PHYSICS OF SUSTAINABLE ENERGY II: USING ENERGY EFFICIENTLY AND PRODUCING IT RENEWABLY
1401(2011); http://dx.doi.org/10.1063/1.3653841View Description Hide Description
1401(2011); http://dx.doi.org/10.1063/1.3653842View Description Hide Description
This article will discuss how my colleagues and I have promoted energy efficiency over the last 40 years. Our efforts have involved thousands of people from many different areas of expertise. The work has proceeded in several areas:
• Investigating the science and engineering of energy end‐use,
• Assessing the potential and theoretical opportunities for energy efficiency,
• Developing analytic and economic models to quantify opportunities,
• Researching and developing new equipment and processes to bring these opportunities to fruition,
• Participating in the development of California and later federal standards for energy performance in buildings and appliances,
• Ensuring that market incentives were aligned with policies, and
• Designing clear and convincing graphics to convey opportunities and results to all stakeholders.
1401(2011); http://dx.doi.org/10.1063/1.3653843View Description Hide Description
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 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.
1401(2011); http://dx.doi.org/10.1063/1.3653844View Description Hide Description
1401(2011); http://dx.doi.org/10.1063/1.3653845View Description Hide Description
The five billion persons at the lower economic levels are not only poor, but commonly use technologies that are less efficient and more polluting, wasting their money, hurting their health, polluting their cites, and increasing carbon dioxide in the atmosphere. Many first‐world researchers, including the authors, are seeking to help these persons achieve a better life by collaborating on need‐driven solutions to energy problems. Here we examine three specific examples of solutions to energy problems, and mitigation strategies in the developing world:
(1) Energy Efficiency Standards and Labeling in China. Between 1990 and 2025, China will add 675 million new urban residents, all of whom expect housing, electricity, water, transportation, and other energy services. Policies and institutions must be rapidly set up to manage the anticipated rapid rise in household and commercial energy consumption. This process has progressed from legislating, and setting up oversight of minimum energy performance standards in 1989 (now on 30 products) to voluntary efficiency labels in 1999 (now on 40 products) and to mandatory energy labels in 2005 (now on 21 products). The savings from just the standards and labels in place by 2007 would result in cumulative savings of 1188 teraWatt—hours (TWh) between 2000‐2020. By 2020, China would save 110 TWh/yr, or the equivalent of 12 gigaWatts (GW) of power operating continuously.
(2) Fuel‐efficient biomass cookstoves to reduce energy consumption and reduce pollution. Compared to traditional cooking methods in Darfur, the BDS cooks faster, reduces fuel requirement, and emits less carbon monoxide air pollution. A 2010 survey of 100 households showed that users reduced spending on fuelwood in North Darfur camps from 1/2 of household non‐fuelwood budget to less than 1/4 of that budget. The survey showed that each $20 stove puts $330/year in the pocket of the women using the stove, worth $1600 over the stove‐life of 5 years. Per capita income of these households is about $300/year.
(3) Super Efficient Appliance Deployment. Global domestic electricity consumption is expected to double in 25 years, from 5,700 TWh/yr in 2005 to 11,500 TWh/yr in 2030. The four appliances using largest shares of domestic electricity (lighting, refrigeration, air‐conditioning, television) would use some 5,000 TWh/yr in 2030, or 43% of the total, in the baseline scenario. More than 50% of this consumption will be in China, India, European Union and US. We outline efforts to save up to 1.5 gigatons of carbon dioxide emissions per year in 2030 by helping deploy the most efficient commercially available technologies in these four categories. Furthermore, if this effort is extended to twenty‐four categories of appliances and equipment, the projected savings in emissions increase to 6.7 gigatons per year by 2030.
1401(2011); http://dx.doi.org/10.1063/1.3653846View Description Hide Description
We are exploring a collaborative development model where US students study in a developing country with local students, in this case in San Pablo, Guatemala—a village of 800 at elevation 3000 m near the Mexican Boarder. The Cal Poly summer study abroad program “Guateca”, to commence July 1, 2011, was jointly conceived with San Pablo leadership on August, 2010, and has since grown through input from both Cal Poly and San Pablo communities. The program aims to build cross‐cultural community and explore choices both societies have in the context of the rapidly changing energy landscape to develop in a way that preserves the environment and builds independence from increasingly expensive conventional energy sources.
1401(2011); http://dx.doi.org/10.1063/1.3653847View Description Hide Description
This manuscript presents an overview and a relevant framework for thinking about the nexus of energy and water. Here are the key points of this article:
• Energy and water are interrelated; we use energy for water and water for energy,
• The Energy‐water relationship is under strain, and that strain introduces cross‐sectoral vulnerabilities (that is, a water constraint can become an energy constraint, and an energy constraint can induce a water constraint),
• Trends imply that this strain will be exacerbated because of 1) growth in total demand for energy and water, primarily driven by population growth, 2) growth in per capita demand for energy and water, primarily driven by economic growth, 3) global climate change, which will distort the availability of water, and 4) policy choices, by which we are selecting more water‐intensive energy and more energy‐intensive water.
1401(2011); http://dx.doi.org/10.1063/1.3653848View Description Hide Description
We present a condensed version of the American Physical Society's 2008 analysis of energy efficiency in the transportation and buildings sectors in the United States with updated numbers. In addition to presenting technical findings, we include the report's recommendations for policy makers that we believe are in the best interests of the nation.
1401(2011); http://dx.doi.org/10.1063/1.3653849View Description Hide Description
California has set an ambitious goal of pursuing all cost‐effective energy efficiency and increasing the percent of electrical power generated by renewable energy sources to 33% by 2020. Through a large mixture of projects, many overseen by the California Public Utilities Commission, the state is aiming to greatly increase its reliance on sustainable energy.
1401(2011); http://dx.doi.org/10.1063/1.3653850View Description Hide Description
The U.S. Congress directed the U.S. Department of the Treasury to arrange for a review by the National Academy of Sciences to define and evaluate the health, environmental, security, and infrastructural external costs and benefits associated with the production and consumption of energy—costs and benefits that are not or may not be fully incorporated into the market price of energy, into the federal tax or fee, or into other applicable revenue measures related to production and consumption of energy. In response, the National Research Council established the Committee on Health, Environmental, and Other External Costs and Benefits of Energy Production and Consumption, which prepared the report summarized in this chapter.
The report estimates dollar values for several major components of these costs. The damages the committee was able to quantify were an estimated $120 billion in the U.S. in 2005, a number that reflects primarily health damages from air pollution associated with electricity generation and motor vehicle transportation. The figure does not include damages from climate change, harm to ecosystems, effects of some air pollutants such as mercury, and risks to national security, which the report examines but does not monetize.
1401(2011); http://dx.doi.org/10.1063/1.3653851View Description Hide Description
This chapter describes progress in the field of “detection and attribution” (D&A) research, which seeks to identify certain “fingerprints,” or patterns of climate change, and to correlate them with possible human factors influencing the climate. Such studies contributed to the scientific confidence with which the Fourth Assessment Report of the Intergovernmental Panel on Climate Change was able to assert that anthropogenic greenhouse gases had had a discernible effect on global warming since the century. D&A methods have greatly improved to incorporate many more climate variables and to include increasingly finer variations in space and time. The chapter also describes the intercomparison of global climate models and the comprehensive data base of model simulations now available to anyone free of charge.
The following is the testimony given by Benjamin Santer to the U.S. House of Representative Committee on Science and Technology, Subcommittee on Energy and Environment, on November 17, 2010. It is adapted from a chapter that Tom Wigley and Benjamin Santer published in a book edited by the late Stephen Schneider  and from previous testimony given by Dr. Santer to the House Select Committee on Energy Independence and Global Warming.
1401(2011); http://dx.doi.org/10.1063/1.3653852View Description Hide Description
The arctic permafrost is thawing, releasing organic matter that was frozen in the ground into the bottoms of lakes. This organic matter feeds microbes that produce methane, which in turn escapes to the atmosphere. Permafrost, a rich source of organic carbon, covers 20% of the earth's land surface, and one third to one half of permafrost is now within to of thawing. New estimates indicate that by 2100, thawing permafrost could boost emissions of methane—a greenhouse gas that's 25 times more potent than carbon dioxide—by 20 to 40 percent beyond what would be produced by all natural and man‐made sources. As a result, the earth's mean annual temperature could rise by an additional further upsetting weather patterns and sea level.
1401(2011); http://dx.doi.org/10.1063/1.3653853View Description Hide Description
One strategy proposed to mitigate the climate change associated with increased greenhouse gases is to plant more trees, which absorb carbon dioxide in the process of photosynthesis. We have used a climate model to explore the possible impact of a large‐scale afforestation, both in the Arctic and at mid‐latitudes in the northern hemisphere. The global climate responds in surprising ways, largely because of the water vapor released by plant transpiration. The experiments illustrate the importance of exploring the entire spectrum of consequences from any proposed action to deal with climate change.
1401(2011); http://dx.doi.org/10.1063/1.3653857View Description Hide Description
Petroleum fuel uses make up essentially all of transportation fuel usage today and will continue to dominate transportation fuel usage well into future without any major policy changes. This chapter focuses on low‐carbon transportation fuels, specifically, biofuels, electricity and hydrogen, that are emerging options to displace petroleum based fuels. The transition to cleaner, lower carbon fuel sources will need significant technology advancement, and sustained coordination efforts among the vehicle and fuel industry and policymakers/regulators over long period of time in order to overcome market barriers, consumer acceptance, and externalities of imported oil. We discuss the unique infrastructure challenges, and compare resource, technology, economics and transitional issues for each of these fuels. While each fuel type has important technical and implementation challenges to overcome (including vehicle technologies) in order to contribute a large fraction of our total fuel demand, it is important to note that a portfolio approach will give us the best chance of meeting stringent environmental and energy security goals for a sustainable transportation future.
Technology Status and Expected Greenhouse Gas Emissions of Battery, Plug‐In Hybrid, and Fuel Cell Electric Vehicles1401(2011); http://dx.doi.org/10.1063/1.3653858View Description Hide Description
Electric vehicles (EVs) of various types are experiencing a commercial renaissance but of uncertain ultimate success. Many new electric‐drive models are being introduced by different automakers with significant technical improvements from earlier models, particularly with regard to further refinement of drivetrain systems and important improvements in battery and fuel cell systems. The various types of hybrid and all‐electric vehicles can offer significant greenhouse gas (GHG) reductions when compared to conventional vehicles on a full fuel‐cycle basis. In fact, most EVs used under most condition are expected to significantly reduce lifecycle GHG emissions. This paper reviews the current technology status of EVs and compares various estimates of their potential to reduce GHGs on a fuel cycle basis. In general, various studies show that battery powered EVs reduce GHGs by a widely disparate amount depending on the type of powerplant used and the particular region involved, among other factors. Reductions typical of the United States would be on the order of 20‐50%, depending on the relative level of coal versus natural gas and renewables in the powerplant feedstock mix. However, much deeper reductions of over 90% are possible for battery EVs running on renewable or nuclear power sources. Plug‐in hybrid vehicles running on gasoline can reduce emissions by 20‐60%, and fuel cell EV reduce GHGs by 30‐50% when running on natural gas‐derived hydrogen and up to 95% or more when the hydrogen is made (and potentially compressed) using renewable feedstocks. These are all in comparison to what is usually assumed to be a more advanced gasoline vehicle “baseline” of comparison, with some incremental improvements by 2020 or 2030. Thus, the emissions from all of these EV types are highly variable depending on the details of how the electric fuel or hydrogen is produced.
1401(2011); http://dx.doi.org/10.1063/1.3653859View Description Hide Description
This paper explores the limiting energy efficiency for the energy uses in a particular office building. This limit might be viewed as the “Carnot efficiency” for the entire building. It assumes that all energy‐consuming services in the building are provided at the minimum energy value that does not violate physical law. Rigorous physical limits such as the Carnot efficiency are used where applicable; in other cases, a plausible approximation has been adopted. Based on the assumptions made, it would be possible to provide all of the energy‐based services currently provided in the building using approximately This limiting value is less than 1% of the energy used by a typical office building in the United States. Examination of expected advances in individual technologies suggests that it may be possible to construct a building that uses approximately within the next decade.