Publications of Vorsatz, D.

Defining a standard metric for electricity savings

The growing investment by governments and electric utilities in energy efficiency programs highlights the need for simple tools to help assess and explain the size of the potential resource. One technique that is commonly used in that effort is to characterize electricity savings in terms of avoided power plants, because it is easier for people to visualize a power plant than it is to understand an abstraction like billions of kilowatt-hours. Unfortunately, there is no standardization around the characteristics of such power plants. In this article we define parameters for a standard avoided power plant that have physical meaning and intuitive plausibility, for use in back-of-the-envelope calculations. For the prototypical plant this article settles on a 500-megawatt existing coal plant operating at a 70% capacity factor with 7% T&D losses. Displacing such a plant for one year would save 3 billion kWh/year at the meter and reduce emissions by 3 million metric tons of CO2 per year. The proposed name for this metric is the Rosenfeld, in keeping with the tradition among scientists of naming units in honor of the person most responsible for the discovery and widespread adoption of the underlying scientific principle in question - Dr. Arthur H. Rosenfeld. © 2011 American Institute of Physics.

Defining a standard metric for electricity savings

The growing investment by governments and electric utilities in energy efficiency programs highlights the need for simple tools to help assess and explain the size of the potential resource. One technique that is commonly used in this effort is to characterize electricity savings in terms of avoided power plants, because it is easier for people to visualize a power plant than it is to understand an abstraction such as billions of kilowatt-hours. Unfortunately, there is no standardization around the characteristics of such power plants. In this letter we define parameters for a standard avoided power plant that have physical meaning and intuitive plausibility, for use in back-of-the-envelope calculations. For the prototypical plant this article settles on a 500MW existing coal plant operating at a 70% capacity factor with 7% T&D losses. Displacing such a plant for one year would save 3billion kWh/year at the meter and reduce emissions by 3 million metric tons of CO2 per year. The proposed name for this metric is the Rosenfeld, in keeping with the tradition among scientists of naming units in honor of the person most responsible for the discovery and widespread adoption of the underlying scientific principle in question - DrArthur HRosenfeld. © 2010 IOP Publishing Ltd.

Residential lighting in Lithuania

A wider use of compact fluorescent lamps (CFLs) offers a significant opportunity for Lithuania in reducing wasteful electricity consumption, and making progress towards retiring the Chernobyl-type Ignalina nuclear power reactors. We evaluate the conservation potential of compact fluorescent lamps for managing the residential electrical energy demand in Lithuania. The analysis is undertaken from the three separate perspectives of (1) the national economy, (2) the consumers and (3) the utilities. In our analysis we use the most recent available data on Lithuanian residential lighting. The costs of conserved energy of 15 and 23 W CFLs range from $0.007 to 0.031 per kW h depending on CFL price and assuming 4-hour daily lamp use. Replacing only the two most used 60 W incandescent lamps per household with CFLs would save 190 GW h of electrical energy for Lithuania annually worth 12 million US dollars at the long run marginal cost. We compare the current residential lighting situation in Lithuania with that in Hungary and Poland, where introduction of CFLs has been much more successful. We then discuss factors that could explain the much higher CFL penetration in Hungary and Poland, barriers to immediate large-scale introduction of CFLs in Lithuania, and policy instruments that could be used for promoting the diffusion of CFLs in the residential sector of Lithuania. We conclude that future success of CFL-penetration in Lithuania will depend on aggressive information and promotion efforts by at least the CFL manufacturers, and/or by any of the stakeholder institutions (e.g. the state agencies responsible for energy and environment, electric utilities, international agencies, etc.). Given the small size of the Lithuanian market, it would make sense to 'team up' with one or more neighboring countries to address the CFL issues.

A spatially and temporally resolved biogenic hydrocarbon emissions inventory for the California South Coast Air Basin

Spatially and temporally resolved inventories for green leaf biomass and biogenic hydrocarbon emissions were developed for the California South Coast Air Basin (SoCAB) using a geographic information system (GIS) and digitized land-use data based on low altitude aerial imagery. Urban, agricultural, and natural land-use distributions in the SoCAB were combined with biomass factors for each land-use category to produce a spatially resolved biomass inventory. As of 1990, about 80% of the approximately 6 x 106 metric tons of green leaf biomass was concentrated primarily in the forested mountains on the northern and eastern boundaries of the SoCAB. A biogenic hydrocarbon emissions inventory was developed by combining the biomass inventory with hourly emission rates for 278 tree, shrub, and ground cover species identified in the study area. Correcting for environmental factors, including light intensity, canopy shading, and temperature (from data for the period 9/87-6/92), combined isoprene and monoterpene emissions were estimated to be approximately 125-140 tons d-1 (t d-1) for an average summer day, 180-200 t d-1 for an average high ozone-episode day, and approximately 40 t d-1 for an average winter day. The ratio of monoterpene to isoprene emission inventaries ranged between approximately 1 and 2 for the summer and winter, respectively. Isoprene emissions were highest in the mountains and certain urbanized portions of the SoCAB whereas monoterpene emissions were highest in the mountains and the sagebrush/chaparral-dominated portions of the study area. On a mass basis, the biogenic hydrocarbon emissions inventory for the SoCAB obtained in this study represents approximately 10% of the anthropogenic VOC emissions in the Basin on a summer day.Spatially- and temporally-resolved inventories for green leaf biomass and biogenic hydrocarbon emissions were developed for the California South Coast Air Basin (SoCAB) using a geographic information system and digitized land-use data based on low altitude aerial imagery. Urban, agricultural, and natural land-use distributions in the SoCAB were combined with biomass factors for each land-use category to produce a spatially-resolved biomass inventory. On a mass basis, the biogenic hydrocarbon emissions inventory for the SoCAB represented approximately 10% of the anthropogenic volatile organic compound emissions in the Basin on a summer day.

Determination of atomic local order in thyroid hormones by extended x-ray absorption fine structure {EXAFS} for radiation dose estimates

Dosimetry from 125I emitting Auger electrons in the follicles of the thyroid will improve when their complete interaction with the molecular structure about the Auger emitting atoms is known to Angstrom distances. Extended x-ray absorption fine structure (EXAFS) can provide this information. EXAFS experiments gave intermolecular and intramolecular distance for pure solid L-thyroxine (T4) (C15H11I4NO4) using a model based on crystalline T4 hydrochloride monohydrate (C15H11I4NO4HCl.H2O). For a solution of L-thyroxine the structure consists of the intramolecular distances found for T4 and an additional shell of four carbon atoms distances of 2.01 Å. Atomic density functions from Fourier transformed EXAFS measurements are suitable for estimating very short range interactions of Auger electrons in thyroid thyroglobulin over a radial distance of 7.71 Å. Examination of density functions provided a plausible argument for the difference in biological effect between 131I and 125I in the thyroid.Dosimetry from 125I emitting Auger electrons in the follicles of the thyroid will improve when their complete interaction with the molecular structure about the Auger emitting atoms is known to Angstrom distances. Extended x-ray absorption fine structure (EXAFS) can provide this information. EXAFS experiments gave intermolecular and intramolecular distance for pure solid L-thyroxine (T4) (C15H11I4NO4) using a model based on crystalline T4 hydrochloride monohydrate (C15H11I4NO4HCl.H2O). For a solution of L-thyroxine the structure consists of the intramolecular distances found for T4 and an additional shell of four carbon atoms distances of 2.01 angstroms. Atomic density functions from Fourier transformed EXAFS measurements are suitable for estimating very short range interactions of Auger electrons in thyroid thyroglobulin over a radial distance of 7.71 angstroms. Examination of density functions provided a plausible argument for the difference in biological effect between 131I and 125I in the thyroid.