Implications of sustainability constraints on UK bioenergy development: Assessing optimistic and precautionary approaches with UK MARKAL

► We assess UK bioenergy resources under optimistic and precautionary approaches. ► Using MARKAL, we find that sustainability constraints add to decarbonisation costs. ► Preferred use of bioenergy is similar in optimistic and precautionary cases. ► Best use of bioenergy is heat and power, not transport, if CCS is available. ► The marginal value of additional land availability to the energy system is high.