Is economic optimism hampering long term energy efficiency goals? The role of energy system models

摘要

Energy system models as TIMES or PRIMES support policymakers in energy and climate change mitigation policies, as theEU-wide energy efficiency (EE) goal of 30 % by 2030. Model outputsare determined by assumptions, some of which are tested.However, the economic development assumptions considered inthe models are less experimented with. Economic growth is presentin all long-term energy scenarios as it might not be politicallyacceptable to consider otherwise. Thus, energy system modelsshow an energy future with growing energy services demand.We explore to what extent such economic optimism affectsthe definition of long term energy efficiency goals. We usethe linear optimization bottom-up TIMES_PT energy systemmodel implemented for Portugal. We model in TIMES_PThow six different macro-economic trajectories lead to differentenergy efficiency goal formulation. The Base scenario has aGDP growth of 1.5 % pa over the period 2020–2050, whereasthe High scenario considers a GDP growth of 3.0 % pa. We thendeviate from economic optimism with two scenarios with constantor decreasing energy services demand till 2050. The Sufficiencyscenario has a constant energy services demand from2014 till 2050. The Revolution scenario considers a decreasein energy services demand of 7 % every 5 years from 2014 till2015. Additionally, we then model Base_Transport and Base_Industry, where we lower demand for mobility and for productsfrom energy intensive industries.With the traditional economic optimistic vision, the finalend-use energy consumption in 2050 is 15 % lower (Base) or31 % lower (High) compared to 2010. In the Sufficiency andRevolution scenarios the Final Energy Consumption (FEC)in 2050 is 42–65 % lower. We find a substantial difference forenergy efficiency target setting depending on the consideredeconomic scenario. Energy system models inherently considerall possible energy efficiency improvement due to deploymentof more efficient technologies. We argue that this is not enoughwhen looking into long-term energy futures requiring an openmind frame. One way to do so is, together with policy makers,explore futures where the demand for energy services is notnecessarily growing. By doing so the importance of policies focusedon the drivers affecting energy services demand can bemade visible.