The eighth edition of DC Dialogue, on October 11 in Riyadh, discussed the role of District Cooling in the growth and development of Saudi Arabia as well as how the industry is meeting the expectations of stakeholders in terms of environmental stewardship, delivery of service and optimisation of cost.

The conference, produced by CPI Industry, co-hosted by Dalkia EDF Group and chaired by George Berbari, CEO, DC PRO Engineering, featured an industry leadership address, a plenary discussion, techno-commercial presentations, a panel discussion, project profile presentations and a debate.

Steve Lemoine, CEO Middle East, Dalkia EDF Group, opened the floor to discussions with a special address, during which he underscored the importance of District Cooling networks in efforts being taken to combat climate change. Lemoine added that emphasis must be placed on the need for a comprehensive approach, aligning with the goals of the Paris Agreement to limit the temperature increase to 1.5 degrees C. Furthermore, he highlighted the importance of decarbonising energy production and improving energy efficiency, pointing to Saudi Arabia’s commitment to be net-zero by 2060.

Lemoine said that Dalkia EDF Group is committed to decarbonisation initiatives and added that the Group is working on many innovative projects in the Middle East region, spanning District Energy networks, solar initiatives, consultancy services, energy-efficiency initiatives and operational maintenance. Moreover, he underlined the importance of addressing the entire value chain, including equity, extension and development of District Energy networks, and said that decarbonisation initiatives could be accelerated through a combination of innovative projects and ensuring energy efficiency and operational excellence. Lemoine also briefly discussed various innovative energy efficiency and sustainability approaches, including seawater cooling, underground water usage for data centres, and geothermal energy with both low- and high-temperature applications.

Speaking after Lemoine, Berbari presented an overview of the District Cooling industry in the Middle East region. Berbari, an industry veteran, said that initially, the industry relied on natural gas for power generation, and was content and less inclined towards significant advancements, despite attempts to push for innovation. He added that the role of District Cooling has become crucial due to the intermittence of power from solar and wind sources, as the world now collectively aims for decarbonisation. Berbari said that in such a scenario, ensuring efficient storage of energy is crucial, and currently, battery storage is priced at USD 200 per kilowatt-hour compared to District Heating systems.

Furthermore, Berbari delved into the advantages of District Energy systems and underlined that they have a longer lifespan and cause low losses. He also spoke on the potential of Abu Dhabi to transform itself into a carbon-neutral city, leveraging its nuclear and solar power capabilities. In the latter half of his presentation, Berbari shifted his focus to Riyadh, pointing to the major challenges faced by the District Cooling industry, including water scarcity. He added that there is a need for industry-wide collaboration and suggested that potential solutions include the use of artificial intelligence to optimise District Cooling systems to enhance efficiency and reduce costs. He concluded his overview by highlighting the need for proactive measures in retrofitting existing cities and addressing challenges in the residential sector’s energy consumption.

Francois Courtrot, R&D Manager, EDF China, gave the pivotal ‘Industry Leadership Address’ of the event, during which he spotlighted the District Cooling industry in China, and demand for as well as the challenges confronting District Cooling projects in China. He said, “There is a surge in the demand for District Cooling projects in China, in response to the increasing demand for cooling driven by climatic conditions, urbanisation and industrialisation.” Furthermore, pointing to the criticism faced by District Cooling projects in China relating to underperformance and slower-than-expected load, Courtrot underlined the importance of accurate planning and addressing operational challenges. He said that the emphasis must be on ensuring client satisfaction and avoiding complaints by maintaining consistent operations.

One of the major highlights of his address was the discussion around the concept of the digital twin, EDF’s digital solution to replicate and optimise system functioning using a pool of models. He said: “The ability to replicate the complete functioning of a system and optimise its operation using a pool of models is a powerful approach. The emphasis on human expertise being the core value and digital tools serving as support resonates with the idea that these tools enhance efficiency rather than replace human judgment and skill.” Furthermore, while explaining the various use cases and practical applications of digital twin, he added that the integration of Artificial Intelligence and physics, alongside a focus on human expertise, offers a holistic approach to navigating the complexities of District Cooling projects in the rapidly evolving energy landscape.

Malla Alahmadi, Business Development Manager, Diarona District Energy Limited, and Bakulesh Kanakia, CIO, Diarona District Energy Limited, next addressed the delegates, during which they delved into the District Cooling industry in Saudi Arabia, especially with regard to new investments and new opportunities arising in the country, in line with the environmental goals of the country. Alhamadi said that even though the government has implemented initiatives to promote District Cooling projects, making the market more attractive for investors, there are challenges, such as a lack of public awareness, the availability of water and electric tariff differentials. Furthermore, Alahmadi underlined the importance of collaboration in tackling these challenges and added that the involvement of government entities, utilities, District Cooling developers, real estate and the public is vital. Furthermore, he discussed in detail the integrated solutions offered by Diarona, which include design, procurement, building, rapid deployment and customer support. He said that Diarona has deep relationships with key suppliers and employs advanced technologies, including artificial intelligence, for optimum plant performance.

For his part, Kanakia discussed Diarona’s collaboration with Tabreed and Qatar Cool and the company’s initiatives in the UAE. Kanakia said that the company aims to make valuable contributions that align with the dynamic needs of customers. Further pointing to the District Cooling sector’s evolution over the past two decades, he said that recognising past mistakes helps the company to navigate challenges and plan for a more effective future. He added that it is important to prioritise user benefits.

Zaki Ahmed Mohammed, Director – Sustainability Advisory, of Qatar-headquartered GORD, spoke next. In his presentation, Mohammed shared the details of Arcadia Suite, a District Energy assessment tool developed by GORD. He said that it can be used for design in existing plants and for the optimisation of projects, as it has the ability to provide immediate insights and can drive changes. Mohammed said, “Arcadia Suite is a performance tool that can be used to assess how and what the current energy performance or the seasonal energy efficiency ratio is.” He also said that the tool is applicable for baseline establishment, and certification, offering silver, gold and platinum levels. Furthermore, Mohammed’s presentation delved into the services offered by GORD and the Global Sustainability Assessment System (GSAS). He also discussed GORD’s carbon credit programme and said that GORD is involved in converting the electricity savings achieved through optimisation projects into an additional revenue stream.

Speaking after Mohammed, Jalal Al Kurdi, Sales Director – Projects, Hussein & Al-Hassan G. Shaker Bros. for Modern Trading Co. Ltd., shared a snapshot of the global presence and financial standing of Midea Group, Midea Building Technology, R&D facilities as well as the Group’s manufacturing facility in China. Kurdi also said that the company focuses on six pillars: Green design, green purchase, green logistics, green manufacturing, green recycling and green services.

Rajiv Sawhney, CEO, Smart Energplus, also spoke during the event, on the topic, ‘Sustainability starts with Energy Management’. Sawhney’s presentation focussed on energy management in District Cooling applications. He said that the growth of the urban population and increased energy demand underlines the importance of sustainable practices. Furthermore, pointing to the Global Sustainable Development Goals, he emphasised the importance of a holistic approach involving end-users, optimising supply chains and collaborating on a unified business model in this sector. Sawhney also underscored the importance of certified sensors and their potential in existing cooling networks. He said that the sensors can contribute to data-driven decision making as well as predictive maintenance. Smart Energplus’ integrated solutions, he added, extend beyond traditional metering, incorporating IoT and contributing to a comprehensive energy management strategy.

Subsequently, giving a techno-commercial presentation on adopting sustainable refrigerant technologies in District Cooling applications, Amir Naqvi, General Manager, Honeywell Advanced Materials (META region), spoke on the dynamic landscape of global regulations and the impact of sustainability, decarbonisation and circular economy initiatives. Naqvi said that in the Middle East region, where energy-efficient solutions can significantly reduce environmental impact, Honeywell focuses on District Cooling and building insulation. Naqvi added that the region’s commitment to achieving carbon neutrality is being shaped by regulatory drivers like the Paris Agreement, COP28, Saudi Arabia’s clean and efficient dream initiatives and the mandates of the Kigali Amendment.

Furthermore, he said that Honeywell emphasises transitioning to low-global-warming-potential (GWP) refrigerants, particularly HFOs, to enhance sustainability in the industry. While the sector commonly concentrates on the supply side of energy efficiency, he said that Honeywell focuses on addressing demand-side opportunities. Naqvi also touched on the critical role of insulation in reducing energy consumption, especially in District Cooling pipes, and the use of HFO solutions to enhance energy efficiency, pointing to examples of projects from the UAE where HFOs play a significant role in their carbon reduction goals.

Speaking after Naqvi, Saeed Al-Laham, Applied Business Developer – KSA, Trane, delved into refrigerants and their impact on carbon footprint. Through his presentation, titled ‘A sustainable DCP, refrigerants and CO2 impact’, Al-Laham discussed the importance of sustainability in refrigeration, direct and indirect emissions, the calculation of carbon footprints, and the transition of refrigerants. In addition, he said that the transition to lower-GWP refrigerants is gaining momentum due to several factors, including technological advancements, compliance with regulations, economic considerations and voluntary initiatives by companies committed to sustainability. The economic factor, he added, is influenced by the scalability of HFOs, making them more cost-effective, and the expected increase in prices of high-GWP alternatives, like HFCs. He also added that several projects in the Middle East region opt for refrigerants with lower GWP, as it aligns with their sustainability goals.

The last techno-commercial presentation of the day was delivered by Kingson Jebaraj, Managing Director, Innovative Water & Energy Technologies. His presentation revolved around the importance of ensuring condenser performance in District Cooling while utilising non-potable water. He discussed the solutions offered by his company, including an automatic condenser tube cleaning system and an integrated unit for reverse osmosis. He also added that his company emphasises the importance of integrating filtration and automatic tube cleaning for reliable and sustainable District Cooling operations and of addressing the complexities of using non-potable water in District Cooling.

The conference also featured two project profile presentations, namely ‘Sea Water District Cooling – challenges and benefits’ by Ibrahim Hassanien, Lead Projects Engineer, Allied Consultants, and ‘The Avenue Riyadh (by Shomoul Holding Co., a subsidiary of Mabanee Company, Kuwait)’ by Guillermo Martinez, Commercial Director, Araner. Hassanien, in his presentation, discussed District Cooling systems that utilise sea water and emphasised the benefits, such as reduced water consumption and space flexibility. Further, Hassanien pointed to the various challenges, namely, material costs, environmental considerations and regulatory approvals, and said that a feasibility study is crucial for this kind of a project to deliberate on factors such as project location, environment and stakeholder engagement.

Martinez, speaking after Hassanien, said, The Avenue Riyadh is a mixed-use development in North Riyadh, spanning 390,000 square metres, and featuring a total area of 1.8 million square metres. He said that the project includes a mall and five luxury towers for hotels, residential apartments, medical clinics and offices. Furthermore, he said that the District Cooling project, within this development project, is designed to provide cooling energy to all consumers, showcasing an integrated and comprehensive approach to serve diverse needs within the development. He also said that by integrating the cooling plant into the basement of the mall, the need for a dedicated block for the plant had been eliminated. He also said that coordination among contractors, the adaptive design approach used in the mall and stakeholder involvement, pose challenges; in that context, he said, consultancy with current experience is crucial for overcoming the challenges and ensuring smooth project operation.

Big numbers, big investments

The eighth edition of DC Dialogue, featured a plenary discussion, titled ‘Big numbers, big investments and the energy mix in the making’. Moderated by George Berbari, CEO, DC PRO Engineering, the discussion delved into topics such as Saudi Arabia’s 3 million TR District Cooling target, mega projects, sources of energy, the contribution of legacy District Cooling companies in the country and emerging District Cooling companies. It featured, Takuma Hosaka, CEO, Diarona District Energy Limited and Dominic McPolin, Freelance Strategic Planning Advisor. Excerpts from the plenary discussion…

Following the introduction of the panellists, Berbari kicked off the discussions by asking Hosaka about the potential Diarona envisions in Saudi Arabia and the technologies it plans to introduce in the country. Hosaka began by providing a brief overview of Diarona District Energy Limited. He said, “The joint venture includes three key shareholders: Ajlan & Bros for Trading, Marubeni Corporation, and United District Energy International (UDEI), the international arm of Qatar Cool, the largest District Cooling provider in Qatar.” Hosaka said that the primary motivation behind the formation of the joint venture lies in recognising the potential and excitement in market opportunities for District Cooling in Saudi Arabia. Furthermore, Hosaka said that all the shareholders have collectively contributed their experience, expertise and enthusiasm to the establishment of the joint venture. He added that the primary focus of the venture is the development of District Cooling. In addition, Hosaka underlined that Marubeni Corporation is actively involved in areas such as renewable power, geothermal and global green hydrogen, and that it represents the comprehensive offerings the company aims to provide.

Joining the conversation, McPolin spoke on his experience in developing District Cooling projects in Bahrain and how the lessons learnt from these experiences can be applied to ensure a more successful approach to projects in Saudi Arabia. McPolin said his colleagues and he have made numerous mistakes in the industry and have learnt from them. He said, “There is a tendency to overly focus on technical expertise, and the main challenges in bringing District Cooling into a holistic approach to climate change are psychological, commercial and related to government attitudes.” Moreover, he added that the call for a shift from project-led to plan-led innovation in climate change underscores the need for a radical change in industry perspective. McPolin also briefly addressed the psychological issues associated with trusting private companies with people’s lives, livelihoods and property. The challenge, he said, is balancing commercialisation while ensuring government-sponsored, guaranteed and certified alternatives for cooling. McPolin also underlined the importance of a comprehensive urban planning perspective, pointing to the current approach of heating urban areas with air conditioning units.

Shifting the discussion to regulations, McPolin said there is a need for more significant change in the financial model. Moreover, he added, there has to be a shift towards collaboration, with governments sharing benefits with product-developing companies and developers sharing savings with implementation companies. The ultimate goal, McPolin said, is to reduce District Cooling costs for consumers, positioning it as a vital infrastructure for the region’s next generation. “Acknowledging that time is of the essence, the call for action is clear,” he said. “Government intervention requires decisive policies and regulations to propel the industry beyond a project-based marketing exercise. The urgency for government action is paramount, recognising the need for a swift and comprehensive transformation to meet the challenges of the present climate crisis.”

Berbari then encouraged the participants to speak on the use of hydrogen. Saying that hydrogen is projected to contribute to 10% of the energy demand, and pointing to the fact that companies are investing in hydrogen fuel cells, Berbari said that advancements are being made to make the operations more cost-effective. In terms of practical applications, Berbari added that the UAE is starting to use hydrogen in some fine-diesel applications. On a global scale, he added, countries like France and China are working to reduce hydrogen production costs, focusing on electrolysis. Given the growing interest in hydrogen, he said, in Japan and many European countries the role of hydrogen in District Energy is significant and evolving, with ongoing efforts to explore its potential applications. Berbari also brought such topics as the role of heat recovery systems in energy efficiency and introduction of single-effect absorption to the fore.

Hosaka picked up the thread through sharing a similar perspective as Berbari. He said that adopting a holistic approach to energy usage is crucial in the market and the country. He said that Saudi Arabia now relies heavily on fossil fuels for around 90% or more of its energy needs.

He added that while District Cooling can significantly cut down energy consumption for cooling, the emphasis should be on addressing the input side, particularly electricity.

Shifting the discussion to the pivotal role of networks in addressing the challenges faced by the District Cooling sector, McPolin raised the pivotal question about the possibility of interconnecting two District Cooling companies operating in the same urban area to form a network. This, he said, will address the essence of regulatory seriousness, as it is fundamental to ensuring continuity, backup, alternative energy supplies and the creation of a city-wide resource using the combined resources of multiple companies. Furthermore, he said that the fundamental importance of this interconnection is for ensuring continuity, backup, alternative energy supplies and the efficient utilisation of resources from multiple companies.

Existential issues

The 8th Edition of DC Dialogue featured a panel discussion on the topic, ‘Existential issues, raising the appeal of District Cooling’. The discussion, moderated by George Berbari, CEO, DC PRO Engineering, featured Larbi Behloul, Director – Facilities Management, UAPM; Dan Mizesko, President, Dalkia US Chiller Services; Hassan Younes, Co-CEO & Co-Founder, GRFN Global and Mohamed R Zackariah, Chief Consultant, Suhaimi Design- Protecooling. Berbari kicked off the discussion by introducing the topics, including the traditional BOO model of District Cooling projects and how it enables integrating new technologies, geothermal energy, use of hydrogen, trigeneration and Artificial Intelligence. Excerpts from the panel discussion…

Zackariah highlighted the importance of aligning project intent, design and execution. He emphasised that the intent of project owners is not always executed onsite. He said that it is also crucial to question whether stakeholders truly possess the determination to follow through on intentions. Furthermore, highlighting his many years of experience in Saudi Arabia, Zackariah said he has now come to appreciate the effectiveness of a top-down, collaborative approach involving building partnerships with stakeholders at various levels, ensuring a cooperative effort that bridges the gap between intent and actual design. He also underlined that by fostering alignment with ongoing initiatives, the divide between intent and implementation can be narrowed.

Joining the conversation, Behloul touched on the role of regulators and the need for them to extend beyond simply regulating designs. He said that regulators should consider moving beyond the confines of solely regulating the design phase. Instead, he added, they could focus on regulating consultants and contractors during the entire process. The current regulatory framework, Behloul said, seems somewhat arbitrary and may not effectively narrow the gap between intent and execution. He added that the government, in particular, needs to play a pivotal role in a change in the regulatory approach.

For his part, Mizesko said that one of the prevalent issues he has observed in his career, which spans over 46 years in the chillers industry, is that plant designs lack kilowatt-per-ton performance data upon commissioning. This problem, he said, can be attributed mainly to inadequate scrutiny during the commissioning phase, which underscores the importance of meticulous examination of chillers for genuine energy savings. Furthermore, highlighting the transformative impact of chiller retro-commissioning, Mizesko said that the benefits include cost-savings and improved energy efficiency.

Speaking after Mizesko, Younes emphasised the significance of collaboration and a tailored approach in addressing energy efficiency in new projects and in existing plants. Younes said, “Collaboration is integral while tackling energy efficiency, be it in new construction or in an existing facility requiring multiple retrofits.” In such a scenario, he said, integrated design and an approach including different stakeholders become crucial to navigating the challenges and bridging the gaps. For instance, he added that while a particular technology may be highly efficient in one case, it is essential to establish a fair comparison and understand the unique profiles of different plants for best outcomes.

In addition, Younes discussed the significance of measurement and verification in ensuring energy-efficiency, its relevance in ESCO projects and the importance of guiding consultants in advising clients on suitable technologies for effective solutions.

Shifting the discussion to District Cooling in the residential sector, Zackariah said that District Cooling for the residential sector holds significant potential for energy savings, but the current economic model in use is not easily applicable. While there’s optimism about the benefits, especially in city master planning, he said that the challenge lies in adapting economic models to the unique characteristics of residential areas. He further said that a collaborative global approach, with governments supporting infrastructure development, could be one of the solutions, and financial assistance, diverse economic models and cooperative participation will play critical roles. Zackariah also added that technology is not a hurdle; the key lies in addressing administrative, managerial and financial aspects to overcome current frictions and facilitate widespread adoption.

Taking the cue from Zackariah, Behloul said the implementation of District Cooling in the residential sector faces significant challenges. For instance, he added, service providers must demonstrate efficiency, ensuring that the benefits achieved at the plant level are effectively conveyed to tenants and consumers. Furthermore, in new projects, he said, District Cooling providers must prove their reliability and efficiency to attract investments for infrastructure expansion, and this becomes particularly challenging in regions with widespread low-density layouts, such as Saudi Arabia, Dubai or Doha. He also pointed out that the rise of technologies, such as Variable Refrigerant Flow (VRF) systems, adds another layer of complexity, as it is presented as an alternative. Navigating these challenges, he said, requires a strategic focus on addressing consumer concerns, efficiently conveying benefits and adapting to technological competition. “Moreover, the success of District Cooling in the residential sector hinges on effectively managing these complexities and ensuring that the advantages of the system are apparent to both developers and end-users,” Larbi said.

Berbari, steering the discussion to innovations in compression technology for the residential sector, underlined the challenges and advantages of different approaches. He said that the goal is to bring this innovation to the residential sector. He said that compression technology plays a crucial role in the residential sector, and advancements are being made to address efficiency and noise concerns. Alternatively, he said, VRF systems operate at variable speeds, offering efficiency benefits under partial loads.

Meanwhile, Mizesko said that the comparison between chilled water systems and VRF systems by ASHRAE revealed that the chilled water system is currently more efficient. He said that concerns about the future of VRF systems have emerged, particularly regarding changes in the use of refrigerants.

Air-cooled vs water-cooled DCPs

One of the highlights of the eighth edition of DC Dialogue was ‘The Great Debate’ on the topic of air-cooled versus water-cooled DCPs. The session moderated by George Berbari, featured Ibrahim Hassanien, Lead Projects Engineer, Allied Consultants; Kingson Jebaraj, Managing Director, Innovative Water & Energy Technologies; Larbi Behloul, Director – Facilities Management, UAPM; Dan Mizesko, President, Dalkia US Chiller Services; Mohamed R Zackariah, Chief Consultant, Suhaimi Design – Protecooling; Mohiuddin Shaikh, Technical Manager, Qatar District Cooling Company and Guillermo Martinez, Commercial Director, Araner. Excerpts from the debate…

Hassanien kicked off the discussions by saying that efficiency is a pivotal factor, especially in arid regions where water scarcity prevails. In the absence of viable water solutions, he said, prioritising efficiency becomes imperative and added that when faced with the challenges of a water-deficient environment, emphasising electrical efficiency stands out as the primary avenue for sustainable solutions.

For his part, Jebaraj said that coming from a background of working with water-cooled DCPs, he would like to emphasise the significance of exploring water-cooled plants, even in regions that face water scarcity. Despite considerations about water availability, he added that utlising water, whether potable water or treated sewage effluent, presents a sustainable choice. He said that through proper treatment and refinement, water can meet high standards and contribute to the efficiency of District Cooling systems. In addition, he pointed out that from a holistic perspective, the overall carbon footprint is more favourable with water-cooled plants, and underlined the importance of considering water as a resource in District Cooling projects.

Joining the discussion, Zackariah shifted the discussion to decarbonisation strategies and said that the focus must be on renewable power generation in the context of achieving decarbonisation goals. However, he added that there are challenges related to the limited availability of specific equipment combinations from certain suppliers and manufacturers and the reluctance among some stakeholders to share information openly, treating certain technologies and partnerships as proprietary. He also underlined that overcoming these barriers is essential for fostering collaboration and advancing decarbonisation efforts in the industry.

Speaking after Zackariah, Shaikh provided an overview of the District Cooling industry in Qatar. Pointing to a recent study led by Qatar University, in which the impact of cooling tower blowdown on the sewer network was assessed, he said the study revealed that the blowdown was effectively diluting sewer waste, reducing Total Dissolved Solids (TDS) levels and chemical concentrations. Moreover, he added that this result prompted further studies, and a joint initiative is now underway to comprehensively investigate the positive effects of cooling tower blowdown. He said that the study highlighted the water coming from domestic use as more contaminated, making cooling tower blowdown a beneficial practice. In addition, Shaikh touched on the concerns about noise and the location of cooling plants, especially in residential areas, and emphasised the importance of environmentally friendly practices in the industry.

Behloul joined the discussion by saying that to choose between air-cooled and water-cooled DCPs, a comprehensive evaluation considering efficiency, lifespan, space requirements, scalability and capital expenditure (CAPEX) is required. While water-cooled systems are generally more efficient, he said, achieving the desired efficiency throughout the lifespan demands proper operation and maintenance. For instance, he added, air-cooled systems may seem less efficient, but if not operated correctly, the benefits of a more efficient system may not be realised. Behloul said that the decision-making process should account for the project’s growth, available space, investor commitment to CAPEX, and operational considerations, to ensure optimal performance and efficiency over time.

Joining the discussion, Mizesko said, “I have consistently supported water-cooled chillers for their efficiency, but there has been a significant shift with the introduction of oil-free magnetic bearing air-cooled chillers.” He added that these chillers, operating at one kilowatt per ton, stand out, especially in water-scarce areas like Saudi Arabia. Furthermore, Mizesko said that the absence of condenser water, water treatment, long-term concerns and silent operation makes them a compelling choice. Mizesko added, “This technology addresses challenges, such as water scarcity and high construction costs, presenting a viable and efficient cooling solution for regions like Riyadh where water resources are limited.”

Martinez shared a similar perspective as Mizesko and said that with advancements in core technology, the efficiency of air-cooled chillers has improved significantly. Martinez also discussed plants operating with solar power and hydrogen and said that the shift towards cleaner green energy solutions reduces the environmental impact. Martinez also said that the challenges related to water scarcity, chemicals and pollution, which were once primarily issues in the Middle East region, are now becoming global concerns. Many projects, he added, even in regions like Saudi Arabia, are opting for air-cooled systems due to the increasing availability of greener energy and a more sustainable approach.