The European Commission on Wednesday proposed a system for EU countries to jointly buy strategic reserves of natural gas, a move drawn up in response to soaring energy prices and gas supply concerns. read more The proposal must be negotiated and approved by EU countries and the European Parliament, so is unlikely to take effect in time to combat the soaring gas prices Europe is facing this winter. But record-high prices, combined with concerns over the security of Europe"s gas supply - amid lower than expected exports from Russia and political tensions over the build-up of Russian troops on its border with Ukraine - have left some EU governments seeking ways to shore up stocks in future. EU countries including Spain, Greece and Romania have said joint gas buying could also help secure better conditions in global markets. WHO WOULD BUY THE GAS? Under the Commission"s proposal, countries" transmission system operators (TSO) could jointly buy strategic stocks of gas. Joint buying would be open to all TSOs in the EU that want to take part. Participating countries must notify the Commission of the plan and provide details on the volume of gas to be bought, the duration of the scheme, its operating procedures, how the supply would be activated in an emergency, and the expected costs and benefits. EU countries are responsible for running their own energy systems, and the proposal leaves it up to member states to design how joint buying schemes would work. The EU could offer an opinion on the scheme, and said deals on joint buying must comply with the bloc"s competition rules. WHAT ARE STRATEGIC GAS STOCKS? Put simply, strategic gas stocks are those that can be used in an emergency. Countries" systems of jointly purchasing gas would need to be designed so that they can be used as part of EU-coordinated actions in response to a regional or bloc-wide emergency, the proposal said. The EU defines an emergency as when there is exceptionally high gas demand and a significant disruption of supply, and a market-based response has failed to secure enough fuel. In that instance, EU countries can declare an emergency and the EU can step in to coordinate a joint response. WHY IS GAS STORAGE IMPORTANT? The EU has the capacity to store over 117 billion cubic meters of natural gas, or roughly a fifth of its annual consumption, according to Gas Infrastructure Europe. EU gas storage is lower than usual for this time of year. EU gas storage was roughly 68% full at the end of November, meaning the bloc would need to import 5%-10% more in a cold winter, according to a Commission document shared with EU countries ahead of a Dec. 16 summit, seen by Reuters. Gas storage sites are typically salt caverns or depleted gas fields. Storage is needed to balance fluctuations in daily and seasonal demand. It can secure the supply of gas in times of disruptions, major outages at infrastructure, or particularly high demand in cold spells. Storage capacity in the EU is unevenly distributed with large facilities in France, Germany, Italy and the Netherlands, but interconnection by pipelines means member states can use stored gas in neighbouring countries. Reporting by Kate Abnett Editing by Mark Potter Our Standards: The Thomson Reuters Trust Principles.