<html><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><b><font class="Apple-style-span" size="3"><span class="Apple-style-span" style="font-size: 12px;">Continental-Scale HVDC Grid Based on Massive Metallic-Conductor Electric Pipelines</span></font></b><div><b><br></b></div><div><b><font class="Apple-style-span" size="3"><span class="Apple-style-span" style="font-size: 12px;">Roger Faulkner and Ron Todd of Electric Pipeline Corp.<br><br>MIT Laboratory for Electromagnetic and Electronic Systems (LEES) Colloquium</span></font></b></div><div><b><br></b></div><div><b><font class="Apple-style-span" size="3"><span class="Apple-style-span" style="font-size: 12px;">Nov. 19, 2009</span></font></b></div><div><b><font class="Apple-style-span" size="3"><span class="Apple-style-span" style="font-size: 12px;">4:00 PM </span></font></b></div><div><b><font class="Apple-style-span" size="3"><span class="Apple-style-span" style="font-size: 12px;">MIT Room 32-144<br><br></span></font></b><font><font class="Apple-style-span" size="3"><span class="Apple-style-span" style="font-size: 12px;">By its very nature, a continental grid must link asynchronous AC areas; for this and other reasons it is desirable for any such grid to be DC. This lecture considers HVDC continental scale supergrids based on massive underground conventional metallic conductors (aluminum or sodium) which are too large to be installed as wires or cables. One can imagine busbars similar to those used in power plants or aluminum factories for example as conductors, but our preferred designs are underground or partially underground electric pipelines (elpipes), with polymeric insulation. This lecture concerns a proposal to the MIT LEES Laboratory to participate in an ARPA-E proposal to look at many aspects of an elpipe grid, such as:</span></font></font><ul><font><li><font class="Apple-style-span" size="3"><span class="Apple-style-span" style="font-size: 12px;">Insulator behavior and reliability under high voltage DC stress</span></font></li><li><font class="Apple-style-span" size="3"><span class="Apple-style-span" style="font-size: 12px;">Semiconductive films and surface treatments on insulators</span></font></li><li><font class="Apple-style-span" size="3"><span class="Apple-style-span" style="font-size: 12px;">Electric field management</span></font></li><li><font class="Apple-style-span" size="3"><span class="Apple-style-span" style="font-size: 12px;">Mechanical and electrical stress management in materials seeing thermal gradients</span></font></li><li><font class="Apple-style-span" size="3"><span class="Apple-style-span" style="font-size: 12px;">Low cost, fail-safe heat transfer</span></font></li><li><font class="Apple-style-span" size="3"><span class="Apple-style-span" style="font-size: 12px;">HVDC circuit breakers & methods for fail-safe redundancy</span></font></li><li><font class="Apple-style-span" size="3"><span class="Apple-style-span" style="font-size: 12px;">Magnetic shielding options</span></font></li><li><font class="Apple-style-span" size="3"><span class="Apple-style-span" style="font-size: 12px;">Insulation degradation detection</span></font></li></font><li><font><font class="Apple-style-span" size="3"><span class="Apple-style-span" style="font-size: 12px;">Interfacing elpipe grid node points with superconducting lines at high voltage</span></font></font></li></ul><font class="Apple-style-span" size="3"><span class="Apple-style-span" style="font-size: 12px;"><br></span></font><font><font class="Apple-style-span" size="3"><span class="Apple-style-span" style="font-size: 12px;">The concept of elpipes to form a continental grid is being promoted by Electric Pipeline Corporation (EPC), a clean tech startup venture. Certain EPC inventions cannot be disclosed yet, due to patent considerations, but this lecture will discuss design trade-offs on such a conventional elpipe, including design voltage, conductor selection, methods to make splices, alternative means to remove waste heat, and thermal expansion joints.<br><br>Theoretically, cost of conventional aluminum conductor + polyolefin insulator would be minimized for an elpipe between ±2-3MV (minimizing cost of conductor, insulator, and converter stations). However it took more than 10 years to go from a proven ±500kV design to a proven ±800kV design for HVDC/AC converters. We have therefore conservatively adopted ±800kV as the design voltage for elpipes.<br><br>In a typical transmission project, the purchase price of the conductive metal per se is less than 2% of the project cost. Elpipes are massive by comparison, using up to 200 cubic meters of aluminum per km; conductor per se can represent up to 25% of the project cost. Among the conventional conductors, copper is about 7.7 times more expensive than aluminum on an equal conductivity basis, and aluminum is about 5-7 times more expensive than sodium (the least expensive feasible conductor). Aluminum is favored for initial designs of the elpipe, with the possibility that the hollow conductors can later be filled with sodium to further reduce electrical resistance. Heat transfer is a critical issue for any high power underground non-superconductive power line; we will show that it is feasible to design passively cooled electric pipelines up to about 40 GW, and above that one must use active (non-cryogenic) cooling. <br><br>The needed power generation capacity in the US would be greatly reduced if all generators and users could share power; the capital savings could pay for a continental scale grid. Considerable attention and research funding has been given to the "superconducting supergrid" option, which most experts agree cannot be implemented sooner than several decades into the future due to the need to meet US reliability standards. This lecture looks at a technologically simpler, yet still challenging alternative technology. The conventional HVDC supergrid is robust, and mechanically simpler than the superconducting grid, and it appears feasible to prove reliability sooner than is feasible for a superconducting grid. The hybrid design is interesting because the robust, relatively simple elpipe-based HVDC supergrid design can be augmented by a superconductive grid that only needs to connect to the elpipe HVDC grid at a few points, yet these few superconducting links would greatly improve the efficiency of coast-to-coast transmission. In this instance though, the reliability of the superconducting links need not be as high as would be the case if they are the only connections; the hybrid design also has hybridized reliability & efficiency.<br></span></font></font><font class="Apple-style-span" size="3"><span class="Apple-style-span" style="font-size: 12px;"> <br><br></span></font><font><font class="Apple-style-span" size="3"><span class="Apple-style-span" style="font-size: 12px;"><b>Roger Faulkner</b> is the founder of Rethink Technologies, Inc. (</span></font></font><font class="Apple-style-span" size="3"><span class="Apple-style-span" style="font-size: 12px;"> </span></font><a href="http://www.rethink-technologies.com/" eudora="autourl"><font color="#0000FF"><u><font class="Apple-style-span" size="3"><span class="Apple-style-span" style="font-size: 12px;">www.rethink-technologies.com</span></font></u></font></a><font color="#0000FF"><font class="Apple-style-span" size="3"><span class="Apple-style-span" style="font-size: 12px;"><u></u></span></font></font><font class="Apple-style-span" size="3"><span class="Apple-style-span" style="font-size: 12px;"> </span></font><font face="Times New Roman, Times"><font class="Apple-style-span" face="Helvetica" size="3"><span class="Apple-style-span" style="font-size: 12px;">) and is a polymer scientist who studied at Akron University. His Ph.D. research was on one of his inventions, reaction wave polymerization, and most of his 30 year career since then has had to do with pursuing and developing this and other inventions, not all in the area of polymer science. He has a strong scientific/technical interest in enabling technologies for renewable energy, including development of a long distance multi-terminal HVDC grid based on “electric pipelines” (which is the basis of Electric Pipeline Corporation). He has also had a strong interest in energy policy issues for many years, and was a full party and public intervenor in the Wisconsin PSC’s Advance Plan 6 hearings in 1991, where he first introduced the concept of HVDC pipelines in testimony he presented with Professor Willis (Bill) Long of UW-Madison, a leading expert in HVDC power transmission. Since November 2008, Faulkner has been pursuing the concept of HVDC electric pipelines (elpipes) as a business startup/spinout from Rethink Technologies, Inc. <br><br><b>Ronald Todd</b> is a technologist and a serial entrepreneur, having been a founder of and managed 7 high-tech companies. These have been in the areas of instrumentation, computing, automated test, electronic imaging, housewares, utility-scale solar energy balance-of-system, and now underground electric power transmission. Additionally he led a 100 person electronics and software consulting firm technically, and set up and ran a 50 engineer telecommunications IC design center. He is the co-founder and CTO of Electric Pipeline Corporation, and has BS and MS degrees in Electrical Engineering from MIT.</span></font><br></font></div></body></html>