With　the　increasing　penetration　of　renewable　energy,　short-term　energy　storage　technology　represented　by　electrochemical　energy　storage　will　make　it　difficult　to　meet　the　demand　for　new　power　systems　to　consume　renewable　energy,　and　at　the　same　time,　flexibility　will　become　the　core　and　key　to　the　operational　characteristics　of　the　system.　Therefore,　this　paper　proposes　a　joint　long-term　and　short-term　energy　storage　planning　method　considering　the　flexibility　of　supply-demand　balance.　First,　for　the　characteristics　of　energy　storage　technologies　in　different　time　scales,　this　paper　integrates　the　dual　regulation　of　short-term　power　and　long-term　energy,　considers　the　flexibility　of　supply-demand　balance　combines　the　price-based　demand　response　mechanism,　and　establishes　a　joint　planning　model　of　long-term　and　short-term　energy　storage　with　the　lowest　annualized　comprehensive　cost　of　the　system　as　the　optimization　goal.　Second,　to　simplify　the　problem　size,　typical　scenarios　are　extracted　each　month　to　re-sculpt　the　whole　year＇s　time　sequence　using　a　deep　convolutional　embedding　clustering　algorithm,　and　the　model　is　optimally　solved　through　two　stages　of　capacity　planning　of　wind,　photovoltaic,　and　energy　storage　and　flexibility　calibration.　Finally,　the　effectiveness　of　the　planning　method　proposed　in　this　paper　in　considering　the　economics　and　operational　flexibility　of　a　new　power　system　with　high　penetration　of　renewable　energy　in　the　future　is　verified　by　using　a　region　in　eastern　China　as　an　example.　©　2024　Power　System　Technology　Press.　All　rights　reserved.