Professional rendering "artist's impression" of new technology

Information on the business: UCL - engineering research
Industry: Technology
Design details: I do research on the solar thermal chimney - a type of solar power plant. It needs a particularly large chimney and I am researching and designing the "suspended chimney" - a chimney manufactured from high-strength fabrics and held aloft with envelopes of lighter-than-air gas (probably helium).

I have a lot of media interest at present and I need a few good images to show my concept to the world. Media organisations interested in my work include The Engineer (a technical magazine), and Reuters.

The Engineer has already published an article on my work online, and will publish in the print magazine with the appropriate accompanying images:

http://www.theengineer.co.uk/energy-and-environment/news/per-lindstrand-plans-1km-high-inflatable-solar-energy-chimney/1017508.article
Ideas for the visual style: Ideally quite realistic, though not necessarily so highly-detailed. Open to expert advice.
Where the design will be used: Reuters, The Engineer, all future PR
Extra notes: