Exowatt, a Sam Altman-backed energy startup, plans to revolutionise AI data centre energy consumption by harnessing the power of concentrated solar energy stored in high-temperature hot rocks to provide round-the-clock, dispatchable electricity.
A Viable Alternative to Traditional Grid-Based Power?
Co-founded by Hannan Happi, who has a background in energy innovation and technology development, Exowatt aims to address the AI industry’s growing demand for sustainable and reliable power. With this in mind, the company’s flagship product, the Exowatt P3 system, is designed to solve the solar energy industry’s most significant challenge, i.e., providing consistent, 24-hour electricity. By capturing solar energy, storing it as heat, and converting it into electricity when required, Exowatt aims to deliver a viable alternative to traditional grid-based power, which is not always reliable or sustainable for energy-hungry industries like AI.
How Exowatt’s P3 System Works
The Exowatt P3 is a modular system that functions differently from conventional solar panels. Instead of converting sunlight directly into electricity, the system uses concentrated solar power (CSP) technology, a method that has been around for decades but has yet to achieve widespread commercial success.
Heats A Brick And Blows Air Over It
As the company says on its website, “Exowatt delivers power on demand by capturing and storing solar energy in the form of high-temperature heat and converting it into dispatchable electricity as needed.”
In order to do this, the system works by using fresnel lenses (a type of light-focusing lens) to concentrate sunlight into a tight beam. This beam heats a special brick inside a box, which serves as a thermal battery. A fan blows air over the brick, carrying the heat to a Stirling engine, a heat engine that converts thermal energy into mechanical energy, which is then used to generate electricity. The P3’s thermal storage capacity allows it to provide dispatchable power, meaning it can supply electricity whenever needed, even when the sun isn’t shining. This addresses the intermittent nature of traditional solar energy, which can only generate power when there is direct sunlight.
Can Store Heat For 5 Days
The P3 units can store heat for up to five days, ensuring continuous operation. Also, the units are modular, meaning they can be scaled depending on the energy requirements of the user. Exowatt has designed the system to be easy to deploy, requiring minimal maintenance and a small physical footprint compared to other renewable energy solutions.
Why It Matters for the AI Industry
The AI sector is growing at an unprecedented rate, with increasing energy demands driven by the need to train complex models and power massive data centres. For example, according to estimates, data centre energy consumption will increase by 150 per cent by 2030, with AI models expected to be one of the largest contributors to this demand. Traditional energy grids, however, are not equipped to handle this surge in consumption, especially as the need for clean and reliable energy grows.
Exowatt’s approach could, therefore, significantly reduce reliance on fossil-fuel-powered backup generators, which many data centres currently use to ensure uptime during power shortages. These backup systems, often powered by gas, are not only expensive but contribute to carbon emissions, directly contradicting the industry’s shift towards more sustainable practices.
The Exowatt P3 promises a cleaner, more sustainable alternative by providing a reliable power source that does not depend on the grid. This is particularly important for companies building data centres in remote areas, where access to stable grid power may be limited or non-existent. By positioning itself as a dispatchable energy solution, Exowatt gives AI companies a way to meet their energy needs while maintaining their commitment to sustainability.
What Makes Exowatt So Different?
Unlike traditional solar power systems, which require battery storage to hold electricity until it is needed, Exowatt’s thermal storage system offers a number of advantages. For example, the P3 system’s reliance on heat storage rather than electric battery storage avoids many of the issues associated with lithium-ion batteries, such as their reliance on rare-earth minerals, the environmental impact of battery disposal, and the rapid cost reductions in solar panel production which have outpaced improvements in battery technology.
Exowatt’s system is designed to work in sunnier regions where traditional solar systems are most effective. Happi notes that Exowatt’s P3 units can be deployed near new data centre developments, often located in sunny areas, thus overcoming grid limitations. The modular nature of the system means that power capacity can be increased simply by adding more P3 units, making it a scalable solution.
Pricing and Availability
Exowatt appears to be aggressively scaling production, having raised a total of $140 million in funding to date, including a recent $50 million extension to its Series A round. The company has set a target price of $0.01 per kWh, which would position its energy cost below current prices for many types of renewable power. To achieve this, Exowatt hopes to manufacture 1 million units per year, which would bring production costs down and make it competitive with other forms of renewable energy.
While the technology is still in its early stages, Exowatt has already secured a backlog of 90 GWh in demand, with customers in the AI data centre and energy developer sectors. As production ramps up, Exowatt plans to roll out the P3 system to large-scale data centre projects in regions that are sun-rich, making it an ideal fit for AI companies seeking reliable, sustainable power solutions.
Other Companies in the Space
It should be noted here that Exowatt is not the only company exploring the potential of thermal storage and concentrated solar power. Several other firms are pursuing similar solutions, though each has its own approach and focus. These include:
– Vast Energy, which is developing modular concentrated solar thermal power systems designed to deliver clean, dispatchable energy for utility-scale and industrial applications. Their CSP v3.0 technology captures the sun’s energy and stores it as heat, allowing for efficient and reliable power delivery when needed, similar to Exowatt’s P3 system.
– Heliogen, which focuses on solar thermal technologies and aims to replace fossil fuels in industrial applications. Their systems use concentrated solar power to generate high-temperature heat, which can be used to produce electricity or replace gas in manufacturing processes.
– SolarReserve and eSolar, which are earlier players in the CSP field, though their commercial activities have slowed in recent years. These companies have contributed to the development of solar thermal technology, but they are less active or have shifted their focus due to challenges with scalability and cost.
While Exowatt’s approach is similar to these companies, its focus on modular, scalable systems tailored for AI and high-density computing environments could set it apart, particularly if it can prove its technology is both cost-effective and adaptable to different locations and energy demands.
Broader Implications and Challenges
Exowatt’s technology looks as though it has the potential to disrupt the renewable energy and data centre industries, offering a way to tackle AI’s increasing energy demands sustainably. For example, for data centre operators, the system presents an opportunity to reduce their carbon footprint while ensuring that power is always available, even during peak demand periods or at night.
However, Exowatt faces some stiff competition. Photovoltaic solar panels and lithium-ion batteries have come down in price rapidly in recent years, making them more attractive options for many companies. Also, concentrated solar power projects have faced challenges in the past due to high upfront costs and the need for specific geographical conditions. Exowatt will need to prove that its system can scale effectively and remain cost-competitive as production increases.
One of the key challenges for Exowatt’s system is land use. For example, while the P3’s efficiency is comparable to traditional photovoltaic solar panels, the system requires a significant amount of land to scale up production, particularly in regions with less sunlight. This may limit the system’s appeal in areas where land is scarce or where sunlight is insufficient. The large land footprint required to deploy large numbers of P3 units could also pose logistical challenges, especially in urban areas where space is at a premium. These factors are likely to be crucial for Exowatt to overcome if it aims to scale effectively and meet the growing demand for sustainable AI infrastructure power.
Looking Ahead
As Exowatt continues to scale its operations, it could well become a leading player in the transition to sustainable energy for AI data centres. For example, with major backers like Andreessen Horowitz and Sam Altman, the company has the resources to expand rapidly, and its innovative approach to solar energy storage could set a new benchmark for the energy demands of AI.
However, its success looks likely to depend on whether it can overcome the inherent challenges of large-scale deployment and prove that its technology can compete with existing energy solutions. If Exowatt can deliver on its promises, it could reshape the way data centres, and indeed, entire industries, think about their energy needs in the age of artificial intelligence.
What Does This Mean For Your Organisation?
Exowatt’s P3 system seems to offer a compelling vision for how AI data centres can meet their energy needs sustainably, addressing the increasing demand for 24/7 power in an industry heavily reliant on high-performance computing. The system’s ability to store solar energy as heat and convert it into dispatchable electricity sets it apart from traditional solar and battery solutions, offering a reliable and cleaner alternative to fossil-fuel-powered backup systems.
However, while the P3 system presents a promising solution for reducing data centre emissions, its success could hinge on overcoming several challenges. Scaling production efficiently and managing the land footprint required for deployment are two critical obstacles. Although Exowatt has the potential to deliver energy at an exceptionally low cost, competing technologies, such as photovoltaic solar and lithium-ion batteries, have quickly become more cost-competitive. Exowatt will need to demonstrate that its system can meet these challenges, particularly in less sunny regions where land availability and sunlight are limited.
Looking to the future, Exowatt’s modular, scalable approach could make it an attractive option for AI companies looking to ensure reliable power while maintaining sustainability goals. For UK businesses, particularly those involved in AI, data centres, and energy-intensive industries, the success of Exowatt could signal a new era of energy independence and sustainability. If Exowatt can continue to scale and prove its technology’s viability, it could reshape the energy landscape for data centres globally, offering UK companies a reliable and affordable path to meet the growing demands of the digital age.
Despite the hurdles, Exowatt’s ambition and innovative approach may be precisely what’s needed to meet the unique energy challenges of the AI sector, paving the way for a more sustainable and resilient energy future.