Arthur H. Rosenfeld

Practical issues for using solar-reflective materials to mitigate urban heat islands

Solar-reflective or high-albedo, alternatives to traditionally absorptive urban surfaces such as rooftops and roadways can reduce cooling energy use and improve urban air quality at almost no cost. This paper presents information to support programs that mitigate urban heat islands with solar-reflective surfaces: estimates of the achievable increase in albedo for a variety of surfaces, issues related to the selection of materials and costs and benefits of using them. As an example, we present data for Sacramento, California. In Sacramento, we estimate that 20% of the 96 square mile area is dark roofing and 10% is dark pavement. Based on the change in albedo that is achievable for these surfaces, the overall albedo of Sacramento could be increased by 18%, a change that would produce significant energy savings and increase comfort within the city. Roofing market data indicate which roofing materials should be targeted for incentive programs. In 1995, asphalt shingle was used for over 65% of residential roofing area in the U.S. and 6% of commercial. Built-up roofing was used for about 5% of residential roofing and about 30% of commercial roofing. Single-ply membranes covered about 9% of the residential roofing area and over 30% of the commercial area. White, solar-reflective alternatives are presently available for these roofing materials but a low-first-cost, solar-reflective alternative to asphalt shingles is needed to capture the sloped-roof market. Since incoming solar radiation has a large non-visible component, solar-reflective materials can also be produced in a variety of colors.

Conservation screening curves to compare efficiency investments to power plants

CONSERVATION SCREENING CURVES TO COMPARE EFFICIENCY INVESTMENTS TO POWER PLANTS: APPLICATIONS TO COMMERCIAL SECTOR CONSERVATION PROGRAMS Jonathan Koomey, Arthur H. Rosenfeld, and Ashok Gadgil Center for Building Science Lawrence Berkeley Laboratory, Bdg 90-4000 Berkeley, CA 94720 (510) 486-5974, (510) 486-4247 Fax Published in the Proceedings of the 1990 ACEEE Summer Study on Energy Efficiency in Buildings Asilomar, CA, August 1990 The work described in this paper was funded by the Assistant Secretary for Conservation and Renewable Energy, Office of Buildings and Community Systems, Building Systems Division of the U.S. Department of Energy, under Contract No. DE-AC03-76SF00098.

Building Energy use Compilation and Analysis (BECA): An international comparison and critical review. Part A: New residential buildings

Abstract The potential for energy conservation in space heating of new residential buildings is characterized using results from computer analysis, and from a survey of low-energy houses. Simulations of the energy requirements of a prototypical house in the United States at different levels of conservation have shown that much higher levels of conservation than those presently employed in new houses result in minimum life-cycle cost. Measurement taken in actual houses indicate that very low space heating energy requirements — comparable to that now used for domestic water heating — can be achieved in new houses by attention to insulation, infiltration, and solar-design principles. We conclude that building standards should be made more stringent to hasten the adoption of cost-effective conservation measures.

Energy-efficiency research, development and demonstration: New roles for US states☆

Abstract At least eight states have established energy research, development and demonstration (RD&D) programmes. In contrast to federal and utility energy RD&D, most states emphasize applied research on end-use efficiency and renewable energy. States also try to closely link research and technology deployment, in some cases deliberately blurring the line between the two. The states discussed in this paper spend about US

Analysis and design of solar buildings using the CAL--ERDA computer programs

39 million per year for energy RD&D, or one-fifth of the US Department of Energy (DOE) budget for conservation and renewable energy RD&D. When indexed per capita or per energy dollar, the average rate of state RD&D spending on conservation and renewables is about 65–75% that of the US DOE.

Increasing Economic Growth and Reducing Carbon Emissions Through Improved Energy Efficiency

A new set of computer programs have been developed which are capable of rapid and detailed analysis of energy consumption in buildings. These computer programs allow an architect/engineer to study various design options including detailed computations of the thermal performance of solar collectors, heat storage apparatus, and conventional heating and cooling equipment. In order to allow a simplified manipulation of the many variables used to describe a building, and to allow users the widest versatility in the design of solar buildings, a new user-oriented computer input language, called BDL, a Building Design Language, has been developed. This language is used to describe each component of a building, to analyze the input commands, and to notify the user of possible mistakes. BDL also controls data retrieval from a large set of libraries containing information on building components, materials, and operation schedules. It is also used to control the operation of the four primary computational programs which simulate the building LOADS, its Heating, Ventilating, and Air Conditioning (HVAC) SYSTEMS, the PLANT and solar equipment, and to compute ECONOMIC parameters.

ENGINEERING-ECONOMIC STUDIES OF ENERGY TECHNOLOGIES TO REDUCE GREENHOUSE GAS EMISSIONS: Opportunities and Challenges

Recent studies highlight the large potential for electricity and fuel savings through improved energy efficiency. These studies show that E/GNP (primary energy use/

Economic comparison of white, green, and black flat roofs in the United States

of GNP) could be reduced by nearly 50% for the U.S. for optimum economic growth over a period of 10–20 years, the typical turnover time for automobile, appliance, and equipment stocks and the time needed for building retrofits. This paper discusses recent progress and potential future savings in automobiles, refrigerators, windows, lighting, and through urban heat island mitigation. These energy savings are translated into savings of carbon dioxide (CO2).