www . refrigerationandaircon . co . za RACA Journal I August 2023 29
Feature periods . Municipalities play a crucial role in determining energy rates , including peak demand tariffs and time-of-use benefits . The availability of such incentives can influence the adoption of thermal storage technology in different regions .”
Van der Merwe sums up the attraction of thermal storage technology as enabling any business not to install their maximum capacity , but only 60 % of peak chiller demand and supplement it on demand with stored cooling according to the 60 / 40 rule . “ Whether a bank or a shopping mall or any commercial building , peak demand typically occurs at lunchtime ( bank ) or midafternoon ( office ) for an hour or two .”
That is when stored cooling is required . They run their chiller all day , and when it runs out of capacity , the storage kicks in at low-cost rather than premium-cost rates . Then the system has the whole night to recharge for peak the next day .”
It is not a separate system – the chiller that is in any case there , creates ice and stores it like in a battery for the next day . Chillers can be retrofitted to accomplish this , he explains .
“ Until a few years ago – with the emergence of loadshedding – people never saw thermal storage as ‘ backup .’ That concept gained traction as South African industries requiring continuous refrigeration for critical cooling - such as theatres , hospitals , clinics and data centres - sought alternatives to expensive diesel generators or less reliable renewable energy plants . These establishments often experience significant fluctuations in their heating and cooling demands . For instance , office buildings may have varying occupancy levels throughout the week , while theatres and cinemas might see a surge in visitors during specific hours or days . Thermal storage provides an effective solution by allowing excess thermal capacity to be built during off-peak periods and released quickly when required .”
This led to a shift in perception , with clients exploring the feasibility of integrating thermal storage systems as backup cooling during power outages . “ We are now getting many enquiries for this usage as opposed to taking advantage of timeof-use tariffs .
“ Compared to alternative solutions like solar and diesel generators , thermal storage presents an economical option . Although no system is 100 % tailored for universal efficiency , building ice as a form of energy storage provides a highefficiency return . Moreover , the design of the thermal storage system plays a crucial role in optimising its cost and operational effectiveness . By supplying cooler glycol at a lower temperature range , smaller piping , air handling units , and electrical components can be used , resulting in reduced first costs and operational expenses .”
Van der Merwe explains that in the realm of refrigerated distribution centers , thermal storage has found its niche in South Africa . “ These centres are vital for ensuring the freshness and preservation of perishable goods , and thermal storage technology enhances their efficiency . This demonstrates
“ SA industries requiring continuous refrigeration for critical cooling - such as theatres , hospitals , clinics , theatres and data centres - sought alternatives to diesel expensive generators or less reliable renewable energy plants .”
www . refrigerationandaircon . co . za RACA Journal I August 2023 29