Sofia Simoes

Top-down and bottom-up modelling to support low-carbon scenarios: climate policy implications

Bottom-up and top-down models are used to support climate policies, to identify the options required to meet GHG abatement targets and to evaluate their economic impact. Some studies have shown that the GHG mitigation options provided by economic top-down and technological bottom-up models tend to vary. One reason for this is that these models tend to use different baseline scenarios. The bottom-up TIMES_PT and the top-down computable general equilibrium GEM-E3_PT models are examined using a common baseline scenario to calibrate them, and the extend of their different mitigation options and its relevant to domestic policy making are assessed. Three low-carbon scenarios for Portugal until 2050 are generated, each with different GHG reduction targets. Both models suggest close mitigation options and locate the largest mitigation potential to energy supply. However, the models suggest different mitigation options for the end-use sectors: GEM-E3_PT focuses more on energy efficiency, while TIMES_PT relies on decrease carbon intensity due to a shift to electricity. Although a common baseline scenario cannot be ignored, the models’ inherent characteristics are the main factor for the different outcomes, thereby highlighting different mitigation options. Policy relevance The relevance of modelling tools used to support the design of domestic climate policies is assessed by evaluating the mitigation options suggested by a bottom-up and a top-down model. The different outcomes of each model are significant for climate policy design since each suggest different mitigation options like end-use energy efficiency and the promotion of low-carbon technologies. Policy makers should carefully select the modelling tool used to support their policies. The specific modelling structures of each model make them more appropriate to address certain policy questions than others. Using both modelling approaches for policy support can therefore bring added value and result in more robust climate policy design. Although the results are specific for Portugal, the insights provided by the analysis of both models can be extended to, and used in the climate policy decisions of, other countries.

Renewable energy sources availability under climate change scenarios — Impacts on the Portuguese energy system

This paper presents an assessment of the impacts on the Portuguese energy system due to climate change induced water availability variations. Two different scenarios were evaluated on the 2050 time horizon: strong and weak decrease of water availability compared to a reference scenario. The impact of water availability decrease, in particular for the power sector, was assessed using a bottom-up technology based linear optimization model: TIMES (The Integrated Markal-EFOM System) calibrated and validated for Portugal. Results indicate that currently planned hydropower capacity is highly overestimated. Results also suggest that under strong decrease of water availability, marginal CO2 abatement costs in 2050 are doubled for moderate reductions targets but, as restrictions are tightened, different scenarios of water availability have little impact on the marginal CO2 abatement costs.

Energy Policies Influenced by Energy Systems Modelling—Case Studies in UK, Ireland, Portugal and G8

A key objective of IEA-ETSAP is to assist decision makers in robustly developing, implementing and assessing the impact of energy and climate mitigation policies. This chapter focuses on four case studies, in which there is clear evidence of a direct link between the use of MARKAL and TIMES scenario modelling activities and the resulting policy decisions. The case studies selected assess how the (i) UK MARKAL model informed the development of energy and climate mitigation policy in the UK, focusing on the Energy White Paper in 2003, the Energy White Paper in 2007 and the Climate Change Act in 2008; (ii) Irish TIMES model informed the development of climate mitigation legislation in Ireland in 2014 and Ireland’s negotiating position regarding the EU 2030 Climate Energy Package in 2014; (iii) TIMES_PT model informed climate policy in Portugal in the last 10 years and has supported the design of climate mitigation policies; (iv) IEA ETP Model informed the G8 in responding to the 2005 Gleneagles Plan of Action and has supported the work of the Major Economies Forum and Clean Energy Ministerial. This chapter collates methodologies and results from these different case studies and summarizes some key findings regarding (i) policy frameworks and goals; (ii) how policy makers have been intertwined with the modelling tool during the modelling process; (iii) the role of the economic stakeholders dialogue; (iv) main insights from the modelling exercises; (v) lessons learnt: from effective contributions to real limitations and (vi) recommendations.

Long term energy scenarios under uncertainty

Traditionally a set of equally feasible scenarios is built to represent possible future energy outcomes. However, current approaches do not handle properly different scenarios appointing to divergent situations. This paper illustrates the fragilities of the state-of-the-art deterministic long term energy scenarios approach through the study of uncertain scenarios for fossil fuel prices and energy demand, using TIMES model for Portugal. Results show quite divergent power sector profiles and divergent investments options, when oil prices or demand for useful energy changes. Regarding the relevance of energy decision making under uncertainty, the paper proposes a methodology to deal with long term energy scenarios under uncertain parameters evolution. The methodology assumes a stochastic approach and connects a top-down and bottom-up model. The linkage is made through a calibration process based on iterative simulations, combining top-down properties with a bottom-up outcome.

Solar buildings in Austria: Methodology to assess the potential for optimal PV deployment

A high rate of integration of distributed photovoltaic systems (PV) may cause problems in the distribution grid. We propose a methodology to spatially and temporally analyze the potential reverse load in the distribution grid of Austria. The goal lies in determining the maximum generation of PV with no investments into grid enforcements. First, we use measured load profiles for households and simulate stochastic load profiles for commercial consumers. We combine the generated load profiles with data on PV output to determine the net demand load profiles at 1 km2 grid. Thirdly, we study the effects of a large scale implementation of rooftop PV on the energy system using the JRC EU TIMES model. We find that (excluding night hours) on average in 9% of the hours supply exceeds demand, differing between 0% and 60% depending on the grid cell. When only including household load profiles, surplus production increases to 23%. This suggests to giving priority to decentralized PV development in areas with a higher share of commercial consumers. Lastly, we show that a large scale deployment of distributed PV leads to reduced imported electricity.

The impact of location on competitiveness of wind and PV electricity generation - Case study for Austria

The generation potential of renewable energy sources and their time profile of production depends on geographic characteristics. Furthermore, the integration of renewable energy technologies into the energy system is constrained by existing distribution infrastructure. The paper does a preliminary assessment on how the availability of spatially and temporally highly resolved data on resource potentials may affect the projections on the development of wind and photovoltaic electricity generation in Austria, using the technology bottom-up JRC EU TIMES optimization model. In particular, we assess the differences in costs and CO2 emissions between a spatially disaggregated and an aggregated approach. Results show that disaggregating RES locations significantly affects results especially for wind leading to higher electricity generation from wind and reduced electricity trade with other countries.

The PrioritEE Approach to Reinforce the Capacities of Local Administrations in the Energy Management of Public Buildings

In the Mediterranean area most of the public authorities need to enhance their institutional capacity in the field of Energy Efficiency (EE) and use of Renewable Energy Sources (RES) in order to contribute to the Energy Performance of Buildings and the Energy Efficiency Directives, developing solutions suited to various regional contexts. The PrioritEE project, funded by the Interreg MED programme, aims at reinforcing the capacities of public administrations in selecting and implementing eco-friendly and cost-effective energy planning measures. This paper aims to describe the main efforts carried out by local public authorities and professional institutions from five MED countries (Italy, Portugal, Spain, Greece and Croatia) in order to reduce energy consumption and prioritize EE investments in Municipal Public Buildings (MPBs). In particular, it focuses on the methodological framework describing the main components of the proposed toolbox, the main objectives and expected outcomes but also the current achievements and the way forward.

Portugal as an electricity exporter country: environmental and economic implications

This paper aims to explore the impacts of transforming Portugal into an electricity exporter country up to 2030 and 2050. The technological bottom-up model TIMES_PT is used to generate a range of electricity export scenarios. Results show that the increase of electricity exports contributes to a decrease of renewable electricity (RES-E). As mature renewable technologies achieve their maximum technical potential, natural gas is largely deployed to allow for increased exports. In the more ambitious export scenarios this can lead to non-compliance with the current national RES-E target in 2030 and also has consequences in terms of increased greenhouse gas emissions. Turning Portugal into a net electricity exporter also affects the average electricity price. Although higher exports result in higher generation costs, in 2050 export levels close to the projected increase of the interconnection capacity can lead to lower electricity prices.

Trade-Offs Between Climate Change Adaptation and Mitigation Options for Resilient Cities: Thermal Comfort in Households

Sustainable development within the broader context of climate change is a fairly recent research topic that underpins positive trade-offs between mitigation, adaptation and societal objectives. Many decisions regarding energy and transportation infrastructures, buildings, sanitary and storm-water management, flood risk assessment and also biodiversity protection take place at the city level. In this context, climate change issues have been recognized as fundamental for urban planning, requiring an integrated response with combined mitigation and adaptation strategies.

Assessing critical metal needs for a low carbon energy system in 2050

This paper estimates the amounts of critical metals required for the deployment of the 2050 Low Carbon Roadmap for Portugal and assesses how including concerns with their availability within the TIMES_PT energy system model affects the profile of low-carbon electricity technologies for 2050. We conclude that long-term availability of dysprosium, neodymium, tellurium and indium might be a cause of concern for deploying wind and PV plants in the long-term. We estimate that if limited supply of critical metals is considered in the model there will be less 4.65 GW of PV, less 2.89 GW of wind and more 4.54 GW of wave power.