2024 — Present
Bitcoin Mining — Norway
Waste-heat-recovery mining site: the miners warm a warehouse via its existing water loop. Planning immersion-cooling conversion next.
Mechanical Engineering · Sheffield
Oscar Hoeltschi
builds things.
Mechanical engineering student at the University of Sheffield and founder of a waste-heat-recovery Bitcoin mining site in Norway. Boats, bikes, solar arrays, custom PCs, electrical infrastructure — always a little project in the works.
About
Engineer by training, builder by instinct.
I'm a first-year Mechanical Engineering student at the University of Sheffield. Alongside my degree I run a Bitcoin mining operation in Norway that repurposes waste heat to warm a warehouse — and I've spent the last few years taking on progressively bigger hands-on projects: a speed boat restoration, two motorised bicycles, a ground-mount solar array, a custom utility trailer, a full workshop build, and a growing pile of custom water-cooled PCs.
My A-levels were Maths (A*), Physics (A*), Chemistry (A) and Further Maths (A). I learn fastest by making the thing, so most of what's on this page exists as a physical object, a running process, or a working prototype.
Timeline
A chronological sweep.
Projects, builds and businesses that got me here — newest first.
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2025 — Present
Mechanical Engineering — University of Sheffield
Started my BEng in Mechanical Engineering. Focus areas I'm drawn to: thermodynamics, fluid systems and energy.
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2024 — Present
Bitcoin Mining Site — Norway
Operating a Bitcoin mining site in Norway built around waste-heat recovery: the miners warm a warehouse via the building's existing water loop. I designed the electrical distribution (custom APDU + schematic below), commissioned every unit on the bench, and I'm now planning an immersion-cooling conversion so the miners plumb directly into the hydronic system.
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2024 — Present
Custom APDU & Electrical Infrastructure
Designed and commissioned the custom APDU / power distribution for the mining site. 350 A, 230 Vac 3φ DELTA input, per-branch hydraulic-magnetic protection, wired and configured with its own monitoring meter.
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2023 — Present
Ground-Mount Solar Array
Built out a ground-mount solar array on a farm site — fabricated the steel A-frame structure myself, transported the panels in on the custom trailer, and wired the array. Experimenting with intermittently powering low-gen ASICs outdoors in harsh UK weather.
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2023
Custom Utility Trailer
Built a custom utility trailer from a bare axle and frame — OSB bed, fabricated sides, road-legal. First haul: transporting the solar panels to the array site.
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2022 — 2023
Speed Boat Renovation
Bought a derelict speed boat and restored it end-to-end: stripped the hull, re-primed, re-painted, re-upholstered the cockpit, and rebuilt the outboard motor from scratch. Launched and running under her own power.
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2022 — 2023
Outboard Motor Rebuild
Tore down the original outboard, sandblasted and primed the castings, resprayed the cowling and fitted it back onto the boat — running on the rebuilt powerhead.
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2022 — 2024
A-Levels — Maths A*, Physics A*, Chemistry A, Further Maths A
Sat four A-levels with a focus on maths and sciences. Took a gap year after finishing school to get more hands-on projects done before starting my degree.
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2022 — 2023
Work Experience — MicroBrit, Splash Orthodontics, Greggs
MicroBrit (CNC machining for ultra-precise medical structures) — built a Blender 3D model of a glucose-powered implant prototype (no battery required) that was used to pitch the concept to investors.
Splash Orthodontics — built custom PCs for the practice, set up the network, handled day-to-day IT troubleshooting.
Greggs — Customer Service Assistant: transactions, food prep, stocking and service.
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2021 — 2022
Motorised Bicycle Builds
Converted two pushbikes into motorised bikes with two-stroke engines — fabricated the engine mounts, fitted the fuel tanks, tuned the carbs, and rode them on the road.
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2021
Workshop Lean-To Build
Ran out of space in the garage, so I built my own lean-to workshop onto the side of the house — framed it, clad it, fitted it out, and moved the projects in.
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2020 — Present
Crypto Mining — Origins
Started mining in 2020 using spare hardware at home. That turned into the idea that became the Norway site: repurpose the waste heat instead of throwing it away. Built monitoring and control tooling along the way (Home Assistant + custom YAML pipelines tracking hash-rate, power draw and efficiency).
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2019 — Present
Phone Repair & Refurbishment
Fixing, refurbishing and selling phones on eBay on the side — screens, batteries, logic-board level work.
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2018 — Present
Custom PC Builds
Built my first PC in 2018. Since then: custom hard-line water-cooled builds, servers, and standard daily-drivers for friends and family.
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Ongoing
Jet Ski Restoration
Current project: stripping and rebuilding a green Kawasaki jet ski. Engine work, cosmetics, trailer-ready.
Projects
Selected work.
The headline builds, in one view.
2024
Custom APDU
Designed and wired a 350 A 3φ power distribution unit for the site — per-branch hydraulic-magnetic protection, integrated metering.
2023 — Present
Ground-Mount Solar Array
Fabricated the steel A-frame, transported panels on the custom trailer, wired it up. Powering low-gen ASICs intermittently.
2022 — 2023
Speed Boat Restoration
End-to-end hull restoration plus a full outboard-motor rebuild. Running under her own power.
2023
Custom Utility Trailer
Built from a bare frame and axle — OSB bed, fabricated sides, road-legal. First job: hauling the solar panels in.
2021 — 2022
Motorised Bicycles
Two pushbikes converted with two-stroke engines — fabricated mounts, tuned carbs, rode on the road.
2018 — Present
Custom PC Builds
Hard-line water-cooled systems, servers, and daily-drivers for friends and family.
2021
Self-Built Workshop
Ran out of garage space, so I framed and clad a lean-to workshop onto the side of the house.
Let's talk
Summer 2026 placement — available.
Looking for a placement in mechanical engineering, data centres or energy. Keen on anything hands-on.