Designing Cato
This is how the strategy lands on the ground.
Not all data centres are the same. Some are powered by gas. Some draw heavily on drinking water. Some are designed without the question of sustainability having ever been asked. Cato is different by design.
Powered by 100% renewables
Cato will be powered by 100% renewable electricity. The power strategy reflects our twenty years of experience developing Scotland’s clean energy infrastructure. The first piece is a direct grid connection into Scotland’s renewable-rich electricity network. Cato will also connect directly to nearby renewable generation and storage, together with renewable electricity secured through Power Purchase Agreements, including from offshore wind. The specifics are subject to live commercial discussions and will be set out as those arrangements firm up. The direction is fixed.
Why locating demand in Scotland helps the wider electricity system
Locating large, stable demand in Scotland makes the wider UK power system work more efficiently. The north of Scotland produces more renewable electricity than the grid can carry south to where most of it is used. When that happens, the National Energy System Operator (NESO) pays Scottish wind farms to switch off and pays other generators like gas plants further south to switch on in their place. Both costs ultimately end up on household bills.
The scale is significant. In 2024/25, NESO spend £2.7 billion balancing the electricity system, including around £1.7 billion managing transmission constraints (NESO, 2025). In the first half of 2025, Scottish wind was paid to switch off around 37% of their planned output because the network could not transport all the electricity being generated (Montel Analytics, 2025)
The long-term answer is more transmission capacity, and those upgrades are underway. In the meantime, locating large, stable demand in Scotland, close to where the surplus is being generated, reduces the volume of curtailment payments and puts existing grid investment to more productive use. But the case doesn’t rest on curtailment alone. Demand belongs where the clean power is. It cuts transmission losses and network stress even on a fully upgraded grid, and locating it next to Scotland’s renewables makes better use of clean power the country has already built.
How does this demand fit into Net Zero plans?
UK and Scottish Government plans for net zero both assume that electricity demand will more than double as transport, heating, and industry move away from fossil fuels.
Data centres are part of that picture and are factored into that calculation. NESO’s Clean Power 2030 advice – the independent plan commissioned by the UK Government setting out how Great Britain’s electricity system can run on clean power by the end of this decade – expects around 5 GW (gigawatts) of new data centre capacity to come online by the end of this decade. That capacity is already built into the pathway.
Rather than throwing the country off course, the data centre capacity of projects like Cato is already factored into our net-zero calculations.
Low water use, by design
Some older data centres, in hotter climates elsewhere around the world have traditionally used massive quantities of water. We knew that wasn’t the right fit for the company, or for the country.
We recognised that the direction of travel for data centres was away from high water use / low water efficiency, to a much higher standard where the water could be looped sustainably. We found the best, most water efficient data centres in the industry and set that as the standard we would achieve.
Cato’s design prioritises the technologies that need least water: highly efficient cooling systems, supported by the Scottish climate, which is cool enough that a large share of the year’s cooling can come from drawing in cool outside air rather than running mechanical chillers — a process sometimes called free cooling because it uses no additional energy. Rainwater harvesting and process water reuse are designed in.
The result: over a year, Cato is expected to use 34,000 m3 of water per year.. For context, Aucthertool, uses 300,000m3/yr and Mossmorran used 4,380,000 m3/yr.
That is far less than the major industrial users operating in this part of Fife, including Mossmorran before its closure.
Cato will not draw from the local pipe network that supplies the neighbouring village of Auchtertool. The water supply to the village will not be affected. Scottish Water has confirmed existing capacity for the project, and their assessment was concluded before the ExxonMobil plant at Mossmorran closed, which means there is now substantial additional headroom.
Heat designed to be useful
The heat that a facility of this kind produces (created by the friction of billions of microscopic electrical movements inside its computer chips) can be put to very good use, and Cato has been designed with that in mind. Allowance has been provided for within the Planning Application for heat network equipment that could form the hub of a future network. Initial viability work for a district heating connection has been undertaken. An alternative use, in food production, has also been explored in support of the Food for Fife initiative. The final commitments will follow the studies that are underway.
Designed with the landscape
Cato is a large development. The independent Landscape and Visual Appraisal is clear that it will change how parts of the surrounding landscape look, particularly from close-range viewpoints to the north and east of the site. What the design has sought to do is limit that change as far as the topography and layout allow, and to deliver measurable improvements to biodiversity and landscape structure alongside it.
On our first visit to the community, we committed to keeping the lower portion of the site – the area closest to the village – free from any development. We stuck by that commitment, and that area is earmarked for a wild-flower meadow within our landscape designs. Similar commitments were made, and kept, in relation to access to the site, and to the existing wooded areas, and the Auchtertool Linn which are enhanced in our proposals to achieve a bio-diversity net gain overall.
The natural topography of the site and surrounding hilly landscape means that despite its scale, the project is not especially visible from the neighbouring village of Auchtertool. Indeed, it is possible to stand within the planning application boundary of the site itself and not see the buildings, because of that natural topography screening. Had the project been a few hundred metres to the north or south, then the impacts might have been different, but it has been designed such that this is not the case, with building heights varying and stepping up across the site so that it is screened (as much as possible) from key viewpoints.
The development will be visible from higher ground to the north, and these views are accurately represented in the planning application. For most of Auchtertool, however, the natural topography substantially reduces visibility, meaning the visual impact is considerably less than a site plan alone might suggest.
Shaped with the community
We have been engaging with the local community in Auchtertool for over a year, and much of what is now in the planning application, including the wildlife and habitat work, was shaped by what residents told us.
Alongside the development, ILI intends to establish a community benefit fund and to fund skills, training and apprenticeship opportunities linked to the project, with a particular focus on people affected by the closure of the neighbouring ExxonMobil plant at Mossmorran. How the fund is shaped should be done with the community rather than for it. If you have priorities you would like to put forward, and would like to participate in shaping this fund, please get in touch.
Open about the evidence
Our planning application is supported by a full assessment of the environmental impacts and all of the documents are available in full on the Fife Council Planning Portal. These reports cover noise, air quality, water, landscape, and ecology. If you wish clarity, or have any questions, we encourage you to get in touch with our team directly.
