Regardless of the energy mix, the EU needs to use less energy. European Commission analysis shows that Europe will not reduce emissions on the scale needed in the long term without reducing energy consumption and waste. 
This is confirmed by the International Energy Agency (IEA), which estimates that half of the EU's emission cuts must be delivered through energy savings policies by 2035.  Currently, the Commission is envisaging a 17-21% reduction in energy use below 2005 levels by 2030.  This is aiming very low.
In a study for the German Environment Ministry, Fraunhofer ISI, a research group, estimates that by 2030 energy consumption could be reduced by 50% below current levels. 
The impact of such large energy savings on emissions reductions would be dramatic. Fraunhofer ISI estimates that cost-effective energy saving investments could reduce emissions in the EU's transport, industry, tertiary and household sectors by about 52% by 2030.  This is the kind of action the EU needs to seriously address climate change.
A further consideration is that it is cheaper and easier for the EU to meet its renewables target – which is expressed as a percentage of final energy – when final energy consumption is reduced.
The EU cannot afford not to reduce energy use. But even though efficiency measures are cost-effective, they are not automatic, and resolve is needed to make sure Europe gets the policies it needs to bring all the benefits of energy savings. A binding target is the only way to ensure energy savings really happen. The EU made the mistake of not setting a binding target for energy savings for 2020 and the current voluntary target has proved wholly ineffective.
 Decarbonisation is conditional on reducing energy use, according to the European Commission:, ‘energy roadmap 2050’, page 10, http://eur-lex.europa.eu/LexUriServ/LexUriServ.do?uri=CELEX:52011DC0885:EN:NOT
 2012 presentation from International Energy Agency to the Coalition for Energy Savings. Available on request
 European Commission (2011), ‘energy roadmap 2050’, estimate based on graph page 9, http://eur-lex.europa.eu/LexUriServ/LexUriServ.do?uri=CELEX:52011DC0885:EN:NOT
 Fraunhofer ISI (2012), table page 206: ‘Concrete Paths of the European Union to the 2° Scenario’
 Fraunhofer ISI, ibid, table page 209