EU energy strategy for the next decade envisages a shared gas and electricity supply network, and the renovation of draughty buildings to cut bills.
Unveiling "Energy 2020", Energy Commissioner Guenther Oettinger called for investment of 1tn euros (£0.9tn, $1.3tn) to "Europeanise energy policy".
Money would come from taxpayers and energy companies themselves.
The EU hopes a shared network will protect individual member states from disputes with suppliers such as Russia.
In January 2009, several EU states saw imports of Russian gas via Ukraine cut for up to three weeks.
"By 2015, no member state should be isolated," said a European Commission statement.
BBC News
