The humblest object on a British wall, the light switch, has gone roughly unchanged since Reyrolle started selling Bakelite rockers in the 1920s. Tewke, a London climate tech company founded in 2020, would like to change that. Its first product, the Tewke Tap, is a wall switch with a quad-core 1.8 GHz processor, 2 GB of RAM, 16 GB of storage, and sensors for temperature, air quality, and humidity [T3] [Electrical Contracting News]. It also runs TewkeAI, a voice assistant powered by Google Gemini [T3]. For something that turns the lights on and off, that is a generous bill of materials.
The bet behind the spec sheet is straightforward. Roughly 30% of electricity is consumed by homes, and a meaningful share of that is wasted [TechFundingNews]. Tewke's founder, serial entrepreneur Piers Daniell, who previously built the connectivity company Fluidata, argues that the smart grid does not start at the substation. It starts at the device people actually touch [Crunchbase] [TechFundingNews]. Replace the switch, and you get a sensor mesh, a control surface, and a local compute node in every room, sold to consumers one box at a time rather than negotiated with utilities one decade at a time.
The bet
Tewke is selling hardware to homeowners, with TewkeAI baked in and over-the-air updates promised to extend the Tap's capabilities into automation, notifications, and voice control without requiring new hardware [Electrical Contracting News]. A companion mobile app, built in Flutter, ties the system together [IT Jobs Watch]. The wedge is the install: a switch is one of the few smart-home objects that genuinely belongs on the wall, replaces something already there, and does not demand a hub. If Tewke can make swapping a switch feel like swapping a bulb, the distribution problem looks tractable.
The company raised €3.1 million in seed funding in November 2024 to launch the Tap [EU-Startups, Nov 2024], with total disclosed seed capital of around $3.4 million [TechFundingNews]. Investors include Cur8 Capital, JamJar Investments (the Innocent Drinks founders' fund), Energy Mix Ventures, Project Ventures, and Revolut co-founder Vlad Yatsenko. Tewke is also a Google Accelerator participant, which goes some way to explaining the Gemini integration.
| Metric | Value |
|---|---|
| Seed round (Nov 2024) | 3.1 EUR M |
| Total disclosed seed | 3.4 USD M |
| Tap RAM | 2 GB |
| Tap storage | 16 GB |
| Tap CPU clock | 1.8 GHz |
Why it could be big
The consumer smart-home category has spent a decade trying to justify itself on convenience. Tewke is trying to justify itself on kilowatt-hours, which is a more durable pitch in a UK market where the Ofgem price cap still hovers well above pre-2021 levels and where heat pumps, solar, and EV chargers are quietly turning every home into a small power station with terrible software. A switch that knows the temperature in the hallway, the humidity in the bathroom, and the air quality in the bedroom is, in principle, the cheapest way to give a house a nervous system.
Back of envelope. A typical UK household uses roughly 2,700 kWh of electricity per year. If Tewke's mesh of switches, automations, and gentle nudges trims even 8% of that (estimated), call it 215 kWh saved per home per year. At a 27 p/kWh cap, that is about £58 a year per household. The carbon math at the current UK grid intensity of roughly 200 gCO2/kWh works out to about 43 kg of CO2 avoided per home per year, or 4,300 tons across 100,000 homes. Modest per unit, meaningful at scale, and entirely dependent on Tewke shipping enough switches to make the mesh real.
The team and traction
Daniell is Co-founder and CEO [FoundersToday], with Rowan Dixon as co-founder leading technical development, prototypes, the touchscreen device design, and the supply chain [Rowan Dixon Resume] [T3]. The team includes Guy Adderley and Krzysztof Wancerski, the latter with an Imperial College London affiliation that fits the company's research ties: Imperial has separately written about Tewke's switch as a building block for a smart grid [Imperial College London] [LinkedIn]. The company has been hiring Flutter and full-stack engineers in London [IT Jobs Watch] [StudySmarter Talents], which lines up with a hardware company that knows its bottleneck is software.
The honest counterfactual
What bears will say is that the smart-switch shelf is already crowded with Lutron, Shelly, Aqara, and the Matter-compliant offerings from every major platform, and that consumer hardware on €3.1 million is a tight runway when the bill of materials includes a quad-core SoC and 2 GB of RAM [T3]. Selling a premium switch into a cost-of-living-squeezed UK retrofit market is genuinely hard. What bulls will answer is that none of those incumbents ship a switch that is also a multi-sensor and a Gemini endpoint, and that Tewke's OTA roadmap means the same hardware can grow into automation and voice without a second purchase [Electrical Contracting News]. The Google Accelerator relationship and the Gemini integration suggest a software partner that lowers the AI cost curve over time. Whether that adds up to a defensible consumer brand or a beautifully engineered niche is the open question.
What to watch
The next twelve months are about whether the Tap actually ships in volume, whether reviewers beyond T3 corroborate the experience, and whether Tewke can convert its Kickstarter community, hinted at in team posts [LinkedIn], into a recurring direct-to-consumer motion. A Series A in late 2025 or 2026 would likely hinge on unit economics per switch and attach rates for additional Taps per home. If the company can credibly claim more than two Taps per installed household, the smart-grid story starts to look real rather than aspirational.
The incumbent Tewke must beat: Lutron, whose Caseta line has spent fifteen years convincing electricians and homeowners that a premium switch is worth paying for. Tewke's argument is that Lutron solved the dimmer and stopped there, while the wall is ready for something that thinks.