Achieving Energy Efficiency in Building Heating and Cooling by Optimising Solar Energy-Based Control

Abstract

This paper examines the optimisation of control for a building heating and cooling system integrated with solar energy and a heat pump under the climatic conditions of Fergana Region. Solar irradiance G(t), outdoor air temperature T_a (t) and wind speed v_w (t) were included directly in the model as external disturbances. The model combines building thermal dynamics and wind dependence with electricity generation by the photovoltaic (PV) system and temperature-dependent heating and cooling models for the heat pump. The control problem was formulated as a model predictive control (MPC) method using a mathematical model and future weather forecasts; the objective function simultaneously minimised grid electricity use, deviations from the comfort temperature and frequent compressor changes. A representative year was constructed from monthly values obtained from open meteorological data for Fergana. Daily short-wave solar irradiation on a horizontal surface ranges from 2.0 to 8.0 kWh/m²·day, monthly mean air temperature from 0.6 to 28.3 °C, and mean wind speed from 1.48 to 3.17 m/s. For a 150 m² building equipped with a 6 kWp PV system and an 8 kW heat pump, model calculations showed that optimised control reduced the heat pump’s annual electricity consumption from 6,007 to 4,578 kWh, a reduction of 23.8%. By aligning PV generation with the load over time, electricity drawn from the grid fell from 3,764 to 1,435 kWh per year.