As AI data centers spring up across the country, their energy needs and resulting greenhouse gas emissions are a priority. Because servers and energy-intensive cooling systems are always running, these buildings can eat as much as a couple of megawatts of electricity for a small data center greater than 100 megawatts for a hyperscale data center. To put that in perspective, the typical large natural gas power plant inbuilt the United States generates electricity lower than 1,000 megawatts.
If the electricity for these data centers comes from fossil fuels, they may grow to be a serious source of climate-warming emissions into the atmosphere – unless the facility plants first capture after which sequester their greenhouse gases.
Google recently entered into a novel enterprise power purchase agreement to support this Construction of a natural gas power plant in Illinois, which goals to just do that through carbon capture and storage.
So how does carbon capture and storage (CCS) work for a project like this?
I'm an engineer who wrote a 2024 book about several types of carbon storage. Here's the short version of what you’ll want to know.
How CCS works
When fossil fuels are burned to generate electricity, they’re created release carbon dioxidea robust greenhouse gas that continues to be within the atmosphere for hundreds of years. As these gases accumulate within the atmosphere, they grow to be act like a blanketand keeps heat near the earth's surface. Too high a concentration heats up the earth an excessive amount of, trigger climate changesincluding increasing heatwaves, rising sea levels and intensifying storms.
Carbon capture and storage involves capturing carbon dioxide from power plants, industrial processes, and even directly from the air after which transporting it, often via pipelines, to locations where it may be safely injected underground for everlasting storage.
Congressional Budget Office, US Federal Government
The carbon dioxide could possibly be transported as supercritical gas – which is situated directly on the phase transition from liquid to gas and has the properties of each – or is dissolved in a liquid. Once the carbon dioxide is injected deep underground, it may grow to be permanently trapped within the geological structure, dissolve in brine, or be mineralized, becoming rock.
The goal of carbon storage is to be certain that carbon dioxide will be kept out of the atmosphere for a very long time.
Types of underground carbon storage
There are several ways to do that Storage of carbon dioxide underground.
Depleted oil and natural gas reserves have loads of cupboard space and the added advantage that almost all are already mapped and their boundaries are known. They have been holding onto hydrocarbons for tens of millions of years.
Carbon dioxide will also be injected into lively oil or gas reservoirs to displace more of those fossil fuels while leaving many of the carbon dioxide behind. This method, often known as improved oil and gas productionis that most often is now utilized by carbon capture and storage projects within the United States, and One of the explanations CCS attracts complaints from environmental groups.
Volcanic basalt rock And Carbonate formations are considered good candidates for protected and long-term geological storage because they contain calcium and magnesium ions that interact with carbon dioxide. convert it into minerals. Iceland was the pioneer of this method Using its bedrock of volcanic basalt to store carbon. Basalt also covers many of the oceanic crust, and scientists have been studying the potential for it Storage reservoirs beneath the seafloor.
In the US, a fourth option is probably going has the best potential for industrial storage of carbon dioxide – deep saline aquifers that Google wants to make use of. These widespread aquifers are porous and permeable sedimentary formations manufactured from sandstone, limestone or dolomite. They are full of highly mineralized groundwater that can not be used directly as drinking water, but could be very suitable for storing CO2.
Deep saline aquifers even have large storage capacities, ranging between around 1,000 and 20,000 gigatons. In comparison, that of the nation Total carbon emissions from fossil fuels in 2024 was about 4.9 gigatons.
From autumn 2025 21 industrial plants According to the Global CCS Institute's 2025 report, carbon capture and storage is getting used across the U.S., including industries that produce natural gas, fertilizers and biofuels. Five of those utilize deep saline aquifers, the rest involve enhanced oil or gas production. Eight additional industrial carbon capture facilities were under construction.
Google's plan is exclusive since it features a power purchase agreement that enables the facility plant to be built with carbon capture and storage.
Google's storage plan for deep saline aquifers
Googles 400 megawatt natural gas power plantbe built with Broadwing Energyis designed to capture roughly 90% of the power's carbon dioxide emissions and pipe them underground for everlasting storage in a close-by deep saline aquifer Mount Simon sandstone formations.
The Mount Simon Sandstone Formation is an enormous saline aquifer that lies beneath most of Illinois, southwestern Indiana, southern Ohio, and western Kentucky. It has a layer of highly porous and permeable sandstone This makes it an excellent candidate for carbon dioxide injection. In order to maintain the carbon dioxide in a supercritical state, this layer should be present at the least 800 meters deep.
Overlying the Mount Simon Formation is a thick layer of Eau Claire shale. serves as a capstone This prevents stored carbon dioxide from escaping. With the exception of a couple of small regions near the Mississippi River, the Eau Claire Shale is considerably thick—greater than 300 feet (90 meters)—in many of the Illinois Basin.
The estimated storage capability the Mount Simon Formation ranges from 27 gigatons to 109 gigatons of carbon dioxide.
The Google project plans to make use of an existing injection well site that was a part of the primary large-scale demonstration of carbon storage within the Mount Simon Formation. Food producer Archer Daniels Midland began injecting carbon dioxide there in 2012 from nearby corn processing plants.
Carbon capture and storage has presented challenges over time because the technology has evolved, including but not limited to: Burst pipe In 2020, evacuations occurred in Satartia, Mississippi, leading to several people losing consciousness. According to a recent Leak deep underground at Archer Daniels Midland site In Illinois, the Environmental Protection Agency in 2025 required the corporate to enhance its monitoring. Stored carbon dioxide had migrated to an unauthorized area, but no threat to water supplies was reported.
Why is CCS essential?
Data centers are growing quickly and utilities need to construct more power capability to maintain up. The artificial intelligence company OpenAI is asking on the USA to do that Build 100 gigawatts recent capability yearly – a doubling of the present rate.
Many energy experts, including the International Energy Agency, imagine so Carbon capture and storage might be essential to slow climate change and stop global temperatures from reaching dangerous levels as energy demand increases.
