Coupling equipment operation parameters with the hourly heat balance model, this study realized the integrated estimation of energy consumption and costs. Meanwhile, two typical greenhouse growth settings were investigated: one at an average temperature of 22.5 °C (25/20 °C and 30/15 °C) and another at 25 °C (35/15 °C and 30/20 °C). Based on the simulation results, in an average temperature of 22.5 °C, the target temperature of 30/15 °C is suggested, whereas in an average temperature of 25 °C, the target temperature of 30/20 °C is suggested. Moreover, two different electricity rate systems, mainly unit-form and time-of-use rates, were used to analyze the running costs of the greenhouse. Due to the energy demand, peaks often happened between 12:00 and 14:00, requiring the manipulation of mechanical environmental control strategies to keep the target temperature; the total electricity cost in time-of-use rates system was a little higher than that in unit-form rate. Results of the dry weights analysis suggest that the DIF30/20 scenario is more practical due to the substantial rise in electricity costs relative to its modest yield improvement for the others. This method achieved an RMSE of less than 2.7 °C for estimating summer greenhouse cooling energy consumption and can provide growers with quantitative temperature setting schemes during hot summers.
Wang et al. (Thu,) studied this question.