Conference Year
July 2018
Keywords
demand side management, thermal storage, air-source heat pump, control strategy
Abstract
Motivation: The use of vapor-compression heat pumps for space heating and domestic hot water preparation can help to improve the flexibility of the electric power generation from solar source and to reduce its impact on the grid, by increasing self-consumption from PV systems and the autonomy of the household. However, achieving this goal requires to improve demand management strategies. To this regard, it is necessary to control the load by planning it, when it is possible (e.g. appliances programming) or by shifting it to different intervals of time (using storage systems). Electric storage with batteries and thermal storage with water tanks are the most widespread storage techniques in the residential sector. The high cost of batteries is still an obstacle to their large-scale deployment, whereas water storage tanks are typically more convenient. As assessed by many authors, a large volume of water storage does not improve the efficiency of the system and, if not properly controlled, it can lead to a poorer overall performance. However, simple control strategies based on the actual PV generation, the outdoor temperature, the hour of the day and the building characteristics can help in shifting the demand, by taking advantage of the global storage capacity of the system. What was done: In this study, the operation of a single family house, equipped with a radiant floor and an air-source inverter-driven heat pump for space heating and domestic hot water preparation, was simulated with the TRNSYS simulation suite. Rule based algorithms were applied to the system. The targets are to reduce the peak power taken from the grid, to minimize the occupants’ discomfort and to increase the self-consumption of solar energy. Expected benefits of what was done: To evaluate the different level of benefits obtained depending on the applied strategies and on the system configuration. To this purpose, the objective key figures are evaluated and presented for all the analyzed cases.