MechChem Africa September-October 2022

Heat recovery, energy efficiency and decarbonisation goals

Erik Roels, senior sales accelerator at Danfoss, talks about the role of heat recovery and reuse as a key opportunity for improving the energy efficiency of HVAC systems and the essential contribution this makes to the carbon neutral drive. C urrent challenges around energy security, energy prices and the cost of living have intersected with the climate crisis, highlight ing the fact that energy efficiency is now more indispensable than ever. solutions. With more than 90% of energy related emissions coming from electricity, the firm’s next priority is to decrease energy consumption from electricity use. It plans to achieve this by reducing the energy use; reusing the energy it has already used once; and replacing fossil energy sources with renewables.

So says the International Energy Agency (IEA), in its recently released report: ‘The value of urgent action on energy efficiency’. The paper states that “the cleanest, cheap est, most reliable source of energy is what countries can avoid using, while still provid ing full energy services for citizens. That is why the IEA refers to energy efficiency as the ‘first fuel’. Without early action on ef ficiency, the energy transition to net zero emissions will be more expensive and much more difficult to achieve.” The new report highlights opportunities for rapid energy efficiency gains in all sec tors of the global economy, most of which involve readily-available technologies. Not only this, but these solutions also offer a speedy return on investment based on lower running costs, particularly in light of today’s rising energy prices. By 2030, around a third of the avoided energy demand will come from deploy ing more efficient equipment, ranging from air conditioners to cars, it states. Approximately a fifth is derived from elec trification, such as switching to heat pumps or electric cars, with digitalisation and the use of more efficient materials in industry providing much of the rest. “Energy efficiency has huge potential,” says Erik Roels, senior sales accelerator at Danfoss, on a recent visit to South Africa. “The improvement of energy efficiency means that the overall energy demand is reduced and that the remaining energy needs are covered in a more efficient way.” An ‘energy efficiency first’ principle is very close to Danfoss’ heart, with the organ isation aiming to become carbon neutral in its global operations by 2030. Thus far, the company has doubled its energy productiv ity and halved energy intensity, nine years ahead of time. Danfoss will continue to prioritise en ergy efficiency in buildings and processes, in particular through the use of its own

Through its green initiatives, Danfoss has managed to source 100% green electricity for its more than 250 000 m² headquarters in southern Denmark. In fact, 2022’s figures showcase that 85% of its heating demand is covered by green energy from carbon neutral district energy, utilisation of excess heat and heat pumps. “Danfoss itself is an excellent example of using heat recovery to boost energy efficiency,” says Roels. “At our Nordborg campus, excess heat produced by manu facturing processes and the data centre on site is reused to heat our offices and production areas using our own solutions in addition to installing heat pumps. As part of our green initiatives, we were thus able to cut our emissions last year by 80%, putting us well on track to reach carbon neutral status in 2022.” “This strong focus on waste heat recov ery is playing a vital role in energy efficiency and energy saving, and can be embraced by organisations across Africa too,” Roels explains. “While there may not be the same access to the type of district heating infra structure more common in parts of Europe, there is still an argument to bemade for heat recovery locally.” This pertains in particular to any industry that has a requirement for cooling, he adds. “For instance, a local butchery, which uses refrigeration to ensure that its meat prod ucts remain cool, could reuse excess heat generated by the cooling equipment to heat water at the establishment. “Alternatively, we could consider the requirements of an African dairy farm. As a highly perishable food, fresh milk must be refrigerated as soon as the cow is milked in order to adhere to strict processing and handling require ments. The heat generated by the milk stor age tanks could again be reused to heat up water for the cleaning and sterilisation of

equipment. “On the other hand, heat could also be sold on, and it doesn’t have to be on the same scale as a city-wide district heating system. For example, a local supermarket could use heat extracted for other nearby shops, perhaps in a strip mall, or for neigh bouring residences. In fact, a small retail store could generate enough heat to be used by more than 14 nearby houses. “Any organisation with its own data centre also has an opportunity to recover heat generated. Not only do the racks and rows of serverswithin a data centre produce heat but the cooling equipment needed for these machines can also generate signifi cant heat.” Typically, data centres produce heat at between 25 to 30 ˚C. Danfoss uses highly efficient heat pumps to further boost this temperature to 60 to 70 ˚C for greater effi cacy. Installing this kind of system is actually an excellent way of decarbonisingwhilst still keeping the costs relatively low. "Global ly, we have serious cl imate targets to meet, in l ine with the Paris Agreement’s goals to avoid dangerous cli mate change and limit global warming. Heat recovery will most definitely be part of the solution, allowing organisations to work in a smarter, more cost effective way," Roels concludes. www.danfoss.com

28 ¦ MechChem Africa • September-October 2022