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Thermally Activated Cooling: A Regional Approach for EstimatingBuilding Adoption

Description: This paper examines the economic potential for thermally-activated cooling (TAC) technologies as a component of distributed energy resource (DER) systems in California. A geographic information system (GIS) is used to assess the regional variation of TAC potential and to visualize the geographic pattern of potential adoption. The economic potential and feasibility of DER systems in general, and especially TAC, is highly dependent on regional factors such as retail electricity rates, building cooling loads, and building heating loads. Each of these factors varies with location, and their geographic overlap at different sites is an important determinant in a market assessment of DER and TAC. This analysis uses system payback period as the metric to show the regional variation of TAC potential in California office buildings. The DER system payback with and without TAC is calculated for different regions in California using localized values of retail electricity rates and the weather-dependent variation in building cooling and heating loads. This GIS-based method has numerous applications in building efficiency studies where geographically dependent variables, such as space cooling and heating energy use, play an important role.
Date: June 1, 2005
Creator: Edwards, Jennifer L. & Marnay, Chris
Partner: UNT Libraries Government Documents Department

Distributed generation capabilities of the national energy modeling system

Description: This report describes Berkeley Lab's exploration of how the National Energy Modeling System (NEMS) models distributed generation (DG) and presents possible approaches for improving how DG is modeled. The on-site electric generation capability has been available since the AEO2000 version of NEMS. Berkeley Lab has previously completed research on distributed energy resources (DER) adoption at individual sites and has developed a DER Customer Adoption Model called DER-CAM. Given interest in this area, Berkeley Lab set out to understand how NEMS models small-scale on-site generation to assess how adequately DG is treated in NEMS, and to propose improvements or alternatives. The goal is to determine how well NEMS models the factors influencing DG adoption and to consider alternatives to the current approach. Most small-scale DG adoption takes place in the residential and commercial modules of NEMS. Investment in DG ultimately offsets purchases of electricity, which also eliminates the losses associated with transmission and distribution (T&D). If the DG technology that is chosen is photovoltaics (PV), NEMS assumes renewable energy consumption replaces the energy input to electric generators. If the DG technology is fuel consuming, consumption of fuel in the electric utility sector is replaced by residential or commercial fuel consumption. The waste heat generated from thermal technologies can be used to offset the water heating and space heating energy uses, but there is no thermally activated cooling capability. This study consists of a review of model documentation and a paper by EIA staff, a series of sensitivity runs performed by Berkeley Lab that exercise selected DG parameters in the AEO2002 version of NEMS, and a scoping effort of possible enhancements and alternatives to NEMS current DG capabilities. In general, the treatment of DG in NEMS is rudimentary. The penetration of DG is determined by an economic cash-flow analysis that determines adoption ...
Date: January 1, 2003
Creator: LaCommare, Kristina Hamachi; Edwards, Jennifer L. & Marnay, Chris
Partner: UNT Libraries Government Documents Department

Building a market for small wind: The break-even turnkey cost of residential wind systems in the United States

Description: Although small wind turbine technology and economics have improved in recent years, the small wind market in the United States continues to be driven in large part by state incentives, such as cash rebates, favorable loan programs, and tax credits. This paper examines the state-by-state economic attractiveness of small residential wind systems. Economic attractiveness is evaluated primarily using the break-even turnkey cost (BTC) of a residential wind system as the figure of merit. The BTC is defined here as the aggregate installed cost of a small wind system that could be supported such that the system owner would break even (and receive a specified return on investment) over the life of the turbine, taking into account current available incentives, the wind resource, and the retail electricity rate offset by on-site generation. Based on the analysis presented in this paper, we conclude that: (1) the economics of residential, grid-connected small wind systems is highly variable by state and wind resource class, (2) significant cost reductions will be necessary to stimulate widespread market acceptance absent significant changes in the level of policy support, and (3) a number of policies could help stimulate the market, but state cash incentives currently have the most significant impact, and will be a critical element of continued growth in this market.
Date: March 1, 2004
Creator: Edwards, Jennifer L.; Wiser, Ryan; Bolinger, Mark & Forsyth, Trudy
Partner: UNT Libraries Government Documents Department

U.S. Regional Demand Forecasts Using NEMS and GIS

Description: The National Energy Modeling System (NEMS) is a multi-sector, integrated model of the U.S. energy system put out by the Department of Energy's Energy Information Administration. NEMS is used to produce the annual 20-year forecast of U.S. energy use aggregated to the nine-region census division level. The research objective was to disaggregate this regional energy forecast to the county level for select forecast years, for use in a more detailed and accurate regional analysis of energy usage across the U.S. The process of disaggregation using a geographic information system (GIS) was researched and a model was created utilizing available population forecasts and climate zone data. The model's primary purpose was to generate an energy demand forecast with greater spatial resolution than what is currently produced by NEMS, and to produce a flexible model that can be used repeatedly as an add-on to NEMS in which detailed analysis can be executed exogenously with results fed back into the NEMS data flow. The methods developed were then applied to the study data to obtain residential and commercial electricity demand forecasts. The model was subjected to comparative and statistical testing to assess predictive accuracy. Forecasts using this model were robust and accurate in slow-growing, temperate regions such as the Midwest and Mountain regions. Interestingly, however, the model performed with less accuracy in the Pacific and Northwest regions of the country where population growth was more active. In the future more refined methods will be necessary to improve the accuracy of these forecasts. The disaggregation method was written into a flexible tool within the ArcGIS environment which enables the user to output the results in five year intervals over the period 2000-2025. In addition, the outputs of this tool were used to develop a time-series simulation showing the temporal changes in electricity forecasts in ...
Date: July 1, 2005
Creator: Cohen, Jesse A.; Edwards, Jennifer L. & Marnay, Chris
Partner: UNT Libraries Government Documents Department

Assessment of (mu)grid distributed energy resource potential using DER-CAM and GIS

Description: This report outlines an approach to assess the local potential for deployment of distributed energy resources (DER), small power-generation installations located close to the point where the energy they produce will be consumed. Although local restraints, such as zoning, building codes, and on-site physical barriers are well-known frustrations to DER deployment, no analysis method has been developed to address them within a broad economic analysis framework. The approach developed here combines established economic optimization techniques embedded in the Distributed Energy Resource Customer Adoption Model (DER-CAM) with a geographic information system (GIS) analysis of local land-use constraint. An example case in the San Diego area is developed from a strictly customer perspective, based on the premise that future development of DER may take the form of microgrids ((mu)Grids) under the control of current utility customers. Beginning with assumptions about which customer combinations h ave complementary energy loads, a GIS was used to locate specific neighborhoods in the San Diego area with promising customer combinations. A detailed energy analysis was conducted for the commercial/residential area chosen covering both electrical and heat energy requirements. Under various scenarios, different combinations of natural gas reciprocating engines were chosen by DER-CAM, ranging in size from 25 kW to 500 kW, often with heat recovery or absorption cooling. These generators typically operate throughout the day and are supplemented by purchased electricity during late-night and early-morning hours, when utility time-of-use prices are lowest. Typical (mu)Grid scenarios displaced about 80 percent of their annual gas heat load through CHP. Self-generation together with absorption cooling dramatically reduce electricity purchases, which usually only occur during nighttime hours.
Date: January 1, 2002
Creator: Edwards, Jennifer L.; Marnay, Chris; Bartholomew, Emily; Ouaglal, Boubekeur; Siddiqui, Afzal S. & LaCommare, Kristina S.H.
Partner: UNT Libraries Government Documents Department

Effects of a carbon tax on combined heat and power adoption by a microgrid

Description: This paper describes the economically optimal adoption and operation of distributed energy resources (DER) by a hypothetical California microgrid ((mu)Grid) consisting of a group of commercial buildings over an historic test year, 1999. The optimization is conducted using a customer adoption model (DER-CAM) developed at Berkeley Lab and implemented in the General Algebraic Modeling System (GAMS). A (mu)Grid is a semiautonomous grouping of electricity and heat loads interconnected to the existing utility grid (macrogrid) but able to island from it. The (mu)Grid minimizes the cost of meeting its energy requirements (consisting of both electricity and heat loads) by optimizing the installation and operation of DER technologies while purchasing residual energy from the local combined natural gas and electricity utility. The available DER technologies are small-scale generators (< 500 kW), such as reciprocating engines, microturbines, and fuel cells, with or without CHP equipment, such as water- and space-heating and/or absorption cooling. By introducing a tax on carbon emissions, it is shown that if the (mu)Grid is allowed to install CHP-enabled DER technologies, its carbon emissions are mitigated more than without CHP, demonstrating the potential benefits of small-scale CHP technology for climate change mitigation. Reciprocating engines with heat recovery and/or absorption cooling tend to be attractive technologies for the mild southern California climate, but the carbon mitigation tends to be modest compared to purchasing utility electricity because of the predominance of relatively clean generation in California.
Date: October 1, 2002
Creator: Marnay, Chris; Edwards, Jennifer L.; Firestone, Ryan M.; Ghosh, Srijay; Siddidqui, Afzal S. & Stadler, Michael
Partner: UNT Libraries Government Documents Department

Distributed energy resources customer adoption modeling with combined heat and power applications

Description: In this report, an economic model of customer adoption of distributed energy resources (DER) is developed. It covers progress on the DER project for the California Energy Commission (CEC) at Berkeley Lab during the period July 2001 through Dec 2002 in the Consortium for Electric Reliability Technology Solutions (CERTS) Distributed Energy Resources Integration (DERI) project. CERTS has developed a specific paradigm of distributed energy deployment, the CERTS Microgrid (as described in Lasseter et al. 2002). The primary goal of CERTS distributed generation research is to solve the technical problems required to make the CERTS Microgrid a viable technology, and Berkeley Lab's contribution is to direct the technical research proceeding at CERTS partner sites towards the most productive engineering problems. The work reported herein is somewhat more widely applicable, so it will be described within the context of a generic microgrid (mGrid). Current work focuses on the implementation of combined heat and power (CHP) capability. A mGrid as generically defined for this work is a semiautonomous grouping of generating sources and end-use electrical loads and heat sinks that share heat and power. Equipment is clustered and operated for the benefit of its owners. Although it can function independently of the traditional power system, or macrogrid, the mGrid is usually interconnected and exchanges energy and possibly ancillary services with the macrogrid. In contrast to the traditional centralized paradigm, the design, implementation, operation, and expansion of the mGrid is meant to optimize the overall energy system requirements of participating customers rather than the objectives and requirements of the macrogrid.
Date: July 1, 2003
Creator: Siddiqui, Afzal S.; Firestone, Ryan M.; Ghosh, Srijay; Stadler, Michael; Edwards, Jennifer L. & Marnay, Chris
Partner: UNT Libraries Government Documents Department

Distributed Generation Potential of the U.S. CommercialSector

Description: Small-scale (100 kW-5 MW) on-site distributed generation (DG) economically driven by combined heat and power (CHP) applications and, in some cases, reliability concerns will likely emerge as a common feature of commercial building energy systems in developed countries over the next two decades. In the U.S., private and public expectations for this technology are heavily influenced by forecasts published by the Energy Information Administration (EIA), most notably the Annual Energy Outlook (AEO). EIA's forecasts are typically made using the National Energy Modeling System (NEMS), which has a forecasting module that predicts the penetration of several possible commercial building DG technologies over the period 2005-2025. Annual penetration is forecast by estimating the payback period for each technology, for each of a limited number of representative building types, for each of nine regions. This process results in an AEO2004 forecast deployment of about a total 3 GW of DG electrical generating capacity by 2025, which is only 0.25 percent of total forecast U.S. capacity. Analyses conducted using both the AEO2003 and AEO2004 versions of NEMS changes the baseline costs and performance characteristics of DG to reflect a world without U.S. Department of Energy (DOE) research into several thermal DG technologies, which is then compared to a case with enhanced technology representative of the successful achievement of DOE research goals. The net difference in 2025 DG penetration is dramatic using the AEO2003 version of NEMS, but much smaller in the AEO2004 version. The significance and validity of these contradictory results are discussed, and possibilities for improving estimates of commercial U.S. DG potential are explored.
Date: June 1, 2005
Creator: LaCommare, Kristina Hamachi; Edwards, Jennifer L.; Gumerman,Etan & Marnay, Chris
Partner: UNT Libraries Government Documents Department

Evaluating state markets for residential wind systems: Results from an economic and policy analysis tool

Description: The market for small wind systems in the United States, often defined as systems less than or equal to 100 kW that produce power on the customer side of the meter, is small but growing steadily. The installed capacity of domestic small wind systems in 2002 was reportedly 15-18 MW, though the market is estimated to be growing by as much as 40 percent annually (AWEA, 2002). This growth is driven in part by recent technology advancements and cost improvements and, perhaps more importantly, by favorable policy incentives targeted at small wind systems that are offered in several states. Currently, over half of all states have incentive policies for which residential small wind installations are eligible. These incentives range from low-interest loan programs and various forms of tax advantages to cash rebates that cover as much as 60 percent of the total system cost for turbines 10 kW or smaller installed in residential applications. Most of these incentives were developed to support a ran ge of emerging renewable technologies (most notably photovoltaic systems), and were therefore not specifically designed with small wind systems in mind. As such, the question remains as to which incentive types provide the greatest benefit to small wind systems, and how states might appropriately set the level and type of incentives in the future. Furthermore, given differences in incentive types and levels across states, as well as variations in retail electricity rates and other relevant factors, it is not immediately obvious which states offer the most promising markets for small wind turbine manufacturers and installers, as well as potential residential system owners. This paper presents results from a Berkeley Lab analysis of the impact of existing and proposed state and federal incentives on the economics of grid-connected, residential small wind systems. Berkeley Lab has designed the ...
Date: December 1, 2004
Creator: Edwards, Jennifer L.; Wiser, Ryan; Bolinger, Mark & Forsyth, Trudy
Partner: UNT Libraries Government Documents Department

Effects of a carbon tax on microgrid combined heat and power adoption

Description: This paper describes the economically optimal adoption and operation of distributed energy resources (DER) by a hypothetical California microgrid consisting of a group of commercial buildings over an historic test year, 1999. The optimization is conducted using a customer adoption model (DER-CAM) developed at Berkeley Lab and implemented in the General Algebraic Modeling System (GAMS). A microgrid is a semiautonomous grouping of electricity and heat loads interconnected to the existing utility grid (macrogrid) but able to island from it. The microgrid minimizes the cost of meeting its energy requirements (consisting of both electricity and heat loads) by optimizing the installation and operation of DER technologies while purchasing residual energy from the local combined natural gas and electricity utility. The available DER technologies are small-scale generators (< 500 kW), such as reciprocating engines, microturbines, and fuel cells, with or without combined heat and power (CHP) equipment, such as water and space heating and/or absorption cooling. By introducing a tax on carbon emissions, it is shown that if the microgrid is allowed to install CHP-enabled DER technologies, its carbon emissions are mitigated more than without CHP, demonstrating the potential benefits of small-scale CHP technology for climate change mitigation. Reciprocating engines with heat recovery and/or absorption cooling tend to be attractive technologies for the mild southern California climate, but the carbon mitigation tends to be modest compared to purchasing utility electricity because of the predominance of relatively clean central station generation in California.
Date: November 1, 2004
Creator: Siddiqui, Afzal S.; Marnay, Chris; Edwards, Jennifer L.; Firestone, Ryan M.; Ghosh, Srijay & Stadler, Michael
Partner: UNT Libraries Government Documents Department