Barclays Sustainable Impact Capital
1 Churchill Place, London, E14 5HP, United Kingdom
Overview
Sustainable Impact Capital portfolio, led by Barclays’ Principal Investments team, will invest £500m by 2027 in the equity of fast-growing, innovative and environmentally-focused early-stage technology companies.
- Total investments
- 11
- Lead investments
- 5
- Investments · 12mo
- 4
- Active investors
- 2
Investment portfolio
- Advanced Electric Machines
Led · Equity · Aug 2026
Advanced Electric Machines develops and manufactures rare earth- and magnet-free electric motors, with technology applicable across passenger cars, motorcycles, ATVs, trucks, buses, construction machinery and marine sectors. Its platform eliminates permanent magnets and rare earth materials and replaces copper windings with aluminium, aiming to reduce supply-chain risk while delivering competitive performance, efficiency and reduced weight. AEM's technology portfolio includes advanced control strategies, aluminium coils, and higher-speed, smaller, lighter designs that have been productionised. The company manufactures at a commercial-scale facility in Washington and is leveraging that capability to develop higher-torque products for demanding powertrain and industrial applications. The recent funding will support expansion of production capacity and accelerate next-generation product development. The platform was developed at Newcastle University and is supported by existing regional investors who have backed AEM through its evolution.
- Naked Energy
Participated · Equity · Aug 2026
Naked Energy develops the Virtu product range of high-density solar thermal and solar PVT systems that generate renewable heat and, in the case of VirtuPVT, both heat and electricity from the same rooftop footprint. The company also builds digital tools for system design, monitoring and performance optimisation to support deployment across commercial, industrial and public-sector buildings. It holds more than 20 patents and emphasizes low-profile panels that increase usable roof-area compared with conventional tilted solar panels. Naked Energy has delivered projects at notable UK sites such as the British Library and the All England Lawn Tennis Club, Wimbledon, and is active across Europe and North America. Founded in 2009, the company is scaling manufacturing capacity in the UK following prior fundraising, including a €6.12 million Series A in 2019 and a €19.8 million Series B in 2024, to support international growth and export opportunities.
- AirEx
Participated · Equity · May 2026
AirEx, launched in 2020, develops the first smart air brick technology that uses sensors to monitor conditions and regulate airflow under floors to reduce heat loss. Its product aims to improve energy performance and resident health without requiring expensive or disruptive interventions. AirEx has established commercial partnerships with dozens of housing providers and Tier 1 contractors, including Warmworks, Peabody and Together Housing. To date the company reports over 39,000 smart air bricks installed across more than 6,400 homes, delivering an estimated £40 million in lifetime energy bill savings for households in fuel poverty and more than 40,000 tonnes of lifetime carbon emissions abatement. The company plans to use the £2.1 million funding to accelerate large-scale deployment, develop new products and expand into new partnerships and broader market rollout. AirEx positions itself to scale commercially alongside government retrofit funding and social housing upgrade programmes.
- Iceotope
Led · Series B · May 2026
Founded in 2005, Iceotope develops chassis-based precision liquid cooling systems that replace traditional air cooling to improve efficiency and reduce energy and water usage in data centres, AI infrastructure, HPC, and edge environments. Its technology is purpose-built for demanding cooling constraints across core data centers and distributed edge deployments. The company holds more than 200 granted and pending patents covering its liquid cooling approach. Iceotope plans to scale product and engineering efforts, expand its patent portfolio, and grow ecosystem partnerships following its recent fundraise. Financially, the company secured a $26 million Series B to support these initiatives; the article does not disclose revenue or other operating metrics.
- Mixergy
Led · Equity · Mar 2025
Mixergy develops grid-connected smart hot water tanks that act as distributed energy storage, optimizing energy use and enabling better integration of renewable power. Its technology is said to cut hot water bills substantially (the article cites reductions up to 60% in one place and up to 40% for its top-down heating approach). The company offers hardware, software and a Mixergy App that uses machine learning to optimise consumption, and has an integrated hot-water heat pump with regulatory approval. Mixergy plans to pivot toward a technology-licensing and strategic-partnership model focused on new builds, social housing retrofits and commercial properties, and to expand R&D capabilities. It has partnerships with energy companies including British Gas and targets social housing providers, property developers, energy utilities and HVAC OEMs. The company positions its tanks to store cheap or excess renewable energy and ease grid pressure during peak demand, supporting UK net-zero goals. Mixergy was founded at Oxford University and emphasizes reducing carbon emissions while cutting household costs. Mixergy is a Cassington, UK-based developer of smart and connected hot water tanks and home energy management technologies. The company holds a suite of IP around hot water heating, heat pump and home energy management, including a patented approach that exploits thermal stratification to heat only what users need. Its smart tanks enable households to save money and reduce their environmental impact. Mixergy also connects a decentralized digital network of tanks that can provide flexibility to the grid and support the clean energy transition. Led by CEO Peter Armstrong, the company plans to use new funds to open an R&D centre at its Oxfordshire headquarters, further develop its technology, and pursue international expansion beginning in Portugal. Mixergy raised £9.2M in the disclosed funding round. Mixergy develops residential smart hot water tanks that use machine learning and engineering to heat only the water a user needs. Its tanks can save residents up to 20% on hot water bills, provide up to 30% more usable hot water, and deliver hot water up to five times faster. The product is the first hot water product certified to deliver grid‑balancing services to the UK National Grid and can be controlled via sensors and software across a national network dubbed the “Internet of Tanks.” Mixergy is a 2014 spin‑out from the University of Oxford’s Energy and Power Group and has partnered with British Gas to launch and roll out products to households. The company says it plans to expand across the UK, Western Europe and North America and to leverage low‑cost manufacturing supply chains to address a global market.