The commission stated that the power capacity mechanisms of Belgium, France, Germany, Greece, Italy and Poland comply with the rules for maintaining single-market competition.
The Belgian and German programs are for strategic reserve, and some of the power generation capacity outside the electricity market can only be activated in an emergency.
In France and Greece, these programs have been particularly responsive to demand. In times of power shortages, customers can get paid to reduce their electricity usage.
Similar initiatives exist in Italy and Poland where capacity providers can also purchase available electricity from users when needed.
Margrethe Vestager, EU Commissioner for Competition, said: "The power capacity mechanism can help to maintain the security of the electricity supply, but the design must avoid distorting competition in the energy market."
"We are pleased to work closely with all countries to promote the outstanding power capacity mechanism designed by six EU countries that will promote competition among all potential capacity providers in the interest of consumers and the European energy market." Vestager Added.