How a Billionaire's Investment Is Powering the World's Largest Thermal Battery: A Step-by-Step Guide

Introduction

When Australian tech billionaire Mike Cannon-Brookes, through his investment firm Grok Ventures, decided to back a U.S. thermal storage company, he didn't just write a check—he helped unlock the first gigawatt-scale thermal battery project on the planet. This monumental bet on thermal storage marks a turning point in renewable energy, proving that clean, dispatchable power can be stored at grid-scale. But how does such a project actually happen? This guide walks you through the crucial steps—from securing visionary funding to flipping the switch on a massive battery that can power hundreds of thousands of homes. Whether you're an investor, a clean energy enthusiast, or just curious about the mechanics of big bets on storage, here's the roadmap.

What You Need

• Visionary capital – A lead investor willing to back unproven technology at scale (e.g., Grok Ventures or similar deep-pocketed funds).
• Thermal storage technology – Proprietary systems that store energy as heat (e.g., using molten salt, sand, or other medium) with round-trip efficiency above 80%.
• Project site – Large land area with grid connection capacity, preferably near renewable generation or industrial load.
• Permits and approvals – Environmental impact statements, construction permits, and grid interconnection agreements.
• Engineering, procurement, and construction (EPC) contractor – Experienced builder for energy infrastructure.
• Grid interconnection study – Verification that the battery can safely connect and supply power to the local transmission network.
• Offtake agreements – Contracts to sell stored electricity (e.g., to utilities or corporate purchasers).

Step-by-Step Guide

Step 1: Secure Visionary Investment

Every massive project starts with a conviction bet. In this case, Mike Cannon-Brookes through Grok Ventures provided the anchor funding that allowed the U.S. thermal storage company to move from pilot to gigawatt scale. To replicate this, you need a lead investor comfortable with long timelines and technological risk. The investment should cover early-stage engineering, site acquisition, and initial permitting. The key is to find a backer who understands that thermal storage's ability to deliver dispatchable renewable energy is worth the upfront capital.

Step 2: Choose the Right Technology

Not all batteries are lithium-ion. Thermal storage uses materials like molten salt, crushed rock, or phase-change materials to store energy as heat, then release it via steam turbines or heat exchangers. For a gigawatt-scale project, you need a proven design with high energy density and low degradation. The company in Cannon-Brookes' portfolio had tested its technology at smaller scales; for your project, conduct a technology readiness assessment and patent review. Aim for a system that can deliver 10+ hours of storage at rated capacity.

Step 3: Identify a Suitable Location

Site selection is critical. Look for land near existing transmission infrastructure and near renewable generation (solar or wind) to charge the battery. Also consider proximity to industrial heat users if the battery provides combined heat and power. In the U.S., desert areas with high solar insolation are ideal because thermal storage pairs naturally with concentrated solar power (CSP). Secure lease or purchase options and perform environmental surveys to avoid delays.

Step 4: Obtain Permits and Grid Interconnection

This step can take 1–3 years. File for environmental impact statements, local building permits, and negotiate a grid interconnection agreement with the regional transmission operator. The battery must pass system impact studies to ensure it doesn't destabilize the grid. In the Cannon-Brookes project, the developer likely engaged with the local utility and independent system operator (ISO) early to streamline approvals. Hire a regulatory specialist familiar with your region's rules.

Step 5: Procure Materials and Begin Construction

With financing and permits in hand, order long-lead items: the thermal storage vessels, turbines or heat exchangers, piping, and controls. For a gigawatt-scale project, you'll need custom fabrication. Construction includes civil works, assembly of the storage system, and integration with the grid. The U.S. thermal storage company likely broke ground after finalizing EPC contracts. Use modular construction techniques to speed up timelines and reduce on-site risk.

Step 6: Commission and Test

Once built, the system enters commissioning. Charge the thermal battery using renewable electricity (via resistive heating or from a CSP field), monitor heat retention, and discharge through the power block. Test full-load runs, ramp rates, and emergency shutdown procedures. This phase often takes 6–12 months and is when the investor's patience pays off. In Cannon-Brookes' project, successful commissioning would prove that thermal storage can compete with lithium-ion on cost and duration.

Step 7: Achieve Gigawatt-Scale Operation

Finally, scale up. After proving the first unit, replicate the design to reach a gigawatt of discharge capacity. This may involve building multiple modules or expanding the storage medium volume. Connect all modules to a single substation and coordinate dispatch with the grid operator. The project backed by Cannon-Brookes is now among the biggest batteries in the world, providing reliable, long-duration storage that strengthens the grid.

Tips for Success

• Start small, scale fast – Test your technology at a pilot scale (10–50 MW) before jumping to 1 GW. Use lessons from the pilot to optimize design.
• Partner with utilities early – They can help secure interconnection and may become offtakers. In the Cannon-Brookes deal, the U.S. company likely had utility interest lined up.
• Embrace hybrid architecture – Combine thermal storage with solar or wind to maximize utilization and lower levelized cost.
• Plan for long-duration storage – Thermal storage's sweet spot is 8–24 hours of discharge, providing a complement to lithium-ion's 1–4 hours.
• Monitor policy incentives – In the U.S., the Inflation Reduction Act provides investment tax credits for standalone storage, including thermal. Leverage these to improve returns.
• Communicate the 'big bet' story – Like Cannon-Brookes did, use your project as a beacon to attract more capital and talent to thermal storage.

By following these steps, you can replicate the formula that turned a billionaire's bet into one of the world's largest batteries. The future of clean energy storage is hot—literally.