I’m cruising back to London on the train from mid-Wales, where I’ve been on a quick round-trip to visit friends in Cardiff and Macynlleth, home of the Centre for Alternative Technology (CAT). Lots of deep green, drizzle and wind turbines are whizzing past out of the window, and I’m feeling recharged from my trip, like a deep cycle battery.
I haven’t been to CAT for years. They have some good displays there, but for me, the real experience is finding out what’s going on behind the scenes. First stop was a really informative chat with a chap called Toby, who was manning the information desk. I had been recommended his expertise from friends, and he didn’t disappoint. We chatted wind, hydro and PV, and he showed me some of the PV-tracking experiments that were going on – that were exploring the potential for mirrors (also known as ridge concentrators) to boost output. Some of these ideas are outlined in this paper by Poulek. It could be interesting to explore this some more for their applicability and potential in the East Africa context.
He pointed me to the useful PV-GIS website where we looked up the additional benefits of tracking on a single axis – seems to be up to 35% in East Africa which is good! It feels tracking has good potential if there is space and a simple tracker is easy to manufacture, otherwise, why not just invest in one extra PV panel, and have them fixed in place? Then you don’t have to worry about the tracking going wrong – because if it does, then you will have even less generation than a static panel.
As for the mirrors and their potential to further boost generation, the effect of increased temperature on the panels needs to be considered, since the efficiency of generation is reduced by increased surface temperature, but this relationship depends on the type of panels. All very interesting stuff to investigate.
Next, I met up with an old friend Suneil, who showed me to his office where he is working on a 3D-printer (info here). This is an open-source project, involving a worldwide community for developers. He showed me how he is using the wonderful Arduino chips to control the axis and plastic extrusion. Lots of potential here for enabling localized production of affordable components for engineers. We also talked about the potential for quick fabrication of cheap wind turbine blades and other components using this system, and some of the open source turbine projects going on.
All in all, a good trip. CAT is an inspiring place, and doing some really important work. The people I met were full of ideas, enthusiasm and were very welcoming, and very lucky to be in such beautiful surroundings.
More photos over at Flickr.