University of California Energy Institute

In California there are 16 different climate zones as defined in the California Energy code (Title 24). The code requires slightly different types of buildings in each zone. These different building code requirements make it important for architects, builders, contractors, and homeowners to understand the resources of their unique local climate and how it will influence the performance of their buildings. The objective of this project is to create a tool called Climate Consultant 4.0 that adds a number of features to those in the prior version 3.0, including new graphic screens such as a Monthly Diurnal Averages plot. It also calculates a set of the Top 20 Design Guidelines based on your unique climate, and displays a sketch illustrating how each applies. A new dynamic graphic tutorial has been created to explain the Psychrometric Chart, and how the relationship between air temperature and humidity influences human thermal comfort and HVAC systems design. Climate Consultant 4.0 helps people who are designing, building, and maintaining buildings throughout the world to understand their local climate and how it impacts their building’s energy consumption.

Municipal solid waste (MSW) is an attractive cellulosic resource for sustainable production of transportation fuels and chemicals because of its abundance, the need to find uses for this problematic waste, and its low and perhaps negative cost. However, significant heterogeneity and possible toxic contaminants are barriers to biological conversion to ethanol and other products. In this study, we obtained six fractions of sorted MSW from a waste processing facility in Fontana, California: 1) final alternative daily cover (ADC Final), 2) ADC green, 3) woody waste, 4) grass waste, 5) cardboard, and 6) mixed paper. Application of dilute sulfuric acid pretreatment followed by enzymatic hydrolysis gave the highest sugar yields in cardboard and ADC final fractions at enzyme loadings of 100 mg enzyme protein/g sugars of raw materials. Treatment with our non-catalytic protein detoxification technology before adding enzymes improved sugar yields at low enzyme loading of 10 mg enzyme protein/g (glucan plus xylan) of raw materials. Pretreatment with 1% dilute sulfuric acid for 40 min followed by bovine serum albumin (BSA) supplemented enzymatic hydrolysis at an enzyme loading of 10 mg enzyme protein/g glucan recovered 79.1% of potential glucan and 88.2% of potential xylan in solution from ADC final, and 83.3% of potential glucan and 89.1% of potential xylan from ADC green. Experimental results were incorporated into an economic model to determine the economic feasibility of converting MSW to ethanol and identify opportunities for improving the economics. The minimum ethanol selling price for ADC final and ADC green was estimated as $0.6 per gallon and $0.91 per gallon, respectively.

Data centers greatly impact California’s natural environment and economy. These buildings host computer equipment that provide the massive computational power, data storage, and global networking that is integral to modern information technology. The concentration of densely packed computer equipment in data centers leads to power demands that are much higher than those of a typical residence or commercial office building. Data centers typically consume 15 times more energy per square foot than a typical office building and, in some cases, may be 100 times more energy intensive (Greenberg et al. 2003). Nationally, data centers consumed 61 Terawatt hours in 2006; equivalent to the practical power generation of more than 10, 1 Gigawatt nuclear power plants (Brown et al., 2007). This is approximately equal to annual electricity consumption for the entire state of New Jersey (EIA, 2006). California has the largest data center market in the U.S., indicating that a significant portion of this energy is consumed within the State (Mitchell-Jackson, 2001).

This research project focused on identifying how data centers are currently designed and exploring potential energy saving associated with alternative building design options. The energy savings were quantified to understand when design changes resulted in significant benefits and when the benefits from alternative designs were minimal. The potential energy savings benefits were juxtaposed against changes to the environmental conditions in data centers and evaluated within the context of computer reliability concerns. The objective of this research is to provide data center designers and other decision makers with a better understanding of the benefits and concerns associated with data center energy efficiency, thereby reducing the unknown consequences that may hinder attempts to shift away from conventional design practices.

Because of frequent acceleration and slowing down and the high speed of most transportation systems, lightweight structural materials are needed to reduce their energy consumption while maintaining safety. Considering the extensive use of energy intensive transportation systems in the United States even a small increase in energy efficiency will result in significant energy savings and reduction in pollutant emissions. Closed-cell solid foams and microfoams are of particular interest since they are light and feature outstanding combination of mechanical, electrical, acoustic, and thermal properties.

Studies of high-temperature morphological evolution of controlled-geometry surface cavities and of controlled-geometry internalized pores etched into (100) and (111) surfaces of yttria-stabilized zirconia (YSZ) have been conducted. Results show significant crystallography-dependent variations in the morphologies and evolution rates. The terraceledge structures on (100) and (111) YSZ surfaces differ substantially. Internalized pores that are largely or partially bounded by {111} surfaces are particularly stabilized with regard to shape relaxation and axial instability. The results suggest that controlled variation of thermal barrier coating (TBC) texture and microstructure could result in significant changes in stability and lifetimes.

In California there are 16 different climate zones, as defined in the California Energy Code (Title24). The code requires slightly different types of buildings in each zone. These different building code requirements make it important for people who are designing, building, or maintaining these buildings to understand the unique attributes of their climate and how it will influence the design and performance of their buildings. In this UCEI project we developed a simple, free, easy-to-use, graphic-based computer program called Climate Consultant 3, and we have posted it on the State of California’s Flex Your Power web site and on the UCLA Energy Design Tools web site. Our objective is to make it freely accessible to architects, builders, contractors, and homeowners, etc., to help them understand their local climate and how it impacts their building’s energy consumption.

The object of this research is to examine the flow in a plenum of an underfloor air distribution system (UFAD). UFAD installations have often performed poorly because the air entering the space through different vents attached to the plenum has different temperatures. The temperature differences vary in time and can be as much as 5 °C from diffuser to diffuser. It is believed that these temperature inhomogeneities are a result of circulating patterns established in the air flow in the plenum, and that these circulations, in turn, are a result of specific supply and plenum geometries. We have carried out laboratory simulations and numerical modeling of the plenum flow in an attempt to establish the dependence of the flow patterns on the supply configurations. We have conducted a systematic study of the flow patterns for different forcing arrangements and discuss the implications for plenum design. In each case the plenum is square in plan form and the configurations studied are:

One source jet in the middle of a side wall Two source jets in the same side wall with the same direction Two source jets in opposite side walls with opposite directions Four source jets in four side walls to generate an initial torque For the first configuration, we investigate laminar and turbulent jet behavior for two the aspect ratios of the horizontal and vertical length scales in order to assess the two-dimensionality of the flow. For the two co-flowing and counterflowing arrangements we investigate the effects of coalescence of the jets. In the multiple jet cases the interactions of the jets established strong and, in many cases, persistent circulations. These flows were studied in the laboratory using Particle Image Velocimetry (PIV). A RNG K-e turbulent closure was used for numerical calculations. The numerical calculations also allowed the thermal performance to be evaluated by the addition of heat transfer into the plenum from the top and bottom boundaries

Understanding the flows of fluids and carbons on continental margins is of great importance to understand their role in carbon budgets one important source of these fluid flows is marine hydrocarbon seeps (cold seeps). Seeps are found on all continental margins (Judd et al., 2002) and are important to global atmospheric budgets of the important greenhouse gas, methane, contributing an estimated 35-45 Tg yr-1 (Etiope and Klusman, 2002). Of this, marine seeps are estimated to contribute ~20 Tg yr-1 (Kvenvolden et al., 2001) or ~13% of natural emissions and primarily arises from methane hydrates and thermogenic source. Methane hydrates are a form of ice that is stable at high pressure and low temperature wherein methane gas is trapped in the ice crystal lattice. Methane hydrate deposits are estimated at 2000 Tg (Collett and Kuuskraa, 1998; Kvenvolden, 1999), and pose a significant climate threat should oceanic warming occur and lead to increased atmospheric greenhouse gases (Kennett et al., 2003; Leifer et al., 2006). Yet, despite methane’s importance of methane to global climate atmospheric budgets, significant uncertainty exists in the sources and sinks. Marine seeps are also an important source of petroleum to the ocean. During the 1990s, natural seeps annually emitted an estimated 600,000 tons (150 M gals) of oil into the ocean, approximately half the annual total oil entering the ocean, ~1,300,000 tons. For comparison, spills from marine vessels accounted for 100,000 tons, terrestrial run-off, 140,000 tons, and pipelines just 12,000 tons. In North America, seeps emit an estimate of 160,000 tons (NRC, 2005).

To date, few quantitative emission rates have been published for gas and even fewer for oil emissions. Gas emission rates have been quantified by sonar quantification (e.g., Hornafius et al., 1999), turbine-tent flow measurements (Leifer and Boles, 2004), and bubble emission 2 measurements (Leifer and MacDonald, 2003). Even fewer quantitative measurements of petroleum emission rates have been published. Methods include estimation from oil slicks (Clester et al., 1996) and direct capture from individual seep vents (Leifer and Wilson, 2004; 2006; Mikolaj and Ampaya, 1973). The latter study showed an increase in oil emission with decreasing tidal depth.Further, in areas where oil and gas are emitted together, petroleum increases the challenge of measuring gas emissions. In this study, we developed and field-tested an approach to allow simultaneous quantification of oil and gas emissions from shallow marine seeps in the Coal Oil Point seep field.

Private sector and governmental organizations have been promoting the deployment of small-scale, distributed electricity generation (DG) technologies for their many benefits as compared to the traditional paradigm of large, centralized power plants. While some researchers have investigated the impact of a shift toward DG in terms of energy use and even air pollutant concentrations, it is also important to evaluate the air pollutant exposure implications of this shift. We conducted a series of case studies within the state of California that combined air dispersion modeling and inhalation exposure assessment. Twenty-five central stations were selected and five air pollutant-emitting DG technologies were considered, including two that meet the 2003 and 2007 California Air Resources Board DG emissions standards (microturbines and fuel cells with on-site natural gas reformers, respectively). This investigation has revealed that the fraction of pollutant mass emitted that is inhaled by the downwind, exposed population can be more than an order of magnitude greater for all five DG technologies considered than for large, central-station power plants in California. This difference is a consequence mainly of the closer proximity of DG sources to densely populated areas as compared to typical central station, and is independent of the emissions characteristics of the plants assessed. Considering typical emission factors for the five DG technologies, the mass of pollutant inhaled per unit electricity delivered can be up to three orders of magnitude greater for DG units as compared to existing California central stations. To equalize the exposure burden between DG and central station technologies, DG emission factors will need to be reduced to a range between the level of the cleanest, new central stations in California and an order of magnitude below those levels, depending on the pollutant and siting. We conclude that there is reason to caution against an unmitigated embrace of DG technologies that emit air pollutants so that they do not pose a greater public health burden than the current electricity generation system.

The relationship between surface bubble composition and gas flux to the atmosphere was examined at Coal Oil Point seep field, which is located about 3 km offshore of Santa Barbara County, CA in the Santa Barbara Channel. The field research was conducted using a spar buoy designed to simultaneously measure the surface gas flux, the buoy’s position with differential GPS, and collect gas samples. Results show that the gas composition varies by 10-20% at sub-seeps within seep areas. The nitrogen mole fraction correlated directly with oxygen mole fraction (R2 = 0.94) and inversely with methane mole fraction (R2 = 0.97). These data demonstrate that the bubble composition is modified by gas exchange during ascent from the seafloor: dissolved air enters and hydrocarbon gases leave the bubbles. While compositional differences were observed at sub-seeps, there was no relationship between flux and composition. Factors other than seep intensity controls the amount of gas transfer between the ocean water and bubbles. Therefore, when calculating the atmospheric source function of specific gases such as methane or ROGs from marine seeps, it is best to use mean compositional values determined for bubbles collected near the sea surface.