System design for a solar powered thermal storage – to obtain reduction of demand side power peaks

Abstract

Demand side management is an efficiency tool to manage the consumption of energy. In this thesis a load controller is developedand used to store self-produced renewable energy as hot water in a domestic hot water heater. There are challenges associated with the grid,which is operating near max capacity. Instead of expandingthe grid and make huge investments to handle grid peak periods, the power consumption can be controlled and utilized better. To utilize all of the self-produced energy, an accontroller is installed and monitoredfrom a computer. A sensor for the temperature, a valve controllerand information about self-produced solar powerare installed for the domestic hot water heater andareset up in a programto drive the system. Information about the grid peak period are used to choose when the heating element is turned onto raise the temperature. The valve is dischargingthe tank based on a water consumption profilefor an average house. The minimum temperature is set to avoid bacteria and avoid affecting the end user. The results show that up to 8.9kWh is storedas hot water each daywhich means the grid is reduced with the same amount of energy. The energy isstored duringlow grid load periods and used in the peak periods to obtain reduction of demand sidepower peaks.In this setup,PV system has maximum capacity of 1 kWand it could be installed more PV panels to reduce the grid loadevenmore. The test results showthatit is possible to reducethe load on grid in peaksbetween 27.9 to 54.3%,depending on the self-produced powerfrom the PVsystem. Demand side management has the ability to deliver technical and economic benefits to customers as well as network operators.