Test Reference Year Research Articles

Test Reference Year for wave energy studies: Generation and validation

In a perspective of impoverishment of the fossil fuel and preservation of the natural environment, the sea wave energy is being increasingly regarded as alternative and promising resource. A key aspect to take in consideration for the deployment of Wave Energy Converters is the local characterization of the wave climate. In this contribute, a methodology for the calculation and validation of a site-specific Test Reference Year (TRY), from a multiyear dataset such ERA-Interim and ERA-5, to be used in wave energy conversion studies is proposed. Comparison of the two datasets with observed data gives ERA-5 as the best dataset.The methodology applied for the TRY generation has proven to be very effective, with the daily sum of Hs and Tm being the most effective indices for the TRY generation and in general Hs about twice more important than Tm. Once obtained, the TRY is applied in order to force an implementation of the Simulating WAves Nearshore (SWAN) model in an area of the central Adriatic Sea to characterize the area.

Correction of Precipitation Data in Weather Files for the Subtropical Climate in Southern Brazil

The thermal performance of buildings can be evaluated prior to its construction by modeling it using a specialized software. Climate boundary conditions must be represented by a weather file that is composed of a weather dataset organized hourly according to a defined year structure such as Test Reference Year (TRY) or Typical Meteorological Year (TMY). Before this study, there were a few weather files available for cities in southern Brazil, notably, Santa Maria, RS, classified as a humid subtropical climate. The most recent available weather file was built in 2014 and presents inconsistencies with respect to precipitation data. Therefore, the objetive of this study was to process and analyze the climate data of Santa Maria over an eighteen-year period (2002-2020), to generate a more reliable weather file. The applied method considered the following procedures: data collection and processing; TRY (TRY17) and TMY2 (TMY0220) definition; solar radiation data calculation; EPW files generation; and comparison between the new EPW files and the previous existing files. As a result, in a short period of time (2014-2020), significant differences among the weather files were observed. The importance of updating weather files in time intervals shorter than 30 years was emphasized. In relation to the comparative analysis, both weather files (TRY17 and TMY0220) presented dry bulb temperatures in consonance with the other files previously available. Although, the correction of precipitation data could originate building simulations closer to the reality.

Model predictive approaches for cost-efficient building climate control with seasonal energy storage

Due to the increasing share of fluctuating renewable energy, a seasonal energy storage with a high capacity is needed, which stores the summer surplus electricity to satisfy the winter heating demand.It is assumed that the control integration of a novel thermochemical seasonal energy storage concept into a building energy system can meet this requirement and save operating costs. For this purpose, a model-predictive control concept with a prediction horizon beyond that of public weather forecasts is crucial.A state-based model is developed consisting of a building, a water buffer and a heat supply. To assess the effects of seasonal storage, different heat supply configurations are considered. On this basis, two Model Predictive Control (MPC) concepts are designed to efficiently operate the system over one year. Since public weather forecasts are reliable in the time range of several days, test reference year data are used to approximate the weather forecast beyond the public forecast period. Additionally, the control hierarchy is comprised of a superordinate optimal generation scheduling (OGS) and a subordinate MPC. The concepts follow the scheduled long-term lime storage trajectory and realise possible short-term yields based on the current public forecast. The trajectory tracking is formulated either in the objective function or the constraints.The integration of the novel lime storage module into the heat supply of a building allows a reduction of operating costs of 18% in the realistic scenario and up to 80% in case of highly fluctuating electricity prices. This reduction potential is fully exploited by the developed control approaches, but it is very sensitive to the change of the controller parameters, the fluctuation of the electricity price and the weather data. Moreover, by applying the objective-based reference tracking approach, the higher-level scheduling hierarchy could be avoided.Through the results of this work, it is confirmed that the integration of a seasonal energy storage system can greatly reduce annual operating costs and that it is not crucial to apply a prediction horizon beyond that of public forecasts.

Characterization of the annual regime of surface solar irradiance over Argentine Pampean Region using GL1.2 satellite-based data

Detailed description of the solar resource (spatial distribution and temporal variations) is highly desirable in the context of climate monitoring, agricultural planning and energy technologies; however, one shortcoming is the low density of solarimetric networks in many extended regions. Satellite-based estimations have become a potential key tool, provided their data show adequate temporal frequency, high resolution and acceptable accuracy. GL1.2 Model currently runs at Brazilian National Institute for Space Research (CPTEC/INPE), based on GOES VIS channel imagery. It was tested for characterizing solar radiation regime over Pampa Region in Argentina, which extends over more than 600,000 km2. Comparison with time series of nine stations of the Pampa network in the period 2011–2018 showed close agreement for daily mean irradiance using 10-days as well as monthly values (mean bias error generally |MBE| < 6 W m-2 standard deviation STD ≈ 10-15 W m-2 and resulting root mean square error RMSE ≈ 10–16 W m−2). Completeness of GL time series and high spatial definition (0.04°) allowed further time and space analysis of solar radiation regime. It confirmed that Pampean region is rather homogeneous with annual mean GL increasing from 185 W m−2 on coastal region up to 220 W m−2 on the western and northern limits. In addition, GL data detects sharper variations in a scale of few kilometers, such as transition between ground and water in oceanic coast or large rivers. Regional interannual variability is low: COV ≈ 3–4%. All stations in Pampa network show a well definite annual cycle, closely followed by GL estimates. Fourier analysis for GL monthly series shows a dominant deterministic one year signal (H8 harmonic), accounting for 93–95% of variance for all stations and throughout the Pampa region, in phase with the end of Southern Hemisphere spring. The H8 amplitude varies from 100 W m−2 along inner continental boundary up to 120 in southwestern and coastal bound. It is concluded that GL 1.2 model data can be used to accurately describe time series of daily mean irradiance, for 10-days and monthly scales and 4 km resolution, providing a "Test Reference Year" (TRY). This is precious in order to describe spatial-temporal patterns of regional solar climate. An otherwise "random signal" of 20 W m−2 is associated to transient meteorological phenomena with durations shorter than 10-days, such as cold fronts or convective activity. Their deterministic and/or statistical structure could be improved by the combined analysis of short-time scales Pampa network and GL data (daily, hourly or even minutely).

Дулаалгын тунгалаг системүүд

Abstract: In a southerly oriented facade, a Transparent Thermal Insulation (TI) converts incoming solar radiation into usable heat which can be transported to the interior of the building. Transparent insulations are generally installed in front of massive building walls wich serve as energy storage. Different variations of installations have been simulated with a computer program. Real weather data from the Test Reference Year for Ulaanbaatar, Mongolia have been taken into account, a heat gain of as high as 175,8 kWh/m2 seems attainable in wintertime.

에너지 저감을 위한 유지관리형 리모델링의 외벽 단열 성능기준 제안

Purpose: We would like to propose an insulation-resistant design suitable for maintenance-type remodeling that conforms to green remodeling. Method: Permanent rental apartment houses in Seoul were selected for analysis. The current status of the target site was reviewed, and the representative households with similar shade environments and weak insulation were selected in consideration of Seoul’s climatic characteristics. As a research method, after climate analysis of Seoul TRY (Test Reference Year) meteorological data from 2005 to 2014, condensation and thermal bridge analysis were conducted through the THERM program. To this end, the ISO 52016 (formerly ISO 13790) standard program Energy# was used to present the exterior wall insulation performance standards to secure the comfort of the apartment house, and to evaluate the energy performance before and after remodeling for each representative household. Result: An appropriate minimum thickness of insulation to prevent condensation and mold was suggested. When remodeling an apartment house, 45-80㎜ of insulation is the most economical level. It is necessary to study the domestic insulation design method suitable for the living environment.

Regionalized dynamic climate series for ecological climate impact research in modern controlled environment facilities.

Modern controlled environment facilities (CEFs) enable the simulation of dynamic microclimates in controlled ecological experiments through their technical ability to precisely control multiple environmental parameters. However, few CEF studies exploit the technical possibilities of their facilities, as climate change treatments are frequently applied by static manipulation of an inadequate number of climate change drivers, ignoring intra‐annual variability and covariation of multiple meteorological variables. We present a method for generating regionalized climate series in high temporal resolution that was developed to force the TUMmesa Model EcoSystem Analyzer with dynamic climate simulations. The climate series represent annual cycles for a reference period (1987–2016) and the climate change scenarios RCP2.6 and RCP8.5 (2071–2100) regionalized for a climate station situated in a forested region of the German Spessart mountains. Based on the EURO‐CORDEX and ReKliEs‐DE model ensembles, typical annual courses of daily resolved climatologies for the reference period and the RCP scenarios were calculated from multimodel means of temperature (ta), relative humidity (rh), global radiation (Rg), air pressure (P), and ground‐level ozone and complemented by CO2. To account for intra‐annual variation and the covariability of multiple climate variables, daily values were substituted by hourly resolved data resampled from the historical record. The resulting present climate Test Reference Year (TRY) well represented a possible annual cycle within the reference period, and expected shifts in future mean values (e.g., higher ta) were reproduced within the RCP TRYs. The TRYs were executed in eight climate chambers of the TUMmesa facility and—accounting for the technical boundaries of the facility—reproduced with high precision. Especially, as an alternative to CEF simulations that reproduce mere day/night cycles and static manipulations of climate change drivers, the method presented here proved well suited for simulating regionalized and highly dynamic annual cycles for ecological CEF studies.

Proposal and evaluation of typical illuminance year (TIY) generation procedures from illuminance or irradiance data for daylight assessment in the long term

When assessing the long-term daylight availability or the performance of natural lighting systems in a given location, it is necessary to have representative data of local daylight conditions. The use of a daylight test reference year (TRY) becomes a good option in these cases. This paper proposes and evaluates a procedure for the generation of a typical illuminance year (TIY) considering illuminance as the only variable for selecting the typical periods that make up the reference year. Two versions of TIY are presented, one composed of 12 typical months selected from the series of observations and another composed of 365 typical days. Each of these versions is used to obtain a global illuminance TIY (TGIY) and a diffuse illuminance TIY (TDIY) from a 27-year dataset corresponding to the Vaulx-en-Velin station (France). Furthermore, 12 luminous efficacy models have been evaluated in order to obtain a TIY from a TRY generated from irradiance data when no illuminance data are available. Thus, a global luminous efficacy model and a diffuse model are selected after benchmarking different models, considering both their original coefficients and those adjusted to local conditions. The results reveal that the monthly version of the TGIY and the daily version of the TDIY show the best overall fit to the long-term dataset. TIYs obtained from illuminance data are also observed to be statistically indistinguishable from those obtained after applying a luminous efficacy model to an irradiance-based TRY.

Analysis of energy retrofit system using latent heat storage materials applied to residential buildings considering climate impacts

Weather data is an important factor to evaluate the accurate energy performance of the building. However, the objectivity of the results from simulations conducted in South Korea is under debate because only the weather data is based on four locations provided. Therefore, this study demonstrated the importance of the accurate weather data and analyzed suitable PCM applications to be applied for effective building energy savings when accurate weather data were used. In this study, the building energy performance of residential buildings using a PCM is evaluated based on the test reference year (TRY) from ISO 15927-4 and the existing weather data (EWD) of 19 major meteorological locations. According to the analysis results, when the energy performance is analyzed using the existing weather data, the results of the other regions are calculated based on the weather data of the four regions. Therefore, the values of each regions are similar because the geographical characteristics and the climate conditions of each regions are not properly reflected in the results. On the other hand, the energy performance of building based on TRY was accurately calculated by reflecting geographical characteristics and the climate zones proposed by the South Korean government. Consequently, the suitable melting temperature of PCM is different in each region for building energy savings, and the effective energy saving in the building with PCM can be realized based on this study.

Measured and simulated energy performance of OLK NZEB with heat pump and energy piles in Hämeenlinna

In this work, measured energy use of the building space heating, ventilation supply air heating, appliances and lighting is compared against simulated energy use modelled in IDA ICE. As built energy need and detailed measured input data is applied in building model calibration procedure. Calibrated building model energy performance is studied in both measured and test reference year climate conditions. Previously modelled as built plant automation and implemented control logics are compared against measured. Geothermal plant in this study consists of heat pump, solar collectors, boreholes and energy piles. Heat pump SCOP estimated by post processing according to heat pump manufacturer’s performance map is compared against measured SCOP on the monthly basis. Opinion on actual plant operation is given and energy performance improvement potential is quantified. Important parameters for successful building model calibration are presented. Building compliance with Finland NZEB requirements are assessed. The results show good match with measured energy use after the model calibration.

PCSP’s Diagonal Tie Connectors Thermal Bridges Impact on Energy Performance and Operational Cost: Case Study of a High-Rise Residential Building in Estonia

This study analyses the effect of air circulation around diagonal tie connectors in precast sandwich panels on heating energy demand, energy performance value and heating costs of a sample residential building. Dynamic simulations were performed using 4 different climatic boundary conditions: Estonian test reference year, Estonian 48-year weather dataset as well as data from Eastern Germany and Northern Finland. The results show that the effect of the thermal bridge is most noticeable in total room heating energy demand (increase of 10.3%), while the influence on energy performance value was 1.1%. The relative increase of total room heating energy demand was similar (7.0-10.3%) in all studied climatic regions.

Synthesizing test Reference Year files from known climate patterns of nearby cities

The importance of an architecture adapted to its climatic context is often debated. In order to avoid future unexpected environmental behavior or failure of a building during its use, building simulation tools are used in the design and require complete and consistent weather data. However, such data are not always available for the locations where buildings are simulated, and the use of data from neighboring cities becomes usual. There are, though, several uncertainties involved in the behavior of environmental variables when the climate of large urban centers is attributed to nearby localities and areas with more significant vegetation cover, water bodies, different topography, among others. The present paper aims to present the process of preparing a weather file for the Pecém Industrial and Port Complex, located at 40 km from the capital Fortaleza, Brazil, in order to be used in simulations during the design process of buildings. The synthesis of the file was achieved through the collection and treatment of information measured in loco, the application of recommended models for the estimation of missing data, and the development of an alternative method for the estimation of a Test Reference Year of localities without weather data of several years.

Balancing daylight and overheating in low-energy design using CIBSE improved weather files

A new set of CIBSE weather files for building performance simulation was recently developed to address the need for better quality solar data. These are essential for most building performance simulation applications, particularly for daylighting studies and low-energy building design, which requires detailed irradiation data for passive solar design and overheating risk analysis. The reliability of weather data becomes paramount when building performance is pushed to its limits. Findings illustrate how principles of good window design can be applied to a case study building, built to the Passivhaus standard, and how its expected performance is affected by the quality of solar irradiation data. Analyses using test reference years were most affected by changes in the solar radiation model (up to 8.3% points), whereas for design summer years the maximum difference was 1.7% points. Adopting the new model caused overheating risk to be classified as more severe using test reference years than design summer years, prompting a discussion on the design summer year selection method. Irradiance data measured on-site were used as a benchmark to evaluate the new solar radiation model, which was found to significantly improve the accuracy of irradiance data within weather files and so the reliability of overheating assessments. Practical application: CIBSE weather files are widely used for compliance verification of building performance in the UK context. This paper tests how the introduction of a new solar radiation model in weather files will affect daylighting and overheating simulation results. Examples are given on how low-energy building design considerations driven by advanced simulation techniques can help reaching indoor visual and thermal comfort requirements.

Current and future test reference years at a 5 km resolution

Frequently, the computer modelling of the natural and human-made environment requires localised weather files. Traditionally, the weather files are based on the observed weather at a small number of locations (14 for the UK). Unfortunately, both the climate and the weather are known to be highly variable across the landscape, so the small number of locations has the potential to cause large errors. With respect to buildings, this results in incorrect estimates of the annual energy use (sometimes by a factor of 2), or of overheating risk. Here we use a validated weather generator running on a 5 × 5 km grid to create probabilistic test reference years (pTRYs) for the UK at 11,326 locations. We then investigate the spatial variability of these pTRYs and of annual energy estimates and temperatures in buildings generated by them, both now and in 2080. Further pTRYs targeted at understanding the impact of minimum and maximum temperatures are proposed and produced at the same locations. Finally, we place these pTRYs, which represent the first set of reference weather files at this spatial resolution in the world and that include the urban heat island effect, into a publicly accessible database so researchers and industry can access them.Practical applications: Insufficiently localised weather data for building simulations have limited the accuracy of previous estimations of energy use and overheating risk in buildings. This work produces localised probabilistic test reference years (pTRYs) across the whole UK for now and future climates. In addition, a new pTRY method has been proposed in order to overcome an unexpected shortcoming of traditional pTRYs in representing typical maximum and minimum temperatures. These current and future weather data will be of interest to various disciplines including those interested in low carbon design, renewable energy and climate resilience.

A European Database of Building Energy Profiles to Support the Design of Ground Source Heat Pumps

The design of ground source heat pumps is a fundamental step to ensure the high energy efficiency of heat pump systems throughout their operating years. To enhance the diffusion of ground source heat pump systems, two different tools are developed in the H2020 research project named, “Cheap GSHPs”: A design tool and a decision support system. In both cases, the energy demand of the buildings may not be calculated by the user. The main input data, to evaluate the size of the borehole heat exchangers, is the building energy demand. This paper presents a methodology to correlate energy demand, building typologies, and climatic conditions for different types of residential buildings. Rather than envelope properties, three insulation levels have been considered in different climatic conditions to set up a database of energy profiles. Analyzing European climatic test reference years, 23 locations have been considered. For each location, the overall energy and the mean hourly monthly energy profiles for heating and cooling have been calculated. Pre-calculated profiles are needed to size generation systems and, in particular, ground source heat pumps. For this reason, correlations based on the degree days for heating and cooling demand have been found in order to generalize the results for different buildings. These correlations depend on the Köppen–Geiger climate scale.

Summer performance, comfort, and heat stress in structural timber buildings under moderate weather conditions

PurposeThe purpose of this paper is to examine the Summer performance, comfort, and heat stress in structural timber buildings. The research utilises building simulation as a tool to investigate the performance of the case study buildings under non-extreme weather conditions.Design/methodology/approachThe research explores three UK sites using the test reference year (TRY) weather files for the current and future weather conditions. The study focuses on the Summer performance and heat stress in non-extreme weather conditions; therefore, the Design Summer Year (DSY) weather files are not used for the simulations. The simulation data are calibrated and validated using the measured data from the field study.FindingsThe results revealed the mean predicted temperatures varied from 20.2–20.8°C for the 2000s. The mean temperatures for the 2030s ranged from 23.1 to 24.2°C. Higher temperatures are predicted at the buildings in the Southeast site than the Midlands and the Northwest sites. The results revealed that there is no significant improvement in the thermal environment when the floor area and the floor-to-ceiling height are increased. However, the study showed that the integration of different design interventions can improve the future performance and resilience of the buildings in various weather conditions.Research limitations/implicationsBy applying the wet-bulb globe temperature (WBGT) and the Universal Thermal Comfort Index (UTCI) mathematical models to calculate the heat stress at the buildings, the study proposes the WBGT of 20.0°C and the UTCI of 24.1°C as possible heat stress indicators for occupants of the buildings in the 2030s.Practical implicationsOn the one hand, the results revealed the maximum temperatures in some of the case study buildings exceed the comfort threshold (28°C). On the other hand, the study showed that occupants of the buildings are not prone to extreme Summertime overheating and heat stress under moderate weather conditions. However, different outcomes may be predicted if DSY weather files for the selected sites are considered.Originality/valueThis study is the first reported work to explore building simulation and mathematical equations to investigate Summer performance, comfort and heat stress indexes in timber buildings under moderate weather conditions in different regional sites in the UK.

Assessing the requirements from ‘BB101’ 2006 and 2018 for a naturally ventilated preparatory school in the UK

In the UK, BB101 is the guidance document for ventilation design of school buildings. There are significant changes proposed in the new version of BB101. The aim of this paper is to examine the requirements of thermal comfort and CO2-based indoor air quality using both versions on a typical naturally ventilated preparatory school design using dynamic thermal simulations. The findings indicate that the new set of requirements on this school building design (both thermal and CO2 concentration) are much more difficult to meet than the requirements from the old version. One of the new thermal comfort criteria may be too difficult to achieve in practice, as the target value was exceeded for all the rooms of the examined design, using both test reference year and design summer year weather data. The ventilation provision for the school design is believed to be adequate. With appropriate ventilation control strategies, the design is able to meet the revised CO2 concentration criteria. Further examinations of the criteria from the new guidance document are needed to make sure the chosen criteria are fit for purpose. The use of future projected design summer year weather data (2020) also adds extra challenges for the preparatory school building to meet the newly proposed adaptive thermal comfort criteria. Practical applications: The research presents a very first assessment of a preparatory school building design using the newly proposed BB101 guidance document. It will assist further exploration on the appropriateness of the new assessment criteria and the use of design summer year weather data in order to explore the implications of the new BB101 guidelines for designers. The method adopted in the research can also be used for other building types to assess overheating in buildings when adaptive comfort criteria are recommended.

Effect of applied weather data sets in simulation of building energy demands: Comparison of design years with recent weather data

Building energy demands in long-term studies are mostly calculated using the averaged weather data sets, reflecting the changes in environmental conditions over time, thus the different energy consumption each year. This paper reviews and discusses the coupled effects of warming trend in global mean surface temperatures, application of different design weather datasets, and utilization of different methods of building energy assessment on the calculated energy demands. The possible inaccuracies of building energy analyses caused by those three factors are investigated on the example of a residential house in Central Europe. For that purpose eight different weather data sets for Prague, Czech Republic are selected and simulations in two different scales are performed. The analysis of the effect of recent weather data is performed by an improved methodology. First, the simulation brings an increased precision as an advanced hygrothermal model is used for energy calculations. Second, the building performance is assessed, contrary to the Czech national standards, using both heating and cooling energy demands. The simulation results confirm the warming trend in the time period of 2013–2017 as the average heating demands are 3.95% lower and the average cooling demands 3.96% higher in a comparison with the Test Reference Year. In the extreme years, a 12–15% decrease of energy consumed for heating and up to 20% increase of energy necessary for cooling is found. This is in accordance with the presumed warming trend that has been widely discussed during the last few decades. Furthermore, the presented results verify the critical and positive design weather years as suitable for application in the simulation of heating and cooling energy demands in the Czech Republic.

Energy Analysis and Carbon Saving Potential of a Complex Heating System with Solar Assisted Heat Pump and Phase Change Material (PCM) Thermal Storage in Different Climatic Conditions

Building sector still consumes 40% of total energy consumption. Therefore, an improved heating system with Solar Assisted Heat Pump (SAHP) was introduced in order to minimse the energy consumption of the fossil fuels and to lower the carbon dioxide emissions occurring from combustion. An energy analysis of the complex heating system for heating of buildings, consisting of solar collectors (SC), latent heat storage tank (LHS) and heat pump (HP) was performed. The analysis was made for the heating season within the time from October to March for different climatic conditions. These climatic conditions were defined using test reference years (TRY) for cities: Adana, Ljubljana, Rome and Stockholm. The energy analysis was performed using a mathematical model which allowed hourly dynamics calculation of losses and gains for a given system. In Adana, Rome and Ljubljana, it was found that the system could cover 80% of energy from the sun and the heat pump coefficient of performance (COP) reached 5.7. In Stockholm, the maximum COP of 5.12 was reached in March and October.

Avaliação de desempenho térmico em salas de aula no Alto Sertão da Paraíba – estudo de caso no IFPB, Campus Cajazeiras

&lt;p&gt;The search for greater efficiency in the thermal performance of buildings in hot climate places aims to improve living conditions so as to mitigate extreme climatic conditions and to reduce energy consumption with artificial air conditioning. In this sense, thermal comfort evaluations aim to diagnose the environmental conditions offered to users in order to identify existing problems, and propose solutions for them. These evaluations are even more important in school environments, where this influence becomes more considerable due to the direct contribution of the thermal environment in the delicate teaching-learning relationship. This research is a study carried out in the city of Cajazeiras, located in Paraíba, it evaluated the thermal performance of the Instituto Federal de Educação, Ciência e Tecnologia da Paraíba, Cajazeiras campus classrooms. First of all, it tried to analyze local climatic conditions based on the test reference year - TRY calculated on the Instituto Nacional de Meteorologia meteorological station, located in São Gonçalo city / PB, 30km from Cajazeiras. Then, we described the physical characteristics of the classroom blocks, as well as the monitoring of four classrooms, which represented the two existing typologies, from October 11 to 24, 2016. It was found that the classrooms kept the temperature values within the zone of thermal comfort during class times, with the aid of the air conditioner. However, relative air humidity values were lower than the 60% limit suggested by the World Health Organization. &lt;/p&gt;