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J.r. Saenz - One of the best experts on this subject based on the ideXlab platform.
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An adaptive control scheme for Biomass-Based Diesel–wind system
Renewable Energy, 2003Co-Authors: Francisco Jurado, J.r. SaenzAbstract:Control of autonomous Diesel–wind systems is difficult because of time-varying dynamical properties, most of them as a result of plant non-stationary, non-linearity and random disturbances. In this paper, the system is composed of a pitch controlled wind turbine with an induction generator connected to an ac bus bar in parallel with a Diesel generator set having a synchronous generator. A power plant can generate electric power using biomass from the olive tree in Spain. To have optimal response under disturbances, adaptive schemes appear to be a particularly attractive choice. The recursive least squares method and minimum-variance control algorithm is implemented to design the controller. This paper considers the application of an adaptive control methodology that allows the controller to automatically adjust to changing process variables and thereby provide uniform response over a wide range of operating conditions.
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Possibilities for Biomass-Based power plant and wind system integration
Energy, 2002Co-Authors: Francisco Jurado, J.r. SaenzAbstract:In this paper, the integration of a Biomass-Based Diesel–wind system is investigated. The system consists of a pitch controlled wind turbine, which is equipped with an induction generator. The induction generator is connected to an ac bus-bar in parallel with a Diesel-generator set consisting of a Diesel engine driving a synchronous generator. A power plant can generate electric power using biomass from the olive tree in Spain. A gasifier is capable of converting tons of wood chips per day into a gaseous fuel that is fed into a Diesel engine. While there are significant systems whose models may be exactly obtained from physical laws and whose states are measured, it is much less realistic to assume that all the parameters, such as the higher heating value of the biogas or wind speed, are exactly known. It is then natural to investigate what happens to control systems involving unknown, or not precisely known, parameters. In this paper, the derived model of Biomass-Based wind–Diesel systems is quite valid for robust control studies.
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Adaptive control for Biomass-Based Diesel-wind system
11th IEEE Mediterranean Electrotechnical Conference (IEEE Cat. No.02CH37379), 1Co-Authors: Francisco Jurado, J.r. SaenzAbstract:Control of autonomous Diesel-wind systems is difficult because of time-varying dynamical properties, most of them as a result of plant nonstationary, nonlinearity and random disturbances. In this paper, the system is composed of a pitch controlled wind turbine with an induction generator connected to an AC busbar in parallel with a Diesel generator set having a synchronous generator. A power plant can generate electric power using biomass from olive trees in Spain. The recursive least squares method and minimum-variance control algorithm are implemented to design the controller. This paper considers the application of an adaptive control methodology that allows the controller to automatically adjust to changing process variables and thereby provide uniform response over a wide range of operating conditions.
Francisco Jurado - One of the best experts on this subject based on the ideXlab platform.
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An adaptive control scheme for Biomass-Based Diesel–wind system
Renewable Energy, 2003Co-Authors: Francisco Jurado, J.r. SaenzAbstract:Control of autonomous Diesel–wind systems is difficult because of time-varying dynamical properties, most of them as a result of plant non-stationary, non-linearity and random disturbances. In this paper, the system is composed of a pitch controlled wind turbine with an induction generator connected to an ac bus bar in parallel with a Diesel generator set having a synchronous generator. A power plant can generate electric power using biomass from the olive tree in Spain. To have optimal response under disturbances, adaptive schemes appear to be a particularly attractive choice. The recursive least squares method and minimum-variance control algorithm is implemented to design the controller. This paper considers the application of an adaptive control methodology that allows the controller to automatically adjust to changing process variables and thereby provide uniform response over a wide range of operating conditions.
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Possibilities for Biomass-Based power plant and wind system integration
Energy, 2002Co-Authors: Francisco Jurado, J.r. SaenzAbstract:In this paper, the integration of a Biomass-Based Diesel–wind system is investigated. The system consists of a pitch controlled wind turbine, which is equipped with an induction generator. The induction generator is connected to an ac bus-bar in parallel with a Diesel-generator set consisting of a Diesel engine driving a synchronous generator. A power plant can generate electric power using biomass from the olive tree in Spain. A gasifier is capable of converting tons of wood chips per day into a gaseous fuel that is fed into a Diesel engine. While there are significant systems whose models may be exactly obtained from physical laws and whose states are measured, it is much less realistic to assume that all the parameters, such as the higher heating value of the biogas or wind speed, are exactly known. It is then natural to investigate what happens to control systems involving unknown, or not precisely known, parameters. In this paper, the derived model of Biomass-Based wind–Diesel systems is quite valid for robust control studies.
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Adaptive control for Biomass-Based Diesel-wind system
11th IEEE Mediterranean Electrotechnical Conference (IEEE Cat. No.02CH37379), 1Co-Authors: Francisco Jurado, J.r. SaenzAbstract:Control of autonomous Diesel-wind systems is difficult because of time-varying dynamical properties, most of them as a result of plant nonstationary, nonlinearity and random disturbances. In this paper, the system is composed of a pitch controlled wind turbine with an induction generator connected to an AC busbar in parallel with a Diesel generator set having a synchronous generator. A power plant can generate electric power using biomass from olive trees in Spain. The recursive least squares method and minimum-variance control algorithm are implemented to design the controller. This paper considers the application of an adaptive control methodology that allows the controller to automatically adjust to changing process variables and thereby provide uniform response over a wide range of operating conditions.
Julie Witcover - One of the best experts on this subject based on the ideXlab platform.
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Uncertainty, Innovation, and Infrastructure Credits: Outlook for the Low Carbon Fuel Standard Through 2030
2020Co-Authors: James Bushnell, Daniel Mazzone, Aaron Smith, Julie WitcoverAbstract:Author(s): Bushnell, James, PhD; Mazzone, Daniel; Smith, Aaron; Witcover, Julie | Abstract: California’s low carbon fuel standard (LCFS) specifies that the state’s transportation fuel supply achieve a 20% reduction in carbon intensity (CI) below 2011 levels by 2030. Reaching the standard will require substantive changes in the fuel mix, but the specifics and the cost of these changes are uncertain. We assess if and how California is likely to achieve the standard, and the likely impact of infrastructure credits on this compliance outlook. We begin by projecting a distribution of fuel and vehicle miles demand under business-as-usual economic and policy variation and transform those projections into a distribution of LCFS net deficits for the entire period from 2019 through 2030. We then construct a variety of scenarios characterizing LCFS credit supply that consider different assumptions regarding input markets, technological adoption over the compliance period, and the efficacy of complementary policies. In our baseline scenario for credit generation, LCFS compliance would require that between 60% and 80% of the Diesel pool be produced from biomass. Our baseline projections have the number of electric vehicles reaching 1.3 million by 2030, but if the number of electric vehicles reaches Governor Jerry Brown’s goal of 5 million by 2030, then LCFS compliance would require substantially less Biomass-Based Diesel. Outside of rapid zero emission vehicle penetration, compliance in 2030 with the $200 credit price may be much more difficult. New mechanisms to allow firms to generate credits by building electric vehicle charging stations or hydrogen fueling stations have minor implications for overall compliance because the total quantity of infrastructure credits is restricted to be relatively small.
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Status Review of California’s Low Carbon Fuel Standard, 2011–2018 Q1 September 2018 Issue
2018Co-Authors: Julie WitcoverAbstract:From 2011–2017, the share of alternative fuels in California’s transportation energy grew from 6.1 percent to 8.5 percent. Of alternative fuel energy, the portion coming from non-liquid fuels increased from 7.6 percent to 13.5 percent over the period. Through 2018 Q1, total emissions reduction requirements under the regulation were 28.9 million tons (MMT) CO2e. Actual reported emissions reductions were 38.3 MMT CO2e, representing overcompliance of 9.3 MMT CO2e, creating a system-wide credit “bank” that can be used to meet future targets. In 2017 and 2018 Q1, program deficits exceeded credits for the first time, by 0.1 MMT CO2e and 0.4 MMT CO2e, respectively, drawing down the credit “bank.” Increases in alternative fuel use and declines in carbon intensity (CI) rating came primarily from the Diesel pool. Biomass-Based Diesel—bioDiesel and renewable Diesel—accounted for 0.4 percent of liquid Diesel fuel by volume in 2011 and 15.6 percent in 2018 Q1. Natural gas in transportation grew 111 percent from 2011–2017 to 178.1 gasoline gallon equivalent (gge). Of this natural gas, biogas use was close to nil in 2011 but approximately two-thirds in 2017. Among gasoline substitutes, electricity use grew from less than 0.5 percent of alternative energy in 2011 to 4.5 percent in 2018 Q1. Use of ethanol, the largest renewable fuel by volume, remained close to a “blendwall” of 10 percent blended with gasoline. Prices of LCFS compliance credits (each representing 1 MMT CO2e) fluctuated. Average per- credit price increased from $20 to $80 in 2013, ranged between $20 and $30 in 2014 and 2015 under a frozen standard of 1%, rose above $100 in 2016 when the freeze was lifted, and exceeded $160 in summer 2018 as the California Air Resources Board (CARB) was in the process of adopting more stringent targets for 2030. LCFS amendments to be voted on at the September 26-27, 2018, CARB board meeting to take effect in 2019, include: a 2030 target of 20 percent CI reduction below 2010 levels; independent verification and monitoring of fuel pathway CI rating inputs; allowing alternative aviation fuel to generate program credits; a protocol for carbon capture and sequestration credits; credits for low- or zero-carbon intensity electricity use; requiring use of a portion of residential electricity credits to fund a statewide point-of-sale incentive program to electric vehicle (EV) buyers if such a program is approved by the California Public Utilities Commission; and introducing capacity credits for EV fast chargers and hydrogen fuel stations. The “capacity credit” provision would permit credit generation untied to current emissions reductions and favor particular fuels (those used in zero emission vehicles, which have no tailpipe emissions) for the first time. LCFS-like programs are in development in Canada (a Clean Fuel Standard to cover transportation, industry, and building sectors) and Brazil (the RenovaBio program focused on renewable liquid fuels and biogas). Neither plans to account for indirect land use change emissions in carbon intensity lifecycle analysis at program outset. Implementation of the Oregon and British Columbia LCFS programs is proceeding. Click here to see all the California LCFS status reviews
Scott H. Irwin - One of the best experts on this subject based on the ideXlab platform.
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The Price of BioDiesel RINs and Economic Fundamentals
2018Co-Authors: Scott H. Irwin, Kristen Mccormack, James H. StockAbstract:The D4 RIN is the tradable compliance certificate for the Biomass-Based Diesel mandate in the Renewable Fuel Standard (RFS). Understanding the price dynamics of the D4 RIN is important for understanding the RFS because its price sets a ceiling on the ethanol RIN (D6) and because some observers have suggested that RIN price fluctuations are too large to be explained by economic theory. We use option pricing theory to develop a model of the D4 RIN in terms of its economic fundamentals: the spread between the prices of bioDiesel and petroleum Diesel and the status of the bioDiesel blenders’ tax credit. The resulting D4 fundamental price closely tracks actual D4 prices. We conclude that RIN price volatility arises because of the design of the RFS and intrinsic features of the US fuel supply system.
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RFS Standards Beyond 2017—BioDiesel or Bust?
farmdoc daily, 2016Co-Authors: Darrel Good, Scott H. IrwinAbstract:In the farmdoc daily article of May 26, 2016, we reviewed the EPA’s final rule making for the Renewable Fuels Standards (RFS) for 2014-16 and the preliminary rulemaking for 2017 to determine if the implied conventional biofuels (ethanol) mandates represented a “push” beyond the E10 blend wall. The magnitude of the push is calculated as the difference between the implied conventional mandate and the expected level of consumption of conventional (non-advanced) ethanol. We concluded that the EPA policy of establishing mandates high enough to provide a push revealed in the November 2015 final rulemaking for 2014-2016 was continued in the 2017 preliminary rulemaking. Based on projections of domestic gasoline consumption that exceed EPA projections, we calculated that the magnitude of the push for conventional ethanol exceeds 500 million gallons for both 2016 and 2017. To date, the conventional ethanol gap has been filled primarily by increasing the use of bioDiesel and renewable Diesel. At the same time, the EPA raised the Biomass-Based Diesel (“bioDiesel”) mandate from 1.9 billion gallons in 2016, to 2.0 billion gallons in 2017, and 2.1 billion gallons in 2018. Additionally, the EPA has reduced the total advanced biofuels mandate by less than the reduction in the cellulosic mandate, resulting in increased mandates for undifferentiated advanced biofuels which include bioDiesel and renewable Diesel.
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Why is the Price of BioDiesel RINs Plummeting
farmdoc daily, 2015Co-Authors: Scott H. IrwinAbstract:After the EPA issued its long-awaited proposal for the 2014, 2015 and 2016 RFS mandates on May 29, 2015, the price of D4 bioDiesel RINs increased slightly while the price of D6 ethanol RINs dropped precipitously (Figure 1). The relatively small increase in D4 prices after the announcement suggested that the Biomass-Based Diesel mandates were largely as expected, but the sharp drop in D6 prices indicated that the ethanol mandates were smaller than many expected (farmdoc daily, June 3, 2015). After falling sharply in the days following the EPA announcement, D6 RINs prices have since generally traded in a sideways fashion. In contrast, after rising slightly in the days following the announcement, D4 RINs prices have declined at an ever increasing rate, to the point where D4 and D6 prices today differ by only a few cents. The behavior of D4 prices in recent weeks appears to be quite puzzling given the lack of additional important RFS announcements by the EPA. Furthermore, since the RINs price represents the marginal cost of complying with an RFS mandate, it is important to understand why any large change in the RINs price occurs. It turns out that the seemingly anomalous behavior of D4 bioDiesel RINs prices actually has a fairly straightforward explanation based on the behavior of two of the key drivers of bioDiesel RINs prices—soybean oil prices and the bioDiesel tax credit. The conceptual model of the bioDiesel market that we have employed in several previous farmdoc daily articles on the pricing of RINs and implementation of the RFS (e.g., October 10, 2014; October 15, 2014; May 28, 2015; July 22, 2015; August 5, 2015) provides the starting point for the analysis.
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The EPA's Proposed Ethanol Mandates for 2014, 2015, and 2016: Is There a 'Push' or Not?
farmdoc daily, 2015Co-Authors: Darrel Good, Scott H. IrwinAbstract:On May 29, 2015, the EPA announced the long-awaited RFS standards for 2014, 2015 and 2016 and the Biomass-Based Diesel volume for 2017. As outlined in a farmdoc daily article last week (May 28, 2015), market expectations for the proposal were: i) relatively large Biomass-Based Diesel mandates; and ii) ethanol mandates above the E10 blend wall but not returning immediately to statutory levels. These expectations were reflected in RINs market prices last week. The proposal largely confirmed expectations for Biomass-Based Diesel (“bioDiesel”) but did not appear to do so for ethanol. The EPA retained the highly controversial “inadequate domestic supply” waiver arguments that first appeared in November 2013, and based on this waiver argument, proposed reductions in the renewable (ethanol) mandates for 2014-2016 compared to levels specified in the RFS statutes. Criticism from ethanol supporters was swift and severe. For example, Chip Bowling, president of the National Corn Growers Association, made this statement shortly after release of the EPA proposal, “We are evaluating our legal options for defending the law and protecting the rights of farmers and consumers. We will fight to protect and build profitable demand for corn, which is of fundamental interest to NCGA and our farmers.”
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Implying the Probability of an EPA Reversal on the Write Down of the Renewable Mandate from the RINs Market
farmdoc daily, 2014Co-Authors: Scott H. IrwinAbstract:In a farmdoc daily article on February 19th, it was argued that the RINs market provided an early warning signal about another change in EPA policy. More specifically, the rise of D6 ethanol prices relative to D4 bioDiesel prices suggested that RINs traders believed the odds of the EPA reversing the proposed write down of the renewable mandate for 2014 in final rulemaking had increased sharply. The “coupling” of D4 and D6 RINs prices indicated a revised expectation that the renewable mandate for 2014 would exceed the E10 blend wall. Figure 1, updated from the February 19th article, shows that D4 and D6 prices have continued to track one another, albeit with some erosion in D6 prices compared to D4 prices (about 5 cents). Analysis in another article on February 28th indicated that the big winner from a reversal of the write down of the renewable fuels mandate for 2014 was likely to be the bioDiesel industry. The reason is that Biomass-Based Diesel was cheaper than E85 in most scenarios in terms of compliance costs for obligated parties under the RFS. The purpose of today’s article is to drill down further and imply the probability of an EPA reversal by comparing current RINs values with the predictions from a simple joint probability model of RINs valuation.
Serin Rao - One of the best experts on this subject based on the ideXlab platform.
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A life cycle assessment of pennycress (Thlaspi arvense L.) -derived jet fuel and Diesel
Biomass and Bioenergy, 2013Co-Authors: Jiqing Fan, David R. Shonnard, Tom N. Kalnes, Peter B. Johnsen, Serin RaoAbstract:Abstract Field Pennycress (Thlaspi arvense L.) is a member of the mustard family and may be grown as a winter crop between traditional summer crops to produce renewable biomass for renewable Diesel and jet fuel. This paper estimated total annual biofuel production potential of 15 million cubic metres from rotation between corn and soybeans on 16.2 million hectares in the Midwest without impact on food production. This study also investigated the life cycle greenhouse gas (GHG) emissions and energy balance of pennycress-derived Hydroprocessed Renewable Jet (HRJ) fuel and Renewable Diesel (RD). Both system expansion and allocation approaches were applied to distribute environmental impacts among products and co-products along the life cycle of each biofuel. The life cycle GHG emissions (excluding land use change) for RD and HRJ range from 13 to 41 g MJ−1 (CO2 eq.) and −18 to 45 g MJ−1 (CO2 eq.), respectively, depending on how the co-products are credited. The majority of the energy required for each biofuel product is derived from renewable biomass as opposed to non renewable fossil. The fossil energy consumptions are considerably lower than the petroleum fuels. Scenario analyses were also conducted to determine response to model assumptions, including nitrogen fertilizer application rate, nitrogen content in crop residues, and sources of H2. The results show that pennycress derived biofuels could qualify as advanced biofuels and as Biomass-Based Diesel as defined by the Renewable Fuels Standard (RFS2).