@article{BucksteegWiedmannPoestgesetal., author = {Bucksteeg, Michael and Wiedmann, Michael and P{\"o}stges, Arne and Haller, Markus and B{\"o}ttger, Diana and Ruhnau, Oliver and Schmitz, Richard}, title = {The transformation of integrated electricity and heat systems—Assessing mid-term policies using a model comparison approach}, series = {Renewable and Sustainable Energy Reviews}, volume = {160}, journal = {Renewable and Sustainable Energy Reviews}, doi = {10.1016/j.rser.2022.112270}, abstract = {The development of European power markets is highly influenced by integrated electricity and heat systems. Therefore, decarbonization policies for the electricity and heat sectors, as well as numerical models that are used to guide such policies, should consider cross-sectoral interdependencies and need evaluation. Many model-based policy assessments evaluate potential benefits of combined heat and power. However, the extent of benefits, such as emissions reductions, found in existing studies is subject to considerable variations. While scenarios and model inputs may partly explain such variations, differences in results may also be related to the model formulation itself. Against this background, this study is the first to compare electricity market models in the context of potential benefits of integrated electricity and heat systems in decarbonization. Five large-scale market models covering electricity and heat supply were utilized to study the interactions between a rather simple coal replacement scenario and a more ambitious policy that supports decarbonization through power-to-heat. With a focus on flexibility provision, emissions reduction, and economic efficiency, although the models agree on the qualitative effects, there are considerable quantitative differences. For example, the estimated reductions in overall CO2 emissions range between 0.2 and 9.0 MtCO2/a for a coal replacement scenario and between 0.2 and 25.0 MtCO2/a for a power-to-heat scenario. Model differences can be attributed mainly to the level of detail of combined heat and power modeling and the endogeneity of generation investments. Based on a detailed comparison of the modeling results, implications for modeling choices and political decisions are discussed.}, language = {en} } @article{Ruhnau, author = {Ruhnau, Oliver}, title = {How flexible electricity demand stabilizes wind and solar market values: the case of hydrogen electrolyzers}, series = {Applied Energy, Elsevier}, volume = {307}, journal = {Applied Energy, Elsevier}, doi = {10.1016/j.apenergy.2021.118194}, abstract = {Wind and solar energy are often expected to fall victim to their own success: the higher their share in electricity production, the more their revenue on electricity markets (their "market value") declines. While in conventional power systems, the market value may converge to zero, this study demonstrates that "green" hydrogen production, through adding electricity demand in low-price hours, can effectively and permanently halt the decline. With an analytical derivation, a Monte Carlo simulation, and a numerical electricity market model, I find that - due to flexible hydrogen production alone - market values across Europe likely converge above €19 ± 9 MWh-1 for solar energy and above €27 ± 8 MWh-1 for wind energy in 2050 (annual mean estimate ± standard deviation). This lower boundary is in the range of the projected levelized costs of renewables and has profound implications. Market-based renewables may hence be within reach. simulation, and a numerical electricity market model, I find that - due to flexible hydrogen production alone - market values across Europe likely converge above €19 ± 9 MWh-1 for solar energy and above €27 ± 8 MWh-1 for wind energy in 2050 (annual mean estimate ± standard deviation). This lower boundary is in the range of the projected levelized costs of renewables and has profound implications. Market-based renewables may hence be within reach.}, language = {en} }