Rondo Energy Closes $60 Million to Accelerate Industrial Decarbonization from Global Giants and Other Climate Investors

Rondo Energy Closes $60 Million to Accelerate Industrial Decarbonization from Global Giants and Other Climate Investors

By Press Release, 30 August 2023

ALAMEDA, CA – Rondo Energy, a leading provider of zero-carbon industrial heat and power, has raised $60 million in a new financing planned to speed the rollout of Rondo Heat Batteries worldwide and to transform the global energy storage market. 

The financing brings together funding from current Rondo investors Breakthrough Energy Ventures, Energy Impact Partners, SCG, and Titan, industrial leaders including Microsoft’s Climate Innovation Fund, Rio Tinto, SABIC, Aramco Ventures, and climate investors SDCL Energy Efficiency Income Trust (SEEIT) and John Doerr. Rondo will use this funding to grow its international operations and to develop and build storage projects around the world. 

Rio Tinto, Aramco Ventures, SABIC, SCG, TITAN, and SEEIT have joined Rondo’s Strategic Investor Advisory Board (SIAB). 

“We are honored and excited by this opportunity to go faster by working with these leaders, Our Strategic Investor Advisory Board will help Rondo focus on the simplest, fastest ways to power their operations with low-cost clean energy and shape our priorities for ongoing research and development.” said John O’Donnell, CEO of Rondo Energy. “To tackle our climate challenge, we need tools to build big, low-cost, clean energy infrastructure fast.  The Rondo Heat Battery is one of those tools. This investment will help us grow our capacity to meet customer demand and begin to build at scale.”

Industry uses more energy than any other part of the world economy.  Industrial processes making every commodity from steel to baby food are powered by high temperature heat that consumes a quarter of all world energy and emits a quarter of global carbon pollution. Technologies have long been sought to cost-effectively transform this “hard to decarbonize” sector. U.S. Secretary of Energy Jennifer Granholm outlined DOE’s vision to cut 85% of industrial heat in its Industrial Heat Shot Initiative.

Declining wind and solar power costs are now becoming cheaper than the fuel industry burns for heat.  The Rondo Heat Battery turns these intermittent power sources into the continuous, high temperature clean heat that industry requires, and opens the door to industrial decarbonization at a fraction of the cost of other technologies.

In 2023, Rondo began operations of its first commercial unit, lowering the carbon intensity of biofuel produced by Calgren Renewable Fuels. This project was the first commercially operating electric thermal energy storage system in the US, and the highest efficiency, highest temperature energy storage of any kind worldwide.

In 2023 Rondo, in partnership with Siam Cement Group (SCG), announced current Heat Battery storage production capacity of 2.4GWh/year, with plans to reach 90GWh/year.

Rondo Heat Batteries store energy at half the cost of other technologies such as green hydrogen and chemical batteries.  Rondo based its innovative technology on materials that heavy industry has used for more than a century for heating and heat storage: brick and iron wire.  By building Heat Batteries with materials already made at large scale for more than a century, Rondo has eliminated the safety, durability, and supply chain risks faced by other storage technologies.

Policymakers and business leaders face shareholder pressure to deploy cost-effective and reliable climate solutions, Rondo's technology is a proven and effective tool for rapid and deep decarbonization across the world’s most energy intensive and difficult to decarbonize industries.

Electrification of industrial heat has been called “the next trillion-dollar market.”  Recent studies have found that the decarbonized world will need twice as much heat battery storage as grid battery storage, and that heat batteries will greatly reduce energy costs to produce many key commodities in the coming few years.

Quotes from Investors


“To avoid the worst effects of climate change, businesses and sectors must shift to low-carbon energy, including managing the intermittency of renewables through energy storage. We see a unique opportunity  for Rondo’s thermal storage solution to provide a pathway for industrial businesses to accelerate the clean energy transition.” said Brandon Middaugh, Senior Director, Microsoft Climate Innovation Fund.

Rio Tinto

Rio Tinto Chief Scientist, Nigel Steward, said, “Rio Tinto and Rondo share a vision of a low-carbon future.   It’s vital we invest in innovative companies like Rondo to expedite the growth of energy storage technologies.  Decarbonising our operations by reducing process heat emissions is one of our priorities.   Rondo's technology is addressing the challenge of making electrification of process heat not only possible but highly efficient. We’re really looking forward to seeing the future capacity advancements”.

Siam Cement Group (SCG)

“SCG is excited to collaborate with and increase our investment in Rondo,” said SCG’s Thammasak Sethaudom. “SCG looks forward to deploy Rondo's technology in our operations and supporting SCG Cleanergy in providing green, affordable heat as a service to various industrial producers."


“SABIC Ventures is prioritizing investment in startup companies in the decarbonization space to support SABIC’s goal of becoming carbon neutral by 2050,” said Dhaval Shah General Manager, Corporate Technology & Innovation at SABIC. “Rondo’s technology enables intermittent sources of renewable electricity to provide heat to continuous industrial processes and has potential applications within SABIC’s decarbonization roadmap”


"Cement production is energy-intensive, and at TITAN Group, we're always seeking sustainable alternatives to reduce our carbon footprint, in line with our net zero goal. Our collaboration with Rondo Energy is a testament to this commitment. Their groundbreaking heat battery technology promises to usher in a new era of climate-friendly cement production based on renewable energy, and we're thrilled to be at the forefront of this change," said Fokion Tasoulas, Group Innovation & Technology Director of TITAN.

SDCL Energy Efficiency Income Trust (SEEIT)

Jonathan Maxwell, CEO of Sustainable Development Capital LLP, the Investment Manager of SEEIT said: “Rondo is well positioned to take early advantage of the enormous potential of the thermal energy storage market and our investment, expertise and advice will support the Company’s growth to make the most of these opportunities. Energy efficient solutions like those being developed by Rondo are some of the cheapest and cleanest ways to reduce carbon emissions, and more importantly are integral to the world’s successful transition to net zero.”

Breakthrough Energy Ventures

“The Rondo team has proven the technical readiness of its Rondo Heat Battery and with systems now operating in the field, they’re ready to scale their solution and enable heavy industry to reach zero-carbon emissions at a lower cost than fossil fuels,” said Carmichael Roberts, Breakthrough Energy Ventures. “We’re encouraged by the strategic industrial leaders joining this round of financing, showcasing just how critical zero-carbon industrial heat and power will be for the market.”

Energy Impact Partners
“We are thrilled with the progress Rondo has made since our initial investment,” said Sam Bursten, Principal at EIP. “The successful deployment of Rondo's first commercial unit at Calgren and its partnership with SCG are major milestones in Rondo's journey to decarbonize industrial heat and power.”


About Rondo Energy

Rondo Energy makes industrial decarbonization possible — and profitable — today. The Rondo Heat Battery captures low-cost renewable electricity and delivers the world’s highest temperature, highest efficiency energy storage of any kind, enabling customers to power their operations with zero-carbon energy. Learn more at

 About Aramco Ventures

Aramco Ventures is the corporate venturing subsidiary of Aramco, the world’s leading integrated energy and petrochemical enterprise. Headquartered in Dhahran with offices in North America, Europe and Asia, Aramco Ventures strategic venturing program invests globally in start-up and high growth companies with technologies of strategic importance to its parent, Aramco, primarily supporting the Company’s operational decarbonization, new lower-carbon fuels businesses, and digital transformation initiatives. Aramco Ventures also operates Prosperity7, the Company’s disruptive technologies investment program. Learn more at 

About TITAN Group:

TITAN Group is a leading international business in the building and infrastructure materials industry, with passionate teams committed to providing innovative solutions for a better world. With most of its activity in the developed markets, the Group employs over 5,000 people and operates in more than 25 countries, holding prominent positions in the US, Europe, including Greece, the Balkans, and the Eastern Mediterranean. The Group also has a joint venture in Brazil. With a 120-year history, TITAN has always fostered a family- and entrepreneurial-oriented culture for its employees and works tirelessly with its customers to meet the modern needs of society while promoting sustainable growth with responsibility and integrity. TITAN has set a net-zero goal for 2050 and has its CO₂ reduction targets validated by the Science Based Targets initiative (SBTi). The company is listed on Euronext and the Athens Exchange. For more information, visit the Group’s website at


SDCL Energy Efficiency Income Trust plc is a constituent of the FTSE 250 index. It was the first UK listed company of its kind to invest exclusively in the energy efficiency sector. Its projects are primarily located in the UK, Europe and North America and include, inter alia, a portfolio of cogeneration assets in Spain, a portfolio of commercial and industrial solar and storage projects in the United States, a regulated gas distribution network in Sweden and a district energy system providing essential and efficient utility services on one of the largest business parks in the United States.

The Company aims to deliver shareholder value through its investment in a diversified portfolio of energy efficiency projects which are driven by the opportunity to deliver lower cost, cleaner and more reliable energy solutions to end users of energy. Past performance cannot be relied on as a guide to future performance. Further information can be found on the Company's website at

 About Energy Impact Partners

Energy Impact Partners LP is a global investment firm leading the transition to a sustainable future. EIP brings together entrepreneurs and some of the world’s most forward-looking energy and industrial companies to advance innovation. With over $3 billion in assets under management, EIP invests globally across venture, growth, credit and infrastructure — and has a team of over 80 professionals based in its offices in New York, Atlanta, San Francisco, Washington D.C., Palm Beach, London, Cologne, and Oslo. For more information on EIP, please visit


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