Peter S. Curtiss

Comprehensive Evaluation of Impacts From Potential, Future Automotive Fuel Replacements

In modern society, everything from transportation to commerce to food supply is heavily dependent on the availability of cheap and plentiful energy supplies. In the past few years many have realized that the traditional sources of energy — oil and gas — are in limited supply and that we need to prepare for the approaching production maxima. It is in the interest of national economic security to investigate alternative sources of transportation energy before the extraction of existing supplies becomes prohibitively expensive. This meta-study investigates a number of potential fuels and their sources, including: • agricultural solutions - ethanol (corn and cellulosic), • agricultural solutions - biodiesel, • unconventional refining techniques such as coal-to-liquid, • oil shale retorting and tar sand processing, • traditional petroleum sources. The concentration in the current study is on transportation needs, although it is recognized that building space conditioning and electricity consumption are also significant demands for energy. The results are reported for land use, water use, input-to-output energy ratio, and carbon emissions for each fuel cycle and source. Data are given for the cases of 10, 25, and 50 percent displacements of the 2012 predicted transportation energy needs (i.e., the equivalent of 430 million gallons of gasoline per day). Cradle to grave findings indicate that some novel fuels cannot substitute for conventional fuels without consuming more water or land and emitting more greenhouse gases than fuels in use today. The most sustainable direction for the US transportation fuels sector is suggested.Copyright

Recent developments in the control of distributed electrical generation systems

Successful operation of distributed generation systems requires controls that can integrate building load, electric generator, and grid information in near real time to produce optimal set points for the generator and the HVAC system(s) in the building(s) served by a given generation system. This paper discusses recent developments for distributed generation control in commercial buildings in the context of the U.S. utility industry. Several examples using different building types in different geographical regions of the U.S. are used to show how optimal and near-optimal control provide an economic benefit above simple threshold control. The examples are selected to illustrate the technical approach to system control using typical system characteristics and costs; every system in every location will have its own unique set of control criteria. The objective of this article is to describe the approach, not to solve specific problems.

Algaculture as a Feedstock Source for Biodiesel Fuel: A Life Cycle Analysis

This research investigates algae as a feedstock for producing liquid fuels for the light vehicle sector. It is in the interest of national economic security to investigate alternative sources of transportation energy before the extraction of existing supplies becomes prohibitively expensive. Biofuels are one such alternative liquid fuel supply. The research used the Life Cycle Analysis (LCA) approach for evaluating the production of biodiesel fuel from algae as a feedstock, including processes for growing algae in conventional and accelerated processes in bioreactors. An energy return on investment and comparison with conventional fuels (gasoline, diesel fuel) on an LCA basis and on a resource consumption basis (e.g., land, water, feedstock) is also presented. The results are reported for required land use, water use, input-to-output energy ratio, and carbon emissions for algacultural biodiesel fuel. From the present study it appears that algae-derived biodiesel fuel requires significantly less land, water and energy than do all other biodiesel fuels. It would appear prudent for the US to vigorously pursue this option since a significant fraction of US light vehicle fuel needs can be addressed.Copyright

LIFE CYCLE ANALYSIS OF AUTOMOTIVE ETHANOL PRODUCED FROM MUNICIPAL SOLID WASTE

The trend of increasing petroleum prices has prompted the consideration of other fuels for transportation. Ethanol has received a great deal of attention based on the hope that it is possible to develop a sustainable and relatively environmentally responsible alternative to gasoline. Currently, the biofuels industry depends heavily on the use of cereal crops as the feedstock for the ethanol refineries. This practice, however, has led to concern over the diversion of food supplies to fuel supplies; price increases of corn and corn-dependent products (milk, beef, etc.) have already been blamed on the market forces pushing crops towards fuel production. Additionally, sufficient land water exist in the US for cereal crop-based biofuels. Another method for producing ethanol uses waste products as the main feedstock. The waste can consist of anything fermentable — agricultural field remnants, yard clippings, and paper and food waste all are potentially inputs to the ethanol production process. An added benefit of such a system is the decrease in the amount of material that must be disposed in landfills or dumps. This paper briefly discusses the conversion of municipal solid waste (MSW) to ethanol for use as an automotive replacement fuel.Copyright

Evaluation of Cradle to Grave Impacts From Potential Automotive Fuel Replacements: An Update

In modern society, everything from transportation to commerce to food supply is heavily dependent on the availability of cheap and plentiful energy supplies. In the past few years many have realized that the traditional sources of energy — oil and gas — are in limited supply and that we need to prepare for the approaching production maxima. Recent research has focused on alternative forms of transportation energy including biofuels, unconventional refining techniques, and heavy oil and bitumen. This report is a continuation of earlier research and now considers ethanol produced from municipal solid waste, ethanol from algae, and compressed natural gas. The data presented are maintained in the same format as previous studies to facilitate comparison between the fuels. Results are reported for land use, water use, input-to-output energy ratio, and carbon emissions for each fuel cycle and source. Data are given for the cases of 10, 25, and 50 percent displacements of the 2012 predicted transportation energy needs (i.e., the equivalent of 430 million gallons of gasoline per day). Cradle-to-grave findings indicate that some novel fuels cannot substitute for conventional fuels without consuming more water or land and emitting more greenhouse gases than fuels in use today. The life cycle analysis approach presented here is that which should be used as the US moves toward low carbon fuel standards (LCFS) and carbon cap and trade (CC&T) approaches for reducing carbon loading of the environment.Copyright

Photovoltaic and Solar Thermal Market Penetration Analysis

An overview of the market potential of various solar electric technologies considers the application to both distributed generation (DG) systems and building integrated systems. The State of California is used as an example of the analysis of system performance, economic return on investment and market penetration over the next decade. California was chosen as a test case because of recent central generation and TD therefore they are the fastest source which can be deployed in most locations in California. The approach in this article uses hourly loads derived from standard simulations. Along with the California building inventory by building type, hourly solar system simulations for standard buildings from each sector (e.g., hospitals, restaurants, schools, offices) and microeconomic calculations, returns on investment for each location and each building type are found. Finally the Bass diffusion model is used to calculate the number of solar modules that will be sold each year for the next decade. Results show that much of the output of the US photovoltaic industry could be economically dispatched in California.Copyright

Developments in Light Vehicle Life Cycle Analysis With Application to Electric Vehicles

An LCA tool first reported on at the ASME ES conference in 2007 has been expanded and improved as follows: • More than 400 production vehicles from all over the world are now in the data base. • Conventional and renewable liquid and gas fuels are included. • Electric vehicles (EVs) and plug in hybrid electric vehicles (PHEVs) are included along with hybrid electric vehicles (HEVs) and conventional internal combustion engine vehicles. • The tool is now web-based. The LCA tool includes both fuel and vehicle life cycle coefficients in its data base. To illustrate the LCA ranking of vehicles using electricity (EVs, PHEVs, and HEVs) vs. conventional vehicles this paper will report on greenhouse gas emissions, total life cycle energy use along with NOx , SOx and mercury emissions. It will be shown, for example, that EVs are not the cleanest solution contrary to claims of various commentators in the popular press and of EV enthusiasts who do not take the entire life cycle into account.Copyright