The climate change, volatile geopolitical conditions, energy insecurity, and supply disruptions experienced lately have highlighted the need for a solid strategy to speed up the transition to green ...energy and reduce dependence on fossil fuels. Developing tools and methods for fast assessment of techno-economic, environmental and socio-economic aspects of sustainable energy solutions will contribute to this goal. This paper presents results of a case study using an inhouse techno-economic analysis tool developed to provide access to detailed data settings, reflecting the most important technical as well as economic parameters of studied energy technologies. Five different energy solutions for heating and cooling of a specified building in a given geographical position and thereby economic environment have been assessed and compared using the inhouse analysis tool. Based on the proposed techno-economic framework, the energy efficiencies, costs, subsidies and negative CO2 emissions are estimated and used to identify the critical economic parameters on profitability and policy making recommendations. Using the coal-based heating system as reference case, the comparative study carried out shows the advantages and disadvantages of biomass and natural gas based boilers as well as the geothermal installation. Considering the environmental benefits of the renewable based energy resources, which will become a stronger market driver for every year. The results show that both air-source and ground source heat pumps are currently profitable under current subsidy schemes. The net present value is highly influenced by capital costs and subsidies. In the same way, natural gas prices significantly affect the net present value of gas boilers. As gas prices increase over 43 % of the current level in Poland, heat pumps become more attractive. Replacing a coal-fired boiler with gas will take up to years to pay-off. However, the air source heat pump and ground source heat pump will take longer to pay off, up to 10 years for the air source heat pump and 15 years for the ground source heat pump. The carbon intensity of the ground source heat pump (186 kg CO2 eq) is lower than the levels of the gas boilers (203 kg CO2 eq) and the air source heat pump (263 kg CO2 eq). Ground source heat pump system installation expects to provide a substantial saving of 58 % on CO2 emissions versus coal-fired systems. Air source heat pump P emits 267 kg CO2/kWh/year more than gas boilers, but emissions decrease drastically as the Polish power grid becomes greener in 2030 and 2040.
•Low-carbon heating systems economics•Cost functions are developed.•42 %–58 % CO2 savings
This paper aims to clarify the restoration of detached houses after flood events in terms of construction works and costs. We conducted field research in the six regions affected by the floods which ...included technical surveys asking the builders and the residents what restoration works they performed in 22 houses flooded above the floor. After confirming the three different levels of the works according to the degree of completion, we analyzed what causal relationships the content of the works and the construction costs have with not only the magnitude of the flood but also construction year and building construction methods.
Modern smart meters in heating systems offer building energy data of high temporal resolution. Compared to the annually aggregated readings used for conventional billing, the continuous information ...flow from these smart meters can be made available as time series data containing monthly, daily or even hourly aggregated values. In this paper, the effect of different temporal aggregation levels of commercial smart meter data on building energy model (BEM) calibration is investigated. Four different aggregation levels of a training data set were applied for calibration of six BEM input parameters to set up a Gaussian process emulator of the physical system. The performance of the emulator was subsequently tested on an unseen validation data set. Results reveal a systematic pattern of increasing predictive accuracy as a function of increasing training data resolution.
Cost optimization is one of the key elements of the EU regulatory framework concerning the energy performance of buildings. From this economic point of view, the optimum occurs when the global cost ...over the lifecycle of a building is minimized, and the cost-optimal energy performance level is that related to the minimum global cost. To determine this cost-optimal level by evaluating a great number of design alternatives, it is necessary to exploit automated optimization search procedures. The work presented here concerns the application of cost-optimal methodology, as defined by European regulation, to a low-consumption single-family house in France. The calculation is performed through an iterative input-output process in a computing environment that combines TRNSYS®, transient system simulation tool, with GenOpt®, generic optimization program. The methodology that was adopted allowed around ten thousand building configurations to be simulated in a reasonable computational time. The paper focuses on how the energy system affects the technical and economic optimal design solutions of the building in two different French climate conditions.
•Automated search for cost-optimal energy-efficient building envelopes•Modeling of 3 envelope systems for a single family house•Optimal solutions for 12 envelope/system combinations in two climates•Influence of energy efficiency solutions on cost optimization of building envelope design
This paper proposes a methodology for the assessment of the sustainability among three different structural design alternatives for a single-family home. The response associated with each alternative ...has been measured using 43 indicators considering all stages of the life cycle. A decision-making model is carried out on the basis of a neutrosophic group analytical hierarchy process (NAHP-G) capturing the maximum information in terms of credibility, inconsistency and indetermination. The 9 criteria on which an expert group intervenes are finally evaluated using VIKOR. The results show that non-probabilistic uncertainties influence the weights obtained, with maximum deviations in the criteria between 11.91% and 4.95%, if compared to conventional AHP. From the methodology it is obtained that the technological alternative with non-conventional concrete performs best in sustainable terms. Although the industrialized option has less environmental impact, only the simultaneous consideration of the economic, environmental and social pillars in a project will lead to appropriate sustainable designs.
•Sustainability assessment of structural designs under uncertainty based on 43 indicators.•A traditional reference solution is compared with two non-conventional MMC systems.•The alternative with the best environmental performance is not the most sustainable.•Experts have considered social criteria as the most relevant ones in decision making.•Neutrosophic approach captures 11.9% more reliable information than a conventional AHP.
•A Danish single-family house renovated for durability, functions and energy.•Simulation of the house before and after renovation.•Measurement of energy and indoor climate for a year before and after ...53% reduction in heating consumption with better indoor climate.•Mortgage bank estimates increase in house value corresponds to 77% of the investment.
Building renovation is too often carried out with only one objective: necessary maintenance, updating design and functions, or reducing energy consumption. But, if a necessary maintenance is exploited as an opportunity for renovation, energy improvements can be implemented, house functions can be updated, and indoor climate improved with minimal nuisance and expense. This paper illustrates this approach by documenting the renovation of a single-family house in Denmark, and monitoring its energy consumption and indoor climate before and after the renovation. Building elements were replaced where necessary, and the total energy consumption was reduced by 23%, giving the house owners a saving of about DKK 8400 per year. The energy consumption for heating was reduced by 53%, close to the 58% found using dynamic simulations. The temperatures reached a more comfortable level, and the house owners were satisfied with the result. The increased value of the house was estimated to cover about 77% of the investment.
The article considers the issue what moment/moments shall be deemed as the beginning of the period for finding defects in two objects obtained und the developer agreement, i.e., a flat/a ...single-family house (1) and land, on which the single-family house/building in which the apartment is located is erected (2). The above-mentioned issue has already been commented on by the doctrine, but only in relation to the building. Thus, this study supplements the above-mentioned considerations.
•The hourly heat load for is forecasted up to 42h ahead.•Based on weather forecasts and local observations.•Based adaptive time series modeling.•No additional information about the house is needed ...and resident behavior is included with diurnal curve.•Evaluated with data from sixteen inhabited houses over a two year period.
This paper presents a method for forecasting the load for space heating in a single-family house. The forecasting model is built using data from sixteen houses located in Sønderborg, Denmark, combined with local climate measurements and weather forecasts. Every hour the hourly heat load for each house the following two days is forecasted. The forecast models are adaptive linear time-series models and the climate inputs used are: ambient temperature, global radiation and wind speed. A computationally efficient recursive least squares scheme is used. The models are optimized to fit the individual characteristics for each house, such as the level of adaptivity and the thermal dynamical response of the building, which is modeled with simple transfer functions. Identification of a model, which is suitable for all the houses, is carried out. The results show that the one-step ahead errors are close to white noise and that practically all correlation to the climate variables are removed. Furthermore, the results show that the forecasting errors mainly are related to: unpredictable high frequency variations in the heat load signal (predominant only for some houses), shifts in resident behavior patterns and uncertainty of the weather forecasts for longer horizons, especially for solar radiation.
Der Gebäudebestand benötigt rund 30 % des gesamten Endenergiebedarfes in Deutschland. Der Erfolg der Wärmewende hängt daher maßgeblich vom Einsparpotenzial im Gebäudebestand ab. Dazu gehört neben der ...Sanierung der Gebäudehülle auch der Einsatz einer klimaneutralen Wärmebereitstellung. Für dieses Ziel ist es vorteilhaft und notwendig, die Anlagentechnik von fossilen auf erneuerbare Energieträger umzurüsten. Derzeit gilt zu Recht die Wärmepumpe als Schlüsseltechnologie für das Gelingen der Wärmewende. Dieser Beitrag untersucht den Autarkiegrad der Kombination Wärmepumpe mit Photovoltaikanlage genauer. Um den Autarkiegrad bestimmen zu können, wird für ein konkretes Praxisbeispiel eine Simulationsrechnung mit dem Programm PV*SOL erstellt. Als maßgebend für die Auswertung wird der lastgerechte Autarkiegrad in Abhängigkeit der damit verbundenen Investitionskosten bestimmt und dargestellt.
Translation
Effects of replacing a gas heating system with an outdoor air heat pump in an EFH in terms of CO2 savings, self‐sufficiency and cost‐effectiveness
In Germany, existing buildings account for around 30 % of the total final energy demand. The success of the heating transition therefore depends on the saving potential in existing buildings. In addition to the refurbishment of the building envelope, this also includes the use of climate‐neutral heat supply. To achieve this goal, it is advantageous and necessary to convert the system technology from fossil fuels to renewable energy sources. At present, the heat pump is rightly regarded as the key technology for the success of the heating transition. This article analyses the degree of self‐sufficiency of the combination of heat pump and photovoltaic system in detail. In order to determine the degree of self‐sufficiency, an existing single‐family house as practical example has been analyzed using a building simulation by PV*SOL programme. The load‐based degree of self‐sufficiency is determined and presented as a function of the associated investment costs.
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