Wire power

Zenergy Power has produced a complete set of superconducting coils for a 1.7MW hydro power generator that will be installed into E.ON Wasserkraft's hydro power station in Bavaria, south east Germany, in the early part of 2010.

Zenergy Power shipped all 28 electromagnetic coils, based on its 1G superconducting wire, for the generator to Converteam, its collaborative development partner, which is responsible for the overall generator design.

The hydro power project was originally a European Commission project named Hydrogenie that received European funding to install a 1.25MW superconducting generator into E.ON's commercial hydro power plant. In January 2008, however, E.ON decided to fund an upgrade of the generator's electrical capacity to1.7MW.

As the Bavarian hydro-electric power generator moves into its final assembly stages, researchers at Zenergy Power are turning their attention to developing the company's second-generation, or 2G superconducting wire.

First-generation (1G) superconducting wire is available commercially from a number of companies around the world. During manufacture, the powdered superconductive bismuth-strontium-calcium-copper-oxide material is filled into silver alloy pipes, which are subsequently processed into a multi-filament high-temperature superconducting wire by means of a batch process.

According to Andrew Tan at Zenergy Power, both the silver used and the batch process mean that the 1G technology is expensive. That is the reason, he said, that the company is developing the newer 2G technology, which it claims will produce wire at much lower cost.

Unlike its 1G predecessor, the company's newer 2G yttrium-barium-copper-oxide wire will be made using an all-chemical technique that involves drawing a length of textured nickel carrier tape through a variety of chemical baths that then deposit the superconducting layers on top of it.

To help out with the process of developing the new wire, Zenergy’s German subsidiary received €400,000 (£341,500) in funding in August 2009 from the German Federal Ministry of Economy and Technology. This will allow it to work with materials experts at Theva Dünnschichttechnik to develop the advanced layering techniques it needs to produce the wire.

The new production technique will eventually produce a low-cost wire that can be used in the production of generators for renewable energy. Tan told The Engineer Online that the generators, which it is developing with Converteam, will be the first wind-power generators to use the new 2G wire when they are launched in 2012.

Aside from the German funding, to date, Zenergy Power has secured a variety of third-party support for its development work, which has included money from the European Union and the US Department of Energy. The company has also established long-term agreements with major industrial companies including ThyssenKrupp VDM and Honeywell.

However, the company is not alone in its quest to develop 2G superconducting wire. Both American Superconductor and Sumitomo in Japan are planning to roll-out 2G wire too. But according to Tam, their manufacturing methods vary greatly from the chemical process under development at Zenergy Power.

For its part, American Superconductor uses a vacuum-deposition process to apply the superconductor to textured nickel while Sumitomo's process is based on laser deposition.

While Tam believes that both processes may ultimately produce a higher-quality wire than that produced by Zenergy Power, he said that the performance of the Zenergy wire will more than meet the technical specifications of the commercial generators that the company is targeting for initial use in the renewable-energy industry. Most importantly, it will be inexpensive.

Dave Wilson