18 research outputs found
Recommended from our members
U.S. Building-Sector Energy Efficiency Potential
This paper presents an estimate of the potential for energy efficiency improvements in the U.S. building sector by 2030. The analysis uses the Energy Information Administration's AEO 2007 Reference Case as a business-as-usual (BAU) scenario, and applies percentage savings estimates by end use drawn from several prior efficiency potential studies. These prior studies include the U.S. Department of Energy's Scenarios for a Clean Energy Future (CEF) study and a recent study of natural gas savings potential in New York state. For a few end uses for which savings estimates are not readily available, the LBNL study team compiled technical data to estimate savings percentages and costs of conserved energy. The analysis shows that for electricity use in buildings, approximately one-third of the BAU consumption can be saved at a cost of conserved energy of 2.7 cents/kWh (all values in 2007 dollars), while for natural gas approximately the same percentage savings is possible at a cost of between 2.5 and 6.9 170 billion. To achieve these savings, the cumulative capital investment needed between 2010 and 2030 is about $440 billion, which translates to a 2-1/2 year simple payback period, or savings over the life of the measures that are nearly 3.5 times larger than the investment required (i.e., a benefit-cost ratio of 3.5)
Japan’s Long-term Energy Demand and Supply Scenario to 2050 – Estimation for the Potential of Massive CO2 Mitigation
In this analysis, we projected Japans energy demand/supply and energy-related CO2 emissions to 2050. Our analysis of various scenarios indicated that Japans CO2 emissions in 2050 could be potentially reduced by 26-58% from the current level (FY 2005) (Figure 1). These results suggest that Japan could set a CO2 emission reduction target for 2050 at between 30% and 60%. In order to reduce CO2 emissions by 60% in 2050 from the present level, Japan will have to strongly promote energy conservation at the same pace as an annual rate of 1.9% after the oil crises (to cut primary energy demand per GDP (TPES/GDP) in 2050 by 60% from 2005) and expand the share of non-fossil energy sources in total primary energy supply in 2050 to 50% (to reduce CO2 emissions per primary energy demand (CO2/TPES) in 2050 by 40% from 2005). Concerning power generation mix in 2050, nuclear power will account for 60%, solar and other renewable energy sources for 20%, hydro power for 10% and fossil-fired generation for 10%, indicating substantial shift away from fossil fuel in electric power supply. Among the mitigation measures in the case of reducing CO2 emissions by 60% in 2050, energy conservation will make the greatest contribution to the emission reduction, being followed by solar power, nuclear power and other renewable energy sources (Figure 2). In order to realize this massive CO2 abatement, however, Japan will have to overcome technological and economic challenges including the large-scale deployment of nuclear power and renewable technologies.energy demand, energy supply, GHG emisisons, energy forecasting
Recommended from our members
Towards a Very Low Energy Building Stock: Modeling the U.S. Commercial Building Sector to Support Policy and Innovation Planning
This paper describes the origin, structure and continuing development of a model of time varying energy consumption in the US commercial building stock. The model is based on a flexible structure that disaggregates the stock into various categories (e.g. by building type, climate, vintage and life-cycle stage) and assigns attributes to each of these (e.g. floor area and energy use intensity by fuel type and end use), based on historical data and user-defined scenarios for future projections. In addition to supporting the interactive exploration of building stock dynamics, the model has been used to study the likely outcomes of specific policy and innovation scenarios targeting very low future energy consumption in the building stock. Model use has highlighted the scale of the challenge of meeting targets stated by various government and professional bodies, and the importance of considering both new construction and existing buildings
Recommended from our members
A Buildings Module for the Stochastic Energy Deployment System
The U.S. Department of Energy (USDOE) is building a new long-range (to 2050) forecasting model for use in budgetary and management applications called the Stochastic Energy Deployment System (SEDS), which explicitly incorporates uncertainty through its development within the Analytica(R) platform of Lumina Decision Systems. SEDS is designed to be a fast running (a few minutes), user-friendly model that analysts can readily run and modify in its entirety through a visual programming interface. Lawrence Berkeley National Laboratory is responsible for implementing the SEDS Buildings Module. The initial Lite version of the module is complete and integrated with a shared code library for modeling demand-side technology choice developed by the National Renewable Energy Laboratory (NREL) and Lumina. The module covers both commercial and residential buildings at the U.S. national level using an econometric forecast of floorspace requirement and a model of building stock turnover as the basis for forecasting overall demand for building services. Although the module is fundamentally an engineering-economic model with technology adoption decisions based on cost and energy performance characteristics of competing technologies, it differs from standard energy forecasting models by including considerations of passive building systems, interactions between technologies (such as internal heat gains), and on-site power generation
Recommended from our members
Occupant Control of Windows: Accounting for Human Behavior in Building Simulation
Within the Center for the Built Environment (CBE) and in the greater building research and engineering community, there is growing interest in low energy cooling strategies that take advantage of natural ventilation. To support this rising interest, there is an associated need for more sophisticated models of occupant control of windows. All too often, existing models rely on simplifications that fit occupant behavior into standard control schedules that lack the responsiveness to environmental conditions demonstrated by real people in real buildings. This report is intended to bring these issues to the attention of the CBE audience, and to provide a summary of the origin, implementation, and applicability of the surprising variety of models predicting occupant window control now emerging in the academic literature.
OCCUPANT CONTROL OF WINDOWS: ACCOUNTING FOR HUMAN BEHAVIOR IN BUILDING SIMULATION
Within the Center for the Built Environment (CBE) and in the greater building research and engineering community, there is growing interest in low energy cooling strategies that take advantage of natural ventilation. To support this rising interest, there is an associated need for more sophisticated models of occupant control of windows. All too often, existing models rely o
Recommended from our members
Comfort standards and variation in exceedance for mixed-mode buildings.
Mixed-mode buildings operate along a spectrum from sealed heating, ventilation and air-conditioning to 100% naturally ventilated, but little is known about their occupants' comfort expectations and experiences. Exceedance metrics, which quantify the percentage of time that a building's environment falls outside an expected thermal comfort zone, can help address the comfort trade-offs in building design and operation. Practitioners were polled on exceedance use in practice and comfort models and exceedance metrics were analysed: several comfort standards using EnergyPlus simulations of a mixed-mode building with radiant cooling in California's 16 climate zones. Results indicate that comfort models from ASHRAE Standard 55, EN 15251, and the Dutch NPR-CR 1752 frequently differed by 10 percentage points, often with 2-4 percentage points across the adaptive models. Yet, recommended exceedance limits often fall between 3 and 5% total. Exceedance predictions are also sensitive to uncertainties in predicted neutral comfort temperatures and variations in building envelop performance, solar heat gain, thermal mass, and control precision. Future work is needed to characterize comfort better in support of improved comfort modelling, exceedance targets, building design and building operation, and development of related codes and standards
Recommended from our members
Summary Report: Control Strategies for Mixed-Mode Buildings
The objective of this project was to study the operational control strategies for mixed-mode buildings, with a focus on: 1) developing a framework for understanding issues that guide the decision-making process that informs mixed-mode buildings, and 2) identifying and documenting example control algorithms used in existing buildings. We examined buildings that use a combination of manual and automatic control of windows and mechanical system components and the indoor and/or outdoor environmental conditions used as inputs into their control algorithms.