Volatile wind generation and demand resources are entering the electric power sector and projected to penetrate in significant quantities in the next decades. It becomes critical to better understand their economic and dispatch interactions with each other and with the grid for economic efficiency and operational reliability. The four chapters tackle this challenge. Each chapter builds upon the previous chapters, other scholarly works and industry reports to deliver a central message: wind power, electric vehicles (EVs) and aggregator-facilitated demand response are system-level resources with complex interactions with each other and with the power system. Under various conditions, they synergistically aid the grid; under other conditions, they are competitive substitutes for each other. The characterization and integration of these resources require detailed and comprehensive studies that do not yield to simple "rule of thumb" conjectures. With the first chapter as introduction, the second chapter investigates the system's response to exogenously unregulated and regulated charging of plug-in electric vehicles (PEVs) using optimal power flows, generator dispatches and resultant emissions. Results show regulated charging is preferred over unregulated charging economically, from a system reliability perspective and from an emissions standpoint. The second chapter focuses on PEV charging as an aggregated system-level demand resource in the New York Independent System Operator's (NYISO) two-settlement energy market. The study finds EV charging mostly overnight and sometimes during double load peaks to lower the combination of steady-state and ramping system costs. The third study answers questions regarding the interactions between wind generation and PEV charging not as directly-paired supply and demand resources, but rather as system-level resources while ensuring lowest wholesale energy costs and realistic dispatch patterns. In particular, the chapter finds: (1) the existence of time-series correlation between PEV charging and wind dispatch, and (2) PEVs are adversely coupled to curtailable wind, and decoupled with must-take wind. Lastly, the fourth chapter offers a framework: (1) to understand the probabilistic nature of demand response (DR), (2) to describe the role of utility-scale storage in DR, (3) to improve DR compliance rates using load aggregation and storage dispatch, and (4) to calculate an aggregator's payoff in DR and energy arbitrage.