Zero Carbon Construction Site: Unlocking the potential of hydrogen

Hydrogen: Experimentation, setbacks, and the road to success

Following on from our last diary entry about our all-electric on site experiment, this diary entry explores our efforts to integrate hydrogen technology as an alternative to diesel power at our showcase Towards a Zero Carbon Construction Site at the Royal Botanic Garden Edinburgh (RBGE).

Balfour Beatty firmly believes that hydrogen holds the key to significantly reducing our industry’s carbon footprint[1]. Its versatility is remarkable, offering clean energy storage solutions, low-emission fuel cells for equipment, off-grid energy options, and even contributing to sustainable building material production. What makes hydrogen particularly exciting is its ability to generate energy without producing carbon dioxide, and the fact that it can be produced using low-carbon technologies. Recognising its potential, both the UK and Scottish Governments have included hydrogen as a critical tool in their strategies to achieve net zero goals. However, it is a new technology, and one the industry is still learning to understand.

So far, our project at the Royal Botanic Garden Edinburgh has used an existing electrical connection, avoiding the need for diesel generators. However, as we progress to more energy-intensive tasks, such as stripping paint and rust from the cast iron frame of the Victorian Palm House, we knew that we would need more energy than the existing electrical infrastructure can provide.

The cast iron frame, which supports the glass in this important heritage structure, requires removal of the paint to allow us to examine it and understand whether it needs to be repaired, reused, or replaced. Our primary objective is to preserve as much of this important historical structure as possible. Given the energy-intensive nature of the paint-removal process, relying solely on the existing electrical connection was not feasible. Putting in place another electrical connection would have caused significant local disruption, including road closures near the site, not to mention the considerable expense involved. In line with our commitment to embrace net zero solutions whenever possible, we turned to hydrogen technology, guided by our Fuel Hierarchy principles and our roadmap to zero emissions, which aid us in selecting the right energy sources for our plant, equipment, vehicles, and buildings.

Our team first looked at the use of renewable technology or a hybrid solar diesel generator as we know these are very successful in reducing emissions. However, as the power demand when paint removal was taking place would always exceed what the battery could provide us, it wouldn’t have offered any carbon savings. We then extensively evaluated the use of hydrogen generators and hydrogen power units. We determined that a hydrogen generator would be the one needed on the site to meet the peak load power requirements. This solution not only delivers the necessary power but also allows us to monitor and understand our energy usage and emissions.

However, the compact live operational nature of the RBGE site posed a challenge. As hydrogen is less energy dense than diesel, a typical hydrogen storage unit for construction plant will take up a footprint of approximately 12m x 5m, whereas the same diesel unit would be less than 2m x 2m. Unfortunately, no matter how many ways we tried to make it work, the space requirements and footprint of the hydrogen setup, including the need for large storage tanks, made using hydrogen unworkable. This was a disappointing setback for our team. Innovation often demands resilience and acceptance of setbacks, and this was one such instance. Transitioning to hydrogen infrastructure is not a like-for-like replacement for existing systems, which means that we will have to make a number of changes in how we approach it, including designing in hydrogen storage areas in at bid stage so we are able to set aside the space. Nonetheless, our understanding of these requirements has expanded thanks to this work, equipping us to explore other operations with more available space where hydrogen can be used effectively. This includes a number of other projects where logistics are less challenging and which are benefiting from Hydrogen power generation – not least at our HS2 Balfour Beatty Vinci site near Birmingham where we have Hydrogen Generation powering a large temporary accommodation building. We are planning to supplement this with a retrofitted Solar Roof at the same location in the second half of 2023.

Our push towards hydrogen is also taking other forms. Not far from our current scheme, we have joined forces with the Scottish Government to set up Scotland’s first Construction Hydrogen Hub on the M77/Glasgow Southern Orbital project. In collaboration with ULEMCo, experts in converting vehicle and construction engines to operate with hydrogen, we are currently retrofitting existing diesel vehicles to run off a hydrogen hybrid technology, replacing 40% of the diesel usage. This successful initiative received 50% funding from the Scottish Government’s Hydrogen Innovation Scheme, which is designed to support innovation in renewable hydrogen production, storage and distribution, and integration into Scotland’s energy system. This scheme will see us retrofit two gritters, a traffic management vehicle, and an impact protection vehicle. A hybrid transition is very important for several reasons:

• The provision of green hydrogen (hydrogen produced from renewable power) is variable. Over the course of our project so far, our initial project partner for supplying the green hydrogen is no longer operating and we are now in discussions with other suppliers. The gritters we are retrofitting have to operate in some of the worst weather conditions to ensure that the M77 and Glasgow Southern Orbitals can remain open. The hydrogen retrofit technology means that the equipment can still run on diesel should there be a fault with the new technology, or the fragile and new hydrogen network not be able to operate in the same conditions.
• Although we want net zero vehicles and equipment now, typically, the lifespan of these vehicles is from 10 to 12 years. Simply discarding our existing fleet for newer cleaner technology is neither sustainable nor possible across our whole fleet. Furthermore, all-hydrogen vehicles are rare, and it will be several years yet before they are manufactured at scale. We simply can’t wait this long. Our aim is to use this project to send a clear signal to our plant and vehicle manufacturers that the construction industry is ready for hydrogen.
• Hydrogen producers need to be able to begin to ramp up supplies, but to remain viable, they need to do this at a pace that matches the industry demand. This project allows us to better understand and be able to model hydrogen demand across the industry to help the hydrogen structure across Scotland and the rest of the UK develop.

Initiatives like the M77 retrofit are crucial stepping stones in introducing hydrogen to the industry and making it a mainstream solution. However, we couldn’t have achieved this without the generous funding from the Scottish Government. Transitioning to hydrogen is a huge task that no individual business can shoulder alone. Our concern is that, without financial support, our sector, and even the broader economy, might struggle to achieve the ambitious decarbonisation goals Governments have set. While the cost of hydrogen is likely to decrease eventually, we need more funding like this to bridge the current affordability gap, ensuring a smoother and faster transition to this sustainable energy source.

The work at the M77 should be complete by spring 2024 and isn’t just an experiment for us. This work will inform the budget and costings to enable our transition to hydrogen fuels around 2030 and beyond, as per the ambitions in our scope 1 and 2 emissions roadmap. We will continue to share our learnings and allow the Governments, our customers and our supply chain to see and experience our hydrogen depot to allow them to learn from our experiences and help de-risk the transition to low carbon fuels.

Taking a broader perspective on hydrogen, our aim is to collaborate with industry partners, including our supply chain partners and fuel companies. As leaders in the field, we’re leveraging our position to drive the adoption of hydrogen technology. Despite the excitement surrounding hydrogen, there are still uncertainties and a sense of caution. Factors such as availability, cost, and certainty pose significant challenges. The lack of necessary infrastructure for widespread distribution, as well as a shortage of suppliers, further complicates the situation. For hydrogen to truly succeed, everyone within the hydrogen network must step up – from hydrogen producers to plant manufacturers offering hybrid or fully hydrogen-powered equipment, and every stakeholder in between.

We’re committed to advancing this agenda, using our position as the largest infrastructure provider in the UK to drive change, learning from the challenges we face, and transforming hydrogen from a concept to a reality. We will continue to look at opportunities to use hydrogen where a mains connection is not available and funding can be leveraged to pay for hydrogen fuel. Our efforts involve bringing hydrogen to our sites, demonstrating its effectiveness, and inspiring our supply chain to innovate and adopt this sustainable solution. By accelerating the process of bringing these hydrogen solutions to the market, we can speed up the industry’s transition towards a greener future.

While our attempts at implementing hydrogen solutions on this site encountered obstacles, they provided invaluable insights and knowledge. These experiences underscore the enormous potential of hydrogen technology in driving the construction industry’s decarbonisation efforts.