Product launch: the Rondo Heat Battery (RHB), providing the world’s lowest-cost, zero-carbon industrial heat

Two RHB models are commercially available today for companies aiming to rapidly reduce fuel costs and eliminate scope 1 & 2 emissions

RHB300 (Graphic: Business Wire)

ALAMEDA, Calif.--()--Rondo Energy, a leading provider of zero-carbon industrial heat, today announced commercial availability of two models of its revolutionary Rondo Heat Battery (RHB), the RHB100 and RHB300.

The Rondo Heat Battery (RHB) captures intermittent electricity, stores the energy from that electricity as high-temperature heat in brick materials, and delivers the stored energy on demand as high-temperature heat and/or electricity. The RHB stores heat energy at temperatures up to 1500°C for hours or days — delivering zero-carbon heat for processes ranging from steel, cement, chemical manufacturing, and all the way to low-temperature food processing.

The RHB meets the demanding needs of industry for safe, simple, low-cost energy and economically replaces fuel-fired furnaces and boilers—unlocking energy prices for America’s industries that are both affordable and more predictable. When connected to the grid, the RHB can make use of otherwise curtailed solar and wind energy, cut the cost of clean energy, and strengthen grid stability and security. Rondo is manufacturing its heat batteries in its facilities in California and has begun commercial deliveries.

RHBs are easily integrated into facilities alongside existing process heating equipment, delivering large-scale emissions reductions without a facility overhaul. The heat battery models available today are designed for a wide range of industrial uses and directly replace the operation of fuel-fired boilers, furnaces and kilns. Both models are fully automatic, charge intermittently either from local wind or solar facilities or from the grid, and deliver heat on demand 24 hours a day.

Rondo’s unique thermal core uses brick materials that have been producing steel for over a century in a new patented configuration. Charging in as little as four hours, Rondo’s patented “brick toaster” rapidly and uniformly heats these brick materials to deliver continuous, constant temperature heat, 24 hours a day.

Applications and Industries

From food processing to fuel production, from cogeneration to calcination, the RHB delivers energy in the form needed for more than 90% of the world’s industrial process heat. RHBs are easily configured to serve the unique capacity and temperature requirements of each facility. The RHB units announced today are direct drop-in replacements for large industrial boilers.

Rondo’s simple, low-cost technology delivers unique value in these key areas:

  • Fast charging. Rondo heat batteries charge in as little as four hours, capturing zero-carbon energy at the absolutely lowest costs, when the wind is blowing and sun is shining.
  • High temperature. RHBs deliver heat at up to 1500°C.
  • Long service life. With fully automatic operation using proven subsystems and materials, RHBs offer a 40+ year life without performance degradation.
  • Safety. RHBs are intrinsically safe, made of completely inert materials, and fail-safe in all loss of power or process upset conditions. Made of only brick and iron, the hazards of other energy storage technologies are eliminated.
  • Site efficiency. RHBs store more than 1 MWh per square meter, far denser than any other storage technology, and preserve critical plant area.

Rondo Heat Batteries enable a simple, practical switch to zero-emission electricity as the source of continuous high-temperature heat for processes across a range of industries, including steel, cement, chemical, pharmaceutical, low-carbon fuels, food and beverage, and mining industries. Unlike electric furnaces or electric boilers, Rondo Heat Batteries are a load that follows the available renewable generation, being dispatched by the grid operator or the renewable energy fields to charge but delivering consistent firm heat to the industrial facilities.

As a result, RHBs deliver electrification at the absolute lowest cost and create no additional peak loads on the electricity grid, while enabling the integration of more renewable electricity generation. Rondo Heat Batteries maintain continuous output power (95% annual capacity factor) while operating on input power as low as 15% capacity factor (4 hours a day).

Beyond direct industrial heat supply, the RHB is a least-cost source of energy for other applications, including district heating and combined heat and power, providing 24/7 clean heat and power.

Rondo SVP Jeremy Keller said, “Rondo’s mission is simple: lower cost heat and energy for large industrial processes. We’ve been excited by the work now underway with key customers. We’re finding that deep emission reductions are now both practical and affordable for many of the world’s most energy-intensive facilities. Our studies of customer facilities are showing 50% to 90% reductions in emissions and reductions in operating costs of 30% or more.”

Rondo Heat Batteries deliver large, concentrated, permanent emissions reductions and provide an immediate, low-cost, practical way to repower the giant industrial heat market. A single RHB300 eliminates more than 40,000 tons CO2 per year-- more than is eliminated by 8,700 electric vehicles. Replacing just the industrial heat used today in California with RHB zero-carbon heat would eliminate five times more CO2 than all of the EVs on the road in the US today (13.6M EVs).

With early manufacturing now underway, Rondo is open for business. We’re thrilled to be announcing the launch of the RHB100 and RHB300 and look forward to serving our customers with first installations in 2023,” said Rondo CEO John O’Donnell.

The Rondo Heat Battery could prove critical to eliminating emissions, and its commercial availability will help companies turn to its zero carbon heat for their processes,” said Carmichael Roberts, Breakthrough Energy Ventures. “The Rondo Heat Battery will help companies in industries such as cement, fuels, food and water desalination to begin leveraging the falling costs of renewables without modifying their facilities.”

To download the RHB datasheet or to configure and purchase an RHB for your facility, get started on our website at

Rondo Energy is backed by Bill Gates-founded Breakthrough Energy Ventures and utility-backed Energy Impact Partners.

About Rondo Energy:

Rondo Energy, the leading provider of zero-carbon industrial heat, makes industrial decarbonization possible — and profitable — today. The Rondo Heat Battery captures low-cost renewable electricity and delivers continuous high-temperature heat, enabling customers to power their operations with zero-carbon energy. Learn more at

About Breakthrough Energy Ventures

Founded by Bill Gates and backed by many of the world’s top business leaders, BEV has raised more than $2 billion in committed capital to support cutting-edge companies that are leading the world to net-zero emissions. BEV is a purpose-built investment firm that is seeking to invest, launch and scale global companies that will eliminate GHG emissions throughout the economy as soon as possible. BEV seeks true breakthroughs and is committed to supporting these entrepreneurs and companies by bringing to bear a unique combination of technical, operational, market and policy expertise.

BEV is a part of Breakthrough Energy, a network of investment vehicles, philanthropic programs, policy advocacy and other activities committed to scaling the technologies we need to reach net-zero emissions by 2050. Visit to learn more.

About Energy Impact Partners

Energy Impact Partners, LP (EIP) is a global venture capital firm leading the transition to a sustainable future. EIP brings together entrepreneurs and the world's most forward-looking energy and industrial companies to advance innovation. With over $2 billion in assets under management, EIP invests globally across venture, growth, credit, and infrastructure – and has a team of nearly 60 professionals based in its offices in New York, San Francisco, Palm Beach, London, Cologne, and Oslo. For more information about Energy Impact Partners, please visit


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