Ex-post decomposition analysis of passenger car energy demand and associated CO2 emissions

This paper investigates, quantifies and ranks the factors influencing passenger cars energy demand and emissions. A vehicle stock-model approach is used for an ex-post decomposition analysis, based on administrative data, examining the impact seven underlying factors driving energy demand. The impact of methodological choice and model disaggregation are also explored. In light of the 2015 vehicle emissions scandal, the paper quantifies the difference between manufacturer-test vehicle performance and real world or â on-roadâ performance for a national stock model and determines the relative impact on passenger cars energy consumption. When examining the technical performance improvement, the choice of metric can lead to a distortion of 2.2 percentage points (14% overestimate) in the quantification of the efficiency improvement of the vehicle stock. The analysis pays particular attention to the influence of fuel or technology switching â which is often quoted as a factor influencing energy use and emissions but rarely quantified. Even when using litres per hundred-kilometre gasoline equivalent to measure the performance improvement, changes in the makeup of the stock can lead to distortion in the efficiency measure. The results of a full decomposition analysis highlight that technical performance improvements (energy efficiency improvements for the purpose of this paper), will not provide significant energy and emission savings when the impact on-road consumption is included. The paper concludes that technology switching in conjunction with policies targeting ownership and usage are the most effective measures to control passenger car energy consumption and associated CO2 emissions

Private car transport and the 10% RES-T target - quantifying the contribution of EVs and biofuels

In 2008, renewable energy accounted for less than 1% of final energy consumption in the Irish transport sector. In order to increase this share to 10% by 2020 as required under EU directive 2009/28/EC, the Irish government has introduced two specific measures: 10% of the transport fleet is to be powered by electricity by 2020, and an obligation on road transport fuel suppliers that biofuels account for a certain portion of their fuel sales. This study forecasts the impact of these existing measures towards meeting the 10% RES-T target by 2020, focussing on private car transport. The methodology presented is derived from a forecast of private car fuel demand based on a technological stock model of Ireland’s fleet. This paper demonstrates the use of this as a tool firstly as an energy forecasting technique and secondly as a method for evaluating the effects of policy measures on the technological composition and consequent renewable energy demand and related CO2emissions of private cars. Technological scenarios examined in this light are electric vehicles, compressed natural gas vehicles and biofuel blendin

Quantifying transport energy efficiency savings

The importance of quantifying energy savings and improvement in energy efficiency for each sector of the economy is now widely recognized in order to demonstrate progress towards targets and compliance with legal obligations. The focus of this paper is specifically on evaluating energy efficiency in transport using the ODEX methodology. More detailed data has recently become available on transport energy trends and the underlying factors that allow the authors improve the calculation of Ireland’s transport ODEX. Through data mining of administrative databases mileage, volume, age, engine type and size data are available at a disaggregated level for each mode of road transport. In particular this paper examines private car energy efficiency, quantifying the change arising from improved data. There was an overall slight improvement (0.71 percentage points) in the Irish private car ODEX when both proposed changes of using MJ/km as the unit consumption measure and modeling the stock by vintage were applied. The overall effect of the revised transport ODEX calculation does not show a significant increase in energy savings associated with the value of the ODEX indicator (0.82%). However the purpose was to improve the methodology of how the ODEX was being calculated, not necessarily increasing the savings

Electric vehicle: infrastructure regulatory requirements

In 2009 the European Union (EU) Directive on Renewable Energy placed an obligation on each Member State to ensure that 10% of transport energy (excluding aviation and marine transport) come from renewable sources by 2020. The Irish Government intends to achieve part of this target by making sure that 10% of all vehicles in its transport fleet are powered by electricity by 2020. Stakeholder groups include but are not limited to policy makers, the public, regulatory bodies, participants in the electricity retail market, the transmission and distribution system grid operators, the automotive industry, private enterprise, civil engineers, electrical engineers, electricians, architects, builders, building owners, building developers, building managers, fleet managers and EV owners. Currently it appears both internationally and Nationally the automotive industry is focused on EV manufacture, governments and policy makers have highlighted the potential environmental and job creation opportunities while the electricity sector is preparing for an additional electrical load on the grid system. The focus of this paper is to produce an international EV roadmap. A review of current international best practice and guidelines under consideration or recommended is presented. An update on any EV infrastructure charging equipment standards is also provided. Finally the regulatory modifications to existing National legislation as well as additional infrastructure items which may need control via new regulations are identified

Investigating 100% renewable energy supply at regional level using scenario analysis

Energy modelling work in Ireland to date has mainly taken place at a national level. A regional modelling approach is necessary however, for Ireland to reach the ambitious targets for renewable energy and emissions reduction. This paper explores the usefulness of the energy modelling tool EnergyPLAN in investigating the energy system of the South West Region of Ireland. This paper estimates a 10.5% current renewable energy share of energy use, with 40% renewable electricity. We build and assess a reference scenario and three renewable energy scenarios from a technological and resources perspective. The results show that sufficient resources are available for the South West Region energy system to become 100% renewable and quantifies the land-use implications. Moreover, EnergyPLAN can be a useful tool in exploring different technical solutions. However, thorough investigations of as many alternatives as possible, is necessary before major investments are made in a future energy system

Adding value to EU energy policy analysis using a multi-model approach with an EU-28 electricity dispatch model

The European Council has agreed ambitious EU climate and energy targets for 2030, including a 40% reduction in greenhouse gas emissions compared to 1990 levels and a minimum share of 27% renewable energy consumption. This paper investigates the challenges faced by the European power systems as the EU transitions towards a low carbon energy system with increased amounts of variable renewable electricity generation. The research here adds value to, and complements the power systems results of the PRIMES energy systems model that is used to inform EU energy and climate policy. The methodology uses a soft-linking approach that scrutinizes the power system in high temporal and technical detail for a target year. This enables generation of additional results that provide new insights not possible using a single model approach. These results point to: 1) overestimation of variable renewable generation by 2.4% 2) curtailment in excess of 11% in isolated member states 3) EU interconnector congestion average of 24% 4) reduced wholesale electricity pricing and few run hours raising concerns for the financial remuneration of conventional generation 5) maintenance of sufficient levels of system inertia in member states becomes challenging with significant penetrations of variable renewable generation

From technology pathways to policy roadmaps to enabling measures – A multi-model approach

Integrating a range of complementary energy models is becoming an increasingly common method for informing low carbon energy pathways at both national and global levels. Multi-modelling approaches facilitate improved understanding of the detailed technology pathways required to meet decarbonisation targets; however, to-date there has been limited attention on the policy roadmaps and enabling measures that might achieve these decarbonisation targets. This paper addresses this gap by developing a multi-model approach using an energy systems optimisation model, a sectoral simulation model together with scrutiny of individual policy measures to explore decarbonisation of the private car sector in the Irish transport system commensurate with an 80% reduction in national carbon emissions by 2050. The results comprise a cost optimal technology pathway for private cars in a future energy system constrained by a maximum level of carbon emissions, a policy roadmap identifying annual changes in energy efficiency, renewable energy and electrification, and a suite of enabling measures including changes to vehicle registration tax, a biofuel obligation on suppliers and a suite of measures to increase the share of electric vehicles in the fleet. The level of confidence in the different enabling measures to achieve the policy goals is compared and discussed

Building and calibrating a country-level detailed global electricity model based on public data

Deep decarbonization of the global electricity sector is required to meet ambitious climate change targets. This underlines the need for improved models to facilitate an understanding of the global challenges ahead, particularly on the concept of large-scale interconnection of power systems. Developments in recent years regarding availability of open data as well as improvements in hardware and software has stimulated the use of more advanced and detailed electricity system models. In this paper we explain the process of developing a first-of-its-kind reference global electricity system model with over 30,000 individual power plants representing 164 countries spread out over 265 nodes. We describe the steps in the model development, assess the limitations and existing data gaps and we furthermore showcase the robustness of the model by benchmarking calibrated hourly simulation results with historical emission and generation data on a country level. The model can be used to evaluate the operation of today's power systems or can be applied for scenario studies assessing a range of global decarbonization pathways. Comprehensive global power system datasets are provided as part of the model input data, with all data being openly available under the FAIR Guiding Principles for scientific data management and stewardship allowing users to modify or recreate the model in other simulation environments. The software used for this study (PLEXOS) is freely available for academic use

Reconciling high renewable electricity ambitions with market economics and system operation: Lessons from Ireland's power system

The integration of variable generation challenges electricity systems globally. Using Ireland's electricity sector as a case study, we highlight multiple challenges in reconciling ambition for variable renewable integration with market economics and system operation. Ireland has the highest share of non-synchronous variable renewable electricity on a single synchronous power system. This case study examines the strategy being implemented to optimally balance between efficiency, flexibility and adequacy while maintaining a fully functional system that strives to adapt to evolving conditions. The transition that the Single Electricity Market underwent to comply with the EU Target Market was a major overhaul of what made the all-island market a success. Volume-based reliability options have distinct advantages over capacity payments. System services are critical for system stability and 14 separate system services are being developed. These actions, when taken together, provide an insight into the lengths to which this electricity market must go to transform from its cost-based nature to a value-based alternative that rewards flexible and reliable capacity with the ability to evolve with market conditions of the future

Quantifying the "merit-order" effect in European electricity markets

The increase in renewable energy sources has contributed to containing and even lowering electricity wholesale prices in many markets (although not necessarily retail prices) by causing a shift in the merit order curve and substituting part of the generation of conventional thermal plants, which have higher marginal production costs. This merit order effect along with priority dispatch can affect revenues of conventional power plants, especially in Member States experiencing rapid deployment of variable renewables. In some Member States, this raises the question of how to ensure adequate investment signals on generation guaranteeing capacity and balancing power at the lowest possible cost. This Rapid Response Energy Brief quantifies the merit order effect in 2030 and 2050 in European electricity wholesale markets by comparing electricity systems in a Reference and Mitigation Scenario for both years. Scenario results show for the Scenario modelled that the reduction in wholesale electricity price between scenarios is on average €1.6/MWh and €4.2/MWh for 2030 and 2050 respectively. A simplified approach is also used to assess the impact of Demand Response on system costs