The EU is planning to create a single European energy market, thereby undercutting dependence on Russia for its supplies.
EU countries import 53% of their energy at a cost of around €400bn, according to EU figures.
Some member states rely heavily on Russia for their gas, particularly the Baltic states, Slovakia and Hungary.
In total, Russia supplies 23% of the EU's gas, making it Europe's biggest supplier.
Russia cut off supplies to Ukraine last June in a dispute over unpaid bills, but eventually restored supply as part of an EU-brokered deal.
Since then, the deteriorating situation in Ukraine and the sanctions against Russia have led to fears that gas supplies could again be stopped.
Europe has been trying for some years to lessen its need for Russian gas.
The European Commission believes its Energy Union plan would enable it to negotiate well on gas supply contracts and be able to bring down prices.
EU climate action and energy commissioner, Miguel Arias Canete, met opposition from environmental groups by saying the plan was "not about using more gas".
"It is about using gas from different suppliers and using it more intelligently."
The proposal needs approval from member states, but some may not back the plan.
