This was the question posed by Stuart Watson of RICS Modus to industry experts including RLB Partner, Jon Clark.
Big tech firms face a pressing problem: how to power their ever-growing portfolios of datacentres while still meeting their pledges to reduce carbon emissions. Recent tie-ups between the likes of Google and Meta suggest next-generation geothermal power could be a crucial element of the solution.
In August, Sage Geosystems announced an agreement to provide Facebook owner Meta with 150MW of geothermal power. For comparison, 1MW of electricity would be needed to meet the power demand of around 750 homes. Sage will use its Geopressured Geothermal System, which harvests pressure and heat from water stored deep underground, to provide carbon-free power to Meta’s datacentres at a site located “east of the Rocky Mountains” in the USA.
Geothermal energy generation is not an entirely new technology. But it has hitherto been viable only in the few geological regions where the heat simmers just below the Earth’s crust, such as Iceland and parts of the western US. Next generation geothermal drills burrow down into areas where underground “hot rocks” are present, which are much more widespread. Using techniques developed by the shale gas fracking industry, water is pumped in to be heated by the Earth’s temperature to around 150oC, then the steam is brought back to the surface, where a turbine converts the heat and pressure to electricity.
For datacentre operators and developers, the technology represents a potential breakthrough. This is because pressure is growing for them to find affordable sources of what is termed “clean firm energy” – a steady, uninterrupted supply of low carbon power. The volume of electricity required to power datacentres has rocketed in recent years, fuelled first by the widespread adoption of cloud applications and now by the boom in datacentres used for “training” artificial intelligence (AI) applications.
Modern microchips are far more energy-intensive than earlier generations, with the consequence that server racks which once needed one to three kilowatts (KW) of electricity now require 40KW. Meanwhile datacentre buildings have got larger. Two decades ago, a typical facility would have consumed just a few megawatts at most. Today the most power-hungry datacentres require more than 100MW.
Meanwhile, big tech firms have set ambitious decarbonisation goals. Google has committed to operate all its datacentres and office campuses on “24/7 carbon-free energy” by 2030. Meta has targeted reaching net zero emissions over the same period.
Going off-grid
The combination of power scarcity and pressure to decarbonise is driving tech giants to look at off-grid, or “micro-grid” solutions, says Jon Clark, a sustainability and ESG strategist at construction and property consultancy Rider Levett Bucknall. “They are providing their own power to sites, and if possible, providing surplus power back to the grid. We are seeing huge demand for solar and hydropower, where it is available, and new technology starting to come through like geothermal and small modular nuclear reactors.”
Hydro-electric generation is already in widespread use to power datacentres in regions where it is plentiful, such as the Nordics. Solar and wind will also meet some of the need, but because they are weather-dependent and therefore unable to guarantee a steady supply, they need to be backed up by gas-fired generators or expensive battery storage. They can also be land-hungry and unsightly.
Modern drilling techniques will open up many more areas for geothermal, but how deep you have to drill and how hot it is, depends on the area’s geology, says Drew Nelson, Project Innerspace’s vice president for programmes, policy and strategy. In some places, it will still not be cost effective to drill deep enough to get to a temperature that will produce power, he admits.
With coal and gas-fired stations being wound down and datacentres’ appetite for power only likely to increase, developers and operators will look to a mixture of sources including geothermal, renewables, nuclear, and other innovative technologies like gas with carbon capture to fill the short-term gap between supply and demand.
That means it is vital to support pilot projects so that they are up and running as quickly as possible, says Nelson. “We want to make sure that as this boom in datacentres and other electricity demand happens, that that all these clean technologies, particularly geothermal, are well positioned to take advantage of it. As citizens of Earth, we need these solutions, and we need them now.”
This is an abridged version of an article that appeared in RICS Modus.
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