Probabilistic framework for evaluating food security of households in the aftermath of a disaster

For households of all income levels, and especially for those that are food insecure, food access can be threatened by natural hazards. Extreme natural hazards can disrupt critical infrastructure systems, such as the transportation or electrical power networks, damaging the roads and bridges critical for food supply chains or electrical transmission lines providing electricity for food preservation. Interdependencies among infrastructure systems within the food supply chain make it vulnerable to unanticipated and cascading consequences. Maintaining food security in the aftermath of a natural hazard challenges a community’s resilience, recovery, and social well-being. This study introduces a methodology to consider how the interconnectedness among civil infrastructure systems impacts food-security of urban inhabitants. To this end, different infrastructure systems along with their spatial distribution are modeled to evaluate the restoration of food security within a community. Food security metrics, including food availability, accessibility, and affordability, are defined and quantified to provide risk-informed decision support to policymakers in the aftermath of an extreme natural hazard. The methodology proposed herein that considers system interconnectedness and uncertainties in demand and supply can be applied to identify practical policy interventions to hasten recovery of food systems and reduce the adverse impacts of food-insecurity on a community.     

The duck curve in a drying pond: The impact of rooftop PV on the Western Australian electricity market transition

Rooftop solar photovoltaics (PV) are significantly influencing the electricity market and system operability in Western Australia. Qualitative methods are used to determine likely impacts and solutions to associated technical and market challenges in this islanded electricity system. Solutions focus on flattening the load curve and addressing minimum system load issues, including via; tariff reform, new ancillary services, automation, storage and energy productivity; targeted markets to match energy supply to the new demand curve; together with enabling technologies such as; improved inverter functionality and control systems. A parsimonious model demonstrates the impacts of rooftop PV on the local mid-day wholesale energy prices.     

Environmental impact of building-related and user-related energy consumption in dwellings

Energy consumption in dwellings contributes significantly to their total negative environmental impact. This paper quantitatively assesses the environmental impact of building-related and user-related gas and electricity consumption in a Dutch apartment dwelling using life cycle assessment (LCA) methodology. Several scenarios for gas and electricity consumption are compared to assess what effect changes in building characteristics and user behaviour have on the environmental impacts of energy consumption. This study shows that gas consumption significantly contributes to four environmental impact categories, which can be most effectively countered by reducing the heat demand of the dwelling. A 23% reduction in gas consumption leads to up to 13% less overall environmental impacts. Particularly in buildings with low heat demand, electricity consumption dominates all environmental impact categories. These can most effectively be reduced by changing the electricity demand of the user: 47% less electricity consumption leads to a 9–45% reduction in the total environmental impact. However, since electricity consumption continues to rise, the environmental effects of electricity use may be better reduced by changing the environmental impact of the electricity supply. Theoretically, when electricity consumption remains the same, over 90% less environmental impact could be reached by using 100% wind power to generate electricity.     

Time-based pricing and electricity demand response: Existing barriers and next steps

Interest in Demand Response (DR) is increasing due to its potential to improve reliability and save costs for electricity systems. DR can provide a sustainable and cost-effective option for supply balancing, especially in a scenario with more volatile inflows from renewable energy sources. End-users can be incentivized to provide DR through time-based pricing in general and dynamic pricing in particular. This paper provides a theoretic framework and practice-oriented review of the status of DR in Europe, outlining the major challenges currently hampering further DR development. Important challenges involve the split-incentive issue for investments in enabling technologies, traditional market rules for flexibility that favor large generation units and the need for electricity market and network operation coordination.     

An exergy application for analysis of buildings and HVAC systems

The paper presents an extended method for exergy analysis of buildings and Heating Ventilation Air Conditioning (HVAC) systems, according to an energy demand build-up model from the building side to the energy supply side. The HVAC systems comprise a thermal energy emission and control system, a thermal distribution system, an electricity distribution system and an energy conversion system. Energy and exergy that are required by a building and a HVAC system are posed into the external part and classified by different forms of energy carriers. The external part is out of the boundary of the study. The method is illustrated with an office building equipped with low-temperature heating and high-temperature cooling systems situated in the Netherlands. Thermal exergy and thermal energy demands of the building and thermal energy and thermal exergy losses occurring in the HVAC systems are discussed. The building and the HVAC systems to be considered meet standard Dutch energy performance regulations. Nevertheless their overall exergy efficiencies are low in both cases (17.15% and 6.81% subsequently). The exergy analysis also pinpoints that the thermal energy emission and control system and the energy conversion system are the main causes of the exergy inefficiencies in the heating and cooling cases, respectively.     

Solving electric power distribution uncertainty using deep learning and incentive-based demand response

Recent Demand Response (DR) struggles with the end user's uncertainty in Electric Power Consumption (EPC), which affects the system's generation costs and stability. Incentive-based DR has offered to be an effective technique for mitigating supply and demand imbalances. However, it presents complex issues, such as electricity consumption uncertainty. This article proposes an incentive-based integrated DR model for Demand Side Management (DSM) program to handle the EPC uncertainty. In addition, the applicability of DR has been enhanced by the deep learning-based Bi-directional Long Short Term Memory (B-LSTM) model to forecast and curtail the load of the participated end users in the DSM program. Finally, results indicate that the proposed DSM program can achieve a win-win situation in reducing end-user uncertainty, lowering costs, and enhancing system stability.     

The underlying factors in the uptake of electricity demand response: The case of Poland

Demand response (DR) is considered crucial for a more reliable, sustainable, and efficient electricity system. Nevertheless, DR's potential still remains largely untapped in Europe. This study sheds light on the roots of this problem in the context of Poland. It suggests that unfavorable regulation is symptomatic of the real, underlying barriers. In Poland, these barriers are coal dependence and political influence on energy enterprises. As main drivers, supply security concerns, EU regulatory pressure, and a positive cost-benefit profile of DR in comparison to alternatives, are revealed. A conceptual model of DR uptake in electricity systems is proposed.     

Domestic demand-side response with heat pumps: controls and tariffs

ABSTRACT

Electric heat pumps feature prominently in projected energy transitions in the UK and elsewhere. Owing to their high electricity consumption, heat pumps are viewed as important targets for demand-side response (DSR). Findings are presented from a field trial of a new control system that aims to optimize heat pump performance, including under time-varying tariff conditions. The trial involved monitoring 76 properties with heat pumps, but without dedicated heat storage; 31 of these received the control system. Interviews were conducted with a subsample of 12 participants. The controller successfully evened out electricity demand over the day (reducing the evening peak), but this was associated with increased late night and daytime temperatures. Interview participants reported some disturbance owing to overnight heating and noise, as well as usability issues with the controller interface and hardware. These issues present risks to the future acceptability of such systems. While the system delivered short-term demand reductions successfully, longer-term demand shifting risked causing unacceptable disturbance to occupants. Future control systems could overcome some of the issues identified in this pioneering trial through more effective zoning, using temperature caps or installing dedicated heat storage, but these may either limit the available flexibility or be challenging to achieve.     

北京2008奥运场馆配电系统

介绍了奥运场馆配电系统依据的标准、指南.根据场馆用电负荷的重要性及需求,采用了负荷分组相互独立、多电源相互独立并分别向分组负荷供电、临电并网切换的多电源配电系统,将奥运会期间断电的负面影响降到最小.合理地计划、选择及配置系统设施,以满足奥运会期间及奥运会结束后的需求.     

Implementing automated residential demand response in South Korea: Consumer preferences and market potential

In recent years, electricity demand response (DR) has attracted attention as the most cost-effective way to balance the electricity grid. This study analyzes the preferences of South Korean energy consumers on residential DR and calculated the potential capacity of peak reduction in summer. The estimation demonstrates that consumers have heterogeneous preferences for automated residential DR programs and highly value reducing their monthly electricity bills. A scenario analysis shows that approximately 60.0% of metropolitan consumers in South Korea would participate in a residential DR program, and the corresponding reduction in the peak load is forecasted to be approximately 1.74 GW.     

Performance assessment of fuel cell micro-cogeneration systems for residential buildings

The reduction of greenhouse gas emissions in the building sector to a sustainable level will require tremendous efforts to increase both energy efficiency and the share of renewable energies. Apart from the lowering of energy demand through better insulation and fenestration, small combined heat and power (micro-cogeneration) systems may help improve the situation on the supply side by cutting both the non-renewable energy demand for residential buildings and peak loads in the electric grid. Though still on the brink of market entry, fuel cells are the focus of interest as the prime technology for such systems. In this study, a methodology for assessing the performance of such systems in terms of primary energy demand and the CO₂ emissions by transient computer simulations is established, and demonstrated for a natural gas driven solid oxide fuel cell (SOFC) and, to a lesser extend, a polymer electrolyte fuel cell (PEFC) home fuel cell cogeneration system. The systems were evaluated for different grid electricity generation mix types and compared to traditional gas boiler systems. The interaction with hot water storage and solar thermal collectors, and the impact of storage size and predictive control was analyzed. Typical heat and electricity demand load profiles for different types of residential buildings and occupancy were considered, and the sizing of the fuel cell system in relation to the heat demand of the building was analyzed. Primary energy savings decline for cases with lower heat demand and for cases with solar thermal systems, and peak for fuel cell systems sized in accordance with the heat demand of the building. Future assessments of fuel cell systems will need a refined methodology, and depend on realistic performance characteristics and models that accurately consider dynamic conditions.     

The projected impacts of NOx emissions reductions on electricity prices: a case study for the State of Indiana

This paper examines the impact of various nitrogen oxides (NO_x) emission control scenarios on the price of electricity. Specifically, various scenarios are presented to illustrate the price impacts for the state of Indiana. The scenarios represent different methods for reducing NO_x emissions levels to either 0.15 or 0.25 lb/mmBtu. The analyses were performed using a traditional regulation forecasting model that equilibrates between price and demand. Thus, the effects of price changes on demand levels were captured. Price impacts are presented at an overall average level as well as by customer class. The impacts of various assumptions made in the selection of the scenarios are analyzed.     

Direct chiller power limiting for peak demand limiting control in buildings—Methodology and on-site validation

Large electricity consumers are often charged of a high price for their peak demand for the purpose of reducing the capacity and cost, as well as the operation reliability of electricity transmission facilities. As a result, even one spike in the monthly demand profile would result in a significant increase in electricity bill. Peak demand limiting techniques provide an effective and efficient means to reduce such cost. For instance, the methods to utilize cooling/heating stored in building thermal mass by resetting space air temperature set-point have been proofed effective in many studies. This study proposes a direct chiller power limiting control strategy for peak demand limiting control in buildings, particularly during the period of chiller starting when the peak demand occurs mostly. Validation tests were conducted on-site in a super high rise building and on a dynamic simulation platform. Results showed the strategy was effective in reducing the peak demand during chiller starting periods.     

Cybersecurity and resilience in the swiss electricity sector: Status and policy options

Electricity systems are critical infrastructure. With increasing digitalization, they become particularly vulnerable to cyberattacks. Cybersecurity hence becomes increasingly crucial for the security of supply. Based on a detailed analysis of the status of cybersecurity in the Swiss electricity sector, we derive a set of policy recommendations on how to raise countries’ cybersecurity levels in electricity systems. The analysis builds on a national E-survey that solicited self-assessment of cybersecurity maturity levels of 124 Swiss energy market participants. It was complemented by a detailed, comparative analysis of cybersecurity measures in Switzerland and its surrounding European neighbors. On average, we found a cybersecurity maturity that needs to be ameliorated regarding information and operation technology in the Swiss electricity sector. This situation calls for improved regulatory measures and monitoring to stimulate cyber resilience among market participants.     

Risk of sick leave associated with outdoor air supply rate, humidification, and occupant complaints

We analyzed 1994 sick leave for 3,720 hourly employees of a large Massachusetts manufacturer, in 40 buildings with 115 independently ventilated work areas. Corporate records identified building characteristics and IEQ complaints. We rated ventilation as moderate (approximately 25 cfm/person, 12 ls-1) or high (approximately 50 cfm/person, 24 ls-1) outdoor air supply based on knowledge of ventilation systems and CO2 measurements on a subset of work areas, and used Poisson regression to analyze sick leave controlled for age, gender, seniority, hours of non-illness absence, shift, ethnicity, crowding, and type of job (office, technical, or manufacturing worker). We found consistent associations of increased sick leave with lower levels of outdoor air supply and IEQ complaints. Among office workers, the relative risk for short-term sick leave was 1.53 (95% confidence 1.22-1.92) with lower ventilation, and 1.52 (1.18-1.97) in areas with IEQ complaints. The effect of ventilation was independent of IEQ complaints and among those exposed to lower outdoor air supply rates the attributable risk of short-term sick leave was 35%. The cost of sick leave attributable to ventilation at current recommended rates was estimated as $480 per employee per year at Polaroid. These findings suggest that net savings of $400 per employee per year may be obtained with increased ventilation. Thus, currently recommended levels of outdoor air supply may be associated with significant morbidity, and lost productivity on a national scale could be as much as $22.8 billion per year. Additional studies of IEQ impacts on productivity and sick leave, and the mechanisms underlying the apparent association are needed.     

基于时空行为特征的商业空间优化研究——以南京市雨花台区为例

商业空间布局与人的时空行为不匹配导致出现大量使用效率低下甚至空置的商业空间,研究通过手机信令数据、微博签到数据以及POI兴趣点分析等多源数据相结合的方式,分析商业空间布局与人的行为特征,针对南京市雨花台区城市商业空间高供给低需求、低供给高需求,提出商业空间中心体系与时空行为热度相匹配、商业空间布局与时空行为强度相匹配、商业空间布局与时空行为强度相匹配的规划对策,优化商业空间布局与业态。     

Competition in Urban Water and Sewage: The Case of Sydney,Australia

Policy makers have long grappled with the problems associated with introducing competition into natural monopoly industries such as railways, telecommunications, electricity and gas in order to eliminate excess profits and assure efficient provision of services. In the case of water supply and wastewater disposal in urban centres this process has tended to be even more difficult. This article analyses the circumstances surrounding the granting of third party access to infrastructure facilities in the water and wastewater industry in Australia's largest city, Sydney, and identifies difficulties that have been involved in this process. The effective introduction of competition into the water and wastewater industries, through robust access arrangements, would provide an additional path for the diversification of water sources, and potentially in ways that minimise environmental impacts.     

Priorities for tariff compensation of distributed electricity generation in Brazil

The economic, financial, environmental, social, and regulatory impacts of distributed generation influence energy policymaking. In 2012, Brazilian National Electricity Regulation Agency issued Normative Resolution 482/2012 to regulate the access and compensation of energy produced by micro-generation and mini-generation distributed to electric energy distribution systems. The paper aims to contextualize the history of the Brazilian electricity industry and its focus on centralization to demonstrate the need for expanding decentralized (distributed) generation. It is expected to contribute to the discussion about the decentralization of the natural monopoly from the expansion of distributed energy generation and its regulation. It is also expected to contribute to the discussion on the compensation of distributed generation in the electricity tariff in Brazil considering the regulatory basis/update and additional aspects like prosumer as a new player in the electricity market, diversification of renewable sources in the energy and in the electricity matrix, financing of investments in distributed generation, electricity supply versus GDP growth, and security of electricity supply to the country.     

Optimal control of a commercial building's thermostatic load for off-peak demand response

This paper studies the optimal control of a commercial building's thermostatic load during off-peak hours as an ancillary service to the power grid. It provides an algorithmic framework that commercial buildings can implement to cost-effectively increase their electricity demand at night while they are unoccupied, instead of using standard inflexible setpoint control. Consequently, there is minimal or no impact on user comfort, while the building manager gains an additional income stream from providing the ancillary service. By introducing a novel benefit-cost ratio of ancillary service payment to night-time price of electricity, we are able to study the building's capability to provide a service that is both useful to the power grid and profitable to the building manager. Numerical results show that there can be an economic incentive to participate even if the payment rate for the ancillary service is less than the price of electricity.     

Analysis of annual heating and cooling energy requirements for office buildings in different climates in Turkey

A great amount of world energy demand is connected to the built environment. Electricity use in the commercial buildings, accounts for about one-third of the total energy consumption in Turkey and fully air-conditioned office buildings are important commercial electricity end-users since the mid-1990s. In the presented paper, the interactions between different conditions, control strategies and heating/cooling loads in office buildings in the four major climatic zones in Turkey – hot summer and cold winter, mild, hot summer and warm winter, hot and humid summer and warm winter – through building energy simulation program has been evaluated. The simulation results are compared with the values obtained from site measurements done in an office building located in Istanbul. The site-recorded data and simulation results are compared and analyzed. This verified model was used as a means to examine some energy conservation opportunities on annual cooling, heating and total building load at four major cities which were selected as a representative of the four climatic regions in Turkey. The effect of the parameters like the climatic conditions (location), insulation and thermal mass, aspect ratio, color of external surfaces, shading, window systems including window area and glazing system, ventilation rates and different outdoor air control strategies on annual building energy requirements is examined and the results are presented for each city.