It doesn’t stop me thinking about solar computing though and in this post I’m going to compare a set of devices and some technologies that will be important for the job of Solar PC 2010.

Before I do that I want to highlight a few things that really haven’t changed much in the last 3 years. It’s a sad story of minimal progress.

• Solar panels – NOTHING has changed. They’re still expensive and inefficient.
• Battery Tech – NOTHING has change. They are still expensive and use the same technology as before.
• Operating system choice – Nothing has really changed. If you want to work efficiently you need to choose the same OS as you use on the desktop. Mobile operating systems have come a long way but there are still too many potential roadblocks for the average productivity user. Windows 7 is nice but compared to XP it’s less efficient which in my book, makes it the best choice for efficient and productive mobile computing.
• Screen technology. Outdoor users are still fighting the sun with LED backlights although this is a great step forward from the CCFL backlighting I used in 2007. Transflective screens are coming in 2010 though. See below.
• Weather – Ah, there’s something that hasn’t changed much either! Still, constant chaos. (Thank goodness!)

The device shortlist.

Click for more information.

Luckily the computing platforms have moved on somewhat and along with better engineering and components so there are some great contenders out there. Lets take a closer look at the best ones under 1KG. From top left in the images above:

• Viliv X70
• UMID BZ
• Fujitsu U820
• Fujitsu UH900
• ASUS EeePC T91
• Viliv S5
• Viliv S7
• Sony Vaio P-Series

Viliv appears three times in that list and is shows that they’ve done a great job of working around the Intel Menlow platform and producing some amazingly high-quality and efficient UMPCs that are focused on mobile productivity. Take the S7 for example. It has an excellent keyboard, SSD hard drive (rugged) and convertible touchscreen and comes with a built-in 3G option. The 34wh battery can last for 6-9hrs depending on usage. The tiny BZ is even more efficient though. The 17wh battery lasts for 5hrs…online and it comes with an external battery charger adaptor for 9V charging.

ARM-based devices.

You’ll notice that I haven’t included a single ARM-based device or ‘smartbook’ in the list above and the reason is simple. There aren’t any productivity-focused devices available. You might think that the ‘cloud’ provides the answer but the cloud is a long way away from being a mobile solution right now so despite the increased efficiency of ARM-based tablets and notebooks, I’m afraid it’s not a solution for the main computing device. For a smartphone though, yes! It’s the only solution.

Waiting for the screen.

My problem with all of the above solutions now is that I’m aware of two technologies that are close to hitting the market in 2010. Both Pixel-Qi and Mirasol have solutions that can save a lot of power when in high ambient light situations. Up to 1.5W in sunlight on a netbook-sized device. That’s a huge saving in a device that might be using only 6W. A 25% saving is huge and also helps to keep things cool in the device which helps other components too!

The advantage is so, so great that I’d hesitate to buy any device for a mobile tour unless it had the technology included. I’ve tested it and heard that it’s coming and if it hits a netbook soon (likely before UMPC style devices) I would seriously consider it…despite the extra weight of a netbook. 600gm extra weight to save 20-25% energy and to enable full-sun usage is a huge benefit. It also brings a bigger screen and keyboard for even more efficient working.

One of the most interesting 10” devices I’ve seen recently is the Viliv  S10 ‘Blade’. It’s a slick, SSD-based device built on the Menlow platform. It’s one of the lightest 10” devices at 1.2KG and it’s very slim. Once again it looks like Viliv have made it super efficient; the marketing claims up to 10hr battery life on a relatively small battery so I’m wondering…how about an S10 with a Pixel-Qi retro fit which could take it to 12hrs or more. For 1.2KG that’s a huge advantage and if there’s a way to charge a second battery separately, direct from solar power then we’re cooking with gas (as they say.) Oh, i forgot to mention that there’s a 3G and 2.0Ghz CPU option! I have a little worry about the convertible screen hinge but that’s the only potential issue right now.

Smartphones

One thing that has changed since 2007 is the smartphone. The capabilities of a high end smartphone are almost unrecognisable from those of 2006. Cameras, processing power, screens, keyboards, operating systems have all changed for the better and there is serious potential to be doing a lot of ‘microblogging’ work on a smartphone which would increase mobility and save battery life for full-on productivity sessions. I’m a big Google user and the choice of phone for me would be relatively simple. The Android operating system offers a fast, easy and efficient way to access my emails, docs, chats and maps and through the huge number of applications available in the Android market I would have no problem finding easy ways to keep people updated with my location and latest photos. The Motorola Milestone (Eu version of Droid) is clearly the best choice at the moment although the landscape is changing every two or three months here. I’d be looking for a phone with a keyboard, a superb camera and GPS and a large, easy-to-read rugged screen. (The Milestone uses Gorilla Glass) Battery life is of course important but at this level, the differences are unmeasurable based on technical specifications and the limited number of details reviews.

Summary.

I feel a plan coming together but I need to work on that PC solution. 1.2KG isn’t my ideal choice (600gm and a much smaller form factor – The Viliv S7 perhaps) would be better but if that new screen technology hits the ground, it’s a must-have. It just so happens that an S10 sample is coming my way soon (for testing on UMPCPortal) and I also happen to know that there are some 10” Pixel-Qi screen samples knocking about. I think it’s time to give Pixel-Qi a call to see if they want to help out with a new solar computing tour!

I’ve been testing it for the last week and as a standalone UMPC its a really flexible solution. SSD and 3G options, high quality build and very long battery life. In tests, I’ve been getting 5-6hrs battery life and seeing great productivity levels using either the on-screen keyboard or a USB keyboard and mouse. The best thing is that the car-kit includes an adaptor plug for 12v => 9.5 but the input voltage can rise to 24v making it perfect for attaching direct to a 24w or even 12W solar panel. One issue however is the gloss finish on the screen. Viliv are producing a filter though so this should help a lot. I will get one and test it soon.

Initial plug-in test worked but I need to work-out the minimum sun power level needed and the full-sun charging time.

Stay tuned for more test results. In the meantime, check out my full review at UMPCPortal.

iUnika have announced a range of very low end, low-cost netbooks which include one with a solar-panel on the back. The price: $260.

• 700gm
• 8″, 800×480
• 400Mhz MIPS CPU

It’s eco friendly too “..the system body’s is made from bioplastics and other biodegradable materials derived from starch and cellulose” [source]

Here’s my take. Using a PC in the sun is hard work on the eyes and hard work on the battery as you need to pump up the backlight. The solar panel is also very small (I estimate 4W max output) so with a device that’s likely to be in the 3-4W operating power range, it’s at best, a trickle charger that can keep the device topped up when not in use. Putting panels on PC’s does a nice job of cutting out the losses you get when charging external power banks but they need to be detachable to get the best use out of them.

Still, bravo to iUnika for doing this. There are definitely some customers that would benefit from this. Education in hot countries with poor infrastructure comes immediately to mind.

Source: Gearlog

Take a look at the diagram again below. it shows the loss-points along the route from the sun to the UMPC.

More efficient UMPCs?

Of course! Any improvement in efficiency here would help. Currently a good average is around 9W and if this could be reduced to 6W average, it would be a major improvement.

Bigger battery life?

No. For my tour, the battery life or battery capacity was really not an issue. 50W/hr per day total capacity (via two battery packs; one that can be used and one that can be charged, is ideal.)

Solar Panel improvements.

From 1.2KW that hit the panel, only 660W hits the solar cells and those cells are only around 8% efficient and this is the first place we can look for improvements.

Current top-end production solar panels are 22% efficient but these are hard panels. To get the equivalent of 25W power you would need a hard panel of about 35x35cm plus frame. Lets say 40cmx40cm in total area. By using a hard panel of this size I could have actually put one on the front and one on the back of the bike to achieve a much more powerful solution. Finding a 40x40cm high efficiency panel might have been difficult though and probably less rugged. There could be a weight consideration too. Given the space restrictions on a bike, I think that a hard panel solution might have been better. In the campsite it wouldn’t have made much difference. The foldable panel was light and small and there should be no need for more than 25W of max power.

Battery tech and charging methods.

There’s a lot that needs to be improved here and the improvements can be achieved through a combination of process and of technology. What follows are the most important issues.

Lead-acid out!

The lead-acid battery proved to be a hindrance more than a help. It was heavy. It had no charge level indication and at low charge levels it couldn’t deliver enough current to drive my DC DC converter or even charge the AA batteries. In short, I didn’t use it much at all and I would drop it from my kit list if I did it again.

Li-Ion problems.

I knew that charging a battery just to have it charge another battery would be inefficient but I didn’t realize that it could be so bad. For example, the Li-Ion battery pack I have (Tekkeon/Tablet Kiosk MP3400) appears to lose about 25% energy through the input and Li-Ion charging stage. That is, you have to pump something like 20% more energy into it than it can store. But that’s not the whole story. The voltage conversion process on the output stage kills another 20% of the energy! From input to output you’re losing a shocking 40% or more energy!

But there’s another problem too and i’ve mentioned it before. The charging of Li-Ion batteries occurs at a fixed rate which means however much energy you have available and however quickly you could feed it into a Li-Ion battery, it won’t take it any quicker than its designed for. The MP3400 takes about 15W (about 0.8A at 19V) of energy to charge it and even if I attached a panel capable of delivering 50W, it would still only take 15W wasting a huge amount of available energy.

This last problem is the one that needs attention when designing a solar charging solution. I have detailed some possible solutions at the end of this article.

Direct charging UMPCs from solar.

One thing that I found annoying was that the only was I could charge my UMPC battery safely was to charge it from the Li-Ion battery. Obviously this is inefficient for the reasons mentioned above but why can’t I charge the UMPC direct from the solar panel? The main problem is that the DC input circuitry on the UMPC is an unknown factor. There’s no way to tell if there is over-voltage protection or whether it will charge a through varying input voltages and its just too much of a risk to try it out. When the DC input on the UMPC is broken, so is the UMPC! I also though about trying to charge the UMPC battery on its own but there’s no standard in connectors or charging currents and voltages so unless you want to build your own charging circuit, this isn’t possible (with the one exception of the OQO Model 02 that has an external battery charger.) I don’t really see this changing much on UMPCs in the near future though. There’s no real reason to increase the complexity of the DC circuit just because Chippy and a few others wish to use solar panels!!

How to improve the solar charging process today…

The Sunlinq 25w panel and Tekkeon MP2400 battery pack is an easy option, readily available and relatively cheap. It works, and if you use the tips above, it can be quite succesful but there are further improvements that could be made, especially if you have the time a flexibility to adjust your solution as you go. Lets assume the lead-acid battery option is too heavy and will not be used.

Ideally you will have the flexibility to add load and add solar capacity as conditions vary. This requires multiple smaller solar panels and multiple smaller Li-Ion batteries that can be set up in different situations. This is currently the only way to provide the most efficient charging solution. Buy multiple slow-charging (500mA for example) Li-Ion battery packs that can be stacked in parallel as energy availability increases.  You will need a voltage regulator on the output of the solar panel and this will need to match the input voltage of your charging solution. Preferably 12V. Fit an ammeter and voltmeter to the output of the voltage regulator so that you can monitor load and voltage. This all takes a lot of time and effort though and for most people its not worth the trouble. Ideally you would have a smart charger that does the monitoring and switches in Li-Ion packs as current availability increases. I have not seen such a solution yet and this, along with some more advanced solutions is what I’d like to see in the near future.

…and in the future.

How about a Li-Ion battery pack that has three levels of charging speed. Low, Med and High. These can be manually adjusted to match the energy available. Ultimately you would have a Li-Ion battery pack that self adjusts to the input current available. I have seen a few advanced components that claim to be able to do this but have never seen a consumer product that is able to do it. If you can get vari-charging Li-Ion batteries then there is really no need for the heavy lead-acid battery at all.

Finally, I’d like to see more UMPCs that have an external battery charger with good, efficient circuitry, over voltage protection and a wide range DC input voltage. Currently there are very few options here.

I’ll be watching this space carefully from now on and I hope that it won’t be long before I can report about new solutions to the issues of solar power and battery charging.

A business issue this morning cost me 25% of my battery power and with the current weather situation, cloudy and wet, that could cost me dearly. There was a brief bright period at around noon where i slammed on the breaks and stopped to put out the panel but it was short, lived. The mobile phone needs a top-up and the GPS too. It’s fair to say that this has not been the best week for solar energy but despite that, it’s been possible to get a few hours of umpc work done every day. The bad weather has also made me think long and hard about how the process can be improved. I have some notes that i am going to try to type up tonight but that, of course, depends on my battery!

View towards Remagen (two bridge towsers can be seen at base of hill) in terrible weather.

No sun, no energy although somehow I’m managing to squeeze enough out of the clouds to charge the phone which is pretty amazing. Luckily I have enough juice on the UMPC battery and the Li-Ion battery to give me about 4 hours of computing. If I spot any sun at all over the next 3 days I’ll have to stop and sap up as much as I can. Its going to be very tight. Will I have enough left for the final report in Duesseldorf?

Right now I’m in Bonn and at home with my wife. I’m only using battery power and won’t be charging anything so there’s no change to the plan. Apart from a long bath and a good sleep tonight ready for the last two legs on Saturday and Sunday.

 Another day completed and I feel like I’m getting into a better rhythm. Checking emails and RSS on the mobile phone and creating rich journal updates with the Q1b. I only wish I had a  mind recorder because I’m thinking of some great ideas while I cycle but forgetting them when I get to a point where I could write them down!

The bike, which I’ve decided to call Berta (the Blue Bakers Bike) is performing fantastically well. I was a bit worried about having no gears but the fixed gear ratio is perfect for around 22km/h which, with 65KG of pack on a 25KG bike is just perfect. The thick tyres help to soak up bumps and now that I’ve pumped up the pressure a bit more, seem to roll without too much resistance. I even clocked 34kn/h on a straight today . Wohoo! Berta is Berta

Tomorrow morning I will cross the Rhein on a ferry over to Bingen, a lovely town that I’ve visited before, and then continue up the left side of the Rhein. The hills meet the rive here and so there could be an issue with mid-afternoon sun dipping behind the hills. If that’s a problem I’ll switch sides again but I can see from my map that the route on the other side takes me up into the hills. Not good!

Time for some sleep now. I had yet another good meal and feel like I’ve capped a good day!

Winter is coming…If you take notice of the geese that is. I saw a flock flying south (following the River perhaps) this morning and wondered if they knew something that I didn’t. Its was lovely and warm yesterday and its pretty much the same today. Is there some nasty weather around the corner or did they get an SMS from some Geese mates in Africa telling them to come early?

Although its been warm its been very cloudy today. Much cloudier than yesterday and yet I still managed to get some charge into the Li-Ion battery and (I think) something into the lead-acid battery. Despite that though I’m using my spare battery and thinking carefully how to use the UMPC more efficiently. Daytime use (like now!) is not the best as the backlight needs to be turned right up. That’s draining an extra 2 watts compared to evening use when I can drop the backlight to minimum.

I felt very strong this morning and powered the 85KG bike/baggage combo through to Mainz in much less time than I had planned. It was really enjoyable. While the clouds where thick I kept on cycling and ended up in Eltville where the was a lovely Rhein terrace restaurant serving Spargel Suppe (Asparagus Soup.) I stayed for an hour while the solar panel and bike rested by a tree and then layed myself down on a bench for an after-lunch nap. After buying, writing and sending a few postcards I carried on the journey. The Rhein-side path was pretty bumpy and at every chance I tried to find another route but this was really the only sensible offering, the other being a trek up to the hills! Then, after about ten minutes I heard a crash behind me and stopped as quickly as I could. I looked back to see the battery packs and cables strewn across the path along with the shattered container. Shit! I gathered it all together, repacked it and then checked everything out.I think I’ve been lucky. Everything seems to be working still so I think it was just a warning from above to tell me not to take afternoon naps!  

Only about 20km to go until the campsite and having looked closely at my plan, it appears that I’m ahead in terms of distance but behind in terms of energy capture. I need to take longer breaks. But no afternoon naps!!

Due to the cloudy weather I decided to cycle all the way through to the campsite in one stage today. I chose a route slightly away from the Rhein which had the advantage of being more direct but the disadvantage of being inland and therefore higher. Hills are not something I enjoy on the 25KG Kronan bike! The route was nice though and it took me through endless lines of grape vines (and loud, gun-like bird scarers going off every ten seconds all over the valley) that are almost ready for harvesting for wine. Every town and village seems to be advertising their Winzer (Wine) Fest!

The mobile phone I have is doing very well as my email notifier and as (filtered) emails come in I get a little beep telling me to stop and take a look. Its nice to be able to say I’m in the middle of a Vineyard’ at the end of each reply! But that’s about it for the mobile phone. Trying to do anything Web-like is slow and terribly inefficient. Firing up the Q1b UMPC every now and then keeps proving how perfect they are for Internet activities. There’s no way I would be able to write so quickly, create the maps, review and edit the images and communicate via IM through all the protocols possible without it.

I’m camped right next to a beach on the Rhein (that’s the Rhein behind me there!) and can hear the waves lapping against the shore. Every 10 or 15 minutes a huge river boat can be heard either coming down from Rotterdam or heading up from the south somewhere. Fuel, sand, containers and even the occasional passenger boat. The Rhein is a business river. I wonder how long it remains efficient compared to trains, trucks and air transport.

I haven’t planned tomorrow in detail but it won’t be as long a journey as today. The Lead-Acid battery I have (2.2KG worth of old technology) didn’t charge well and so I’ll concentrate on loading-up the Li-Ion battery. One bit of good news though is that the mobile phone charges from the solar panel even in bright daylight. If all else fails I’ll have to email the blogs via T9 but I hope that doesn’t happen. I still have a fully charged spare battery for the Q1b so I’m not in trouble yet!

A number of blogs seemed to have picked up on this solution today and are quoting 11-12 hours charging time. This figure is a little misleading. The battery capacity is about 240w/hr and based on a reasonable 5-hour per day full-sun rate its going to take 10 hours. That’s a minimum of 36 hours duration! In middle-Europe, you’ll be waiting for 3 full days of sun!

The other point to consider is that you need to take all your AC converters with you (weight problem) and should recon on 20% energy loss by converting from 12v -> 110V and down to 12, 16, 19 or whatever voltage your device takes. Hardly efficient. Alternatively you can buy 12v car adaptors for all your equipment (can get expensive.)

My recommendation is to use a combination of a Li-ion battery with variable DC output (I’m using the TabletKiosk/Tekkeon MP3400) and a lead-acid battery (I’m using a 2.5kg 6Ah part) This gives you the best of both worlds (lead-acid flexibility and Li-Ion light weight) and cuts the total weight right down to under 4KG. At also avoids having to operate a dangerous 110v. Capacity with my solution is around 130W/hr but here’s the key. Don’t use a notebook PC, use a UMPC. They are far more efficient. With a normal UMPC you’re good for 10 hours of computing on a fully charged system (around 7 hours full-sun charge time.)

News Via GottaBeMobile.