Depending on the particular market environment, VPPs can accomplish a whole range of tasks. In general, the objective is to network distributed energy resources such as wind farms, solar parks, and Combined Heat and Power (CHP) units, to monitor, forecast, optimize and trade their power. This way, fluctuations in the generation of renewables can be balanced by ramping up and down power generation and power consumption of controllable units. But the VPP not only helps stabilize the power grids. It also creates the preconditions for integrating renewable energies into the markets. Individual small plants can in general not provide balancing services or offer their flexibility on the power exchanges. This is because their generation profile varies too strongly or they simply do not meet the minimum bid size of the markets. By aggregating the power of several units, a VPP can deliver the same service and redundancy and subsequently trade on the same markets as large central power plants or industrial consumers.