First Magazine Article on Elpipes Published in Electricity Today

Roger Faulkner and Ron Todd wrote the article, entitled "Using Conventional Elpipes for Long Distance Transmission" (http://my.texterity.com/electricitytoday/201003/?pg=18#pg18) as a sort of response to an earlier article in the same magazine by Jack McCall of American Superconductor (http://my.texterity.com/electricitytoday/20101112?pg=28#pg28).

This article gives an introduction to elpipes, and analyzes the advantages/disadvantages versus high temperature superconducting (HTS) cable as well as the other main alternatives for long distance transmission: overhead high voltage AC (HVAC) and high voltage DC (HVDC) lines, and HVDC cables. Here are some of the key conclusions:

• HTS and GIL are both capable of allowing continental scale transmission.
• HTS requires quadruple redundant cooling systems to achieve the desired reliability levels.
• HTS is intolerant to current surges; if current goes to high, the superconductor becomes an ordinary conductor, with disastrous consequences.
• HTS has the advantage that the magnetic field can be contained.
• Max feasible voltage for HTS at present is 200kV in DC transmission mode. This is well below the conventional voltage range for HVDC technology, so HTS and HVDC cannot work as interoperable components of a future HVDC grid operating at a common voltage between 500-800kV.
• Elpipes can be passively cooled up to about 30GW.
• We suggest that a future grid may contain both HVDC technologies (elpipes, overhead lines, cables, and gas insulated lines "GIL") and HTS technologies, forming different parts of the supergrid. Before this can happen, the maximum operational voltage for HTS must be boosted significantly. (Maximum voltage for HTS is set by the superconductor-to-conventional conductor junctions.)

I will post a link to this article as a pdf at some future date.