Join ThermoVault and shape the future of energy:
ThermoVault is a growing scale-up on a mission to make energy smarter, greener and more efficient. With our cutting-edge IoT hardware and software, we transform everyday thermal appliances like water heaters, accumulators, and heat pumps into intelligent, grid-responsive storage devices. The result? Households automatically save 15-25% on energy, without lifting a finger or sacrificing comfort. In 2025, this represented 750 MWh of savings.
Backed by our main shareholder, Ariston Group, a worldwide leader in heating and hot water solutions, we are scaling fast. We are already managing almost 9,000 installations across Belgium, France, and Italy, with plans to expand into South Africa and beyond. By controlling how and when these appliances use electricity, we help balance the grid and secure contracts with energy players like TSOs, driving our recurring revenue model.
But we are not stopping at retrofits. Our technology is now built directly into Ariston's next-generation appliances, unlocking a global market. As this continuous stream of native devices accelerates our growth, we face an exciting challenge - and this is where you come in!
Your responsibilities:
As a key member of our 3-person optimization team, you focus on the mathematical core of our technology. You translate physical device behavior and market requirements into robust models that power our Virtual Power Plant.
* Modeling & Algorithm Development: You develop and refine the modeling, optimization, and control algorithms for a wide range of residential appliances (electric storage water heaters, heat pump water heaters, heat pumps). Your goal is to capture the balance between the customer's value propositions and flexibility remuneration.
* From Theory to Real Machines: You don't just work in a sandbox. You work directly with Ariston appliances and ThermoVault hardware, validating your models against real-world physical behavior to ensure high-fidelity control.
* Market-Informed Constraints: In collaboration with our experts, you translate energy market rules (such as FCR, aFRR, NEBEF, NEBCO, spot markets and spot markets) into specific optimization constraints. You implement these within our Python-based algorithmic framework.
* Performance Monitoring & KPIs: You define and monitor operational KPIs to ensure the models perform as expected during the delivery phase. You investigate performance drops to identify if the root cause is the mathematical logic or the physical device behavior.
* Sprint-Based Delivery: You work within a structured Sprint methodology, moving from simulation studies to production-ready logic. While you focus on the modeling, you are supported by a dedicated IT team that manages the CI/CD pipeline and cloud infrastructure.
You will be collaborating with all involved experts, including ThermoVault's Demand Response and Product Development teams and the Ariston team on commercial projects on a European scale. You will work in a highly-motivated scale-up environment with a strong focus on delivering real-world solutions.
Your profile:
We are looking for an Energy Systems Algorithm Engineer who understands the rules of the energy game and has the technical coding skills to automate playing it.
Your Market Experience will be most essential:
* You have a deep understanding of the European energy markets (Day-Ahead, Intraday, Balancing/Ancillary Services like FCR/aFRR).
* Experience with bidding strategies is a huge plus.
Technical skills:
* You have a Master in Electrical Engineering, Energy Engineering, Mathematical Engineering, or equivalent.
* You are proficient in Python as a tool for modeling and data analysis. While you aren't an IT integrator, you are comfortable working in a production software environment.
* You have a "hands-on" mindset and enjoy the challenge of making code work on physical hardware rather than just theoretical datasets. You are analytical and structured, but also pragmatic. You prefer the straightest, most effective path to a solution that works in the real world.
* You have an Operational Mindset: You are focused on delivery. You get a kick out of seeing a 99% acceptance rate on bids and a perfect activation score.
* You are a true Collaborator: You speak the language of the Algo Engineers (math/control) and the Business Team (revenue/contracts).
* You are fluent in English and able to explain complex modeling concepts to both technical and non-technical stakeholders. French is a big plus.
Last but not least, you identify with ThermoVault's core values: ownership, excellence, and commitment to delivery
What's in it for you?
* Make an impact. Be part of a fast-growing scale-up leading the energy transition.
* Work with cutting-edge technology. Shape the future of smart energy solutions.
* Go International. Join a company backed by Ariston Group (active in 150+ countries) and scale with us.
* Hybrid work. Mix of home office & HQ in Leuven next to the train station (Mon-Wed-Fri in-office).
* Great team & culture. Work with 15 ambitious, high-performing colleagues who get things done - while having fun.
* Competitive package. Full-time permanent contract with strong salary & benefits.
Ready to join a scale-up with real impact? Let's team up!
Join ThermoVault and be part of a young, dynamic team revolutionizing energy. Together, we shape the future of smart energy and make a difference for our planet.