This study identifies the least-cost heating strategy in the future energy system, by investigating to which extent heat should be saved rather than supplied. Lithuanian case is analysed due to the current energy-inefficient building stock and thereby too much money wasted on heating as well as dependency on imported natural gas, which threatens insecurity of supply.
First, the Lithuania’s energy system for 2030 is constructed applying future prospects, where the key focus in the heating sector is given to the transition from natural gas to local biomass resources. Second, heat saving measures in the building stock, both multi-apartment buildings and individual houses separately, are looked into. The essential point in this study is that the cost of investment strongly depends on whether it is heat conservation in existing buildings or an additional investment in new buildings. For the existing buildings, it is also important whether an investment is made solely for the heat conservation purpose or as a part of renovation, which will be carried out anyways.
By comparing marginal heat production cost with marginal heat saving cost, it is concluded that a suitable least-cost heating solution is a reduction in heat demand for space heating down to 44-51% of current level for multi apartment buildings, whereas for individual houses much more effort is identified to be crucial to reduce heat demand from current level. Also, investments should be primarily made for new buildings and buildings being renovated anyways.
Afterwards, the main existing barriers towards successful buildings renovation are looked into, with a case of multi-apartment buildings. An analysis of private expenditure reveals that renovation might impose a significant financial burden for dwelling owners, if there is no financial support. In order to investigate other potential obstacles, a brief stakeholders’ analysis is made and interviews with the main recognised actors are conducted. It is concluded that a crucial factor in the process is a motivation of dwelling owners, since they have the highest influence. Apart from other identified barriers, mostly legal and organisational, lack of craftsmen turned out to be one of the most significant issues as far as renovation of the building stock in Lithuania is concerned. Finally, recommendations to the identified issues are given.