Researchers Develop GHG-Mitigation Guidelines
Efforts by EETD researchers Ed Vine and Jayant Sathaye have been directed toward devising guidelines that will help nations verify that their actions to reduce greenhouse gas (GHG) emissions are working. In 1997, 176 nations pledged to reduce aggregate emissions of greenhouse gases by at least 5.2% below 1990 levels by 2008-2012. (These nations are parties to the U.N. Framework Convention of Climate Change.) To ascertain that these GHG-reducing efforts will be successful, agencies need protocols and guidelines to estimate energy savings or to standardize data collection and analysis.
Vine and Sathaye speculate that energy-efficiency projects will involve monitoring, evaluating, reporting, verifying, and certifying (MERVC). Guidelines are needed for implementation to accurately determine their impacts. Standard guidelines will also enable nations to increase the reliability of data, introduce consistency across projects, and reduce costs.
In a three-week training course in September 1999, EETD researchers Steve Kromer and Satish Kumar instructed 30 participants from 15 countries in MERVC methods. Kromer and Kumar used U.S. DOE International Performance Measurement and Verification Protocols, which they also helped develop.
New Tool for Measuring Gas Concentrations
Researchers Marc Fischer, Phil Price, Carrie Schwalbe, and Tracy Thatcher and team leaders Ashok Gadgil and Rich Sextro of EETD's Indoor Environment Department have demonstrated a powerful new technique for rapid mapping of tracer gas concentrations in ambient air. The technique combines rapid open-path optical remote sensing and computed tomography. The goal of the current work is to study turbulent transport in large indoor spaces and to provide the data needed to test a computational fluid dynamics (CFD) model being implemented by EETD researcher Elizabeth Finlayson. Once tested, the CFD model will be used to optimize the design and operation of ventilation systems for large spaces (such as auditoriums, factories, and transportation terminals) that minimize both the risk of exposure to gaseous contaminants and energy use. The ingredients for the success of the measurement technique are high speed and spatial resolution. Speed is obtained by using an optically multiplexed tunable diode laser spectrometer to measure tracer gas concentrations—currently methane—over a set of 60 co-planar beam paths in a matter of seconds (conventional techniques require many minutes to collect the same information). Spatial resolution is obtained by using a tomographic algorithm that combines the measurements along a set of beam paths to reconstruct a "best fit" map as a sum of smooth analytic functions. Although the system was only commissioned in late 1999, the air-dispersion team has demonstrated the system's ability to accurately map time-evolving gas concentrations using a large chamber in LBNL's Building 71.
While the current goals of this work focus on indoor air, future projects are being planned to test models of air dispersion used in studies of CO2 exchange between the atmosphere and terrestrial ecosystems. Currently, interpreting the ecological controls on CO2 flux is complicated because the flux measured at a given location comprises contributions from different parts of an ecosystem (such as soils, understory plants, and trees). The three-dimensional weighting function or "footprint" for flux measurements must be determined using a combination of meteorological measurements and sophisticated models of air dispersion. The gas-mapping technique being developed by EETD is expected to play a uniquely powerful role in testing these models. An animation of reconstructed gas concentrations can be found at the Atmospheric Science web site.
LBNL Helps USPS Win Governor's Award
The Post Office just got a little greener. The 1999 California Governor's Environmental and Economic Leadership Award in the category of Environmental Management has been presented to the U.S. Postal Service (Pacific Area) for its efforts to reduce pollution and conserve energy. Ray Levinson, Environmental Compliance Coordinator for the Pacific Area, directed the overall efforts of the team in California, which included William Golove, an EETD Staff Research Associate. Golove provided technical assistance for nearly three years. USPS endeavors included lighting retrofits, high-intensity discharge dimmer controls, and modified air compressors at mail-processing facilities throughout the state. An investment of nearly $1.2 million on the Postal Service's part resulted in energy savings of more than 5.1 million kWh and earned $268,555 in utility rebates. This saved the USPS more than $350,000 in annual energy costs and helped reduce annual CO2 and NOx emissions by 1,900,000 and 2,600 pounds. Additional work by Golove and the USPS is aimed at procuring direct-access green power for the more than 1,300 post offices in California. At present, that possibility is still being studied. Commenting on his efforts, Golove remarked, "It has been a pleasure to see a federal agency taking a leadership role in improving the energy-efficiency of its facilities." The award was presented December 8, 1999, at the state capitol. EETD's Michael Siminovitch of the Lighting Group also provided technical assistance in the USPS energy-efficiency efforts. See an article in EETD News, Vol. 1, No. 1.