From passive to active: Flexibility from electric vehicles in the context of transmission system development

Electrification of transport in RES-based power system will support the decarbonisation of the transportsector. However, due to the increase in energy demand and the large peak effects of charging, the passiveintegration of electric cars is likely to undermine sustainability efforts. This study investigates three differentcharging strategies for electric vehicle in Europe offering various degrees of flexibility: passive charging,smart charging and vehicle-to-grid, and puts this flexibility in perspective with the flexibility offered byinterconnections. We use the Balmorel optimization tool to represent the short-term dispatch and long-terminvestment in the energy system and we contribute to the state-of-the-art in developing new methodologiesto represent home charging and battery degradation. Our results show how each step of increased chargingflexibility reduces system costs, affects energy mix, impacts spot prices and reduces CO2 emissions untilthe horizon 2050. We quantify how flexible charging and variable generation mutually support each other(¿100TWh from wind and solar energy in 2050) and restrict the business case for stationary batteries, whereaspassive charging results in a substitution of wind by solar energy. The comparison of each charging schemewith and without interconnection expansion highlights the interplay between European countries in terms ofelectricity prices and CO2 emissions in the context of electrified transport. Although the best outcome isreached under the most flexible scenario at the EU level, the situation of the countries with the cheapest andmost decarbonised electricity mix is damaged, which calls for adapted coordination policy at the EU level

Demand during peak hours versus peak-driving demand: Revisiting one size fits all dynamic grid tariffs

Electricity grid tariffs should reflect network costs in order to provide efficient incentives for timing electricity use and investment in new technologies. We compare tariff designs that deal with existing and expected future grid congestion. Although common volumetric tariff designs such as Time-Of-Use are partly cost-reflective, their designs have fundamental drawbacks in terms of the principles of cost allocations and potentially may lead to social disparities. In a case study of 1.56 million Danish households divided into 90 socio-techno-economic categories, we compare three alternative grid tariffs and investigate their impact on annual electricity bills. This study shows that penalizing consumption above a certain threshold leads to higher costs for owners of electric vehicles regardless of the timing of their consumption. In contrast, penalizing consumption during system peaks mainly affects the electricity bills of heat pump owners. The results of our design simultaneously applying a time-dependent threshold and a system peak tariff show (a) a range of different allocations that distribute the burden of additional grid costs across both technologies and (b) strong positive outcomes, including reduced expenses for lower-income groups and smaller households. Our study offers policymakers a menu that assigns grid costs to demand technologies, thereby giving them valuable input.Comment: 30 pages, 18 figures, journal articl

Variability in electricity consumption by category of consumer: the impact on electricity load profiles

Residential electrification of transport and heat is changing consumption and its characteristics significantly. Previous studies have demonstrated the impact of socio-techno-economic determinants on residential consumption. However, they fail to capture the distributional characteristics of such consumer groups, which impact network planning and flexibility assessment. Using actual residential electricity consumption profile data for 720,000 households in Denmark, we demonstrate that heat pumps are more likely to influence aggregated peak consumption than electric vehicles. At the same time, other socio-economic factors, such as occupancy, dwelling area and income, show little impact. Comparing the extrapolation of a comprehensive rollout of heat pumps or electric vehicles indicates that the most common consumer category deploying heat pumps has 14% more maximum consumption during peak load hours, 46% more average consumption and twice the higher median compared to households owning an electric vehicle. Electric vehicle show already flexibility with coincidence factors that ranges between 5-15% with a maximum of 17% whereas heat pumps are mostly baseload. The detailed and holistic outcomes of this study support flexibility assessment and grid planning in future studies but also the operation of flexible technologies.Comment: 37 pages, 18 figures, journal articl