It was an early start yesterday. 0445 rise and bus at 0530. 5 hours later after three trains and another bus I arrived at InterSolar 2007 in Freiburg, Germany hoping to find out how I could improve the UMPC Solar kit at Europe’s biggest solar expo. Unfortunately, there wasn’t much there for consumers at all. It was all 200w, $1000 panels and huge thermal heating set-ups. I saw one company that was selling the Voltaic Solar Backpack but I’ve already assessed this product and at 4W max output, its not powerful enough. I was rather hoping to see someone with the Reware Juicebag which, at 6.3W is much more useful.
Actually the most interesting thing that happened yesterday, apart from some awesomely stormy weather, was that the train journey took me on the Rhein route south to where I will start the Solar UMPC tour. Its a gorgeous route. Lovely scenery and I saw loads and loads of great Rhein-side restaurants and camping sites. I’m looking forward to the tour more than ever!
One bit of relevant news from yesterday which came through RSS and has spawned another bit of research was that Sanyo have broken the record for a production solar cell. We’re up to 22% now. In theory, the cell on the left here, a 10x10cm device, should be able to generate over 2W. 100cm2 is about the same area as the face of a UMPC. 4W is the target average power consumption that Intel have set for devices based on Menlow, their UMPC platform for 2008. The interesting thing that I’ve found out is that this cell (or at least the previous version of it) appears in the Sanyo Eneloop solar charger. The charger houses a Li-Ion battery which can store enough energy to charge 4x2000mah batteries. That’s about 10W if my maths is correct. The only problem is the quoted 6 DAYS charging time for the internal Li-Ion battery. I suspect that the cell isn’t exactly being used that efficiently because as I said before, that 10×10 cell should be able to kick out 2W, enough to charge the batteries in a few full days of sun. This little bit of tech will set you back over $150. Eek!
Lesson number one in the Solar-UMPC project is that the weather is chaos and if you live in mid-northern Europe, you can’t rely on it as a source of instant energy. You’ll see how I’ve had to adapt my solution in my first Solar UMPC video. In the video I present the solar charging and storage setup that I’ve decided to use for the tour. Its based on the fag-packet drawing I did a few weeks ago after deciding that Li-Ion batteries weren’t really the best solution.
I’ve introduced the lead-acid battery as a buffer and despite the 100-year old technology and 2.6KG weight, provides the perfect stabiliser to the whole architecture.
A quick rundown of the equipment I’m using (mostly bought from my home country, Germany.)
The new tent has arrived, the bike baggage, and finally, some warmer weather so I’m taking the chance to test things out in the garden. My daughter is nearly asleep in the tent and I’m perched outside with the Samsung Q1b and organizer pack resting on one of my panniers, a clip-on LED lamp a paraffin lamp and a bottle of Germanys best beer!
This is the perfect time to be writing because its dark and you only need the minimum of backlight on the UMPC. As I write this with WiFi on, I’m taking between 6.5 and 8.5W on the UMPC. Its also wonderfully quiet.
Behind me, in the spare bedroom, I have started to lay out everything I need for the tour. I’ve written the pack list and there are only a few more things to buy before I’m ready to go. I hope it all fits into the panniers I bought for the bike which, incidentally, is going to be the blue Kronan.
A few things that haven’t turned up yet are the Lead-Acid battery and the solar panel. They should be here on Monday which will allow me to build the frame that the panel and battery will sit in on the back of the bike. I’ve ordered a could of panel meters too because I want to see what sort of drain each component puts on the panel.
One thing I was a little disappointed to find out tonight is that in theory, DC-DC conversion will cost at least 25% of my energy. That’s rather a lot to be wasting just to transfer energy, especially if I charge the Li-Ion battery from the 12V lead acid battery. I could lose an hours computing time just in that process.
I’ll finalise the packlist (V1.0) in the next few days and post it up. I’m also planning to do a video overview of all the equipment I’m taking, a picture-set of the bike and the charging setup and as many other images as I have time to take. The 9-day forecast is looking OK (not perfect, but OK) and so I’m quite confident that the tour will start at some point next weekend.
there wasn’t much there for consumers at all. It was all 200w, $1000 panels and huge thermal heating set-ups. I saw one company that was selling the Voltaic Solar Backpack but I’ve already assessed this product and at 4W max output, its not powerful enough. I was rather hoping to see someone with the Reware Juicebag which, at 6.3W is much more useful. 
One bit of relevant news from yesterday which came through RSS and has spawned another bit of research was that Sanyo have broken the record for a production solar cell. We’re up to 22% now. In theory, the cell on the left here, a 10x10cm device, should be able to generate over 2W. 100cm2 is about the same area as the face of a UMPC. 4W is the target average power consumption that Intel have set for devices based on Menlow, their UMPC platform for 2008. The interesting thing that I’ve found out is that this cell (or at least the previous 
version of it) appears in the Sanyo Eneloop solar charger. The charger houses a Li-Ion battery which can store enough energy to charge 4x2000mah batteries. That’s about 10W if my maths is correct. The only problem is the quoted 6 DAYS charging time for the internal Li-Ion battery. I suspect that the cell isn’t exactly being used that efficiently because as I said before, that 10×10 cell should be able to kick out 2W, enough to charge the batteries in a few full days of sun. This little bit of tech will set you back over $150. Eek!
