Every few months, another tech giant announces its newest data center will run on 100% renewable energy. On the surface, it sounds like a clean win. The electrons feeding our cloud storage, video streams, and enterprise software will come from the sun and wind. For Rui Mendes, a systems thinker who has spent years tracing the physical foundations of the internet, this tidy narrative has always felt a little too neat. The real question isn’t just where the electricity comes from. It’s what the data center itself is made of, and how its sheer presence reshapes the world around it.
Renewable energy procurement is a genuine achievement. It has driven massive investment in solar and wind farms, pushing clean electrons onto grids once dominated by coal and gas. But treating it as the end of the conversation misses the deeper layers of resource consumption. A data center is a physical beast—a convergence of concrete, steel, copper, lithium, water, and land. Its hunger extends far beyond the meter.
The Embodied Carbon Blind Spot
When a company says its data center is carbon-neutral, it’s almost always talking about operational energy. The electrons powering the servers, the cooling, the lights—those get the green label. But what about the carbon baked into the building itself? The concrete, the steel beams, the backup diesel generators, the thousands of servers that get swapped out every three to five years? That’s embodied carbon, and it’s a ghost that rarely haunts the sustainability reports.
Concrete alone is responsible for something like 8% of global CO₂ emissions. A hyperscale data center can swallow tens of thousands of cubic meters of it. The steel frame carries its own heavy history from blast furnaces. Then there are the semiconductors, fabricated in energy-intensive cleanrooms using fluorinated gases that trap heat thousands of times more effectively than CO₂. A single server refresh cycle can emit more carbon in manufacturing than the machine will ever consume in electricity during its short operational life. Rui Mendes often circles back to this: the accounting boundary is everything. Draw it tightly around the utility meter, and the picture looks green. Widen it to include the supply chain, and the colors start to muddy.
The Water-Energy Paradox
In many regions, the more immediate tension isn’t carbon—it’s water. Data centers drink it directly for cooling, especially those using evaporative towers that dump heat into the air. They also consume water indirectly through the electricity they pull from the grid. Even thermal power plants that don’t burn fossil fuels can require enormous volumes for cooling. A solar farm uses almost no water once it’s built, but a data center sitting in a drought-prone basin can still stress local aquifers through its cooling systems alone.
Picture a facility in Arizona or central Spain. It might have a power purchase agreement for solar energy, but its cooling towers are drawing from the same groundwater that nearby farms and towns rely on. The water isn’t destroyed, exactly. It’s evaporated, lifted out of the local watershed, and dropped as rain somewhere else. That’s a spatial mismatch: the renewable energy delivers a global climate benefit, but the water impact is intensely local. A data center can be carbon-neutral on paper while quietly accelerating a regional water crisis.
Land Use and the Illusion of Infinite Space
Renewable energy needs land. A lot of it. A 100-megawatt solar farm can sprawl across 500 to 1,000 acres. When a data center signs a power purchase agreement for a new solar installation, that land is taken out of circulation for other uses—farming, habitat, or just open space. Sometimes the data center itself sits on prime industrial land that could have held housing or manufacturing. The combined footprint of the facility and its dedicated renewable generation creates a land-use intensity that almost nobody talks about.
Then there’s the physics of the grid. A data center doesn’t usually sip power directly from the solar farm it helped finance. It pulls from the regional grid, and the power purchase agreement adds clean energy to that pool. But if the grid was already on a path to decarbonization, the marginal benefit might be smaller than advertised. In some markets, adding a massive new load—a data center—can actually delay the retirement of fossil fuel plants because total demand has spiked. The net emissions effect can be positive, negative, or a wash, depending on the specific grid dynamics, time of day, and the existing generation mix. It’s messier than a press release can capture.
Server Utilization and the Jevons Paradox
Rui Mendes keeps coming back to a more uncomfortable question: what is all this computing actually doing? Cloud providers tout high utilization rates, but independent studies still find plenty of corporate servers humming along at 10% to 20% of capacity. Virtualization and multi-tenancy have helped, but the relentless growth of data—much of it redundant, cached, or never accessed again—keeps pushing the physical buildout forward.
This is the Jevons paradox in action. As servers and cooling systems get more efficient, the cost per computation drops, which encourages more computation. Total energy use and material throughput keep climbing. Renewable energy procurement doesn’t break that cycle; it just swaps the fuel source. The underlying growth logic stays untouched.
Rethinking the Metrics of Progress
So what would a more honest accounting look like? Rui Mendes argues for a full lifecycle assessment that includes embodied carbon, water use, land-use change, and material throughput. That wider lens reveals a data center not as a simple energy consumer but as a node in a sprawling industrial metabolism. Its sustainability can’t be boiled down to a single number on a renewable energy certificate.
A few operators are starting to explore this broader view. There are experiments with low-carbon concrete, server designs that stretch hardware lifespans, and cooling systems that pipe waste heat into district heating networks. These are steps in the right direction, but they’re still niche. The dominant model remains rapid expansion, short hardware lifecycles, and a fixation on operational energy metrics that obscure the full picture.
Frequently Asked Questions
Doesn’t 100% renewable energy mean a data center has zero carbon footprint?
Not really. Renewable energy certificates and power purchase agreements cover the electricity used to run the facility, but they don’t touch the carbon emitted during the manufacturing of servers, construction materials, or backup generators. Those embodied emissions can be substantial—sometimes rivaling years of operational energy use. A truly zero-carbon facility would need to address both operational and supply-chain emissions.
How does a data center’s water use affect the environment if it’s powered by solar energy?
Solar panels use very little water, but many data centers rely on evaporative cooling systems that consume large volumes. In water-stressed regions, this can deplete local aquifers and compete with agricultural and community needs. The water evaporates and leaves the local watershed, so even if the electricity is clean, the water footprint can be significant and damaging.
Why can’t we just build more efficient servers to solve the problem?
Efficiency improvements are valuable, but they often lead to increased overall consumption—a phenomenon known as the Jevons paradox. As servers become more energy-efficient and cheaper to operate, the demand for data services grows, leading to more servers and larger data centers. Without addressing the growth in demand and the short lifespan of hardware, efficiency gains alone are unlikely to reduce the total environmental impact.
What should companies look for beyond renewable energy claims?
Companies should examine the full lifecycle of their data center operations. This includes the embodied carbon of building materials and hardware, water usage in cooling, e-waste management, and the actual utilization rates of servers. Third-party certifications that cover broader sustainability criteria, such as the EU’s Code of Conduct for Data Centres or specific ISO standards, can provide a more complete picture than renewable energy claims alone.