Shanti Pless

Definition of a 'Zero Net Energy' Community

This document provides a definition for a net zero-energy community. A community that offsets all of its energy use from renewables available within the communitys built environment.

Main Street Net-Zero Energy Buildings: The Zero Energy Method in Concept and Practice

Ongoing work at the National Renewable Energy Laboratory indicates that net-zero energy building (NZEB) status is both achievable and repeatable today. This paper presents a definition framework for classifying NZEBs and a real-life example that demonstrates how a large-scale office building can cost-effectively achieve net-zero energy.

Evaluation of the Low-Energy Design Process and Energy Performance of the Zion National Park Visitor Center: Preprint

In line with the mission of the National Park Service, the Zion National Park Visitor Center was designed to use 70% less energy than a comparable visitor center built to Federal Energy Code 10 CFR 435 (DOE 1995). The authors and NFS staff used an integrated design process, including extensive simulations, to minimize the energy consumption. The result was a passive solar commercial building that has a good thermal envelope, daylighting, and natural ventilation. Passive downdraft cooltowers provide all the cooling. Two Trombe walls provide a significant amount of the heating. After two years of metering, the results show a net energy use intensity of 24.7 kBtu/ft2 (280.5 MJ/m 2 ) and a 67% energy cost saving. Low energy use and aggressive demand management result in an energy cost intensity of

A pathway for net-zero energy buildings: creating a case for zero cost increase

0.43/ft 2 (

Metering Best Practices Applied in the National Renewable Energy Laboratory's Research Support Facility A Primer to the 2011 Measured and Modeled Energy Consumption Datasets

4.63/m 2 ). The paper discusses lessons learned related to the design process, daylighting, PV system, and HVAC system.

Technical Support Document: Development of the Advanced Energy Design Guide for Medium to Big Box Retail Buildings - 50% Energy Savings

To have market relevance and gain widespread market adoption, zero energy buildings (ZEBs) will need to be designed and constructed cost-effectively, and preferably without additional costs. An approach was developed to create low-energy buildings without additional construction costs such that it yielded innovation in building technology and integration by the market. A case study of the implementation of this method is presented to provide a data point that ZEBs can be built with zero cost increase. Documenting cost-control best practices and packaging those strategies for adoption by the commercial building sector will help make the business case for ZEBs for mainstream construction and promote market uptake of the innovative technologies and design approaches needed. The holistic implementation of cost-control strategies will enable ZEBs to be designed and constructed on a typical budget. The current state of ZEB economics is evaluated and a path forward is proposed for greater market penetration of ZEBs. By demonstrating how to combine ZEB technologies and design approaches into an overall efficiency package that can be implemented at minimal (zero, in certain cases) incremental capital cost, the domain of ZEB design and construction can be expanded from a niche market to the commercial construction mainstream.

Control Limits for Building Energy End Use Based on Engineering Judgment, Frequency Analysis, and Quantile Regression

Modern buildings are complex energy systems that must be controlled for energy efficiency. The Research Support Facility (RSF) at the National Renewable Energy Laboratory (NREL) has hundreds of controllers -- computers that communicate with the buildings various control systems -- to control the building based on tens of thousands of variables and sensor points. These control strategies were designed for the RSFs systems to efficiently support research activities. Many events that affect energy use cannot be reliably predicted, but certain decisions (such as control strategies) must be made ahead of time. NREL researchers modeled the RSF systems to predict how they might perform. They then monitor these systems to understand how they are actually performing and reacting to the dynamic conditions of weather, occupancy, and maintenance.

Technical Feasibility Study for Zero Energy K-12 Schools

This Technical Support Document describes the process and methodology for the development of the Advanced Energy Design Guide for Medium to Big Box Retail Buildings: Achieving 50% Energy Savings Toward a Net Zero Energy Building (AEDG-MBBR) ASHRAE et al. (2011b). The AEDG-MBBR is intended to provide recommendations for achieving 50% whole-building energy savings in retail stores over levels achieved by following ANSI/ASHRAE/IESNA Standard 90.1-2004, Energy Standard for Buildings Except Low-Rise Residential Buildings (Standard 90.1-2004) (ASHRAE 2004b). The AEDG-MBBR was developed in collaboration with the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE), the American Institute of Architects (AIA), the Illuminating Engineering Society of North America (IES), the U.S. Green Building Council (USGBC), and the U.S. Department of Energy.

Strategies for Controlling Plug Loads. A Tool for Reducing Plug Loads in Commercial Buildings

Approaches are needed to continuously characterize the energy performance of commercial buildings to allow for (1) timely response to excess energy use by building operators; and (2) building occupants to develop energy awareness and to actively engage in reducing energy use. Energy information systems, often involving graphical dashboards, are gaining popularity in presenting energy performance metrics to occupants and operators in a (near) real-time fashion. Such an energy information system, called Building Agent, has been developed at NREL and incorporates a dashboard for public display. Each building is, by virtue of its purpose, location, and construction, unique. Thus, assessing building energy performance is possible only in a relative sense, as comparison of absolute energy use out of context is not meaningful. In some cases, performance can be judged relative to average performance of comparable buildings. However, in cases of high-performance building designs, such as NRELs Research Support Facility (RSF) discussed in this report, relative performance is meaningful only when compared to historical performance of the facility or to a theoretical maximum performance of the facility as estimated through detailed building energy modeling.

Zero Energy Buildings: A Critical Look at the Definition

A simulation-based technical feasibility study was completed to show the types of technologies required to achieve ZEB status with this building type. These technologies are prioritized across the buildings subsystem such that design teams can readily integrate the ideas. Energy use intensity (EUI) targets were established for U.S. climate zones such that K-12 schools can be zero-ready or can procure solar panels or other renewable energy production sources to meet the zero energy building definition. Results showed that it is possible for K-12 schools to achieve zero energy when the EUI is between 20 and 26 kBtu/ft2/yr. Temperate climates required a smaller percentage of solar panel coverage than very hot or very cold climates. The paper provides a foundation for technically achieving zero energy schools with a vision of transforming the school construction market to mainstream zero energy buildings within typical construction budgets.