Copyright　©　2018　Inderscience　Enterprises　Ltd.　In　wireless　sensor　networks　(WSNs),　sensor　nodes　with　energy　harvesting　components　have　motivation　to　expend　additional　energy　in　conditions　of　excess,　since　the　surplus　energy　would　be　wasted　due　to　energy　buffer　overflow.　In　this　paper,　we　focus　on　using　such　surplus　energy　to　adjust　the　redundancy　level　of　erasure　codes,　so　that　the　data　delivery　reliability　can　be　improved　while　the　network　lifetime　is　still　well　conserved.　For　a　single　flow,　we　formulate　the　problem　as　the　maximisation　of　end-to-end　packet　delivery　probability　under　energy　constraints.　Considering　the　energy　profile　as　a　stochastic　process,　we　propose　a　Lyapunov　optimisation　based　algorithm　called　the　erasure　coding　scheduling　algorithm　(ECSA)　to　solve　the　problem.　Through　a　combination　of　both　theoretical　analysis　and　simulation,　we　show　the　effectiveness　of　ESCA　in　yielding　a　near-optimal　data　delivery　reliability.