* European Commission to review energy efficiency before Aug
* EU member states expected to decide on 2030 goals in Oct
* Efficiency campaigners say target is too weak
BRUSSELS, May 20 (Reuters) - EU policymakers are considering a goal to increase European Union energy efficiency by between 30 and 35 percent by 2030, as part of efforts to cut greenhouse gas emissions, reduce fuel bills and improve energy security, EU sources said.
The crisis in Ukraine, transit nation for around half of the natural gas that Russia ships to Europe, has raised the importance of using less energy as one of the EU's options to curb the bloc's need for imported fuel.
Two EU sources, speaking on condition of anonymity, said documents circulating within the Commission put forward a target range for efficiency savings of between 30 and 35 percent that would be binding across the European Union.
That compares with a goal of saving 20 percent that would be achieved by 2020 through pursuing existing policies, based on measures such as making buildings more energy efficient.
But some campaigners say the suggested 2030 range is too weak.
A report published on Tuesday from Ecofys, consultants frequently used by the Commission, said buildings in the EU used 61 percent of all the gas that is imported into the bloc and renovation could curb the sector's gas use by 95 percent by 2050, as well as cutting emissions.
Knauf Insulation, part of the European Alliance to Save Energy, said it was worried the Commission's concern with protecting its Emissions Trading Scheme (ETS) had added to reluctance for a more ambitious goal.
Reduced energy use could add to a surplus of permits to pollute that has depressed the EU's flagship tool for curbing climate emissions.
"Given the severity of the situation we are faced with in Ukraine, it would be absolutely wrong to address the problems of the ETS by placing an artificial ceiling on energy efficiency," Barry Lynham, head of strategy at Knauf Insulation, said.
The European Commission, the EU executive, has already outlined two climate and energy goals for 2030 - to cut greenhouse gases by 40 percent compared with 1990 levels and to raise the share of renewable energy to 27 percent from 20 percent projected in 2020.
When it mapped out those goals in January, the Commission said it was not ready to announce an efficiency target because it was assessing the impact of a law agreed in 2012 to improve the bloc's energy savings, which so far have lagged behind the 2020 target.
The Commission is working on a progress report on efficiency to be published before August and a report on energy security.
EU leaders will have to consider both and are working towards an October deadline to reach political agreement on a new set of energy and climate goals.
However, the goals are divisive. Coal-dependent nations such as Poland for instance have said there is no point in the EU, responsible for only around 10 percent of all emissions, leading the way when the United Nations is not expected to agree a global climate change pact until next year. (Editing by David Holmes)