VPP can: reduce the fluctuations of large DGU, to move a
certain production amount to better remunerated periods, to
reduce prediction errors to minimize penalties, to increase the
power predictability [8], to participate in secondary power
markets and to achieve fully controllable energy production
through any renewable primary source. In such way any
renewable generator would offer guaranteed production and
may participate in electric markets on equal terms with nonrenewable
generators [9].