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The rapid growth of renewable generation is creating challenges for the California grid in the form of the duck curve, with increasingly steep generation ramping requirements and growing curtailment of renewable resources. In response, there has been increased discussion of promoting dynamic electricity tariffs that vary with conditions on the grid in near-real time, which could incentivize customers to shift consumption and help flatten the duck curve. Dynamic tariffs may raise concerns about financial impacts on utility customers, bill volatility, and equity issues arising from potential cost shifting among customer groups. In this report, we leverage smart meter data for more than 400,000 California utility customers to assess potential customer bill impacts arising from a multi-component dynamic tariff that is conceptually informed by the “California Flexible Unified Signal for Energy” (CalFUSE1 ) tariff structure that has recently been proposed by staff at the California Public Utilities Commission (CPUC). Specifically, we compute impacts on customer bills and bill volatility under the assumption of fully inelastic demand, i.e., where customers do not change their consumption patterns in response to the tariff. Implicit in this assumption is that even flexible loads, such as storage and EV charging, do not respond to the dynamic tariff. In practice, customers would have the opportunity to reduce their bills by modifying their consumption patterns and operational profiles of flexible devices under a dynamic tariff; thus, the results of this study represent a worst-case set of bill impacts, which could provide a useful benchmark for future studies of customer response to dynamic tariffs.We develop a single hypothetical dynamic tariff for each IOU, which applies to all of that IOU’s customers regardless of sector or customer class. The tariff is constructed to be revenue-neutral for the utility, relative to presently active IOU tariffs, so that any increase or decrease in one customer’s bill will be offset by changes in other customers’ bills, allowing us to assess any changes in cost allocation among customer classes (i.e., “cost-shifts”) that would accompany a universal dynamic tariff. The hypothetical dynamic tariff recovers all required utility revenue through a purely volumetric energy charge (i.e., with no demand charges or fixed charges) whose rate varies hourly based on expected conditions on the grid, as reflected in the CAISO day-ahead market.&nbsp

In response to the imperative of the climate crisis, California is in the midst of deployment of low-carbon energy generation and electrified heating and transportation at a rapid pace. In 2018 the grid managed by the California Independent System Operator (CAISO) was already generating 26 percent of its power from non-hydro renewable sources, with an additional ten percent hydroelectric power; and with SB 100, California statute now sets a target of 100 percent carbon free electricity by 2045. Maintaining this fast pace of decarbonization requires action across multiple domains on the grid from generators to loads. This study describes new findings on the scale of the opportunity for enabling load shifting as a form of demand response (DR) in California, as part of this renewable energy transition. We use the shorthand term Shift to refer to this potential load-shifting DR resource. The operating principles for the electric power system mean that achieving California’s renewable energy goals requires careful planning to build and operate the system in a way that maintains reliability at low cost. The most fundamental of these principles is that generation and demand need to be balanced at all times. Historically this has meant building adequate flexible and dispatchable generators that can be operated to match inflexible and uncontrolled loads. Meeting large fractions of demand with variable renewable energy (VRE) generation introduces a new paradigm, exemplified by the “duck curve” in California. In the times of year it occurs, the duck curve illustrates the net electricity demand that must be met by non-VRE generation; it has sharp peaks in morning and evening (the “tail” and “head” of the duck, respectively) and steep transitions to a deep midday trough (the duck’s “belly”) resulting from solar generation. Balancing the duck curve is a key priority for integrating increasing levels of VRE on the California grid. Shift DR is one of several renewables integration planning approaches that can work together to balance a high-VRE system. Others include “overbuilding” renewable energy with the intent to curtail during times of surplus generation, building and operating transmission lines to integrate regional systems, and building and operating energy storage to match generation with loads. Based on the 2019-2020 Integrated Resource Planning (IRP) model for California1—which did not consider Shift among its resource options—the least-cost pathway for achieving California GHG goals includes all of these other approaches. The Reference System Portfolio that is used to inform utility planning includes development of energy storage that is operated to serve about 10 GWh of consumption on the average day in 2020, 70 GWh in 2030, and 400 GWh by 2045. There is also significant curtailment of VRE in this least-cost portfolio, with 4 GWh on the average day in 2020, rising to 15 GWh by 2030 and 100 GWh by 2045. Throughout this report we compare the Shift resource to curtailment and storage as benchmarks, providing context for the results we report related to the quantity, cost, and performance of Shift. The timing of evening peak and curtailment defines times when load shifting is most valuable and would likely be used. The quantity of curtailment and use of storage to balance the system represent how much Shift could be valuable at the upper bound if Shift is inexpensive. The cost of energy storage is also a useful benchmark for the cost of Shift because it is the most comparable “competing” technology option; we therefore use the cost of storage to set a reference price level below which Shift will be most broadly cost competitive.

As the transportation sector undergoes three major transformations—electrification, shared/on-demand mobility, and automation—there are new challenges to analyzing the impacts of these trends on both the transportation system and the power sector. Most models that analyze the requirements of fleets of shared autonomous electric vehicles (SAEVs) operate at the scale of an urban region, or smaller. A quadratically constrained, quadratic programming problem is formulated, designed to model the requirements of SAEVs at a national scale. The size of the SAEV fleet, the necessary charging infrastructure, the fleet charging schedule, and the dispatch required to serve demand for trips in a region are treated as decision variables. By minimizing both the amortized cost of the fleet and chargers as well as the operational costs of charging, it is possible to explore the coupled interactions between system design and operation. To apply the model at a national scale, key complications about fleet operations are simplified; but a detailed agent-based regional simulation model to parameterize those simplifications is leveraged. Preliminary results are presented, finding that all mobility in the United States (U.S.) currently served by 276 million personally owned vehicles could be served by 12.5 million SAEVs at a cost of $ 0.27/vehicle-mile or $ 0.18/passenger-mile. The energy requirements for this fleet would be 1142 GWh/day (8.5% of 2017 U.S. electricity demand) and the peak charging load 76.7 GW (11% of U.S. power peak). Several model sensitivities are explored, and it is found that sharing is a key factor in the analysis.

Commercial lighting represents a significant potential source of demand response (DR) for the electrical grid, via traditional load shedding and rapid-dispatch (fast-DR) ancillary services when DR is enabled by networked lighting controls (NLCs). However, despite the significant opportunity and a regulatory push, DR-enabled lighting is installed in relatively few buildings because most building owners do not recognize its strong value proposition. Although NLCs can reduce energy bills, optimize facilities, and increase revenue, these co-benefits are not well quantified. This project analyzed lighting DR resources and energy-related co-benefits for commercial buildings in California. Using more than 100,000 individual hourly load profiles, the team forecasted the potential DR resources likely available from commercial lighting in 2025 and estimated revenues available from participation of these DR resources in energy markets. Combining these results with field-study estimates for NLC installation costs and energy savings provided a detailed accounting of site-level cost and energy-related co-benefits by building type from NLC’s DR enablement. In many cases, energy savings alone can deliver significant net value, justifying NLC DR-enabled adoption. Additionally, the study considers the sometimes-larger non-energy benefits (NEBs).

The Energy Policy and Conservation Act of 1975, as amended by the Energy Independence and Security Act of 2007 (EISA 2007), requires that, effective beginning January 1, 2020, the Secretary of Energy shall prohibit the sale of any general service lamp (GSL) that does not meet a minimum efficacy standard of 45 lumens per watt. This is referred to as the EISA 2007 backstop. The U.S. Department of Energy recently revised the definition of the term GSL to include certain lamps that were either previously excluded or not explicitly mentioned in the EISA 2007 definition. For this subset of GSLs, we assess the impacts of the EISA 2007 backstop on national energy consumption, carbon dioxide emissions, and consumer expenditures. To estimate these impacts, we projected the energy use, purchase price, and operating cost of representative lamps purchased during a 30-year analysis period, 2020-2049, for cases in which the EISA 2007 backstop does and does not take effect; the impacts of the backstop are then given by the difference between the two cases. In developing the projection model, we also performed the most comprehensive assessment to date of usage patterns and lifetime distributions for the analyzed lamp types in the United States. There is substantial uncertainty in the estimated impacts, which arises from uncertainty in the speed and extent of the market conversion to solid state lighting technology that would occur in the absence of the EISA 2007 backstop. In our central estimate we find that the EISA 2007 backstop results in significant energy savings of 27 quads and consumer net present value of $120 billion (at a seven percent discount rate) for lamps shipped between 2020 and 2049, and carbon dioxide emissions reduction of 540 million metric tons by 2030 for those GSLs not explicitly included in the EISA 2007 definition of a GSL.

A major barrier to effective appliance efficiency program design and evaluation is a lack of data for determination of market baselines and cost-effective energy savings potential. The data gap is particularly acute in developing countries, which may have the greatest savings potential per unit GDP. To address this need, we are developing the International Database of Efficient Appliances (IDEA), which automatically compiles data from a wide variety of online sources to create a unified repository of information on efficiency, price, and features for a wide range of energy-consuming products across global markets. This paper summarizes the database framework and demonstrates the power of IDEA as a resource for appliance efficiency research and policy development. Using IDEA data for refrigerators in China and India, we develop robust cost-effectiveness indicators that allow rapid determination of savings potential within each market, as well as comparison of that potential across markets and appliance types. We discuss implications for future energy efficiency policy development.

In recent years, household LED light bulbs (LED A lamps) have undergone a dramatic price decline. Since late 2011, we have been collecting data, on a weekly basis, for retail offerings of LED A lamps on the Internet. The resulting data set allows us to track the recent price decline in detail. LED A lamp prices declined roughly exponentially with time in 2011-2014, with decline rates of 28percent to 44percent per year depending on lumen output, and with higher-lumen lamps exhibiting more rapid price declines. By combining the Internet price data with publicly available lamp shipments indices for the US market, it is also possible to correlate LED A lamp prices against cumulative production, yielding an experience curve for LED A lamps. In 2012-2013, LED A lamp prices declined by 20-25percent for each doubling in cumulative shipments. Similar analysis of historical data for other lighting technologies reveals that LED prices have fallen significantly more rapidly with cumulative production than did their technological predecessors, which exhibited a historical decline of 14-15percent per doubling of production.

We describe the design and data analysis of the DEEP2 Galaxy Redshift Survey, the densest and largest high-precision redshift survey of galaxies at z ∼ 1 completed to date. The survey was designed to conduct a comprehensive census of massive galaxies, their properties, environments, and large-scale structure down to absolute magnitude MB = -20 at z ∼ 1 via ∼90 nights of observation on the Keck telescope. The survey covers an area of 2.8 deg2 divided into four separate fields observed to a limiting apparent magnitude of RAB = 24.1. Objects with z ≲ 0.7 are readily identifiable using BRI photometry and rejected in three of the four DEEP2 fields, allowing galaxies with z > 0.7 to be targeted ∼2.5 times more efficiently than in a purely magnitude-limited sample. Approximately 60% of eligible targets are chosen for spectroscopy, yielding nearly 53,000 spectra and more than 38,000 reliable redshift measurements. Most of the targets that fail to yield secure redshifts are blue objects that lie beyond z ∼ 1.45, where the [O II] 3727 Å doublet lies in the infrared. The DEIMOS 1200 line mm-1 grating used for the survey delivers high spectral resolution (R ∼ 6000), accurate and secure redshifts, and unique internal kinematic information. Extensive ancillary data are available in the DEEP2 fields, particularly in the Extended Groth Strip, which has evolved into one of the richest multiwavelength regions on the sky. This paper is intended as a handbook for users of the DEEP2 Data Release 4, which includes all DEEP2 spectra and redshifts, as well as for the DEEP2 DEIMOS data reduction pipelines. Extensive details are provided on object selection, mask design, biases in target selection and redshift measurements, the spec2d two-dimensional data-reduction pipeline, the spec1d automated redshift pipeline, and the zspec visual redshift verification process, along with examples of instrumental signatures or other artifacts that in some cases remain after data reduction. Redshift errors and catastrophic failure rates are assessed through more than 2000 objects with duplicate observations. Sky subtraction is essentially photon-limited even under bright OH sky lines; we describe the strategies that permitted this, based on high image stability, accurate wavelength solutions, and powerful B-spline modeling methods. We also investigate the impact of targets that appear to be single objects in ground-based targeting imaging but prove to be composite in Hubble Space Telescope data; they constitute several percent of targets at z ∼ 1, approaching ∼5%-10% at z > 1.5. Summary data are given that demonstrate the superiority of DEEP2 over other deep high-precision redshift surveys at z ∼ 1 in terms of redshift accuracy, sample number density, and amount of spectral information. We also provide an overview of the scientific highlights of the DEEP2 survey thus far. © 2013. The American Astronomical Society. All rights reserved.

We report Chandra observations of a double X-ray source in the z=0.1569 galaxy SDSS J171544.05+600835.7. The galaxy was initially identified as a dual AGN candidate based on the double-peaked [O III] emission lines, with a line-of-sight velocity separation of 350 km/s, in its Sloan Digital Sky Survey spectrum. We used the Kast Spectrograph at Lick Observatory to obtain two longslit spectra of the galaxy at two different position angles, which reveal that the two AGN emission components have not only a velocity offset, but also a projected spatial offset of 1.9 kpc/h70 on the sky. Chandra/ACIS observations of two X-ray sources with the same spatial offset and orientation as the optical emission suggest the galaxy most likely contains Compton-thick dual AGN, although the observations could also be explained by AGN jets. Deeper X-ray observations that reveal Fe K lines, if present, would distinguish between the two scenarios. The observations of a double X-ray source in SDSS J171544.05+600835.7 are a proof of concept for a new, systematic detection method that selects promising dual AGN candidates from ground-based spectroscopy that exhibits both velocity and spatial offsets in the AGN emission features., Comment: 6 pages, 3 figures, submitted to ApJL

We use data drawn from the DEEP2 Galaxy Redshift Survey to investigate the relationship between local galaxy density, stellar mass, and rest-frame galaxy color. At z ~ 0.9, we find that the shape of the stellar mass function at the high-mass (log (M*/Msun) > 10.1) end depends on the local environment, with high-density regions favoring more massive systems. Accounting for this stellar mass-environment relation (i.e., working at fixed stellar mass), we find a significant color-density relation for galaxies with 10.6 < log(M*/Msun) < 11.1 and 0.75 < z < 0.95. This result is shown to be robust to variations in the sample selection and to extend to even lower masses (down to log(M*/Msun) ~ 10.4). We conclude by discussing our results in comparison to recent works in the literature, which report no significant correlation between galaxy properties and environment at fixed stellar mass for the same redshift and stellar mass domain. The non-detection of environmental dependence found in other data sets is largely attributable to their smaller samples size and lower sampling density, as well as systematic effects such as inaccurate redshifts and biased analysis techniques. Ultimately, our results based on DEEP2 data illustrate that the evolutionary state of a galaxy at z ~ 1 is not exclusively determined by the stellar mass of the galaxy. Instead, we show that local environment appears to play a distinct role in the transformation of galaxy properties at z > 1., 10 pages, 5 Figures; Accepted for publication in MNRAS

We present measurements of the color and luminosity dependence of galaxy clustering at z~1 in the DEEP2 Galaxy Redshift Survey. Using volume-limited subsamples in bins of both color and luminosity, we find that: 1) The clustering dependence is much stronger with color than with luminosity and is as strong with color at z~1 as is found locally. We find no dependence of the clustering amplitude on color for galaxies on the red sequence, but a significant dependence on color for galaxies within the blue cloud. 2) For galaxies in the range L/L*~0.7-2, a stronger large-scale luminosity dependence is seen for all galaxies than for red and blue galaxies separately. The small-scale clustering amplitude depends significantly on luminosity for blue galaxies, with brighter samples having a stronger rise on scales r_p, 28 pages, 17 figures, emulateapj format, accepted to ApJ, updated to match published version

Using galaxy samples drawn from the Sloan Digital Sky Survey and the DEEP2 Galaxy Redshift Survey, we study the relationship between star formation and environment at z ~ 0.1 and z ~ 1. We estimate the total star-formation rate (SFR) and specific star-formation rate (sSFR) for each galaxy according to the measured [O II] nebular line luminosity, corrected using empirical calibrations to match more robust SFR indicators. Echoing previous results, we find that in the local Universe star formation depends on environment such that galaxies in regions of higher overdensity, on average, have lower star-formation rates and longer star-formation timescales than their counterparts in lower-density regions. At z ~ 1, we show that the relationship between specific SFR and environment mirrors that found locally. However, we discover that the relationship between total SFR and overdensity at z ~ 1 is inverted relative to the local relation. This observed evolution in the SFR-density relation is driven, in part, by a population of bright, blue galaxies in dense environments at z ~ 1. This population, which lacks a counterpart at z ~ 0, is thought to evolve into members of the red sequence from z ~ 1 to z ~ 0. Finally, we conclude that environment does not play a dominant role in the cosmic star-formation history at z < 1: the dependence of the mean galaxy SFR on local galaxy density at constant redshift is small compared to the decline in the global SFR space density over the last 7 Gyr., 20 pages including 18 figures and 4 tables in emulateapj format; submitted to MNRAS

Using a sample of 19,464 galaxies drawn from the DEEP2 Galaxy Redshift Survey, we study the relationship between galaxy color and environment at 0.4 < z < 1.35. We find that the fraction of galaxies on the red sequence depends strongly on local environment out to z > 1, being larger in regions of greater galaxy density. At all epochs probed, we also find a small population of red, morphologically early-type galaxies residing in regions of low measured overdensity. The observed correlations between the red fraction and local overdensity are highly significant, with the trend at z > 1 detected at a greater than 5-��level. Over the entire redshift regime studied, we find that the color-density relation evolves continuously, with red galaxies more strongly favoring overdense regions at low z relative to their red-sequence counterparts at high redshift. At z ~ 1.3, the red fraction only weakly correlates with overdensity, implying that any color dependence to the clustering of ~ L* galaxies at that epoch must be small. Our findings add weight to existing evidence that the build-up of galaxies on the red sequence has occurred preferentially in overdense environments (i.e., galaxy groups) at z < 1.5. The strength of the observed evolutionary trends at 0 < z < 1.35 suggests that the correlations observed locally, such as the morphology-density and color-density relations, are the result of environment-driven mechanisms (i.e., "nurture'') and do not appear to have been imprinted (by "nature'') upon the galaxy population during their epoch of formation., 19 pages including 10 figures, accepted to MNRAS

Using the first 25% of DEEP2 Redshift Survey data, we probe the line-of-sight velocity dispersion profile for isolated galaxies with absolute B-band magnitude -22, Comment: 8 pages, 5 figures, ApJ accepted

The DEEP2 survey has now completed half of its planned three-year lifespan, and we have collected approximately 50% of the data, putting us exactly on schedule. The survey plan calls for spectroscopic coverage by July of 2005 of \~60,000 galaxies over 3.5 square degrees to a limiting magnitude of R_{AB}=24.1; the great majority of these objects are at 0.7, Comment: 13 pages, 4 figures. To appear in the proceedings of "Observing Dark Energy: NOAO Workshop", Mar 18-20 2004. To download a higher resolution version of Fig. 1, go to http://deep.berkeley.edu/~marc/deep/papers.html