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State policies can support renewable energy development by driving markets, providing certainty in the investment market, and incorporating the external benefits of the technologies into cost/benefit calculations. Using statistical analyses and policy design best practices, this paper quantifies the impact of state-level policies on renewable energy development in order to better understand the role of policy on development and inform policy makers on the policy mechanisms that provide maximum benefit. The results include the identification of connections between state policies and renewable energy development, as well as a discussion placing state policy efforts in context with other factors that influence the...
The primary supposition about renewable forms of energy is that use of such resources will not result in depletion or exhaustion. While it is true that natural energy flows such as sun and wind are not directly subject to degradation by use, there may still be indirect limitations on renewability. The exploitation of natural energy flows may require that systems of nonrenewable "support" resources be used to capture, store, and convert natural energy into useful forms. Poor resource management practices that degrade the support resources may therefore, in effect, endanger renewability. Biomass is an illustrative case of a renewable energy resource with nonrenewable support components. The soil and water management...
The primary supposition about renewable forms of energy is that use of such resources will not result in depletion or exhaustion. While it is true that natural energy flows such as sun and wind are not directly subject to degradation by use, there may still be indirect limitations on renewability. The exploitation of natural energy flows may require that systems of nonrenewable "support" resources be used to capture, store, and convert natural energy into useful forms. Poor resource management practices that degrade the support resources may therefore, in effect, endanger renewability. Biomass is an illustrative case of a renewable energy resource with nonrenewable support components. The soil and water management...
This study proposes a new use of Data Envelopment Analysis (DEA) to measure the operational, environmental and both-unified efficiency measures of US coal-fired power plants. The power plants produce not only desirable outputs (e.g., electricity) but also undesirable outputs (e.g., CO2 and NOx) as a result of their plant operations. A Range-Adjusted Measure (RAM) is used as an original non-radial DEA model. Then, it is reformulated for handling undesirable (bad) outputs. The proposed use of DEA models measures the environmental and unified performance of power plants under two variable alternatives (with and without CO2 emission control) in order to examine both the influence of US Clean Air Act (CAA) on the acid...
The Swedish programme for geological disposal of spent nuclear fuel is approaching major milestones in the form of permit applications for an encapsulation plant and a deep geologic repository. This paper presents an overview of the bedrock and surface modelling work that comprises a major part of the on-going site characterization in Sweden and that results in syntheses of the sites, called site descriptions. The site description incorporates descriptive models of the site and its regional setting, including the current state of the geosphere and the biosphere as well as natural processes affecting long-term evolution. The site description is intended to serve the needs of both repository engineering with respect...
Two grasses, Agropyron smithii and A. inerme , were planted in a seed mixture with Ceratoides lanata in 1977 on two soil disturbances. These grasses were selected to test their responses to the presence of C. lanata . Biomass of leaf, stem, crown and roots were measured for each grass alone, with other plants of the same species, and with C. lanata as nearest neighbor. Total non-structural carbohydrates were determined for all biomass samples. A. smithii produced the lowest amounts of stem and root biomass when grown in close association with another A. smithii plant. In contrast, this species produced the most shallow-root (0-20 cm) biomass when closely associated with C. lanata. A. inerme leaf biomass was lowest...
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Studies were conducted in the central Mojave Desert to quantify how creosote bushes (Larrea tridentata) respond to physical damage during large-scale military training exercises. Creosote bush possesses a resilient growth form that recovers from repeated physical damage via resprouts arising from meristems in stem bark below severed or crushed canopy units. At high levels of disturbance by heavy vehicles, nearly all individuals showed measurable breakage, but without additional damage each plant can regain a full canopy within 5 years under arid field conditions. Resprouts exhibited more vigorous growth and doubled the biomass accumulation stimulated by high rainfall of 1998, an El Niño year, vs. a normal year....
The introduction of biofuels from biomass for transport purposes in an energy system model shows that bioethanol and vegetable oil can compete with oil products without subsidies provided prices of imported energy carriers are high, i.e. crude oil prices around $ 100/bbl. About half of the biomass will be used for motor fuel substitutes, whose share of the final energy in the transportation sector will increase to 10% in 2030. This gives rise to a nearly 9% drop in CO2 emissions in the transportation sector as compared to an emission balance where all real local emissions are fully counted. Despite a strong enhancement of biomass and biomass fuels and quite high prices for oil and gas up to 2030, BtL products like...
Seasonal time of switchgrass (Panicum virgatum L.) harvest affects yield and biofuel quality and balancing these two components may vary depending on conversion system. A field study compared fall and spring harvest measuring biomass yield, element concentration, carbohydrate characterization, and total synthetic gas production as indicators of biofuel quality for direct combustion, ethanol production, and gasification systems for generation of energy. Switchgrass yields decreased almost 40% (from about 7-4.4 Mg ha(-1)) in winters with above average snowfall when harvest was delayed over winter until spring. The moisture concentration also decreased (from about 35070 g kg(-1)) only reaching low enough levels for...
In June 2008, 303,000 L of hydrofracturing fl uid from a natural gas well were applied to a 0.20-ha area of mixed hardwood forest on the Fernow Experimental Forest, West Virginia. During application, severe damage and mortality of ground vegetation was observed, followed about 10 d later by premature leaf drop by the overstory trees. Two years after fl uid application, 56% of the trees within the fl uid application area were dead. Fagus grandifolia Ehrh. was the tree species with the highest mortality, and Acer rubrum L. was the least aff ected, although all tree species present on the site showed damage symptoms and mortality. Surface soils (0–10 cm) were sampled in July and October 2008, June and October 2009,...
The Swedish programme for geological disposal of spent nuclear fuel is approaching major milestones in the form of permit applications for an encapsulation plant and a deep geologic repository. This paper presents an overview of the bedrock and surface modelling work that comprises a major part of the on-going site characterization in Sweden and that results in syntheses of the sites, called site descriptions. The site description incorporates descriptive models of the site and its regional setting, including the current state of the geosphere and the biosphere as well as natural processes affecting long-term evolution. The site description is intended to serve the needs of both repository engineering with respect...
State policies can support renewable energy development by driving markets, providing certainty in the investment market, and incorporating the external benefits of the technologies into cost/benefit calculations. Using statistical analyses and policy design best practices, this paper quantifies the impact of state-level policies on renewable energy development in order to better understand the role of policy on development and inform policy makers on the policy mechanisms that provide maximum benefit. The results include the identification of connections between state policies and renewable energy development, as well as a discussion placing state policy efforts in context with other factors that influence the...
We characterized, at millimeter resolution, bacterial biomass, diversity, and vertical stratification of biological soil crusts in arid lands from the Colorado Plateau. Microscopic counts, extractable DNA, and plate counts of viable aerobic copiotrophs (VAC) revealed that the top centimeter of crusted soils contained atypically large bacterial populations, tenfold larger than those in uncrusted, deeper soils. The plate counts were not always consistent with more direct estimates of microbial biomass. Bacterial populations peaked at the immediate subsurface (1-2 mm) in light-appearing, young crusts, and at the surface (0-1 mm) in well-developed, dark crusts, which corresponds to the location of cyanobacterial populations....
An irrigated study was conducted at the Western Colorado Research Center at Fruita for 6 years to evaluate eight hybrid poplar clones under short-term, intensive culture. The eight clones included in the study were Populus nigra x P. maximowiczii (NM6), P. trichocarpa x P. deltoides (52225, OP367), and P. deltoides x P. nigra (Norway, Noreaster, Raverdaus, 14274, 14272). Data were collected for growth, aerial biomass yield, dry matter partitioning, carbon sequestration, and insect and disease infestation. OP367 and 52225 consistently had larger tree diameters than other hybrids for each of the 6 years. Averaged across clones, yield was 58.4 Mg ha?1. OP367 had the highest yield at 72.2 Mg ha?1 and 14274 had the lowest...
Bioenergy has several advantages over fossil fuels. For example, it delivers energy at low net CO2 emission levels and contributes to sustaining future energy supplies. The concern, however, is that an increase in biomass plantations will reduce the land available for agricultural production. The aim of this study is to investigate the effect of taxing conventional electricity production or carbon use in combination with subsidizing biomass or bioelectricity production on the production of biomass and agricultural commodities and on the share of bioelectricity in total electricity production. We develop a partial equilibrium model to illustrate some of the potential impacts of these policies on greenhouse gas emissions,...
Electric Power Research Institute (EPRI) and the US Department of Energy (DOE) have been funding a number of case studies under the initiative entitled “Economic Development through Biomass Systems Integration”, with the objective of investigate the feasibility of integrated biomass energy systems, utilizing a dedicated feedstock supply system (DFSS) for energy production. This paper deals with the full fuel cycle for four of these case studies. which have been examined with regard to the emissions of carbon dioxide, COZ. Although the conversion of biomass to electricity in itself does not emit more CO1 than is captured by the biomass through photosynthesis, there will be some CO1 emissions from the DFSS. External...
Due to its compatibility with the current energy infrastructures and the potential to reduce CO2 emissions significantly, CO2 capture and geological storage is recognised as one of the main options in the portfolio of greenhouse gas mitigation technologies being developed worldwide. The CO2 capture technologies offer a number of alternatives, which involve different energy consumption rates and subsequent environmental impacts While the main objective of this technology is to minimise the atmospheric greenhouse gas emissions, it is also important to ensure that CO2 capture and storage does not aggravate other environmental concerns This requires a holistic and system-wide environmental assessment rather than focusing...
The success of carbon capture, storage and sequestration as a greenhouse gas mitigation strategy will be, in part, dependent on the regulatory framework used to govern its implementation. Creating a science-based regulatory framework that is designed with enough flexibility to encourage greenhouse gas offset activity, effective means of measuring the costs of taking action to reduce greenhouse gas emissions, and ample protection for human and ecosystem health may prove challenging. For the purposes of this paper we will assume that there is an existing incentive to capture, store and sequester carbon and focus on how to regulate the process. Accounting practices and precursory crediting rules for biological sinks...
On the Westside of California's San Joaquin Valley, the discharge of subsurface agricultural drainage water (DW) is subject to strict environmental regulations due to its high selenium (Se) content and potential risks to wildlife. Re-use of sahne-sodic DW to irrigate salt-tolerant forage crops is attractive because it reduces the volume of DW requiring disposal and the land area affected by salinity, while producing forages to satisfy the large demand for animal feed resulting from rapid expansions in dairy and beef cattle operations in this area. The biomass production and nutritional quality of six forages ('Jose' tall wheatgrass, creeping wildrye, alkali sacaton, 'Alta' tall fescue, puccinellia and 'Salado/801S'...
Biofuels world production has increased sharply in recent years. Oil reserves depletion, the oil high price and the confidence in biofuels “carbon neutrality” are the main causes of this phenomenon. However, claims related to the negative consequences of biofuel programs are frequent; mainly those related to the biofuels/food competition and sustainability. This paper aims to contribute for the development of a framework for sustainability indicators as a tool for performance assessment. The most used indicators to measure the biofuels sustainability are: Life Cycle Energy Balance (LCEB), quantity of fossil energy substituted per hectare, co-product energy allocation, life cycle carbon balance and changes in soil...
map background search result map search result map Resprout characteristics of creosote bush (Larrea tridentata) when subjected to repeated vehicle damage Production of hybrid poplar under short-term, intensive culture in Western Colorado Resprout characteristics of creosote bush (Larrea tridentata) when subjected to repeated vehicle damage