The rooftop unit (RTU) decision tree can be used for preliminary screening for replacement of RTU units with more efficient units. This decision tree organizes RTUs into bins for “retrofit,” “replacement,” “no action,” or “needs further analysis.”
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Defining and Including Energy Goals in the Contractual Process: Examples from the NREL campus presentation given at the NASA Net-Zero Energy workshop June 5-6, 2012
Presentation slides from Defining and Including Energy Goals in the Contractual Process: Examples from the NREL campus presentation given at the NASA Net-Zero Energy workshop June 5-6, 2012.
This video presentation highlights whole building design using a large office building located on the National Renewable Energy Laboratory's campus in Golden, CO as an example.
This guide covers each major step in procuring a solar photovoltaic (PV) system:
- Conducting technical and financial studies
- Financing a PV system
- Project execution
- Operations and maintenance
- Assessing benefits
The guide provides information on the basic steps, key considerations, and where to go for more information. It is intended to provide an overview and some level of detail, with pointers to highly detailed information and resources.
A net zero-energy community (ZEC) is one that has greatly reduced energy needs through efficiency gains such that the balance of energy for vehicles, thermal, and electrical energy within the community is met by renewable energy. Past work resulted in a common zero-energy building (ZEB) definition system of “zero energy” and a classification system for ZEBs based on the renewable energy sources used by a building. This paper begins with a focus solely on buildings and expands the concept to define a zero-energy community, applying the ZEB hierarchical renewable classification system to the concept of community. A community that offsets all of its energy use from renewables available within the community’s built environment and unusable brownfield sites is at the top of the ZEC classification system at a ZEC of A. (A brownfield site is where the redevelopment or reuse may be complicated by the presence or potential presence of a hazardous substance, pollutant or contaminant.) A community that achieves a ZEC definition primarily through the purchase of new off-site, Renewable Energy Certificates (RECs) is placed at the lowest end of the ZEC classification but is still considered a good achievement.
Access to foundational energy performance data is key to improving the efficiency of the built environment. However, stakeholders often lack access to what they perceive as credible energy performance data. Therefore, even if a stakeholder determines that a product would increase efficiency, they often have difficulty convincing their management to move forward. Even when credible data do exist, such data are not always sufficient to support detailed energy performance analyses, or the development of robust business cases.
One reason for this is that the data parameters that are provided are generally based on the respective industry norms. Thus, for mature industries with extensive testing standards, the data made available are often quite detailed. But for emerging technologies, or for industries with less well-developed testing standards, available data are generally insufficient to support robust analysis. However, even for mature technologies, there is no guarantee that the data being supplied are the same data needed to accurately evaluate a product’s energy performance.
To address these challenges, the U.S. Department of Energy funded development of a free, publically accessible Web-based portal, the Technology Performance Exchange™, to facilitate the transparent identification, storage, and sharing of foundational energy performance data. The Technology Performance Exchange identifies the intrinsic, technology-specific parameters necessary for a user to perform a credible energy analysis and includes a robust database to store these data. End users can leverage stored data to evaluate the site-specific performance of various technologies, support financial analyses with greater confidence, and make better informed procurement decisions.
Designed as a resource for those who want to develop community solar projects, from community organizers or solar energy advocates to government officials or utility managers. By exploring
the range of incentives and policies while providing examples of operational community solar projects, this guide will help communities to plan and implement successful local energy projects. In addition, by highlighting some of the policy best practices, this guide suggests changes in the regulatory landscape that could significantly boost community solar installations across the country.
This flowchart details steps for selecting a control strategy to reduce plug and process loads. It accompanies the report: "Selecting a Control Strategy for Plug and Process Loads" https://buildingdata.energy.gov/cbrd/resource/1078.
Miscellaneous electrical loads (MELs) are building loads that are not related to general lighting, heating, ventilation, cooling, and water heating, and typically do not provide comfort to the building occupants. MELs in commercial buildings account for almost 5% of U.S. primary energy consumption. On an individual building level, they account for approximately 25% of the total electrical load in a minimally code-compliant commercial building, and can exceed 50% in an ultra-high efficiency building such as the National Renewable Energy Laboratory's (NREL) Research Support Facility (RSF). Minimizing these loads is a primary challenge in the design and operation of an energy-efficient building. A complex array of technologies that measure and manage MELs has emerged in the marketplace. Some fall short of manufacturer performance claims, however. NREL has been actively engaged in developing an evaluation and selection process for MELs control, and is using this process to evaluate a range of technologies for active MELs management that will cap RSF plug loads. Using a control strategy to match plug load use to users' required job functions is a huge untapped potential for energy savings.