Heating our homes, offices, and public spaces is a significant source of greenhouse gas (GHG) emissions, contributing around 12 gigatons of CO₂ (GtCO₂) annually. This accounts for a substantial share of global energy-related emissions. Residential and commercial heating systems, particularly in colder climates, often rely on fossil fuels, presenting challenges for reducing carbon emissions while maintaining comfort and functionality.
Addressing these emissions requires creative thinking and practical solutions. One such idea comes from Deep Green, a London-based startup backed by . By capturing the heat generated by data centers and using it to warm habitable spaces, Deep Green is repurposing energy that would otherwise be wasted. The approach has clear benefits, but it’s important to evaluate its potential within the broader context of global heating emissions.
Deep Green has received backing from the Octopus Energy Transition Fund (OETF), a fund managed by Octopus Energy Generation, part of the broader Octopus Energy Group. Octopus Energy Group is a UK-based renewable energy company specializing in sustainable energy generation, technology, and customer-focused solutions. Known for its innovative business models, the group’s goal is to accelerate the transition to cleaner, cheaper energy systems worldwide. The OETF specifically invests in companies working on solutions that decarbonize society, making Deep Green a fitting addition to its portfolio.
The reported £200 million ($253 million) investment in Deep Green highlights the involvement of the Octopus Energy Transition Fund (OETF), but it is unclear if this amount represents the total funding package or if other investors or sources of capital were involved. Venture financing for large-scale projects like this often includes multiple contributors, such as co-investors, debt financing, or strategic partnerships, to share the investment load.
Understanding the Emissions from Heating
Heating systems, whether for homes, offices, or public facilities, are a major consumer of energy. In many parts of the world, older infrastructure and reliance on fossil fuels contribute to inefficient energy use and higher emissions. Globally, heating produces 12 GtCO₂ annually, driven by systems such as gas boilers, electric heaters, and industrial heating equipment.
The financial costs of heating are also significant, particularly for energy-intensive facilities like swimming pools. Rising energy prices in places like the UK have put pressure on public amenities, with some councils forced to close pools due to unaffordable heating costs. This dual challenge of high emissions and high costs makes heating a key area for innovation.
Repurposing Data Center Waste Heat
Data centers, which are essential for storing and processing digital information, consume approximately 1-2% of global electricity annually. Much of this energy is used to cool servers, which generate substantial amounts of heat as they operate. Traditionally, this heat has been considered waste, released into the atmosphere without any practical use.
Deep Green sees an opportunity here. By locating small data centers near facilities that require heat, such as public swimming pools, the company redirects this waste energy into a useful purpose. In return, the data centers receive free cooling, creating a mutually beneficial arrangement.
A Practical Example: Heating Swimming Pools
Deep Green piloted its technology in Exmouth, Devon, by installing a small data center under a public swimming pool. The servers’ waste heat was used to warm the pool water, cutting heating costs by up to 60%. Following this success, the company has partnered with Octopus Energy to expand the initiative to 150 public swimming pools across the UK.
The system benefits both parties: pools reduce their energy bills, making them more affordable to operate, while Deep Green avoids additional cooling costs for its servers. Beyond swimming pools, the technology could be applied to other facilities such as apartment complexes or commercial buildings that require heating or hot water.
Evaluating the Global Impact
While the local benefits of repurposing data center heat are clear, it’s important to consider the global scale. ShrinkthatFootprint’s own calculations show that data centers contribute approximately 150 million tons of CO₂ (MtCO₂) annually, or about 0.6% of global energy-related emissions. By comparison, heating contributes 12 GtCO₂ annually—about 80 times more than data centers.
Even in an ideal scenario where all waste heat from data centers worldwide was repurposed for heating, the reduction in global heating emissions would be around 1.25%. This suggests that while initiatives like Deep Green are valuable, their overall contribution to reducing global heating emissions remains limited.
Why It Still Matters
Despite its relatively small global impact, Deep Green’s approach provides several important benefits:
- Local Energy Savings: Facilities such as public swimming pools can significantly reduce their heating costs, allowing them to remain open and accessible to communities.
- Efficiency Improvements: By capturing and reusing waste heat, data centers operate more efficiently, reducing their cooling energy requirements.
- Scalability: While each system has a modest impact, scaling the solution across regions and facilities could produce meaningful cumulative benefits.
- Encouraging Innovation: Deep Green’s model highlights how industries can creatively address energy waste, inspiring similar solutions in other sectors.
- Positive ESG Alignment: Companies adopting such practices can demonstrate environmental, social, and governance (ESG) commitments, which are increasingly valued by investors and stakeholders.
Energy consumption for data centers is expected to rise significantly as companies invest more heavily in AI technologies, which require immense computational power for training and running large models. AI workloads demand specialized hardware like GPUs and TPUs, which are more energy-intensive than traditional servers. This trend has prompted tech giants like Microsoft, Google, and Amazon to explore alternative energy sources to sustain their growing operations. Notably, Microsoft has committed to powering its data centers with nuclear energy, contributing to the planned reopening of the Three Mile Island nuclear plant, as detailed in a recent New York Times article. The training and implementation of AI technologies imposes a considerable carbon cost. One that we have detailed is the carbon cost for training GPT-3, an earlier model released by OpenAI.
A Balanced Perspective
Deep Green’s solution is a thoughtful example of how waste energy can be repurposed to address local challenges. It demonstrates a practical way to improve efficiency and reduce costs, particularly for facilities struggling with high heating bills. At the same time, it’s important to recognize that the global emissions reductions achievable through this approach are modest when compared to the scale of heating emissions worldwide.
Initiatives like this, while not transformative on their own, contribute to the broader effort to reduce carbon emissions and transition to sustainable energy systems. They serve as reminders that solutions often need to operate on multiple levels—local, regional, and global—to make a meaningful difference.
As Zoisa North-Bond, CEO of Octopus Energy Generation, noted, “By using excess heat from data centers to slash energy bills for communities, Deep Green solves two problems with one solution.” While the overall impact may be limited, such initiatives offer valuable insights into how we can make better use of the energy we already consume.
In the journey toward decarbonization, even small steps help us move in the right direction.
