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Complex SystemsLast Updated on 2013-10-24 15:13:11
As Science has begun to ask where the enduring features of nature come from and how they work, the answer seems to be “complex systems”. Every kind of thing and event seems to require them. As the science has advanced, and as the modern problems of economies and environmental conflicts emerge, a new kind of science is emerging that requires being very openly exploratory, using all the tools and combining all the related perspectives of others, to develop complex knowledge systems matching the variety of the complex system problems they respond to.
Systems are storms or “like storms” in many respects, complex distributed phenomena that may be either unexpectedly eventful or highly predictable. There’s still a rather wide range of opinion within science as to what complex systems are, even whether they are made of information or... More »
Net energy analysisLast Updated on 2013-08-25 16:49:49
One technique for evaluating energy systems is net energy analysis, which seeks to compare the amount of energy delivered to society by a technology to the total energy required to find, extract, process, deliver, and otherwise upgrade that energy to a socially useful form. Energy return on investment (EROI) is the ratio of energy delivered to energy costs (see Figure 1). Biophysical and ecological economists argue that net energy analysis has several advantages over standard economic analysis. First, net energy analysis assesses the change in the physical scarcity of energy resources, and therefore is immune to the effects of market imperfections that distort monetary data. Second, because goods and services are produced from the conversion of energy into useful work, net energy is a measure of the potential to do useful work in economic systems. Third, EROI can be used to rank... More »
Energy return on investment (EROI), economic feasibility and carbon intensity of a hypothetical Lake Ontario wind farmLast Updated on 2008-11-20 19:00:56
With an average annual growth rate of over 20% in recent years, wind energy is now the fastest growing energy source in the U.S. To date, although notable projects such as Cape Wind in Nantucket Sound and Bluewater Wind off Long Island are proposed, wind power projects in the U.S. have been entirely limited to onshore locations. Recent market trends toward offshore wind in Europe, the world leader in wind energy development, suggest that future applications of offshore wind will be utilized in the U.S. as well. Offshore wind power is currently more expensive to generate than from comparably windy sites on land. However, turbine technology and construction processes are improving such that the economics of offshore wind are now more encouraging. As additional onshore locations are utilized and the mitigation of aesthetic impacts continues to be important to project viability,... More »
Net Energy Analysis (historical)Last Updated on 2008-11-18 03:00:18
Originally Published As:Title: Net Energy Analysis: Handbook for Combining Process and Input-Output AnalysisAuthor: Clark W. Bullard, Peter S. Penner, and David A. PilatiSource: Resources and Energy 1 (1978) 267 313. Norlh-Holland Publishing Company.Year published: 1978Methods are presented for calculating the energy required, directly and indirectly, to produce all types of goods and services. Procedures for combining process analysis with input-output analysis are described. This enables the analyst to focus data acquisition effects cost-effectively, and to achieve down to some minimum degree a specified accuracy in the results. The report presents sample calculations and provides the tables and charts needed to assess total energy requirements of any technology, including those for producing or conserving energy. ... More »
Ten fundamental principles of net energyLast Updated on 2008-09-23 14:42:48Introduction Energy return on investment (EROI) is the ratio of the energy extracted or delivered by a process to the energy used directly and indirectly in that process. A common related term is energy surplus, which is the gross amount of energy extracted or delivered, minus the energy used directly and indirectly in that process. EROI is a dimensionless number, while energy surplus refers to an actual physical quantity of energy. Suppose an energy delivery system delivers 10 joules of energy, but in the processes consumes 2 joules. The EROI for that process is 5 (10 divided by 2), while the energy surplus delivered is 8 joules (10 minus 2). EROI is a tool of net energy analysis, a methodology that seeks to compare the amount of energy delivered to society by a technology to the total energy required to find, extract, process, deliver, and otherwise upgrade that energy to a... More »
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