To maintain optimal growing conditions, small-scale greenhouses in Quebec require a high heating input, which is ensured by natural gas, propane or oil. To ensure access to low-cost electricity and justify the transition to electric heating, greenhouse farmers must subscribe to the « Additional Electricity Option for Photosynthetic Lighting or Space Heating to Raise Crops » offered by Hydro-Québec. However, this option force farmers to limit their electricity consumption to a strict minimum during peak demand events. The energy transition of the sector is thus hindered by this constraint. Avoiding on-peak energy consumption, electric thermal storage (ETS) devices offer a solution to support the energy transition of the sector, without relying on fossil fuels for auxiliary heating.
The main objective of the research project is to evaluate the potential for small-scale greenhouse decarbonization using ETS devices in Quebec. Building performance software are used to analyse the proposed solution and analyse its performance.
A first analysis was led using pre-existing greenhouse and ETS energy models. The analysis showed that storage losses were converted to useful energy, greatly reducing energy waste. Moreover, the solution allowed for a reduction of up to 77% of the greenhouse’s power demand during peak demand events. The analysis also highlighted some of the challenges tied to ETS implementation in greenhouses. Among those are the accurate representation of heat transfers within the greenhouse, along with the complexity of dimensioning and controlling the storage solution.
To improve the accuracy of the greenhouse’s estimated internal gains, crop heat exchange profiles were proposed. The profiles were produced using dynamic models and cover a wide range of conditions. The resulting values, allowing the representation of the dynamic nature of the plant’s heat exchanges, offer crop load estimates nearly twice as precise as the average annual load, a value usually used when dynamic models are unavailable.
Finally, an adaptive modelling framework for forced-air ETS devices was proposed. This framework allows the characterisation of model parameters using standardised experimental data. This framework and the resulting characterised model, with brick core temperature RMSE values ranging from 0,9 to 40,7°C, are more adapted to greenhouse application and allow for further testing of dimensioning and control strategies.
Laroche, M. (Author),
D'Avignon (Supervisor) &
Monfet (Co-supervisor),
11 Apr 2026Student thesis: Master's thesis › Master in Engineering: Engineering