how engineers can reduce greenhouse gas emissions in sports stadiums

Rio 2016 will be remembered for the stunning achievements of athletes including Usain Bolt, Michael Phelps and Mo Farah. However, broken records were not the only lasting effect of the 31st Olympics.

During both the Olympic and Paralympic Games, these events resulted in emissions of 4.5 million tonnes, approximately one and a half times Fiji’s total emissions in 2022. About 10% was for operations, 16% for facility construction, 19% for infrastructure construction , and 55% for viewers.

The figures, highlighted today (October 23) in a new IMechE report, illustrate the scale of the sports sector’s contribution to climate change. The industry is responsible for approximately 350 million tonnes of carbon equivalent emissions each year, representing approximately 1% of global emissions.

“Engineering Better Sports Venues: Designing for Athletes, Spectators and the Environment” explores the role of engineers in creating sustainable and inclusive sports venues, with a focus on large stadiums used for elite sports.

“Sports facilities are often considered the domain of civil engineers,” said report author Ruth Shilston in an interview with Professional engineering“but any building, especially sports facilities, requires a huge amount of mechanical engineering – especially now that we are so focused on sustainability and low energy consumption.”

Solar cells and recycled urine

Emissions reductions should be considered “from day one” when building or renovating stadiums, said the chief technology officer at consulting firm Mott MacDonald, where she works on the design of sports facilities.

Considerations include making the most efficient use of materials such as concrete and steel, introducing low-energy and passive cooling, and incorporating renewable energy technologies, said an IMechE board member.

This could include, as announced today, the installation of solar cells at West Ham London Stadium, originally built for the 2012 Games. Cleantech company Ameresco will install ultra-thin panels light enough to fit on the stadium’s “membrane” roof, with an expected annual output of 0.85 million kWh.

Other sustainable solutions at facilities could include green roofs and rainwater harvesting, Shilston said, which could help meet some of the huge daily water demand – equivalent to 625 bathtubs – at professional football pitches.

National League club Forest Green Rovers have gone a step further by introducing a space mission-inspired urine recycling system that reuses treated fan urine for pitch maintenance, turning it into clean water and fertilizer. “It reduces water consumption, it’s certainly an innovative solution,” Shilston said.

Known as the world’s first carbon neutral football club, Forest Green also plans to build the world’s first wooden stadium, designed by Zaha Hadid Architects. The project will include on-site solar energy generation. Other innovations include a completely vegan menu and sets made from coffee and recycled plastic.

Flexible design

Venue operators can also reduce their overall environmental impact by hosting more frequent and diverse events, Shilston said – including other sporting events, concerts and conferences – thereby maximizing the use of embodied carbon and preventing the need to create more venues.

Mechanical engineers have a key role to play in this respect by installing systems that enable partial use of facilities without wasting energy. “We should never underestimate the role of the architect in any project. But the engineer’s role is also to ensure that we take all that flexibility into account when we design the building,” she said.

“When you want to turn on the heating of a building, for example, you have separate controls for different parts of the building, and the same goes for the lighting design. It’s the confidence that you’re really designing, having the ability to turn things on and off depending on what you want to use.”

She added that in some large stadiums in the UK the entire building must be switched on to allow a match to be held in one room – which is not an efficient use of energy.

The report, also authored by Dr Anna Coppel, deputy director at Arup, and IMechE’s Kahu Te Kani and Dr Laura Kent, calls for greater consideration of hybrid, temporary and portable facilities. Stadiums built for major events such as the Olympic Games or the FIFA World Cup are not always fully utilized after the events due to lack of regular demand. Instead, temporary facilities can be built and dismantled and even transported, Shilston said. “You can almost imagine that in the future we will have an Olympic venue that follows the Olympic Games.”

She added that temporary facilities are also well-suited for growing clubs and sports venues, making it easier to increase crowds before replacing them with permanent structures after a few years.

I turn down the heat

Reducing emissions and increasing sustainability is becoming increasingly important as the world warms. “Climate change is now something we need to take into account in everything we do, whether it’s heat or flooding,” Shilston said. “As engineers we have a real responsibility to help the customer understand: ‘Here’s the flood risk, here’s the mitigation measures you can take, here’s the heat risk.’”

Events such as the World Cup in Qatar have shown how realistic it is to organize elite sports events in extreme conditions. Although the tournament was held in winter, the stadiums were built for summer temperatures exceeding 50°C, which placed stringent demands on players and spectators.

Cooling and ventilation of the stadium was provided through passive and active shading, insulation, mechanical cooling and shaping the stadium to control airflow. Water mist cooled spectators entering the arena, and cool air from refrigeration units and ventilation systems controlled the temperature on the terraces. Players on the field also benefited from cool air from the stands and air jets located at ground level.

“You can’t do elite sport in a hot and humid environment, the human body can’t do it. We are asking players to push the limits,” Shilston said.

However, such intensive efforts also have a significant impact on the climate. “As an engineer, I don’t want to air-condition the outside world because it’s not responsible. However, I can advise the client on this risk, I can do climate change modeling, I can do thermal comfort modeling.

Thermal comfort may even become a serious issue in the UK, where many major sporting events take place in summer. Sensors scattered throughout facilities should play an important role in monitoring temperature, humidity, carbon dioxide levels and other factors, Shilston said, as should sensors worn by players.

Equal opportunities

The positive impact of sport on society is clearly visible. Participants benefit from exercise and social interaction, and millions of fans enjoy watching their teams compete each week. But can the facilities themselves ever have a net positive impact on the environment – ​​or will this always require mitigation?

“I think it’s possible, but it will be a challenge,” Shilston said. “Most of my clients will say, ‘What’s the innovative solution to fix this?’ What’s the new material? What is the new product?

“The best sustainability is really boring. It’s about having reusable cups, it’s about reducing sunlight entering the building, it’s about how we use the design before we put tons of technology into trying to solve the problem.

“That’s why the best and most sustainable buildings are really simple. They have their own renewables on site, they have greater biodiversity, which the government is starting to push a lot more for… They are designed simply and flexibly.”

The report also calls for greater transparency of net zero efforts, new funding programs for sustainability and accessibility, and more inclusive stadium design using a systems engineering approach to improve accessibility and navigation.

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Content published by Professional Engineering does not necessarily reflect the views of the Institute of Mechanical Engineers.