Energy Research Center Research Articles

Application of selected supervised learning methods for time series classification in Building Automation and Control Systems

Acquiring knowledge from the growing amount of Building Automation and Control Systems (BACS) data is becoming a more and more challenging and complex engineering task. However, it is also a prerequisite for smart and sustainable energy management as well as improving energy efficiency and comfort of building users. This report analyses the prospects of applying selected supervised learning methods for time series classification in BACS. Our training and testing data covered multivariate time series from 5,142 data points located in E.ON Energy Research Center building, describing observations from 22 classes, such as temperatures of gaseous fluid, CO2 concentrations, heat flows, and operating messages. We trained thirteen types of classifiers: complex tree, medium tree, simple tree, linear Support Vector Machines, quadratic Support Vector Machines, boosted trees, bagged trees, subspace discriminant, subspace KNN, RUSBoosted Trees, Fine KNN, Coarse KNN and random forests. The highest demonstrated average classification accuracy concerned bagged trees (56.76%), with the maximum accuracy level of 76.54%. However, the maximum accuracy achieved by random forests was even higher, reaching 78.95%. Finally, we identified factors that may have a substantial influence on performance of particular methods.

System Performance Modelling of a Grid-Connected Photovoltaic System in UiTM, Malaysia

This paper presents the prediction of grid-connected photovoltaic (GCPV) system installed at Green Energy Research Center, Universiti Teknologi MARA, Shah Alam, Malaysia located at latitude of 2 °N 101°E. By using Mathematical approach and climate variations of Malaysia such as module temperature and solar irradiance, the prediction of power systems performance parameters were analyzed. The parameter of the study is limited to 26 consecutive days with filter data of 80W/m 2 irradiance. This study conducted by using monocrystalline and polycrystalline solar cell technologies. The actual and the predicted data measurement of these solar cell technologies were analyzed. The empirical models were compared according to the coefficient of determination ( R 2 ) and percentage error. MathCAD software was used in order to calculate the prediction and detail analysis of electrical parameters. Finally, the results show a good accuracy between actual and prediction data.

Lighting energy consumption in ultra-low energy buildings: Using a simulation and measurement methodology to model occupant behavior and lighting controls

As building owners, designers, and operators aim to achieve significant reductions in overall energy consumption, understanding and evaluating the probable impacts of occupant behavior becomes a critical component of a holistic energy conservation strategy. This becomes significantly more pronounced in ultra-efficient buildings, where system loads such as heating, cooling, lighting, and ventilation are reduced or eliminated through high-performance building design and where occupant behavior-driven impacts reflect a large portion of end-use energy. Further, variation in behavior patterns can substantially impact the persistence of any performance gains. This paper describes a methodology of building occupant behavior modeling using simulation methods developed by the Building Energy Research Center (BERC) at Tsinghua University using measured energy consumption data collected by the University of Washington Integrated Design Lab (UW IDL). The Bullitt Center, a six-story 4831 m2 (52,000 ft2) net-positive-energy urban office building in Seattle, WA, USA, is one of the most energy-efficient buildings in the world (2013 WAN Sustainable Building of the Year Winner). Its measured energy consumption in 2015 was approximately 34.8 kWh/(m2∙yr) (11 kBtu/(ft2∙yr)). Occupant behavior exerts an out-sized influence on the energy performance of the building. Nearly 33% of the end-use energy consumption at the Bullitt Center consists of unregulated miscellaneous electrical loads (plug-loads), which are directly attributable to occupant behavior and equipment procurement choices. Approximately 16% of end-use energy is attributable to electric lighting which is also largely determined by occupant behavior. Key to the building’s energy efficiency is employment of lighting controls and daylighting strategies to minimize the lighting load. This paper uses measured energy use in a 330 m2 (3550 ft2) open office space in this building to inform occupant profiles that are then modified to create four scenarios to model the impact of behavior on lighting use. By using measured energy consumption and an energy model to simulate the energy performance of this space, this paper evaluates the potential energy savings based on different occupant behavior. This paper describes occupant behavior simulation methods and evaluates them using a robust dataset of 15 minute interval sub-metered energy consumption data. Lighting control strategies are compared via simulation results, in order to achieve the best match between occupant schedules, controls, and energy savings. Using these findings, we propose a simulation methodology that incorporates measured energy use data to generate occupant schedules and control schemes with the ultimate aim of using simulation results to evaluate energy saving measures that target occupant behavior.

【基調講演】Session4 産総研 福島再生可能エネルギー研究所の３年間と今後

【基調講演】Session4 産総研 福島再生可能エネルギー研究所の３年間と今後

Best Practices for Quantifying the CO2 Storage Resource Estimates in CO2 Enhanced Oil Recovery

This paper details best practices for carbon dioxide (CO2) storage resource estimates in conventional hydrocarbon reservoirs associated with enhanced oil recovery (EOR) via CO2 flooding (CO2 EOR). The recommendations are based on U.S. Department of Energy-funded research through the Energy & Environmental Research Center using real-world applications and robust numerical simulations, which have led to a better understanding of factors that control CO2 storage in CO2 EOR fields. The approaches outlined in this presentation recognize that the accuracy of the CO2 storage resource estimate for a particular reservoir is directly proportional to the state of knowledge at any given point in time. To accommodate this reality, workflows are presented that guide the user through a series of decision points that help to determine which CO2 storage resource-estimating method is best for a particular situation.

Supercritical CO2 Cycles for Power Production

The Allam Cycle is a Brayton cycle utilizing supercritical CO2 as working fluid providing high thermodynamic efficiency and integrated CO2 capture. The Energy & Environmental Research Center, 8 Rivers Capital, LLC, and the North Dakota Industrial Commission Lignite Energy Council are working to develop lignite-based Allam Cycle technology in support of ALLETE, Inc., and Basin Electric Power Cooperative. Specific challenges are gasifier selection, syngas impurities removal, and corrosion. Results from laboratory experiments and pilot-scale testing to support this effort are presented. No insurmountable technology barriers were found for development of a lignite-based Allam cycle technology.

Monitoring 3.2 Million Tonnes of CO2 at the Bell Creek Oil Field

A research-monitoring program is being conducted at the Bell Creek oil field by the Plains CO2 Reduction Partnership, led by the Energy & Environmental Research Center, to evaluate and demonstrate the cost-effectiveness of strategies for monitoring CO2 storage associated with a commercial enhanced oil recovery (EOR) project. The Bell Creek oil field, operated by Denbury Onshore LLC as a commercial EOR project, is an oil-bearing, Lower Cretaceous sandstone reservoir located in southeastern Montana, USA. CO2 injection for commercial EOR began in May 2013 and has resulted in over 3.2 million tonnes of associated CO2 storage as of July 2016.

Numerical Modeling of the Aquistore CO2 Storage Project

Serving as a storage site for the world's first commercial postcombustion carbon capture, utilization, and storage project from a coal-fired power generation facility, the Aquistore project commenced injection operations in April 2015 at a site near SaskPower's Boundary Dam Power Station. The Energy & Environmental Research Center, through its Plains CO2 Reduction (PCOR) Partnership, is collaborating with the Petroleum Technology Research Centre and SaskPower to continue PCOR Partnership efforts to numerically model and interpret the performance of the project's injection well and observation well to improve monitoring, verification, and accounting strategies based on history-matching and predictive simulation results.

Guest Editorial

Guest Editorial

Slant tube characterization for the implementation of k0 - standardization in Nigerian reseach reactor-1

The result for large sample irradiation are continuously piping into the Center for Energy Research and Training (CERT), Ahmadu Bello University, Zaria. Therefore, characterization of the irradiation channels that can accommodate large samples become a challenge. In the first series of trial for large samples irradiation through slant tube of NIRR-1 which is a miniature research reactor is necessary in order to compare with some standard values reported by the arena of researchers including nuclear regulatory bodies. The thermal to epithermal flux ratio (f), epithermal neutron flux distribution parameters (α) were determined using two slant tube channels of NIRR-1. The adopted methodology here is bared and cadmium covered monitor foils method. The vertical dipstick higher purity germanium detector (HPGE) was calibrated and used for the calculation. The f and α values were calculated as 111.8 and -0.04977 respectively. The good agreement between the certified and experimental values of the shaping factors was achieved.

Recent R&D Results on Fusion Nuclear Technology for ITER and DEMO Reactor in Japan

Several key components, such as superconducting coils, remote handling equipment, heating systems, have been designed and manufactured by JADA (Japan Domestic Agency). These activities have been carried out in accordance with the agreed schedule; in collaboration with the ITER organization and other domestic agencies. As a significant technical program using ITER, to design and to manufacture the TBS (Test blanket system), some R&D and design activities have also been conducted in Japan. Under the IFERC (the International Fusion Energy Research Center) projects of BA (Broader Approach) activities, design and R&D activities on fusion DEMO reactor have been carried out. For the DEMO R&D activity, five basic R&D subjects for a DEMO blanket system have been selected, and been studies under close collaborations between EU and JA: structure materials (RAFM steels and SiC/SiC composites), functional materials (tritium breeders and neutron multipliers), and tritium technology. From 2007, the above projects produced a set of fruitful results. A series of advanced technologies for the DEMO blanket system has also been carried out by Universities in Japan. Some significant basic R&D studies have also been carried out under US-JA collaborative program.

Can a Green University Serve Underrepresented Students?: Reconciling Sustainability and Diversity at HSU

Lecture delivered at Humboldt State University on November 12, 2015 by Sarah Ray. Part of the Sustainable futures speaker series sponsored by the Schatz Energy Research Center and the Environment and Community Program. In this talk, Ray will bring these analyses to bear on the context of HSU’s twin values of “sustainability” and “diversity.” Ray will contend that achieving these goals will require reckoning with the broader historical tensions between environmentalism and social justice.

(Invited) Nano-Scaled Perovskites for Oxygen Evolution in Alkaline Environment

Oxygen electrodes are playing a key role in electrochemical energy conversion devices such as fuel cells and water electrolyzers. In both acidic and alkaline environment, both the oxygen reduction and oxygen evolution reaction (ORR and OER), respectively, are limiting the overall energy/voltage efficiency due to its sluggish kinetics. [1, 2] Whereas in acidic environment, mainly precious metal oxides are used to catalyze the OER (e.g., IrO2), the variety of possible catalysts in alkaline electrolyte is significantly increased and many metal oxide based systems can be employed. Generally the oxygen evolution mechanism is only partly understood independent of the electrolyte environment and material used. In order to help to understand the underlying mechanism for the OER and to support the experimental results, very often computational methods are used, mainly using density functional theory (DFT) calculations. Similar approaches are also used for gaining insights into catalyst stabilities under operational conditions. In this talk, some of your recent findings on non-noble metal catalysts, mainly from the perovskite family will be presented. By employing operando X-ray absorption spectroscopy (both XANES and EXAFS), important insights could be gained with respect to the perovskite electronic structure and the local catalyst structure helping to better understand the underlying mechanism for the OER. Acknowledgement: This work is supported by the Swiss National Science Foundation, the Swiss Competence Center for Energy Research (SCCER) Heat & Electricity Storage, the Swiss Federal Office of Energy and the Competence Center Energy & Mobility Switzerland.

Transition pathways for a sustainable low-carbon energy system in Thailand

As a non-Annex I country, Thailand has pledged its intended nationally determined contribution (INDC) to reduce greenhouse gas emissions by 20% from the projected business-as-usual (BAU) level by 2030 and by up to 25% with adequate and enhanced access to technology development and transfer, financial resources, and capacity building support. The purpose of this paper is to investigate how these targets could possibly be met, as far as energy-related CO2 emissions are concerned, and to propose alternative pathways for fast transition to a low-carbon and cleaner energy system along with its technology and research requirements. The study approach is based on the 6th Edition of APEC Energy Outlook for 2040 and the energy-related CO2 emissions scenarios developed at the Asia Pacific Energy Research Centre. It is found that Thailand's voluntary INDC target on energy-related emissions could be achieved by a combination of energy efficiency improvement efforts and deployment of renewable energy in line with their respective official plans. The higher conditional INDC target of 25% could also be reached by a natural gas dominated power sector, in addition to energy efficiency and renewable energy deployment measures, at the risk of worsening its energy security and increased cost of electricity. An alternative scenario that would not only meet the conditional INDC target but also lead to a fast transition towards a low-carbon and cleaner energy system by 2040 is possible. The scenario is based on a balanced approach, taking into account energy security, cost, and environment. It requires ambitious energy efficiency improvement (particularly in the transport sector) and renewable energy targets, and significant de-carbonization of the power sector. The scenario will see Thailand's energy-related CO2 emissions peaking around 2030 and a 45% cut below the projected BAU level in 2040. The technologies and research required to support the transition have also been identified for the power, transport, commercial buildings, and industry sectors.

Natural Gamma Radiation in Rocks from Kerri-Kerri Formation, Northeastern Nigeria

In a study on uranium favourability in Nigeria, it was suggested that the Kerri-Kerri Formation located in the Upper Benue Trough, Northeastern Nigeria is a potential host of uranium mineralization, hence the need to assess the level of natural gamma radiation from the rocks of the area. Laboratory γ-ray spectrometric analysis was carried out with a HPGe detector by (EG & G Ortec Inc.) at the Center for Energy Research and Training, Ahmadu Bello University, Zaria. Thirty six (36) rock samples were collected from the study area from which nine (9) composite samples were formed for the laboratory γ-ray analysis. The mean concentrations of the radionuclides 238U, 232Th and 40K were 26.9988 Bq/kg, 61.9131 Bq/kg and 91.7042 Bq/kg respectively. The mean absorbed dose rate was 15.646 nGyh−1 which is lower than the world average value of 51.5 nGyh−1. The average internal and external hazard indices were found to be 0.404 and 0.331 respectively which are lower than the acceptable limits of <1. The mean radium equivalent (Raeq) value was 122.60 Bq kg−1 which is well within and less the permissible limit of 370 Bq kg−1. Since the radiological hazard parameters are all lower than the permissible limits, the study area can be considered as safe due to natural gamma radiation and the rocks of the area can be used safely for building and construction purposes.

An investigation of reactivity effect due to inadvertent filling of the irradiation channels with water in NIRR-1 Nigeria Research Reactor-1

Investigation of reactivity variation due to flooding of the irradiation channels of Nigeria Research Reactor (NIRR-1) a low power miniature neutron source reactor (MNSR) located at the Centre for Energy Research and Training, Ahmadu Bello University, Zaria Nigeria using the MCNP code for High Enrich Uranium (HEU) and Low Enrich Uranium (LEU) core has been simulated in this present study. In this work, the excess reactivity worth of flooding HEU core for 1 inner, 2 inner, 3 inner, 4 inner and all inner are 0.318mk, 0.577mk, 0.318mk, 1.204mk and 1.503mk respectively, and outer irradiation channels are 0.119mk, 0.169mk, 0.348mk, 0.438mk and 0.418mk respectively, the highest excess reactivity result from flooding both inner and outer irradiation channels is 2.04mk (±1.72×10−7), the excess reactivity for LEU core was 0.299mk, 0.568mk, 0.896mk, 1.195mk and 1.524mk in the inner irradiation channels, and the outer irradiation channels are 0.129mk, 0.189mk, 0.219mk, 0.269mk and 0.548mk where the highest excess reactivity was 1.942mk (±1.64×10−7) resulting from flooding inner and outer irradiation channels. The reactivity induced by flooding of the irradiation channels of NIRR-1 with water is within design safety limit enshrined in Safety Analysis Report of NIRR-1. The results also compare well with literature.

Estimating NIRR-1 burn-up and core life time expectancy using the codes WIMS and CITATION

The Nigeria Research Reactor-1 (NIRR-1) is a low power miniature neutron source reactor (MNSR) located at the Centre for Energy Research and Training, Ahmadu Bello University, Zaria Nigeria. The reactor went critical with initial core excess reactivity of 3.77mk. The NIRR-1 cold excess reactivity measured at the time of commissioning was determined to be 4.97mk, which is more than the licensed range of 3.5–4mk. Hence some cadmium poison worth −1.2mk was inserted into one of the inner irradiation sites which act as reactivity regulating device in order to reduce the core excess reactivity to 3.77mk, which is within recommended licensed range of 3.5mk and 4.0mk. In this present study, the burn-up calculations of the NIRR-1 fuel and the estimation of the core life time expectancy after 10years (the reactor core expected cycle) have been conducted using the codes WIMS and CITATION. The burn-up analyses carried out indicated that the excess reactivity of NIRR-1 follows a linear decreasing trend having 216 Effective Full Power Days (EFPD) operations. The reactivity worth of top beryllium shim data plates was calculated to be 19.072mk. The result of depletion analysis for NIRR-1 core shows that (7.9947±0.0008) g of U-235 was consumed for the period of 12years of operating time. The production of the build-up of Pu-239 was found to be (0.0347±0.0043)g. The core life time estimated in this research was found to be 30.33years. This is in good agreement with the literature

Nanophotonics of biomaterials and inorganic nanostructures

Optical methods have been used for the sensitive characterization of surfaces and thin films for more than a century. The first ellipsometric measurement was conducted on metal surfaces by Paul Drude in 1889. The word ‘ellipsometer’ was first used by Rothen in a study of antigen-antibody interactions on polished metal surfaces in 1945. The ‘bible’ of ellipsometry has been published in the second half of the ‘70s. The publications in the topic of ellipsometry started to increase rapidly by the end of the ‘80s, together with concepts like surface plasmon resonance, later new topics like photonic crystals emerged. These techniques find applications in many fields, including sensorics or photovoltaics. In optical sensorics, the highest sensitivities were achieved by waveguide interferometry and plasmon resonance configurations. The instrumentation of ellipsometry is also being developed intensively towards higher sensitivity and performance by combinations with plasmonics, scatterometry, imaging or waveguide methods, utilizing the high sensitivity, high speed, non-destructive nature and mapping capabilities. Not only the instrumentation but also the methods of evaluation show a significant development, which leads to the characterization of structures with increasing complexity, including photonic, porous or metal surfaces. This article discusses a selection of interesting applications of photonics in the Centre for Energy Research of the Hungarian Academy of Sciences.

Design, Construction and Performance Evaluation of Earth -to -Air Heat Exchanger for Room Cooling in Sokoto, Nigeria

Tropical climate is characterised by high ambient temperatures and solar radiation, a combination of these factors causes thermal discomfort in buildings. With the rapid increase in population and economic growth of countries in the tropical regions, it is becoming inevitable that passive and low energy strategies must be used as suitable alternatives. Earth air heat exchanger (EAHX)&nbsp; s a subterranean ventilation system that explores soil temperature below the surface to pre-cool or pre-heat ventilationair. Performance of the earth air heat exchanger varies with climatic and soil condition of the area. In this research paper, an Earth air heat exchanger (EAHX) was designed, constructed and installed at Sokoto energy research centre, Usmanu DanfodiyoUniversity, Sokoto, Nigeria, Its actual field performance was evaluated. The results suggested that the earth air heat exchangeralone is not sufficient to create thermal comfort, but can provide significant portion of cooling load. The average coefficient ofperformance (COP) in the hot season was obtained at 3.45 .The earth air heat exchanger was able to cool the hot ambient air by4.50C during hot season.

EVALUATION OF CLIMATE CONDITIONS ON ROCK MASS ENERGY BALANCE IN THE VŠB-TU OSTRAVA RESEARCH POLYGONS

VŠB – Technical University of Ostrava (VŠB-TU Ostrava) has unique conditions for analysing temperature changes in the rock mass while borehole heat exchangers have been operational for a long time. The Auditory building is heated with a system of heat pumps (borehole heat exchangers). It is one of the largest such objects in the Czech Republic. The heat of the rock mass is provided by a system of technological boreholes. The research boreholes are used for monitoring temperature changes in the rock mass while using the Auditory’s heating system. The system for monitoring boreholes within the area of technological borehole activity is called Large Research Polygon (LRP). Apart from LRP, the university also possesses another research polygon – Small Research Polygon (SRP) located at a distance from the LRP near the Energy Research Centre (ERC). All boreholes performed within both research fields are equipped with sensors monitoring the temperature changes while the Auditory building is being heated (thermal energy is recovered from the rock mass in winter) or cooled (thermal energy is transmitted to the rock mass in summer). The main objective of the research carried out in both research fields is checking the functionality and efficiency of the entire system. Certain aspects of thermal energy recuperation from the rock mass are described. The paper is closed with the results of monitoring and calculation of temperature in the surface layers to about 20 m of depth.