Monitoring Building Energy Systems at NASA Langley Research Center Using NASA's Near Real-Time Solar and Meteorological Data and RETScreen International Plus Software for Decision Support

The monitoring, targeting and verification of a building's energy usage depends upon many factors one of the most important of which is the local weather and climate conditions to which it's electrical, heating and air conditioning systems must respond. Incorporating renewable energy systems, including solar systems, to supplement energy supplies and increase energy efficiency is important to saving costs and reducing emissions. Retrofitting technologies to buildings requires a knowledge of building performance in it's current state and potential future climate state, projection of potential savings with capital investment, and then monitoring the performance once the improvements are made.

RETScreenŽ International, is a project sponsored by Natural Resources Canada (NRCan), dedicated to developing and providing clean energy project analysis software for the feasibility design and assessment of a wide range of building projects that incorporate renewable energy technologies. RETScreen has recently developed a new product entitled the RETScreen Suite that includes RETScreen Plus, a performance analysis module that supplies the needed functions of monitoring current building performance, targeting projected energy efficiency improvements and verifying improvements once completed. The RETScreen Plus module requires daily average meteorological and solar parameters that are available within less than a month of real-time. NASA data from the NASA CERES (Clouds and Earth's Radiance Energy System)/FLASHFlux (Fast Longwave and SHortwave radiative Fluxes) provides solar fluxes and the NASA GMAO (Global Modeling and Assimilation Office) GEOS (Goddard Earth Observing System) operational meteorological analysis are directly used for meteorological input parameters.

This presentation will provide an overview of parameters and accuracy of the NASA data sets that are currently incorporated into the new RETScreen Plus tool. Then examples using the tools to identify performance issues in several case studies are shown. Several examples of application of the tool to NASA Langley Research Center buildings are shown, including a solar integrated building. One example shows that the module and NASA data were sufficiently accurate to detect changes in the weekend usage of the building that reduced energy efficiency. Other examples clearly show changes with energy efficiency related to changes in building systems and in personnel usage. These examples show how the tool can be used to estimate energy savings relative to weather and solar resource variability.