An improved approach to minimise energy cost in a small wind-photovoltaic hybrid system

Today recent developments in renewable technology such as wind and photovoltaic systems encourage people to generate electricity with low investment costs. In this manner, this may result in partial reduction in power demand hence import of primary sources may gradually decline as well as foreign dependence on energy. Furthermore this lets decrease power losses in transmission lines by reducing power generation capacity in power stations. The widely use of wind turbines and photovoltaic systems in residential and official buildings depends on being economic investment and operation costs. The unit investment cost shows no big difference in all the renewable systems but, to make operation cost lower the balance between production and consumption at any time interval must be maintained without shedding loads. For instance, in case of an hour time interval this balance should be maintained for 24 times in a day however this may not always be possible since sources of renewable energy are irregular. At some time intervals, a power boost is needed either by adding a power source to renewable system or by shedding loads according to their priorities but this is not desired case. In this study, the problem with 7 constraints was solved by a combinatorial optimization based the real-coded genetic algorithms to reduce operation cost to acceptable level and balance between generation and consumption at all the time intervals. The results are encouraging and meaningful for similar applications.