Proving That Sustainability and Performance Can Share a Racing Car
XElectric FS did not exist in the summer of 2025. Eleven months later, a team of around fifteen students from across the University of Exeter's engineering, computing and business programmes rolled Car #81 into the scrutineering bays at Silverstone for Formula Student UK 2026. We arrived with an electric car built around a single design thesis, one that is easy to put on a poster and considerably harder to defend in front of a design judge: performance and sustainability do not have to be a trade-off.
Most teams treat sustainability as something you add to a car once it works. We wanted to find out what happens if you make it the constraint that shapes the car in the first place. That decision produced a vehicle built on an upcycled chassis rather than a new-build one, with hemp fibre composite bodywork in place of carbon and a deliberately non-lithium accumulator. It also produced a great deal of difficulty, most of it educational.
Working With an Inherited Chassis
Our chassis was not new. It came to us from XRacing, the University of Exeter's internal combustion Formula Student team, and giving an existing steel spaceframe a second competitive life was the first and largest environmental decision we made. Reusing a frame removes a substantial block of embodied carbon and material from the project before any other saving is even considered, and it aligned directly with the University's sustainability goals. It also, it turned out, set the hardest engineering problem of our season.
An electric Formula Student car and a combustion car are not built the same way, and the regulations for the two classes diverge in ways that go well beyond swapping one power source for another. Studying the electric vehicle chassis rules alongside the combustion ones was highly useful, because it told us precisely where an inherited frame would and would not comply, and what would have to change before the car could be presented as an electric vehicle at all.
The work that followed was essentially a conversion. We designed and fitted new motor mounts, machined from aluminium and located against the existing frame geometry rather than an ideal one. We added accumulator mounting structure, which is the most demanding change, since an electric class car must carry its tractive system accumulator within the primary structure and inside a height envelope tied to the impact structures. Our RS Pro toolkit proved highly effective and useful to do this, as their durability and diverse tool profile aided the team in making the necessary changes. Around all of that, we had to work with the mounting points, brackets and fixtures that were already there, placed years earlier for an engine, a fuel system and an exhaust that no longer existed.
The rest of the vehicle followed conventionally. The car runs a 14 kW, 48 V DC motor system through a chain final drive and a limited slip differential. We use a double wishbone suspension with pushrod-actuated Ohlins dampers. It is not an exotic specification, and that is somewhat the point. The interesting engineering is not in the parts we bought; it is in the materials, the reuse and the sourcing.
Hemp Fibre: The Biggest Bet
The most visible sustainability decision on the car is that its bodywork, floor and non-critical structural panels are not carbon fibre. They are a 330 GSM hemp twill dry fabric, supplied by BPreg, laid up in a bio-based epoxy matrix from Easy Composites.
We evaluated e-glass, flax, and hemp before committing. Among the natural bast fibres, hemp gives the best specific strength, showing higher stiffness and a higher fracture stress than flax, which fails at slightly larger strain. Hemp is also a fast-growing annual crop with a substantially lower cultivation of water demand than flax. The bio resin matters too. Both the laminating and infusion systems we used replace a substantial portion of the petrochemical bonding agent in a conventional epoxy with algae-derived material.
Hemp is a fraction of as energy intensive to produce as carbon fibre, which is one of the most demanding reinforcements in common use. Moving every panel we reasonably could onto it took a meaningful weight of embodied impact out of the car.
Three failures taught us the most. Panels laid up without bagging film on the tool face cracked during demoulding; using the film as a combined release and surface layer fixed that and gave a glossy face. Vacuum pressure cracked our early 3D printed moulds, solved with thicker walls, internal bracing and an integral sealing lip. The third is still open: hemp drinks resin, and that matrix mass is the largest weight penalty the car carries.
The Accumulator, and an Honest Trade
The tractive system accumulator is where the environmental argument became sharpest, because it is where it cost us the most. We moved away from lithium entirely, building the pack from AGM VRLA cells with a monitoring, balancing and shunt architecture around them.
The energy density penalty was detrimental and we did not pretend otherwise. What we gained was chemistry with a far less contested supply chain, simpler thermal behaviour and a safer failure mode for a first-year team with no prior high voltage experience. It is also the part of the car most constrained by the inherited frame, since the accumulator must live within the primary structure and under a height ceiling set by the impact structures, in a chassis that was never designed to carry one.
Building it safely was its own discipline. The electrical hardware came almost entirely from RS: connectors, terminals, cable glands, fuses, isolators and accumulator venting. So did the equipment we worked with, including insulated tool sets, insulated torque wrenches and multimeters, which meant a team handling a tractive system for the first time never improvised around live hardware and could torque every high voltage joint to a figure rather than to feel.
The People Behind the Car
XElectric FS ran with around fifteen members, drawn from mechanical, electrical and electronic engineering and from business, with contributions from computing and materials backgrounds. Fifteen is a small number for a Formula Student car, and for the first few months it was the defining problem of the project. There were more tasks than people, and the shortfall was not only in headcount: almost nobody arrived knowing what Formula Student demands, and for most of the team the regulations, machining, electronics and vehicle assembly were all unfamiliar. We were short of hands and short of experience at the same time.
Rather than assigning people narrowly, we inducted every member into all integral processes involved in building the car. It looked inefficient in the first term, but it proved not to be. It bought us redundancy, which matters enormously when a task can otherwise stall because of unavailability, and it lets people discover their interests. By the second half of the year, each person had converged on a specialisation they had chosen rather than been allocated and grew deeper knowledge. That progression, from generalists who did not know what they wanted to do, to specialists who did, is what a first-year team looks like when it works.
Being a small team had one genuine advantage. An engineer picks a supplier, a route and a material, and someone from the business team must defend the consequences of that choice to a judge; in a team of fifteen those are frequently the same table. Every person's strengths filled in somebody else's gaps, and we grew as engineers, as academics and as people.
Silverstone, and What We Learned
We were unable to clear scrutineering at FSUK 2026, which meant Car #81 never ran a dynamic event. After eleven months, that is a hard result to sit with.
What we did instead was deliberate. Rather than stopping at the first station that failed us, we took the car through every scrutineering stage we could, specifically to collect as much direct feedback from scrutineers as possible on the accumulator, the chassis, the electrical system and driver egress. We treated the bays as the most valuable design review we were ever going to get, delivered by people who inspect hundreds of cars a season. Every comment from that week is now a line item on our 2027 design schedule, and we came away with a far clearer picture of the gap between a car that is designed to the rules and a car that demonstrably proves it to an inspector.
We scored in every static event, taking part in the design, cost and business presentations, and finished 58th overall with a car built by fifteen people in eleven months, by a team that did not exist a year earlier.
Several practices are coming with us. Resolving the rules on paper before committing to CAD saved more time than any modelling technique we used, and it was indispensable when adapting a frame designed for a different class of car. Thinking about environmental impact while choosing suppliers, rather than afterwards, changed which suppliers we chose instead of merely describing the ones we had already picked. Treating tooling as a deliverable, with the same design rigour as parts on the car, stopped our jigs and infusion moulds from being improvised. Bench testing for failure rather than for function, deliberately breaking a system to confirm it fails safely rather than only proving that it works, is what scrutineering actually asks about. And above all, the accumulator should be started on day one. It is the longest pole in an electric Formula Student campaign, the most rules constrained and the most supplier dependent, and it should never be the thing that gets finished last.
Where We Go Next
Our 2027 work stays pointed at the same question, with sharper tools.
The biggest change is the one we thought hardest about, because it looks at first glance like a retreat. We intend to move the tractive system accumulator to lithium, but to responsibly sourced lithium, and the reasoning is that sustainability and longevity are the same argument once you look past a single season. A lithium pack lets us push considerably more power through the car and extend the range we can achieve on it, both of which we need if the vehicle is going to complete dynamic events rather than merely be capable of them. Just as importantly, a properly stored and maintained lithium pack keeps its usable capacity for far longer than lead acid does. Cells that serve several seasons are a better environmental outcome than cells that have to be replaced, and the honest lesson from year one is that choosing the chemistry with the lowest headline footprint is not the same as choosing the one with the lowest lifetime footprint. The condition we are holding ourselves to is provenance: responsibly sourced cells, with a supply chain we can actually stand behind in a design event.
We intend to design and build a new chassis, this time as an electric car from the first line of geometry rather than as a conversion. The inherited frame gave us a season we would not otherwise have had, and it taught us precisely where the compromises live. A purpose built electric frame lets the accumulator, the motor mounts and the firewall be designed in rather than fitted around, which removes most of the packaging friction described earlier. It also lets us fix something the current car could never address, which is the cockpit. We want a chassis that comfortably accommodates a genuine range of driver sizes, because a cockpit that only really suits one build limits who can drive the car, and driver comfort feeds directly into control and consistency once the car is moving.
In materials, we are testing basalt fibre and hemp and basalt hybrids, which offer the prospect of raising mechanical performance while keeping a low environmental footprint. We are actively hunting a sustainable reinforcement with lower epoxy absorption than hemp, since matrix mass is the single largest weight penalty the current car carries. We also want to work with thermoplastic pre-pregs on more complex components, where faster processing and improved toughness could open up geometry that is difficult for us today.
Aerodynamics and bodywork are on the list as well, but realistically scoped. With more power and a lighter, purpose built car, the speeds we expect to reach are higher than this year's, though still modest by motorsport standards, and at those speeds the gains that actually pay back are practical rather than dramatic.
The skills generalise further than the car does. Adapting an inherited structure to a purpose it was never designed for teaches you to work with the constraints you have rather than the ones you would prefer. Resolving the regulations before the geometry is the same instinct as writing a specification before code. And weighing environmental impact at the moment of a decision, rather than at the end of a project, is the entire difference between a sustainability claim and a sustainability result.
We did not get on track in 2026. We walked away with the knowledge, the scars and the confidence to build a better car, and with a fairly strong conviction that natural materials and reused structures have a real place in competitive motorsport. This is only the beginning.
Team Xelectric FS thanks the University of Exeter and its Engineering Department, Xracing, Formula Student UK and the IMechE, RS Group, Lynch Motor Company, Bpreg, and every sponsor, partner and team member who made Car #81 possible.
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