Electricity Load Implications of Space Heating Decarbonization Pathways

This study focused on the effects of variable renewable electricity (VRE) on full load hours and energy efficiency of fossil-fired power generation in the European Union from 1990-2014. Member states were aggregated into three groups based on the level of VRE penetration. Average full load hours are found to be decreasing since 2006 for all groups. The decrease is most in the group with the highest VRE penetration level with a 53% decline from 2005 to 2014 (while VRE penetration increased from 8% to 25%). For VRE-medium the decrease was 34% from 2007 to 2014 (while VRE increased from 3% to 13%) and for VRE-low 32% (with 1% to 5% VRE penetration increase). Both the financial crisis and the share of VRE show strong correlations with full load hours. Both can explain the developments for VRE-high. For VRE-medium no significant relation with the recession was found and for VRE-low both factors were not significant. For energy efficiency, the commissioning year shows a strong correlation for natural gas and less for coal. Significant impacts are found for average commissioning year and full load hours on the energy efficiency of natural gas-fired power generation but not for coal.

The aim of this paper is to compare energy consumptions, CO2 emissions, and operative costs of condensing boilers, electric vapour compression heat pumps and gas driven absorption heat pumps to provide space heating and domestic hot water. The analysis is performed for 140 m2 single-family houses in five different Italian cities whose envelope features depend on the location. For each location, two different envelope conditions are considered. The first one is a non-insulated building, while the second one is the same building, but an external thermal insulation is added on vertical walls and roof. To avoid internal renovation, radiators are maintained as emission system. Combined dynamic simulations are performed to appreciate building and system interactions. A 6 second time step is set to evaluate properly interactions and the DHW profile demand. In addition, the GHP dynamic model is a grey box model experimentally validated. The results show that electric vapour compression heat pumps reach the highest non-renewable primary energy savings (>32%) compared to condensing boilers, but their operative costs are higher due to the higher specific cost of electricity in Italy. Gas driven absorption heat pumps achieve a lower consumption reduction than electric heat pumps (>22%), but they have also the minimum operative cost among the three technologies.

The design and analysis of two exhaust heat recovery systems for public shower facilities

The energy mix of Baden-Wurttemberg – one of the most wooded regions of Germany – could be diversified through the optimal valorisation of the existing free potentials of wood resources. Circa 17 PJ of forest residues and landscape wood raw material grow annually over the territory of this federal state. For this reason, an optimisation of the corresponding value chain for power purposes is accomplished in order to identify the most cost-efficient utilisation pathways. Firstly, each unexploited potential of wood resources for up to ten different types of wood chips is estimated at district level. Next, the stages of felling, extraction, debranching, moving and chipping of wood resources are modelled into four specific logistic chains on the basis of the size of forest ownership, the steepness of slope and the variety of tree. Moreover, specific unit costs based on different cost allocation procedures are assigned to the ten identified types of chipped wood resources. Besides the modelling of the transport sector, an array of all feasible technologies for conversion of wood resources into bio-based power are compared to each other in terms of costs. A singular conclusion is drawn according to which, for each particular capacity under the same operation conditions, gasification is more cost-efficient than combustion – except for co-firing. Hence, the fluidised bed gasification coupled to a gas engine or a combined cycle as well as the direct co-firing of wood resources at a 10% co-fire rate are preselected for the intended analysis on account of their higher cost-effectiveness. Lastly, a new MILP model called BioESyMO (Bioenergy System Model for Operation Optimisation) is created for the optimisation of the value chain of wood resources. This optimising tool includes a unique mathematical constraint aiming at assuring profitability of investments within each utilisation pathway. A scenario-based analysis is first developed for remunerations modelled with a high enough value above the breakeven point. Thereby, a combined heat and power cogeneration process consisting of a fluidised bed gasifier coupled to a gas engine of 20 MWe renders electricity production costs of 10.1-13.8 €cent/kWhe for an annual amount of 7,500 full load hours. The co-firing option for the existing coal-fired power plants with bio-based capacities up to 84.3 MWe generates lower electricity production costs of 6.6-11.7 €cent/kWhe, when the facilities are yearly operated for 3,000 full load hours. If a fluidised bed gasifier is connected to a combined cycle of 210/340 MWe (7,500 full load hours per year), this technology turns out to be the most cost-efficient with electricity production costs in the order of 5.6-7.1 €cent/kWhe. These costs ranges can be reduced by progressively decreasing remunerations below each resulting breakeven point. As for the option of co-firing, cheaper bioenergy configurations arise on the basis of cheaper wood resources that enable lower production costs of up to 5.6 €cent/kWhe for 4,000 hours per year at full load. In conclusion, the low incremental capital costs of co-firing as well as the high efficiencies of fluidised bed gasification-based combined cycles together with the valorisation of the more economical deciduous fractions of wood resources might reduce electricity production costs to a rather low range between 4.5 and 9.5 €cent/kWhe. Leveraging such cost reductions, the introduction of appropriate energy policy instruments for the promotion of carbon-neutral baseload power generation is strongly recommended in view of restrictions induced by Germany’s nuclear and coal phase-outs. Although the quality of the results of this study is mainly conditioned by uncertainty and the high spatial aggregation level of the spatial unit, the implemented methodology as well as the performed optimisation analysis represents an interesting breakthrough that may contribute to the initiated energy transition in Baden-Wurttemberg and the whole of Germany.

Industrial demand-side flexibility is essential for power systems with high shares of variable renewables, yet static grid fees and full load hours incentives can suppress flexible electrification by penalizing peaks and rewarding uniform consumption. This paper introduces an open, extensible, regulation-aware optimization platform that integrates market and emission data with a mixed-integer scheduling model of a bi-valent industrial dryer capable of using electricity and gas. The platform is demonstrated through a representative use case from the energy intensive paper manufacturing sector operating under the current reduced static grid fee pursuant. Because the reduction is contingent on meeting a minimum full load hours threshold, the scope for exploiting the bivalent flexibility potential remains limited. As an alternative, a proposed dynamic grid fee regime featuring time-varying low- and high grid fee windows is evaluated. Any reduction of power consumption from the grid during the high grid fee window does not count against meeting the full load hours threshold. With dynamic fees, the optimization concentrates electric operation within low grid fee windows, increasing electrified heat, reducing emissions, and maintaining competitive costs. Notably, during summer months, these windows align well with periods of lower grid carbon intensity, reinforcing cost–emission co-benefits. However, this alignment deteriorates in winter due to higher variability in renewable generation patterns and constrained window timing, limiting incentive effectiveness. The findings demonstrate that tariff parameterization materially shapes realizable industrial flexibility and that regulation-aware optimization can translate latent technical potential into sustained, temporally targeted electrification aligned with system conditions. The platform enables reproducible, policy-relevant scenario analysis and can aid plant operators for scheduling flexible assets and tariff designers in testing tariff parameters against realistic operational responses.

Development of the effective defrosting criterion for electric vehicles transcritical CO2 heat pumps under constant heating capacity operation

Life cycle assessment of domestic fuel cell micro combined heat and power generation: Exploring influential factors

Electrification of passenger road transport and household heating features prominently in current and planned policy frameworks to achieve greenhouse gas emissions reduction targets. However, since electricity generation involves using fossil fuels, it is not established where and when the replacement of fossil fuel-based technologies by electric cars and heat pumps can effectively reduce overall emissions. Could electrification policy backfire by promoting their diffusion before electricity is decarbonised? Here, we analyse current and future emissions trade-offs in 59 world regions with heterogeneous households, by combining forward-looking integrated assessment model simulations with bottom-up life-cycle assessment. We show that already under current carbon intensities of electricity generation, electric cars and heat pumps are less emission-intensive than fossil fuel-based alternatives in 53 world regions, representing 95% of global transport and heating demand. Even if future end-use electrification is not matched by rapid power sector decarbonisation, it likely avoids emissions in almost all world regions.

A significant part of energy in Norway is utilized for space heating due to the cold climate and heat pump technology has gained popularity in the country for space heating. According to the European heat pump association, Norway has the most heat pumps per capita in Europe, providing 16 TWh of heat energy annually. This review paper discusses the most common types of heat pumps in Norway. A comparison between the performance and payback time of different types of heat pumps in Norway is presented. Ground source heat pumps are more suitable than air source heat pumps due to maintaining a higher coefficient of performance during cold periods. The amount of thermal energy extracted using ground source heat pump systems is estimated to be 3 TWh and expected to be 8 TWh by 2030. However, more than 90% of heat pump installations in Norway are air source heat pumps. Compared to air source heat pumps, ground source heat pumps face many challenges, such as high initial cost, lack of public awareness, and insufficient professional workforce. The sales of heat pumps dropped by 13% in 2020, mainly due to the Covid-19 impact on the market. However, the sales increased significantly in 2021 due to the ongoing energy crisis and increase in energy prices.

Optimal design of heat pump integrated low-grade heat utilization systems

The growth of global energy demand and the aggravation of environmental pollution have prompted the rapid development of renewable energy, in which the solar photovoltaic/thermal (PV/T) heat pump system, as a technology integrating photovoltaic power generation and thermal energy conversion, has also ushered in the development and challenges. This paper reviews the relevant literature in detail, and solar PV/T heat pump technology is overviewed from three perspectives. Photovoltaic/thermal collectors are classified into three main types: air-cooled, liquid-cooled, and heat pipe. The advantages and disadvantages of different collectors and applicable scenarios are analyzed. The system energy efficiency, performance enhancement, and optimization strategies of the new coupled system established by PV/T technology and different heat pump technologies are discussed, emphasizing the potential of PV/T heat pump systems in improving the comprehensive energy utilization efficiency, energy saving, and emission reduction. The impact of the outdoor environment and regional applicability on the performance of collector components and systems are analyzed, and the technical, environmental, and market challenges facing the system were identified. Finally, future trends in PV/T heat pump technology are outlined, including technological innovation, cost reduction, and market expansion, as well as their importance in the global energy transition. The results of this study indicate that PV/T heat pump systems play an important role in achieving green and sustainable development; however, further technological breakthroughs and market promotion are still needed.

Techno-economic competitiveness of 50 MW concentrating solar power plants for electricity generation under Kuwait climatic conditions

Production costs for synthetic methane in 2030 and 2050 of an optimized Power-to-Gas plant with intermediate hydrogen storage

Energy Savings through Variable Speed Compressor Heat Pump Systems

Approximately one quarter of energy-related emissions in Germany are caused by the domestic sector. At 81%, the largest share of these emissions is due to heat supply. Many measures are available to reduce these emissions. One of these measures, which is considered to play an important role in many studies, is the replacement of fossil-fired boilers with electric heat pumps. In order to be able to analyse the impact of high penetrations of heat pumps on the energy system, the coefficient of performance (COP) must be modelled with high temporal resolution. In this study, a methodology is presented on how to calculate high-resolution COPs and the electrical load of heat pumps based on thermal load curves and temperature time series. The COP is determined by the reciprocal Carnot factor. Since heat pumps are often designed bivalently due to the cost structure, the methodology described can also be used for evaluating the combination of immersion heater and heat pump (here for the air/water heat pump). As a result the theoretical hourly COPs determined are calibrated with annual performance factors from field tests. The modelled COPs show clear differences. Currently, mostly air source heat pumps are installed in Germany. If this trend continues, the maximum electrical load of the heat supply will increase more than would be the case with higher shares of ground source heat pumps.