen, downtime can get very costly and should be measured when looking at the feasibility of a backup power solution. This also bears weight on the kind of backup power you decide to use and when it will kick in. “This varies between industries and applications. For example, one minute of downtime before backup power kicks in might be too much for certain manufacturing plant.” He advises that organisations should do a breakdown of electrical loads and establish the normal load, the backup load, and the essential load. The Essential load is where you can’t lose a second and a seamless transfer will be needed.
4. Think about seamless transfer
“For organisations who can’t afford a lapse in power supply, a seamless transfer system will be necessary. However, this seamless transfer might not be needed for all loads in the facility. The essential load would be the priority, and would need an uninterruptible power supply (UPS) for mission-critical systems. However, being an expensive commodity, it is important to apply UPS to essential loads only and after determining its feasibility.”
5. Save energy where you can
Reducing your energy requirements is an obvious strategy when it comes to improving your security of supply and reducing costs. “When it comes to saving energy, it is not just about the energy-efficiency of the technology you use. Supplementary power sources are something worth considering. Renewable energy generation in the form of solar, wind and other states of the art generation can be implemented. This has the potential to convert your load into a valuable asset,” advises Oosthuizen.
He says: “One of the biggest mistakes we see is that organisations focus on the glaring symptoms of power cuts and try to heal these with specific power supply elements, without following a holistic approach. They overlook the bigger picture. Different industries have unique load structures serving specific operational needs, each needing different combinations of power supply elements. Each of these elements addresses a very specific area of energy efficiency, such as security of supply, protecting essential loads, saving energy, and avoiding expensive upgrades.”
“An independent energy procurement process should be conducted to provide appropriate and competitive solutions, where tender documentation based on international standards is sent out to various suppliers of different power supply-, seamless transfer- and renewable energy sources to tender. This process will also increase the overall feasibility.”
Oosthuizen advises that a good energy strategy is to utilise utility power augmented by other feasible energy elements and to shift loads to minimise energy usage. “A good energy efficiency strategy is a worthwhile investment as it helps companies to avoid costly downtime and saves energy usage, thus improving the return on the investment made,” concludes Oosthuizen.