The main goal of this study is to increase the renewable energy
ratio of a building located in cold climate by using different
renewable energy conversion technologies. To supply the energy
need of a building, a grid-connected hybrid renewable energy
system has been designed. This energy system may include wind
turbine, PV panels, solar thermal collectors, heat pump, biomass
boiler and heat storage tanks. Fig. 1 demonstrates the arrangement
of the employed energy supply system. A natural gas boiler, air
refrigerators, and grid are utilized as backup systems when the RE
sources are not able to provide the energy demand. It is supposed
that PV panels and wind turbines are the main electricity generators,
where the grid is utilized as a backup source. In other words,
the grid helps in supplying electricity when the produce electricity
by RE resources is less than electricity load.