As renewable energy grows, flexible electricity demand becomes essential. We conducted a field experiment with nine heat pumps in well-insulated homes near Ghent, Belgium. During 287 flexibility interventions, remotely deactivated heating until indoor temperatures reached predefined thresholds or households manually overruled the intervention. After initiating a flexibility event, the heat pump power is initially lowered 250 W on average per unit in the fleet. As some heat pumps in the fleet reactivate, they consume more to restore their threshold temperatures, triggering a rebound effect that gradually reduces net power achieved. On average, net power savings become zero after 18 h, followed by a rebound period. Overall pump consumption was reduced by around 1 kWh per event, stabilizing 36 h after the event start. If flexibility activation is timed strategically, up to e1.1 can be saved through price arbitrage, assuming wholesale at energy-crisis-level, while the capacity benefits value can be up to $175. Smart heating algorithms further increase savings generated by all value streams. Colder weather significantly influences savings, increasing the power available for flexibility but also amplifying rebound effects. This flexibility came moderate comfort impacts: on average, indoor temperatures were 0.38 degrees C lower during interventions. However, 19% of interventions were manually overruled when larger temperature drops occurred, with households citing discomfort, illness, or occupancy as factors on an online dashboard. These findings suggest that residential heating can support renewable energy integration with moderate comfort impacts.

The question of how to optimally decarbonise the buildings sector – especially heating – remains a source of fierce debate. A large amount of uncertainty remains around how to strike the optimal balance between heat demand reduction and heat supply decarbonisation. This paper sheds light on the complex search for the optimal balance between reducing heat demand and decarbonising heat supply. Drawing on economic theory and cost-benefit analysis, the paper proposes an analytical framework that structures and organises the many complex and intertwining parameters to consider when determining this optimal balance. We conclude that increased clarity about the goal, scope of, and method for optimisation efforts are the foundations of a more informed and considered approach when it comes to decarbonising heating. The paper also provides insights for policy makers faced with the challenge of designing policies and regulations in this area.

Reaching the European Union's 2030 targets for primary energy use (PE) and CO2 emissions (CE) requires an accurate assessment of how different technologies perform on these two fronts. To calculate the PE and CE associated with the consumption of electricity (e.g. by an electric vehicle or a heat pump) conversion factors (CFs) are required, namely a primary energy factor and a CO2 intensity factor. Previous theoretical work has shown that the calculation and use of CFs is a contentious and multifaceted issue, but a review of the actual practice in academic literature has so far been missing. 110 recent studies have been systematically reviewed across six methodological aspects, to find that 75% of the studies consider only a single country, 79% apply a purely retrospective perspective, 66% apply a yearly temporal resolution, 75% apply a purely operational (instead of a life-cycle) perspective, 85% make use of average (rather than marginal) CFs, and 77% ignore electricity imports from surrounding countries. Future research in which CFs are used should more carefully consider each of these methodological aspects and explicitly justify the choices that are being made on this front. There is also a strong need in the literature for a publicly available and methodologically transparent database of up-to-date CFs, which would not only enable more accurate and transparent PE and CE calculations, but also support the further development of building energy performance assessment methods and smart grid algorithms.

Reaching the 2030 targets for the EU primary energy use (PE) and CO2eq emissions (CE) requires an accurate assessment of how different technologies perform on these two fronts. In this regard, the focus in academia is increasingly shifting from traditional technologies to electricity consuming alternatives. Calculating and comparing their performance with respect to traditional technologies requires conversion factors (CFs) like a primary energy factor and a CO2eq intensity. These reflect the PE and CE associated with each unit of electricity consumed. Previous work has shown that the calculation and use of CFs is a contentious and multifaceted issue. However, this has mostly remained a theoretical discussion. A stock-taking of how CFs are actually calculated and used in academic literature has so far been missing, impeding insight into what the contemporary trends and challenges are. Therefore, we structurally review 65 publications across six methodological aspects. We find that 72 86 resolution, 65 perspective, 91 electricity imports from surrounding countries. We conclude that there is a strong need in the literature for a publicly available, transparently calculated dataset of CFs, which avoids the shortcomings found in the literature. This would enable more accurate and transparent PE and CE calculations, and support the development of new building energy performance assessment methods and smart grid algorithms.

The European Union strives for sharp reductions in both CO2 emissions as well as primary energy use. Electricity consuming technologies are becoming increasingly important in this context, due to the ongoing electrification of transport and heating services. To correctly evaluate these technologies, conversion factors are needed—namely CO2 intensities and primary energy factors (PEFs). However, this evaluation is hindered by the unavailability of a high-quality database of conversion factor values. Ideally, such a database has a broad geographical scope, a high temporal resolution and considers cross-country exchanges of electricity as well as future evolutions in the electricity mix. In this paper, a state-of-the-art unit commitment economic dispatch model of the European electricity system is developed and a flow-tracing technique is innovatively applied to future scenarios (2025–2040)—to generate such a database and make it publicly available. Important dynamics are revealed, including an overall decrease in conversion factor values as well as considerable temporal variability at both the seasonal and hourly level. Furthermore, the importance of taking into account imports and carefully considering the calculation methodology for PEFs are both confirmed. Future estimates of the CO2 emissions and primary energy use associated with individual electrical loads can be meaningfully improved by taking into account these dynamics.

The ability of homeowning households to finance renovation investments is an often overlooked barrier towards achieving the long-term energy and climate goals. Especially a quantitative assessment of this financial barrier has been missing in the literature. A methodology to perform such an assessment is developed and applied to the Flemish region in Belgium, which can be seen as a proxy for similar regions elsewhere in Europe. Two empirical datasets are combined through a process of stochastic sampling, to estimate both the renovation costs (towards a 2050-proof level of energy performance) as well as financing capacities for a representative sample of households. The analysis shows that approximately half of the homeowning households cannot finance the necessary renovations. This finding holds regardless of whether renovations are financed and executed all at once, or spread over multiple years into the future. When the additional investment costs associated with comfort increasing measures that typically coincide with energy renovations are included, the share of households facing a shortage in financing capacity increases by 7 to 9 percentage points. The fact that half of all households can finance comprehensive renovations and yet decides not to do so indicates that new policies are required to activate them in the coming decade. (c) 2021 Elsevier B.V. All rights reserved.

In the context of increasing environmental awareness, specific methodologies have been proposed for the definition, modelling and assessment of the buildings' energy performance. These Building Energy Assessment Methods (BEAMs) are still far from accurate, when applied on actual individual buildings. New detailed data allows to further optimize the BEAM. This paper presents a preliminary study on the influence of primary conversion factors, applied to two different calculation methods: one with an hourly time interval and one with a monthly time interval. The added value of hourly data is evaluated and the two methods, provided by the new ISO 52000 standard series, are tested. The total energy needs for space heating for both methods coincide quite well. For poorly insulated buildings the monthly calculation method showed higher results, compared to the monthly calculation method. For the well insulated buildings, the opposite became clear. The added value of hourly data on Primary Energy conversion Factors (PEFs), proved to be minimal.

Currently, European electricity markets face depressed wholesale prices as a consequence of (renewable) capacity increases at times with sluggish demand. In several countries, this situation resulted in the creation of generous capacity remuneration mechanisms (CRM), because markets no longer trigger any new investments. However, there are substantial explicit and implicit phase-out scenarios for old nuclear and coal capacity in the next ten years. Especially in Germany and the UK, a significant phase-out of old assets will take place while also smaller countries like Belgium and the Netherlands anounced phase-outs. At the same time, renewable generation capacity is expected to increase significantly as well as interconnection capacity. More countries start to experiment with demand response mechanisms and the share of electric vehicles (EVs) is expected to increase rapidly by 2030. This paper quantitatively estimates the effect of expected conventional capacity phase-outs in a changing landscape on future wholesale prices in Central Western Europe (CWE) . Obviously, general expectations about future electricity prices are of great importance for all involved stakeholders.