Intermittency-Friendliness Coefficient
Modified on Monday, 22 October 2012 12:05 by mbb@et.aau.dk — Categorized as: Uncategorized
Allows for a comparative assessment of the intermittency-friendliness (or wind-friendliness) of relocation options. The relocation coefficient is defined as the statistical correlation between net electricity exchange between plant and grid, and the electricity demand minus intermittent renewable electricity production.
Click here to read the scientific article published in Renewable Energy that introduces the Relocation Coefficient
Researching the etymology of “relocation”, the Oxford English Dictionary and others finds that “relocation” carries two meanings. Its initial meaning arrives from late Latin use of “relocare”, in the sense to renew a lease on a place (relet). The use of late Latin “locare” here originate from late Latin “locus”, which is a place, but in mathematics and thermodynamics also the set of points whose location is determined by stated conditions (Merriam-Webster). Later, “relocation” has been applied widely as a result of combining “re” and “location”, describing “the action of locating afresh; a new allocation” (Oxford English Dictionary, 1989).
In energy systems analysis at Aalborg University, the use of “locus” has particular connotations. In 1986, Assoc. Prof. Klaus Illum with Prof. Henrik Lund published the book “LOCUS-systems: Local Cogeneration Utility Systems for Efficient Utilization of Wind Power”. From this point on, “locus” or “locus energy systems” has been used in our research with reference to the ability of distributed generators to allow for large-scale integration of intermittent heat and power production.
Most recently, “relocation” has been introduced in computer science to describe the process of replacing symbolic references or names of libraries with actual usable addresses in memory before running a program (Wikipedia, modified 23:07, 6 August 2007).
We find it to be a coherent step forward from our established etymological praxis building on “locus” (“locare”, “location”) to “relocation” to describe the feature being introduced into 2nd generation renewable energy systems according to our article.
We have found it to be effective in research and education to apply the term “relocation” and “relocation technology” to describe the introduction of flexibility by bridging energy carriers in 2nd generation renewable energy systems. In the article we are furthermore introducing new metrics allowing for comparing energy options with respect to their ability to support intermittency. We are calling these new metrics for “relocation coefficient” and “relocation cost-effectiveness”, which may, as an illustrative example, in specific analyses be translated into a “wind-friendliness index for distributed generators” and the cost-effectiveness hereof.
We have chosen to use “relocation” in competition with a number of alternatives. Among the alternatives discussed were “redistribution”, reallocation”, “flexing”, “bridging”. The reviewer’s suggested term “redirection” is also very useful, and to the point.
A key consideration in choosing “relocation” is that we needed a term that was not previously used in energy, having alternative energy-related connotations, while at the same time building on our historic research in locus energy systems.
By using “relocation”, we are mainly considering the flexibility introduced by bridging of energy carriers, allowing for completely new “sets of points”, new locuses under given constraints. But we are also knowingly maintaining a connotation to visions about the future role of distributed generators, situated in local communities, and the process of relocating system services and responsibilities, as well as economic activities.
We acknowledge the spatial connotation of “relocation” in its’ prevalent modern use, but it is our hope and ambition that such spatial connotation is in fact suitable to support a tangible understanding of the principles and theories being introduced in 2nd generation renewable energy systems, also supported by the illustration in Fig. 6.