This article discusses the benefits of repowering coal power plants with advanced heat solutions. It is based on our Built Environment Matters podcast featuring TerraPraxis Co-founder Kirsty Gogan in conversation with Bryden Wood's Head of Global Systems, Jaimie Johnston MBE.

In order to avoid catastrophic climate impacts, it’s essential that we tackle the toughest parts of the decarbonisation challenge, applying innovative solutions to those tough to decarbonise parts of the economy. We need to create cleaner, greener responses in order to overcome the environmental damage being caused by coal-fired power plants, industries like aviation and shipping, and liquid fuels such as oil and gas. Due to the site and land use challenges posed by wind and solar power, attempting to meet our vast energy needs with renewable technologies alone would be prohibitively difficult. As a result, we’ll need help from complementary, advanced heat solutions to bend the curve on carbon emissions and meet our net zero goals.

One of the biggest decarbonisation challenges we face, and one of the biggest opportunities presented to us, comes in the form of repowering coal power plants. Incredibly, the coal-fired capacity being used in the world today is emitting around 15 billion tonnes of carbon emissions each year, representing almost half of all our carbon emissions. Bryden Wood is working alongside non-profit TerraPraxis, as part of the Repowering Coal Initiative. We’re developing transformative design and construction solutions aimed at retrofitting the existing coal-fired power plants for suitability with new nuclear, advanced heat solutions, while still retaining the substantial societal and economic value of the existing power plant infrastructure. The process will be both highly efficient and cost-effective, overcoming existing viability barriers and creating a realistic path to sustainable, reliable energy for areas of the world still reliant on coal-fired power. 

Terra Praxis: new nuclear is key to helping achieve net zero

Kirsty Gogan and Eric Ingersoll co-founded non-profit Terra Praxis to facilitate the design and execution of complex, high leverage strategies aimed at inspiring, and mobilising leaders across multiple sectors. Their goal is to initiate sustained action on the environmental crisis and transform our prospects for avoiding catastrophic climate impacts. Gogan says that although we’re starting to see a shift in thinking, the general perception of nuclear power remains a bit outdated, especially when we start to look at new nuclear, advanced heat technologies. She points out that, in actuality, nuclear has consistently been identified as necessary in our climate mitigation roadmaps, by everyone from the Intergovernmental Panel on Climate Change, to the International Energy Agency and the European Commission. 

A leading environmentalist, Gogan says that she too started out as anti-nuclear, but her perception of nuclear technology changed after reading Professor David MacKay’s book, Sustainable Energy Without the Hot Air. The book illuminates just how difficult it would be to meet our decarbonisation goals with renewables alone, and dispels wrong assumptions held about nuclear energy based on old, outdated ideas. 

Now Gogan serves on the UK government's Nuclear Innovation and Research Advisory Board, the board of US NGO, Nuclear Innovation Alliance, as well as the French NGO, Voices for Nuclear. She’s passionate about the substantial opportunities new nuclear presents to help us meet our net zero goals, and is particularly hopeful about small modular reactors and advanced heat sources, which are designed to be manufactured products, largely made in factories. In addition, she highlights the fact that a power plant using advanced heat solutions, costing one to two billion pounds to build, and which is quickly assembled on-site, is much easier to finance, and much better for local communities, than a very large scale, 20 billion pound construction project that creates years of disruption, dust and noise.

Gogan believes that any remaining sceptics will become convinced about the benefits of nuclear as they become more aware of the versatility on offer by these new nuclear, advanced heat solutions, which are capable of delivering so much more than consistent, reliable electricity. In actuality, electricity accounts for just 20% of our energy usage, and we can use these new nuclear technologies to produce not only electricity, but also emissions-free heat, which offers a variety of benefits and uses, from hydrogen production and the desalination of water, to the supply of heat to homes and businesses. 

Problems with renewable energy: wind and solar challenges

Realistically, if we truly want to bend the curve on carbon emissions, we must start diversifying our strategies, relying on more than just renewables. Advanced heat solutions represent excellent complementary technologies to wind and solar power, as these renewables face real challenges. For example, low density means that in order to harness enough energy to power the UK, we would need to build a solar farm of an impossibly large size. Renewables also have problems to do with dispatch power and consistency, as well as challenges with site locations. Last summer, which was a still and cloudy one, wind and solar simply didn’t generate as much energy as we would have liked, and at this stage, all of the easiest, most suitable sites (the ones which may have access to transmission, and are very suited to wind and solar projects), have already been taken. 

Interestingly, while energy systems modelling for wind and solar power often shows a hockey stick curve, as if the upward trajectory of deployment will continue undeterred, in actual fact, this isn’t the case. Over time, we find that the hockey stick turns into an S shaped curve instead. In other words, renewables are getting progressively harder to do. In fact, the more we build, the more challenging renewable energy becomes. 

In addition, public resistance to building out an ever increasing amount of infrastructure is mounting, and this resistance is happening before the conversation even turns to transmission, which, Gogan says, is very difficult to build, as it’s hard to make the case that people will directly benefit from things such as the creation of jobs. This results in real challenges over land use. 

And yet, the net zero transition is undoubtedly going to require a large amount of new infrastructure to be built, raising big questions about where to build it. Gogan points out that it really doesn't matter how cheap something is, if you can't build it in the first place. What we need to do now, she says, is reevaluate the perceived risks of nuclear, against the risks of failing to decarbonise, and adopt advanced heat solutions to help us on our journey. 

At Bryden Wood, we believe it’s important to lean into all of the technologies available to us at this critical time. While it’s possible that thirty years from now we might find other ways to sustainably meet our energy needs without nuclear technologies, to not have these highly beneficial, advanced heat solutions in our toolbox now would be a huge mistake. 

Replacing coal with clean energy

The Net Zero America Report produced by Princeton University suggests that the low renewables scenario would require the US grid to double or triple in size, which, as a strategy, seems both unrealistic and very high-risk. However, if we instead repurpose all of the existing thermal sites, repowering the US coal-fired power plants with new nuclear, advanced heat solutions, we could reduce the amount of new transmission bills by an incredible forty percent.

Gogan says this represents a radical de-risking of our net zero transition, and presents a huge opportunity for decarbonisation. The repowering coal strategy will co-locate an advanced heat source next to an existing coal-fired power plant, decommissioning the coal boiler, while the rest of the plant, including the steam turbine, power island and existing transmission, remain in operation. 

To support the repowering coal initiative, Bryden Wood is developing a standardised, scalable building system, configuring the design in such a way as to be able to meet any kind of site or plant requirements, while also accommodating a range of different heat sources. This is being achieved using a highly automated design, and a design for manufacture and assembly (DfMA) approach. We’ll create algorithmic design tools to assess coal plant viability for boiler replacement, generate initial concepts using a design configurator in just days, and produce detailed design outputs for manufacturing. Our Design to Value strategy will deliver low project costs, as well as the rates of deployment and scale necessary to fully decarbonise the projected two terawatts of coal still in operation worldwide.

Creating clean energy hubs in communities across the world

Gogan believes it would be unforgivably unrealistic to think we could simply abandon the existing coal power plant infrastructure. These plants are the source of reliable electricity for citizens that need it across the world, and maintaining that energy is incredibly important for economic growth in places like Asia, China, India and Africa, as well as being vital for resilience against the climate impacts these areas are already facing. 

Furthermore, in countries with old coal, including the US, Canada and Europe, entire communities are economically reliant on the coal plants. Shutting them down would cause substantial unemployment and hardship. In the United States alone there are 260 gigawatts of operating coal. Repowering the existing coal power plants using advanced heat sources presents a key political opportunity to garner bipartisan support for climate action in a way that maintains jobs, socio-economic benefits and tax revenues in those communities. 

Another key point to consider is that the majority of the existing, global coal fleet is just fourteen years old, representing a trillion dollars of unrecovered capital. The prospect of the retirement of that fleet is highly unattractive for most of those owners and investors. However, if we repower the existing coal power plants with advanced heat sources instead of shutting them down, the plants will likely run at a much higher capacity factor than they do today and at lower cost. This will make them even more profitable. There will also be the potential to add other value driving services, such as atmospheric carbon removal, as well as hydrogen production with the cooling towers. All of this work would turn these communities into clean energy hubs that will operate for decades to come. 

The future of coal

Post-pandemic, we find coal surging to its highest ever level. In the UK we still have two gigawatts of coal in operation, and because the global recovery is an energy intensive process, places like China, Asia and Africa are burning coal to stimulate economic recovery. Of particular concern is the fact that we're currently expecting to see two terawatts of coal still in operation by mid-century, which would use up the entirety of our remaining carbon budget. The urgency of the situation is heightened by the fact that current energy demand projections are likely incorrect, and don’t account for the vast increase in demand we’ll see as a result of the projected population increase of four billion people. 

Coal is contributing not only to electricity generation, but to industrial emissions as well, and unfortunately, the reality is we don’t really know what trajectory we’re on with temperature increase and the climate emergency. The International Energy Agency modelling predicts a 1.8 degree trajectory, but that figure is based on all of the current commitments being met on issues like deforestation, methane emission reductions, and the updated nationally determined contributions (NDCs). Realistically though, it’s unlikely all of the commitments will be met. 

Furthermore, the 1.8 degree figure doesn’t include any meaningful increase in global energy access. Gogan says she hopes that’s wrong, because there are currently four billion people in the world who lack access to enough electricity, and 850 million people who lack access to any electricity at all. In fact, the latter figure is expected to increase to three billion people by 2050. It’s essential that we start addressing where all of this needed energy is going to come from. Eric Ingersoll has conducted analysis which suggests that if everyone on earth had access to just a median level of electricity (about 4,000 kilowatt hours compared to an existing rate of 15,000 kilowatt hours in the U.S.), even then, we’d need to triple our energy infrastructure. It’s vital that we start taking our rising energy demand into account, and building it into our climate mitigation strategies. 

Replacing fossil fuels with sustainable energy infrastructure

Overcoming the climate emergency won’t stop with decarbonising electricity production. We need to replace our entire global, fossil fuel based energy infrastructure by 2050. Transport and industry must be addressed alongside electricity production. We need solutions not only for coal, but also for liquid fuels. Terra Praxis is focusing on the most significant of energy initiatives, including oil and gas. Currently, 100 million barrels of oil are used per day, with more than half of our global energy predicted to still be coming from fossil fuels by mid-century. This reality would lead to a three to four degree trajectory of warming, and a very bad environmental outcome. 

One potential decarbonisation solution Terra Praxis has been exploring is the possibility of very low-cost, large-scale hydrogen production. Hydrogen is difficult to store, transport and move around, so it isn’t particularly useful as an end product, as it would require a lot of new infrastructure for end users. However, it does have strong potential as an ingredient in clean, drop-in, substitute fuels, such as ammonia (which can be used as a Marine shipping fuel), or synthetic hydrocarbons. Importantly, this would mean that existing storage, transport and end-use infrastructure could continue to be used, including the use of today's planes and ships, making these kinds of solutions extremely useful.

The sticking point is that in order for hydrogen to be used successfully as an ingredient in these alternative fuels, it needs to be very inexpensive, costing less than one dollar per kilogram. This is significantly out of range for any of the prospects for renewables until 2050, largely because they are very dispersed, dilute energy sources. Despite building renewables in windy and sunny places, and combining them to increase the capacity factors, there’s still a cost to transport those fuels around the world, leading to high prices. In contrast, with advanced heat sources, it’s possible to move into a shipyard based manufacturing environment to make offshore production platforms. These large, floating platforms are akin to what the oil and gas industries use today, and would enable us to achieve extremely low costs. 

In essence, the proposed model here is the same as for repowering coal. We need to figure out how to make highly productive, manufactured products, in highly automated environments. Ultimately, this would create the opportunity to move away from electricity generation, which is tethered to a transmission system and the electricity market, towards a commodities based system, focused around the production of a product which can be stored, transported and exported to global markets. This is how we can free up siting opportunities, and enable very scalable, offshore siting to really come into its own.

We should also be looking to appropropriate some of the existing petrochemical supply chain, adopting its relevant skills, and the existing oil and gas infrastructure, and moving these elements into a better space. We’ll make the adoption of new, clean fuels much more likely if we create drop-in, substitute fuels that can be produced at a comparable cost, with the same performance, as the fuels we use today, and then distribute them through the existing supply chain infrastructure. 

Reducing risk as we decarbonise

In other words, we want clean energy solutions which won’t require big behavioural changes, or huge investment in associated infrastructure. That’s how we’ll reduce risk, because such fuels won’t require the sequencing of a whole load of investments in order to make the product really work. As with the desired shift to Modern Methods of Construction in the design and construction industry, we need to address the cultural blockers to the change, and lower the barrier to entry so that it becomes both the right thing to do, and an easy thing to do.

We want the transition to cleaner technologies and fuel sources to become an irresistible, straightforward decision for investors, which means making them more profitable, and working with the grain of human behaviour. In the case of repowering coal power plants, the existing workforce is likely to be very interested in the prospect of another sixty years of highly profitable plant operation, but without the pollution and emissions. Similarly, rather than trying to guilt people into not flying, we need to make the necessary changes so that we can all enjoy guilt-free air travel. Approaching our decarbonisation challenges in this way means we’re more likely to succeed, and we’ll do so faster. That’s hugely important because we only have 28 years left to achieve this transition globally. 

At the moment we’re standing at the cusp of a huge opportunity, with a whole new avenue of potential. Nuclear energy’s ability to make both heat and power means we can really start to dig into these tough to decarbonize sectors: industrial heat, domestic heating, desalination, fuels, and repowering coal. What a lot of new technologies really need is simply large amounts of clean heat and power. Once we achieve that, we’ll create a domino effect that unlocks other elements. 

The good news is that we’re starting to see a lot of interest in these types of strategies from governments, policy makers, investors, other NGOs and customers. For example, airlines have shown significant interest in the prospect of having clean, drop-in, substitute fuels that are comparable in price and performance to existing fuels. That’s not something which is on offer to them in the current conversation around sustainable fuel.

Likewise, the oil industry and oil producing nations are coming to a point where they’re having to seriously begin thinking about their transition strategies. Even two years ago the oil industry wasn’t under the level of pressure it is now. People all across the world are starting to experience adverse climate impacts, and it’s not just the poorer countries being affected. The situation is becoming real everywhere, and it’s creating a real appetite for new solutions. 

COP 26: the Global South and nuclear energy

When asked about COP26, Gogan says she noticed a couple of major changes at the event this past year, which stood out from previous conferences. One of the key things she noticed was that representation from the Global South is increasing. The Global South is composed of poor countries who lack access to energy to help build their economies and infrastructure. Gogan notes that the people in these areas are already very exposed to climate impacts, and they’re also much less resilient to them. These countries have a simultaneous demand for both energy growth and decarbonisation, meaning that they’re in very serious need of clean energy solutions. 

Considering that the industrialised world has contributed the majority of historical carbon emissions, Gogan points out that it’s really becoming socially unacceptable for us to continue to move so slowly to decarbonise our own economies, giving support to one technology, but not another. This is heightened by the fact that nuclear plants are currently providing about half of Europe’s clean energy, which leads to the obvious question: how can we justify shutting them down and replacing them with coal and gas? 

Rising Carbon Emissions

Alarmingly, despite having spent decades now talking about action for climate, carbon emissions continue to rise year-on-year. In fact, the COVID-19 pandemic was almost undetectable in terms of carbon emissions, with the highest ever emissions growth in 2019/2020. Although it felt like the world economy stopped in certain ways, it really didn’t. Construction and manufacturing continued throughout the pandemic, as did the production of steel and concrete. What this really highlights though, is that while our own personal behaviour does contribute to the climate crisis, it’s actually the much larger macroeconomy that’s driving very large amounts of the emissions.

Although the reality of this situation is actually invisible to most people, it’s imperative that we start doing more than we’re currently doing. Nuclear power could become a key part of our decarbonisation strategy, and we’re starting to see an interesting shift take place. The traditional, anti-nuclear left is beginning to become marginalised. In fact, Gogan says that the representation from nuclear, and the appetite for these new nuclear, advanced heat technologies, was strong at COP26. She’s also pleased with the decision to have an annual holding to account, rather than the five year timeframe we’ve previously been using. Hopefully, she says, this will put more pressure on wealthy nations to demonstrate progress.

At Bryden Wood, we believe that making a shift towards smaller, repeatable, manufactured elements is an important part of the path forward. Approaching design and construction in this way helps to reduce material waste, producing more efficient and sustainable built assets. When looking at the vast scale of a project like Hinkley Point, at its enormous costs and lengthy timescales, it’s clear to see what the problems are. We need a solution that’s much faster, more scalable and deployable, and we need it right away. Hinkley Point is still a number of years off completion. 

Achieving net zero by 2050

It’s also important to remember that the challenge of turning the climate crisis around rests solely on the shoulders of our working generation. Although future timescales can sometimes feel abstract, 2050 really isn’t far away and our net zero deadline is looming. In fact, half of the emissions in the atmosphere today were emitted in the last thirty years, so we’re going to have to think really expansively on the issue. One of the greatest challenges we have is finance, because there’s still a lot of prejudice against nuclear power in the finance market. The World Bank, for example, won’t finance nuclear projects. In addition, despite the fact that all of the science repeatedly tells us that nuclear is the lowest carbon, clean energy source available, the European sustainable finance taxonomy has remained in a state of consideration for years about whether nuclear energy actually qualifies as green. 

Still, despite the challenges ahead, it’s clear to see that the tide is turning and, of course, urgency related to the climate crisis will only continue to increase. We must be ready to act and put the right strategies into place globally: licensing, siting, public acceptability, supply chain strategies etc. All of these elements need to be designed and ready to go as soon as the world is ready for them. The opportunity will soon be here. If we look back at the last twenty years, examining large sectors like retail, ecommerce and entertainment, we see that all of these areas have undergone enormous, fundamental shifts as a result of rapid technological adoption. Embracing new nuclear, advanced heat solutions as part of our climate crisis toolkit presents a similarly transformative opportunity.

Bryden Wood is delighted to be part of the Repowering Coal project, and to be providing the MMC design solution that will enable the work to be delivered at the necessary scale. The project represents the biggest problem statement we’ve ever faced, and holds the potential for a tremendous social value impact. Hopefully, in another twenty years, humanity will look back at this moment, feeling confident that the climate crisis has been brought under control, with people and industry taking a significantly cleaner and greener approach worldwide. We agree with Terra Praxis, that in order to succeed, it’s essential we work together, bringing all of our individual talents, insights and capabilities to the table. Collaboration is the key to making it through this incredible challenge, and Repowering Coal presents a fantastic opportunity to be harnessed. We believe the initiative gives cause for significant optimism in our conversation about tackling the decarbonisation challenge ahead.


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