Final Energy Demand Research Articles

Occupants' interaction with building services: Development of a camera-based method for detailed monitoring of windows, shadings, and lights

Several energy gains or losses in buildings are influenced by occupant interactions with building services, such as lighting or HVAC systems, thermostat settings, and window and shading operations. Occupant behavior is usually triggered by discomfort, nevertheless actions taken to restore comfort can have an impact on final energy demand. Thus, an accurate energy assessment for both new and retrofit building design must properly account for occupant behavior, based on reliable models developed from real case studies and detailed monitoring. This work presents a new approach for continuous and non-intrusive monitoring of window opening angle, shading position, and lighting operation to determine the net air exchange area for ventilation. A camera-based device and a post-processing algorithm are developed, and a monitoring campaign over 6 month is carried out to showcase the monitoring system. The device consists of a camera setup connected to a microprocessor, and a dedicated script which enables the device to track window opening, shading movement and lighting operation through target and object identification. Results of the prototyping case study show that the proposed system can effectively detect window opening angles and shutter positions, dealing with multiple windows and shutters simultaneously and allowing the deployment of the benefits of continuous monitoring. The explored application is the direct use of the collected data for the calculation of natural ventilation rates from the net exchange area (EN 16798-7) over long term datasets. As future development, the monitoring system will be used to develop accurate behavioral models based on the experimental data to analyze and suggest the occupant’s response to discomfortable conditions in order to improve indoor air quality and save energy.

Endogenous simulation of low-carbon lifestyle change in global climate mitigation pathways

Global Integrated Assessment Models (IAMs) used to characterise mitigation pathways have very limited or no formal representation of lifestyles and lifestyle change. We demonstrate a novel approach to endogenously simulating low-carbon lifestyle heterogeneity and lifestyle change through soft-coupling with our new empirically-based LIFE model. Coupling LIFE to global IAMs enables dynamic simulation of distinctive lifestyle change contributions to targeted mitigation strategies. We set out the empirical basis of the LIFE model, the methodological steps for soft-coupling to a global IAM, and show results from a test application to the residential sector using the MESSAGEix-Buildings model. A first key insight is that coupling with the LIFE model introduces heterogeneous behaviour between ‘engaged’ types, who experience faster and higher reductions in final energy demand compared to ‘disengaged’ types. When we further simulate a widespread shift in normative values, this gap is closed. A second key insight is that drivers of lifestyle change, act differently across ‘Improve’ and ‘Avoid’ dimensions. The ‘disengaged’ types, characterised by lower incomes, are more highly responsive to energy saving ‘Avoid’ behaviours. Our approach demonstrates how improved understanding of lifestyle change dynamics and more realistic, empirically-based quantitative simulations in climate mitigation pathways enriches scientific and policy analysis of how to achieve Paris Climate Agreement goals.

Gothenburg Digital Twin. Modelling and communicating the effect of temperature change scenarios on building demand

The article presents the first prototype of a web-based City Digital Twin (CDT) viewer developed for the city of Gothenburg to promote the understanding of the interrelation between the spatial, energy and climate change domain related to building stocks and to support stakeholders’ collaboration. The focus is on the development process of the viewer and decisions taken to target the users. 3d spatial data about the current city combined with building energy demand modelling following the Intergovernmental Panel on Climate Change scenarios provide the basis that potentially allows local actors to take informed decisions about decarbonization measures in a long-term perspective. First, future climate conditions are modelled for Gothenburg following the IPCC pathways 2.6, 4.5, and 8.5 for the year 2050. Second, a Building Stock Model is employed to simulate the energy use of buildings by using the climate scenarios as climate boundary conditions. Finally, results are visualized in the CDT viewer showing that future climate conditions contribute to an overall decrease in final energy demand up to 18% in spring and autumn months and an increase up to 1.5% in summer months.

Thermal performance of residential and non-residential sectors: describing differences and understanding underlying reasons

This paper presents a comparative analysis of thermal performance and heating demand for selected residential (single-family houses, SFHs and multi-family houses, MFHs) and non-residential sectors (Offices and Schools). The thermal performance and space heating demand of the Swiss building stock were analysed by a bottom-up element-based archetypal model. SFHs are characterised by the best envelope thermal performance (average envelope U-value = 0.62 W/(m2K)), followed by MFH (0.73 W/(m2K)), Schools (0.75 W/(m2K)), and Offices (0.84 W/(m2K). Results show significant differences regarding architectural features between building sectors: SFHs are characterised by the highest envelope factor (median value = 2.00), defined as the ratio between external surfaces and heated area, followed by Schools (1.50), MFH (1.30), and Offices (1.25). As a consequence of the above-mentioned differences, SFHs show higher specific final energy demand for space heating (on average 148 kWh/(m2year)), followed by Schools (117 kWh/(m2year)), Offices (100 kWh/(m2year)), and MFH (93 kWh/(m2year)). Moreover, a high potential for decarbonisation of heating systems in the Swiss building stock was identified: more than 70% of the ERA is heated by fossil fuel-based heating systems, with some differences amongst the studied sectors. This analysis serves as an important starting point to examine possible retrofit pathways and policies across sectors.

Measuring the impact of regional climate change on heating and cooling demand for the Chilean energy transition

The regional impact of climate change on heating and cooling demand is important to consider when designing optimal long-term energy policies. Several studies have addressed this issue, but either at a very aggregated level or without optimizing the whole energy system. The aims of this paper are to fill this gap in a generic way and to assess the impact of climate change on heating and cooling energy demands for residential and commercial sectors at the regional and nodal levels in the context of Chile’s energy transition. We propose a methodology based on high resolution climate simulations for the Representative Concentration Pathways (RCP) RCP 2.6 and RCP 8.5 scenarios. First, a statistical analysis is performed to estimate the long-term trends of so-called heating and cooling degree-days and their impact on final regional energy demands. Then, demand pathways in the energy transition are assessed using a multi-sectoral energy planning model. Numerical experiments using data from Chile show an overall positive economic impact of climate change (limited to heating and cooling demands) for the energy system, with a significant decrease in heating demand compared to a limited increase in cooling requirements. For the RCP 8.5 scenario, cost reductions reach 2.1% of the total discounted system cost on the 2020-2050 period mainly due to a significant decrease of gas consumption for heating. This research highlights the importance for policymakers to consider climate change in efficient energy policies.

Techno-Economic Assessment of CO2-Based Power to Heat to Power Systems for Industrial Applications

Abstract The industrial sector is a major source of wealth, producing about one-quarter of the global gross product. However, industry is also a major emitter of CO2 and it represents a key challenge toward achieving the worldwide CO2 emission reduction targets. Nowadays, about 22% of the overall energy demand is heating for the industrial sector, generating about 40% of the global CO2 emissions. Additionally, 30% of the final energy demand of the industrial sector is electricity. Solutions to decarbonize the industrial sector are needed. This work presents the techno-economic assessment of four different molten salts-based power-to-heat-to-heat and power solutions aiming at decarbonizing the industrial sector, requiring medium temperature heat. The systems are studied under different electric markets. Dispatch strategies and system sizing are identified to ensure optimal techno-economic performance. The main performance indicators investigated are the levelized cost of heat and electricity (LCoH and LCoE), the operational expenditure, and the attainable savings with respect to alternative business as usual solutions. The results highlight that the proposed system can be cost-competitive, particularly in markets characterized by low electricity prices and high daily price fluctuations, such as Finland. In these locations, LCoE as low as 100 €/MWh and LCoH lower than 55 €/MWh can be attained by the base system configuration. The introduction of high temperature heat pumps can provide further LCoH reduction of about 50%. This study sets the ground for further power-to-heat-to-heat and power techno-economic investigations addressing different industrial sectors and identifies main system design strategies.

Material requirements and impacts of the building sector in the Shared Socioeconomic Pathways

The significant weight of the building sector in global material demand has been addressed in several publications, but a lack of consideration of the energy-materials nexus was identified. To fill this gap, we developed a stock-flow dynamic model from 1950 to 2100, using scenarios of the International Energy Agency and the Shared Socioeconomic Pathways of the academic literature. We find that (i) the increasing stocks in the less developed countries results in a rise of the inflows; (ii) strong inequalities are observed in the in-use stocks per capita of materials in the SSPs, despite optimistic material intensities projection, (iii) a growing materials demand translates into larger final energy demand of material production, which could question the feasibility of some low-energy demand scenarios, and that (iv) the recycled concrete aggregated display a significant potential to enhance the reduction of accumulated concrete stocks in landfills and green concrete could decrease the energy demand of concrete production. We furthermore highlight the crucial temporal aspect of policies to successfully implement these solutions, as long lifetimes are observed in the building sector.

The role of hydrogen in a decarbonised future transport sector: A case study of Mexico

In recent years, several approaches and pathways have been discussed to decarbonise the transport sector; however, any effort to reduce emissions might be complex due to specific socio-economic and technical characteristics of different regions. In Mexico, the transport sector is the highest energy consumer, representing 38.9% of the national final energy demand, with gasoline and diesel representing 90% of the sector´s total fuel consumption. Energy systems models are powerful tools to obtain insights into decarbonisation pathways to understand costs, emissions and rate of deployment that could serve for energy policy development. This paper focuses on the modelling of the current Mexican transport system using the MUSE-MX multi-regional model with the aim to project a decarbonisation pathway through two different scenarios. The first approach being business as usual (BAU) which aims to analyse current policies implementation and the second being a goal of net zero carbon emissions by 2050. Under the considered net zero scenario, results show potential deployment of hydrogen-based transport technologies, especially for subsectors such as lorries (100% H2 by 2050) and freight train (25% H2 by 2050), while cars and buses tend to full electrification by 2050.

The impact of methane leakage on the role of natural gas in the European energy transition

Decarbonising energy systems is a prevalent topic in the current literature on climate change mitigation, but the additional climate burden caused by methane emissions along the natural gas value chain is rarely discussed at the system level. Considering a two-basket greenhouse gas neutrality objective (both CO2 and methane), we model cost-optimal European energy transition pathways towards 2050. Our analysis shows that adoption of best available methane abatement technologies can entail an 80% reduction in methane leakage, limiting the additional environmental burden to 8% of direct CO2 emissions (vs. 35% today). We show that, while renewable energy sources are key drivers of climate neutrality, the role of natural gas strongly depends on actions to abate both associated CO2 and methane emissions. Moreover, clean hydrogen (produced mainly from renewables) can replace natural gas in a substantial proportion of its end-uses, satisfying nearly a quarter of final energy demand in a climate-neutral Europe.

Energy Demand Modeling for the Transition of a Coal-Dependent City to a Low-Carbon City: The Case of Ulaanbaatar City

Cities have committed to reducing greenhouse gas emissions and promoting renewable energy. However, many cities continue to rely on fossil fuels, while renewable energy sources are not used or are unable to meet the demand that fossil fuels provide. Depending on the geographic location, climate, and resources, cities must find their own path to energy sustainability. The city of Ulaanbaatar is one of the coal-dependent cities, its electricity and heat consumption mainly coming from coal. In this study, the future final energy demand of a coal-dependent city is identified and analyzed to make it a low-carbon city. Long-term energy demand projections for Ulaanbaatar to 2050 are conducted using the model for analysis of energy demand (MAED) model. Four scenarios are developed based on the existing local and national policies in the socio-economic and energy sectors, as well as more ambitious policy and technology measures recommended by various studies in the MAED_D model. The final energy demand is calculated to be 548, 460, 334, and 264 PJ in 2050 for BAU, REF, NDC, and RM scenarios, respectively, compared to 135 PJ in 2020. The results show that the high penetration of electricity and renewable energy, energy efficiency measures, and energy intensity reduction in all sectors can significantly reduce the future energy demand and help the transition towards a low-carbon city.

Pathway and Policy for China's Provincial Carbon Emission Peak

An effective way for China to achieve a carbon emission peak by 2030 is to encourage developed regions to take the lead in attaining carbon peaking at the regional level. Considering Jiangsu Province as an example, this study established a provincial low emissions analysis platform (LEAP-Jiangsu) model. It combined the improved multilevel logarithmic mean Divisia index (M-LMDI) model, Tapio decoupling model, and the synergistic effect of pollution and carbon reduction model to explore the key influencing factors of carbon emissions and carbon reduction paths. The improved M-LMDI model was used to analyze the factors influencing historical and future carbon emissions in Jiangsu Province. Based on the analysis results and planning objectives, a LEAP-Jiangsu model involving various development scenarios was established to predict the time and value of carbon emission peaks. The Tapio decoupling and synergistic effect models were used to clarify the relationship between carbon emissions and economic development, the synergistic effect of carbon, and air pollutant emission reduction. The prediction results demonstrated that the total primary energy demand of Jiangsu Province in 2035 was predicted to be approximately 401.2-474.6 Mt, and the final energy demand would be approximately 319.2-382.3 Mt. Jiangsu Province was most likely to achieve the goal of carbon peaking in 2025-2030, and the peak carbon emission was approximately 815.3-845.7 Mt. The contribution rates of energy conservation and emission reduction measures such as energy intensity reduction, industrial structure optimization, terminal electrification improvement, and energy structure adjustment were 33.1%, 26.8%, 21%, and 15.2%, respectively.

Energy demand modeling for low carbon cities in Thailand: A case study of Nakhon Ratchasima province

Nakhon Ratchasima is one of the northeastern cities which has been promoted as one of the low-carbon cities in Thailand. The study aims to evaluate policies and measures on greenhouse gas (GHG) emissions mitigation to meet the target at the provincial level. The Low Emissions Analysis Platform (LEAP) is used as a modeling tool to simulate energy demand for each economic sector. The 2019 data is set as a base year, using top-down and bottom-up approaches depending on the availability of data for the analysis. The model consists of two scenarios: (1) Business-as-usual (BAU) scenario and Low carbon scenario (LCS). Transport and industry sectors are the most energy-consuming and CO2-emitting sectors in Nakhon Ratchasima Province. In the LCS case, the final energy demand and CO2 emissions in 2050 will be reduced by about 40% compared to the BAU case. In addition, CO2 emissions in Nakhon Ratchasima Province will peak around 2038, this is not the case with BAU. The study could predict future energy demand and propose a way forward to reducing GHG emissions at the provincial level.

Comparison of Different Coupling Modes between the Power System and the Hydrogen System Based on a Power–Hydrogen Coordinated Planning Optimization Model

Hydrogen is receiving unprecedented momentum and is projected to meet a sizable share of the final energy demand in the future. The coupling between the hydrogen and power systems can help integrate volatile renewable energy, reduce curtailment, and realize long-term energy storage. Different coupling modes are being proposed, yet quantitative comparisons are absent. To fill this gap, this paper firstly summarizes the system composition of potential power–hydrogen coupling modes and analyzes their advantages and disadvantages. Then, a model for power–hydrogen coordinated planning optimization is proposed for quantitative analysis. Southern Xinjiang is chosen as a representative of the northwestern area in China, which has plentiful renewable resources and a relatively small local load at present, for a case study. Through result analysis, it is found that the mode of power–hydrogen coupling at the source side, either for in situ utilization or for long-distance transport via pipelines, shows better economic competitiveness. The discussion provides suggestions and a reference to policymakers for formulating infrastructure or industry plans in advance to better accommodate the rapidly developing renewable energy.

The green transition of industry – An introduction to IndustryPLAN

The green transition of industry has an essential role in meeting the Paris Agreement targets. Transition strategies should integrate a balance between energy efficiency, electrification, and renewable energy. Focus should be on enabling industry to play an active role in the integration of variable renewable energy sources and the sector-coupling needed for the utilisation of excess heat. Industry in the European Commission's net-zero emission scenarios such as EU 1.5 TECH in “A Clean Planet for all” is based on a top-down methodology with the risks of overinvestments, blind investments, non-concrete general pan-industrial investments, and unrealistic implementation rates. This paper introduces seven guiding principles and a freeware tool, IndustryPLAN, to open the “black box” of industry, quantify such strategies and apply them to EU-27 + UK. The tool enables the user to conduct country-specific, sector-specific or aggregated European analyses of climate mitigation measures by implementing best available technologies, innovative measures and technologies, electrification, shift to hydrogen-based processes, and excess heat utilisation. Also, resilience against fluctuating fuel, electricity and technology prices can be analysed to illuminate geopolitical or supply chain issues. The combination of the guiding principles methodology and the IndustryPLAN tool identifies at least 30% short-term feasible final energy demand savings and possible full decarbonisation with a 100% renewable energy supply for industry.

Maximizing the use of hydrogen as energy vector to cover the final energy demand for stand-alone systems, application and sensitivity analysis for the Canary Archipelago by 2040

Fossil fuel-based economies must undergo a deep transition for complete decarbonization. To this end, it is widely recognized that all economies must move towards the electrification of energy end uses. Even though there is a part that cannot be electrified, at least at affordable costs; clear examples are heavy road transport, maritime and air transport, and some industrial processes. As a result of the limitations of electrification in certain energy end uses, the potential use of hydrogen as an alternative energy carrier has been examined in recent decades. Hydrogen is seen as a viable option for the medium to long term. Specifically, efforts are being made in the case of the Canary Islands to move towards a carbon-free energy mix. In fact, the aim is to advance the economy decarbonization by 10 years over the date foreseen for both Europe and the rest of Spain. To this end, the HOMER program has been used to analyze the possibility of producing the necessary hydrogen in a scenario applied to the Canary Islands in which the uses of this energy vector have been maximized. This research considers two possible scenarios, together with a sensitivity analysis under the different uncertain conditions associated with the used technologies. The results have been the estimation of hydrogen production costs for high demands, about 230,000 tH2/year, in 2040 for an isolated archipelago under two totally different generation scenarios. The first scenario is totally renewable, while the other is based on nuclear generation by means of high-temperature SMRs. The results show, that it would be possible to produce at a cost in the range of 1 €/kgH2 using nuclear technology and around 4 €/kgH2 using renewables, with uncertainty cost ranges of around 40%, i.e. costs between 0.85-1.48 and 3.29–4.99 € kgH2 respectively.

Impact of international transportation chains on cost of green e-hydrogen: Global cost of hydrogen and consequences for Germany and Finland

Widely available and low-cost solar photovoltaics and wind power can enable production of renewable electricity-based hydrogen at many locations throughout the world. Hydrogen is expected to emerge as an important energy carrier constituting some of the final energy demand; however, its most important role will be as feedstock for further processing to e-fuels, e-chemicals, and e-steel. Apart from meeting their own hydrogen demand, countries may have opportunities to export hydrogen to countries with area limitations or higher production costs. This paper assesses the feasibility of e-hydrogen imports to Germany and Finland from two case regions with a high availability of low-cost renewable electricity, Chile and Morocco, in comparison to domestic supply. Special attention is paid to the transport infrastructure, which has a crucial impact on the economic viability of imports via two routes, shipping and pipelines. This study has found that despite lower e-hydrogen production costs in Morocco and Chile compared to Germany and Finland, additional transportation costs make imports of e-hydrogen economically unattractive. In early 2020s, imported fuel costs are 39–79% and 34–100% higher than e-hydrogen produced in Germany and Finland, respectively. In 2050, imported e-hydrogen is projected to be 39–70% more expensive than locally produced e-hydrogen in Germany and 43–54% in the case of Finland. e-Hydrogen may become a fuel that is mostly produced domestically and may be feasible for imports only in specific locations. Local e-hydrogen production may also lower dependence on imports, enhance energy security, and add jobs.

Future trends in the sustainable use of biomass

The modern world is facing many challenges such as population growth, the need to provide sufficient food, climate change, increasing environmental pollution, rising energy prices, new environmental regulations, high depletion of oil and other minerals, growing socio-environmental issues, as well as the need for energy security. All these challenges have led to significant progress in the research and development of renewable energy sources, and it is expected that in the search for alternative energy sources in the future the model of renewable energy production from biomass will be a goal to be pursued by most countries. However, in order for this task to be successfully completed in the coming period, it is necessary to overcome several challenges, among which the most important are the economic sustainability of biomass production and collection and its conversion into various forms of bioenergy. Bioenergy is becoming a central issue of sustainability as it reduces greenhouse gas emissions and air pollution and increases diversity and energy security. In this context, the contribution of modern and sustainable bioenergy must be significantly increased in final energy demand, as well as an increase in the share of sustainable low-carbon biofuels in transport fuels. In addition, carbon emissions should be gradually reduced based on life cycle estimates, using biofuels to replace fossil fuels. It should also increase global investment in sustainable and low-carbon bioenergy, including advanced and flexible biorefineries capable of producing energy and products based on biomass and bioeconomy. However, the expansion of the bioeconomy – defined as a set of activities related to innovation, development, production and use of biomass or processes of production of renewable energy, materials and chemical products – should be based on sustainable practices that guarantee greenhouse gas emission reductions and avoidance of adverse effects from ecological, economic and social point of view. Despite the growing consensus on the importance and urgency of accelerating the development of bioenergy and biofuels, investment is not as intensive as necessary, and the implementation of technologies encounters a number of barriers, such as large initial investments, financial risks, volatility in oil and other commodity prices and regulatory uncertainties. This chapter provides an overview of the potentials and future trends in the use of biomass for various types of bioenergy. Special emphasis is placed on the most significant challenges in the processing and use of biomass in the future. Data on the improvement of technologies in the use and processing of biomass in the future, including combustion, co-combustion, gasification, pyrolysis and combined heat and electrical energy, are presented. An overview of some of the most important biofuels of the future is also given, such as: biohydrogen, biobutanol, biooils and bio-dimethyl ether.

A multistory, ultra-strong lignocellulose-based structural material for passive solar heating

Currently, most people spend 90% of their daily time inside, relying on mechanical heating and air conditioning. Space heating is the largest source of final energy demand, making up about 50% of the total each year. Existing buildings often have insulation and central heating added to reduce energy consumption for heating, which increases construction costs and carbon emissions. Here, a potent and attainable strategy was demonstrated to process lignocellulose into a high-performance passive solar heating wood with satisfactory passive solar heating and mechanical properties. The passive solar heating wood could absorb ultraviolet light and convert it into thermal energy, resulting in continuous above-ambient heating during the cold day. Compared to traditional building materials, passive solar heating wood exhibits superior heating performance (average daytime heating of ∼25.6 °C) and thermal insulation performance (mid-IR emissivity of 0.51). In addition, the passive solar heating wood exhibits ultra-strong specific strength (80.1 MPa g−1 cm3) and specific impact toughness (56.33 kJ m−2 g−1 cm3) than the most of common polymers, ceramics, and concrete, which opens the way for practical application of lignocellulose based structural materials in advanced thermal management buildings.

Energy source impact on the economic and environmental effects of retrofitting a heritage building with a heat pump system

In terms of energy efficiency and the quality of the indoor and outdoor environment, heritage buildings are facing sustainability challenges. This study assessed the feasibility of using renewable energy sources based on air-to-water heat pumps with regard to preserving the historic values of the buildings and their ability to coexist with current energy efficiency and decarbonization requirements, and to prevent their neglect and degradation. A new approach is the use of Building Information Modelling to accurately determine energy demand and select a heating system based on renewable energy sources in such an unusual case as a heritage building. The analysis covers a selection of feasible scenario of the modernization of the over 300 years old building. A particular focus of the study is to compare the use different heat pumps systems. One is a reversible gas absorption air-to-water heat pump and the other is an electricity-powered compressor air-to-water heat pump. The building is currently supplied with a fixed-temperature boiler up to 550 kW with an open combustion chamber fed with coal. It was proven that the proposed retrofit scenario reduces final energy demand by 72.9%, while improving thermal comfort, cutting annual emissions by 121.1 Mg CO2 and 1.0 Mg PM10.

Comparative analysis of UK net-zero scenarios: The role of energy demand reduction

Final energy demand in the UK has remained relatively constant since the 1970s. However, most of the scenarios that model pathways to achieve the UK's net-zero greenhouse gas emissions by 2050 indicate that energy demand reduction (EDR) will be an important pillar of climate change mitigation. Despite this, the UK Government has no clearly defined strategy to reduce demand. This comparative analysis explores the role of EDR across twelve UK-based climate scenarios from four organisations that estimate changes in carbon emission and energy consumption from 2020 to 2050. We focus on changes in final demand across the economy, assessing the scale of ambition and the implications for the rest of the energy system in the context of net-zero. All the pathways explored achieve reductions of at least 32.8% in total final energy demand from 2020 to 2050, suggesting that this is the minimum level of demand reduction required to achieve the development and rollout of the supply side technologies necessary to decarbonise the energy system. Reductions in total final demand of up to 52% are demonstrated. We find that pathways with higher levels of EDR mitigate against technological challenges, such as scaling up renewable energy capacities, are less reliant on carbon-dioxide removal technologies and require less investment – but are characterised by higher levels of social change.