The authors proposed grid flexibility dispatch by controlling distributed energy resources (DER) of prosumers to respond to high penetration of variable renewable energy sources. DER are interconnected via DC link and can be controlled flexibly by an energy management system (EMS), which is installed to a prosumer. The prosumers buy/sell electricity and supply flexibility to markets via an aggregator. An operational simulation was performed to evaluate possibility of flexibility dispatch by DER responding to incentives.