To Prevent or Promote Grid Expansion? Analyzing the Future Role of Power Transmission in the European Energy System

Abstract

Future energy supply systems must become more flexible than they are today to accommodate the significant contributions expected from intermittent renewable power sources. Although numerous studies on planning flexibility options have emerged over the last few years, the uncertainties related to model-based studies have left the literature lacking a proper understanding of the investment strategy needed to ensure robust power grid expansion. To address this issue, we focus herein on two important aspects of these uncertainties: the first is the relevance of various social preferences for the use of certain technologies, and the second is how the available approaches affect the flexibility options for power transmission in energy system models. To address these uncertainties, we analyze a host of scenarios. We use an energy system optimization model to plan the transition of Europe’s energy system. In addition to interacting with the heating and transport sectors, the model integrates power flows in three different ways: as a transport model, as a direct current power flow model, and as a linearized alternating current power flow model based on profiles of power transfer distribution factors. The results show that deploying transmission systems contribute significantly to system adequacy. If investments in new power transmission infrastructure are restricted—for example, because of social opposition—additional power generation and storage technologies are an alternative option to reach the necessary level of adequacy at 2% greater system costs. The share of power transmission in total system costs remains widely stable around 1.5%, even if cost assumptions or the approaches for modeling power flows are varied. Thus, the results indicate the importance of promoting investments in infrastructure projects that support pan-European power transmission. However, a wide range of possibilities exists to put this strategy into practice.

Energy system transition pathways to meet the global electricity demand for ambitious climate targets and cost competitiveness

“…Grid interconnections between countries or regions within a world region are expected to bring further benefits to the energy system by enabling system flexibility and cost reduction. In the case of high variable RE shares, combinations of battery storage and the expansion of grid transfer capacities are important elements of load balancing in the system [128,129]. However, it has been argued that very long-distance power transmission networks beyond the dimensions of major regions can transfer only a smaller fraction of electricity and contribute very limited to the overall cost reduction as discussed for various cases around the world [23], and in detail for the Americas [60], East Asia [130], Europe-China [131] and Europe-Eurasia-MENA [132].…”

Considering Life Cycle Greenhouse Gas Emissions in Power System Expansion Planning for Europe and North Africa Using Multi-Objective Optimization

“…For the sake of simplicity, the heat sector is not considered in the present study. This is the main difference with the scenario setup by Cao et al [36], who, for example, also considered the additional electricity demand by heat pumps, electric boilers, and the heat demand to be covered by cogeneration.…”

“…Our scenario setup is based on the model parameterization and the "CSP&H2" scenario in combination with the "Trend" scenario for transmission grid expansion defined in Cao et al [36]. The "Trend" scenario assumes that all major ten-year network development plan (TYNDP) projects [37] are implemented and the current structure of the transmission network will be maintained.…”

“…As shown in panel (a), the cost-optimal power system (outer right bars) is dominated by PV open ground and wind onshore. Temporal flexibility is mainly provided by Li-ion batteries and pumped hydro storage, while the grid is expanded to~320 TWkm, which is in the range of grid expansion needs shown in earlier work with comparable scenario setups [21,36]. Additional flexibility to the system is provided by a small share of combined and open cycle gas turbines.…”

Bridging granularity gaps to decarbonize large‐scale energy systems—The case of power system planning

“…A spatial disaggregation of ESOM output data requires geo‐coordinates of substations. Coupling in the opposite direction is less cumbersome as it mostly comes down to spatial aggregation of costs or technical parameters, such as power transfer distribution factors 45 …”