Techno-economic Analysis of Co-located Corn Grain and Corn Stover Ethanol Plants

The goal of this paper is to evaluate the economic performance of co-located corn grain ethanol (Gen 1) and cellulosic ethanol (Gen 2) facilities. We present six scenarios to evaluate the impact of stover-to-grain mass (SGM) ratios on overall minimum ethanol selling price (MESP). For the Gen 1 plant, MESP is $3.18/ gasoline gallon equivalent (GGE) while for the Gen 2 plant it is$5.64/GGE. Co-located Gen 1 and Gen 2 plants operating at the lowest SGM ratio of 0.4 generates the lowest overall MESP of $3.73/GGE as well as the highest MESP for cellulosic ethanol of$7.85/GGE. Co-located plants operating at the highest SGM ratio of 1.0 achieve the highest overall MESP of $3.94/GGE as well as the lowest MESP for cellulosic ethanol of$5.47/GGE. Sensitivity analysis shows that the prices of feedstocks have the greatest impact on the overall MESP

Optimizing innovation, carbon and health in transport: assessing socially optimal electric mobility and vehicle-to-grid pathways in Denmark

This paper examines the social costs and benefits of potential configurations of electric vehicle deployment, including and excluding vehicle-to-grid. To fully explore the benefits and costs of different electric vehicle pathways, four different scenarios are devised with both today’s and 2030 electricity grid in Denmark. These scenarios combine different levels of electric vehicle implementation and communication ability, i.e. smart charging or full bi-directionality, and then paired with different levels of future renewable energy implementation. Then, the societal costs of all scenarios are calculated, including carbon and health externalities to find the least-cost mix of electric vehicles for society. The most cost-effective penetration of electric vehicles in the near future is found to be 27%, increasing to 75% by 2030. This would equate to a $34 billion reduction to societal costs in 2030, a decrease of 30$1,200 in 2030. However, current vehicle capital cost differences, a lack of willingness to pay for electric vehicles, and consumer discount rates are substantial barriers to electric vehicle deployment in Denmark in the near term

An Approach to Enhance the Conservation-Compatibility of Solar Energy Development

The rapid pace of climate change poses a major threat to biodiversity. Utility-scale renewable energy development (>1 MW capacity) is a key strategy to reduce greenhouse gas emissions, but development of those facilities also can have adverse effects on biodiversity. Here, we examine the synergy between renewable energy generation goals and those for biodiversity conservation in the 13 M ha Mojave Desert of the southwestern USA. We integrated spatial data on biodiversity conservation value, solar energy potential, and land surface slope angle (a key determinant of development feasibility) and found there to be sufficient area to meet renewable energy goals without developing on lands of relatively high conservation value. Indeed, we found nearly 200,000 ha of lower conservation value land below the most restrictive slope angle (<1%); that area could meet the state of California’s current 33% renewable energy goal 1.8 times over. We found over 740,000 ha below the highest slope angle (<5%) – an area that can meet California’s renewable energy goal seven times over. Our analysis also suggests that the supply of high quality habitat on private land may be insufficient to mitigate impacts from future solar projects, so enhancing public land management may need to be considered among the options to offset such impacts. Using the approach presented here, planners could reduce development impacts on areas of higher conservation value, and so reduce trade-offs between converting to a green energy economy and conserving biodiversity

New directions: Potential climate and productivity benefits from CO 2 capture in commercial buildings

Primarily because of humanity’s heavy reliance on fossil fuels, ambient CO2 levels have risen from 280 ppm in preindustrial times to 400 ppm today, and levels continue to rise by a few ppm per year (Tans and Keeling, 2014). Progress toward stabilizing atmospheric CO2 levels can be achieved not only through reducing emissions but also through the engineering of new or enhanced sinks of atmospheric CO2. Research and private sector initiatives on removing CO2 from ambient air (Boot-Handford et al., 2014) lead us to consider this challenge in the context of a well-known indoor air quality concern: elevated CO2 concentrations in occupied buildings.NRF (Natl Research Foundation, S’pore)Accepted versio

Energy and the military: Convergence of security, economic, and environmental decision-making

Energy considerations are core to the missions of armed forces worldwide. The interaction between military energy issues and non-military energy issues is not often explicitly treated in the literature or media, although issues around clean energy have increased awareness of this interaction. The military has also long taken a leadership role on research and development (R&D) and procurement of specific energy technologies. More recently, R&D leadership has moved to the energy efficiency of home-country installations, and the development of renewable energy projects for areas as diverse as mini-grids for installations, to alternative fuels for major weapons systems. In this paper we explore the evolving relationship between energy issues and defense planning, and show how these developments have implications for military tactics and strategy as well as for civilian energy policy

Assessing the economics of large Energy Storage Plants with an optimisation methodology

Power plants, such as wind farms, that harvest renewable energy are increasing their share of the energy portfolio in several countries, including the United Kingdom. Their inability to match demand power profiles is stimulating an increasing need for large ESP (Energy Storage Plants), capable of balancing their instability and shifting power produced during low demand to peak periods. This paper presents and applies an innovative methodology to assess the economics of ESP utilising UK electricity price data, resulting in three key findings. Firstly the paper provides a methodology to assess the trade-off “reserve capacity vs. profitability” and the possibility of establishing the “optimum size capacity”. The optimal reserve size capacity maximizing the NPV (Net Present Value) is smaller than the optimum size capacity minimizing the subsidies. This is not an optimal result since it complicates the incentive scheme to align investors and policy makers' interests. Secondly, without subsidies, none of the existing ESP technologies are economically sustainable. However, subsidies are a relatively small percentage of the average price of electricity in UK. Thirdly, the possibility of operating ESP as both as a reserve and do price arbitrage was identified as a mean of decreasing subsidies for the ESP technologies