MechChem Africa November-December 2020
⎪ PowerGen, PetroChem and sustainable energy management ⎪
Left: EP Intelligence collects data to build reports with energy reduction targets. Above-target energy is identified as waste and site employees are all urged to implement a war on waste. Right: Modern high-efficiency refrigeration technologies are estimated to be able to deliver a further 20% in energy savings to retail.
Renewable energy and PPAs Theron notes that there is now “huge value from multiple perspectives” of adopting re- newableenergy solutions suchas solar power. The benefits are far larger than simply costs. One of our healthcare clients, for example, is achieving an additional 30% in cost savings, simply because the solar systemhas reduced the peak demand charges on the utility bill. “Through EP Solar, we can deliver client- funded turnkey energy plants, but in current leaner times, it is more common for us to set up a power purchase agreement (PPA) for a period of 25-years to attract an investor,” he says, adding that PPA tariffs are typically 30%-40% below the grid rate. “When coupled with other energy man- agement and efficiency initiatives, multiple benefits accrue: for users, investors and for the national grid, which will be better off in the long term if demand is reduced to better match its generationcapacity,” Theronargues. “We in South Africa have among the high- est solar yield in the world, along with very favourable temperature profiles, so solar is an ideal technology for us. But it still needs to be coupledwith storage ifwe are tohelp solve current network problems of peak loading in the morning and early evening. We estimate that by 2023, payback periods on a battery- based storage solutions will drop to as little as five years,” he says. Turning attention back to the current national grid crisis, Theron argues that South Africa cannot continue to increase capacity in order to “fix a broken system”. “We can’t simply carry on adding capacity and running it inefficiently. “Currently, 26 of South Africa’s largest companies consume roughly 40% of the country’s energy. Reducing these companies’ energy consumption by focusing on solutions such as energy storage, renew- able energy, process optimisation, power quality and general energy efficiency, can not only enable them to lessen the strain they place on the grid, but it will also sig- nificantly reduce their operational costs,” Theron concludes. q
for a year,” he tells MechChem Africa. Operating on multiple sites, this was a favourable client for Energy Partners, with relatively few areas of energy consumption: lighting, refrigeration, air conditioning and back-of-house cold rooms and dry shelving areas. “Knowing that every one of this com- pany’s facilities is dealingwith thesame things enables us tomanage all their sites centrally,” he notes. He explains that as soon as data begins to be collected and used to produce load pro- files, it becomes immediately apparent when power is needed, howmuch is being used and where it isbeingwasted. “Wealso incorporate other known factors such as when stores are open, when the shelves are being stocked and when there is a night shift. By starting to suggest changes, suchas turningoff half of the lights when employees are stacking shelves, significant savings become apparent. This is easy, we simply install key switches, one for use when stacking shelves and another to switch all the lights on when the store opens for customers,” he tells MechChem Africa . Across all of this retailer’s sites, EP Intelligence was able to use collected data to build reports with reduction targets. These identified all above-target energy use as waste, and urged every site to implement a war onwaste. “This, alongwith simple behav- iour measures adopted by site staff – never leaving fridge or cold room doors open, for example, or never blocking the air ducts of chiller cabinets with over-stacked product – resulted in 37.5% energy savings. Over the 10 years we have been managing energy in this way, we estimate that R2.7-billion has been saved,” Theron says. Other interventions include replacing dry andbrittle seals on cold roomdoors, installing night blinds over the refrigerated cabinets to better contain the cold air overnight, and manymore. “Most are low cost interventions that, combined, contribute toongoing savings across multiple sites,” he adds. “On the level above, we have developed procedures to optimise the way cold rooms are packed, so that, wherever possible, they
run at full load and best efficiency. We also implemented a general refrigeration mainte- nance programme. On average, refrigeration units consume 50% of this retailer’s total energy consumption, so keeping units at their best possible efficiency presents an obvious savings opportunity,” he says. Theron says thebehaviour of storemanag- erswas, undoubtedly, the lowest hanging fruit for this project. “But we are not done yet. The next stepwill be to lookat changing tomodern high-efficiency refrigeration technologies, whichweestimatecoulddeliverafurther20% in energy savings,” he continues. Rolling out solar energy across the chain is another huge opportunity, whichTheron sug- gests can feasibly contributebetween5.0and 50% of ongoing energy needs in typical com- mercial and industrial enterprises, depending on the roof size and the locationof the facility. PV-solar systems directly reduce grid-based demand and costs, while also contributing to reducing grid dependence and associated tariff uncertainty. “Tariff optimisation is another key and often missed issue with respect to energy optimisation,” Theron continues. “Of all the clients I see, I find 30% of them are on the wrong tariff, which means they have tariff switching options available to them that will immediately reduce their monthly bills. “Many commercial and industrial users are ondemand-basedtariffs,whereasinglerateis applied depending on themaximumdemand. The alternative is a time-of-use tariff, which is almost always better, typically reducing monthly bills basedon the identical consump- tion profile by 10% to 15%. “Because our national grid problem is related to peak demand, it makes sense, for everyone, to encourage people to shift their time-of-use to lower demand and lower cost time periods –the City of Cape Town has already begun to shift all users onto time-of- use tariffs. When paying three to four times more for energy at peak times, it becomes easy to persuade companies to find ways of rescheduling consumption to lower cost periods,” he explains.
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