Harnessing demand flexibility to match renewable production using localized policies

Intermittency of most renewable sources and lack of sufficient storage in the current power grid means that reliable integration of significantly more renewables will be a challenging task. Demand, on the other side, has been largely regarded as non-controllable in the current setting. However, there is strong evidence that a considerable portion of the current and future demand, such as plug-in electric vehicle (PEV) load, is flexible. That is, the instantaneous power delivered to it needs not to be bound to a specific trajectory. In this work we focus on harnessing demand flexibility as a key to enabling more renewable integration and particularly on localized policies, i.e. the ones that only use the load preferences and do not depend on the grid information. We start with a data driven analysis of the potential of PEV load. We then demonstrate that conventional charging policies suffer from high peak-to-average ratios of the aggregate demand and lack of correlation with wind generation. Finally we introduce a localized policy called the Average Rate (AR) policy and show that it reduces the undesired effects of PEV load and increases its correlation with wind generation in average sense. Our work demonstrates the potential of flexible loads in harnessing renewables by affecting the load patterns and mitigating the intermittency of renewables with merely local information. Moreover, our proposed charging policy can be implemented easily in the current PEVs.