May/083
Solar-UMPC-powered web server testing.
Yes, its that time of year again where we get the first encouraging days of sunshine in Europe so I’ve been into the cellar and dusted-off my Sunlinq 24W solar panel.
Sun strength for the last 2.5 days.
I’m not planning a solar-umpc tour this year but I am planning to get some use out of the panel. At the moment, the plan is to run a UMPC from the solar panel that could serve this blog. I doubt i’ll be able to do it 24/7 for the whole of summer but I’m running some tests on the Raon Digital Everun S6S at the moment to see exactly how much I could get out of it with the 24W panel.
The Everun, when configured for 400Mhz with WIfi and screen off, will consume a tiny 4W at idle and about 6W at full power which is about as low as you can go with a PC without having to switch to an ARM architecture. I don’t want to do that because the plan is just to install a basic Ubuntu image, fire up Apache and SSH and serve this blog as a set of static web pages. WIthout Mysql or PHP running it should keep the processor load down to a minimum although i’m not sure that Ubuntu will be able to switch the CPU into 400Mhz mode. It might have to stay locked at 600Mhz.
At 5W drain, the server would need 120Wh of energy to power it for a full day. With a 24Wh panel I’m only going to get about 80-100Wh per day on average (using the 4-hours sun/day rule that applies to this part of the world) so at some point, back-up power is going to be needed. The problem is, how can I switch-over to back-up power (or gracefuly switch over to another server.) Switching the servers is OK but getting the Everun to shutdown when it reaches 5% power is impossible under Linux right now.
The Alternative is to shut-down the server between 0300 and 0900 every day and to try and regulate it that way or just keep topping up the SLA battery from other sources when needed.
I’m going to need a couple of new items for this project though.
1) Power usage measurement tools. I want to feed the data back into the website. Power used, power given by panel, current battery level. Any tips there would be much appreciated. Should I buy a dedicated data logging system with software or are there simpler ways to do this.
2) An ethernet port. The Everun only has a WIfi connection and that would take too much power so I’m looking at a USB to Ethernet adaptor. This one from SMC takes about 150mw which will be fine.
3) Bigger SLA battery. Rather than using the 56whr battery that I have, I should get one that takes about 200wh so that if we have two or three good days of sunshine, I can store the engergy and use it on days where the sun is weaker.
Solar panel positioning is going to be a major problem at my house which is badly oriented for a solar panel. I’m also a bit worried about loss along the length of cable I will need in order to position the solar panel correctly.
Over the next few weeks I hope to at least have a partial solar-powered web server running but if this blog disappears, you’ll know what’s happened!
Aug/070
9 days rain ahead.
I know that weather is supposed to be chaos but this is just silly. The most settled weather we’ve had this year was back in April and since then its been a real mess. It doesn’t look like it wants to change much either. The whole of central Europe is stuck in a mess of clouds that does not want to move and bizarrely, Helsinki, the place I’ve just come back from in northern (and generally colder) Europe is expecting a ton of sun!
Getting everything re-organised in another country is not something I really want to do to be honest. There’s a lot of cost and time issues that would make the project too much trouble for me and my sponsor, VIA Technologies so once again, I’m going to wait. The 9-day forecast takes me up to 18th August. After that point I have about 5 more weeks left in the summer before the sun gets too weak.
Jun/071
Solar charging. Lead Acid vs Li-Ion
In a recent comment here, someone asked why the Lead-Acid battery was needed. Its probably not too clear in the video why I use it so I reproduce my answer (which comes from the best of my knowledge!) here.
There are two main problems with charging Li-Ion batteries from Solar panels.
Firstly, Li-Ion batteries (in notebooks and battery bank) charge using a constant current (stream) of power. For common notebook batteries and battery banks such as the Tekkeon MP3400, this is around 1A. A lot of the 12V portable solar panels only reach this power at high sun levels meaning you can only use them for a few hours mid-day. In fact a 12W panel might not be enough to even start the charging process. Secondly, if you have a huge panel that could deliver, say, twice as much power as needed, its not used. Only the power needed is taken. The rest is wasted.
These two problems can be overcome at the expense of weight with a lead-acid battery.
L-A batteries are more flexible. You can charge them with a trickle and also with a higher charge rate. They are much more suited to pairing with a solar panel. The problem with this solution is weight. Small 12v L-A batteries are over 2KG in weight!
What’s needed is a flexible Li-Ion battery charging solution. Currently there are no products on the market that can archive this but I’m searching hard!
In summary there are 2 solutions.
1 – Get a panel powerful enough to charge a Li-ion battery at 70% of its rated output. For example, a 25W panel and the Tekkeon MP3400 Li-ion battery. This will give you about 4 hours of charge time on a sunny summer day. (Mid-Europe) This should be enough to completely fill up the Li-ion battery.
2 – Go for a heavier solution with a L-A battery and give yourself more charging flexibility.
Jun/070
InterSolar 2007. Nothing for Solar-UMPC fans.
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!
Jun/070
Mobile Internet Connectivity solutions.
I learned a long time ago that WiFi Internet access is not a truly mobile Internet access solution. Its a solution for multi-location access but not a full mobile solution. Fortunately the mobile telephone carriers offer Internet access too and it ‘aint bad!Its going to be the perfect solution for the Solar-UMPC tour.
In Europe, we use the GSM and UMTS (3G) methods of mobile phone communications and they are well advanced. 1.8Mbps is common in and around most cities and towns with 3.6Mbps being available in the most populated places. Even out on the fringes, a 384kbps connection is possible so in terms of availability, there are very few issues.
Issues arise, however, when you start looking at equipment and cost. In order to use a 3G data connection, you need to have a 3G data modem. There are three options. Either you buy a dedicated 3G modem that you can connect to your PC, you buy a PC or notebook or UMPC with a 3G modem integrated or, if your contract allows it, you use the modem that’s part of all 3G mobile phones. In this case you simply connect the phone via USB or Bluetooth and in general, its an easy few steps to get connected. It really solves the costs of hardware because in 2007 we’ve seen a number of high speed 3G-capable mobile phones hitting the market and with the normal contractual discounts, the costs is minimal.
It doesn’t solve the other cost though. The cost of the data. This has been a real issue for early adopters of this connectivity method. Costs of data can be shockingly high and for the average user its just wasn’t worth it. Until, that is, the advent of the data-focused contract. Nearly all the major cellphone carriers in Europe are offering data-oriented connectivity and costs are coming down extremely quickly. In the UK and Finland, 10-15 Euros per month is all it costs to get hundreds of megabytes, sometimes even up to 6GB) of data per month. For the average user that’s is using just a few hundred megabytes a month on their normal broadband connection, this is more than enough. In Germany, I have chosen the Vodafone Data Tariff. Vodafone, along with T-Mobile have the widest coverage of high-speed enabled cellular towers and a good selection of data tariffs. You can start with 30MB per month for 10 Euros and go as high as 50 Euro per month for 5GB of data. In the middle are a couple of attractive 200 and 400MB tariffs and the 200MB tariff is the one I’ve gone for the WebConnect L at 20 Euros per month. I could have got a cheaper tariff but if mobility is an important factor, cellular coverage has to be high on the list of requirements.
Insert SIM card for instant connectivity! Samsung Q1b HSDPA
Combined with the Samsung Q1b HSDPA I’ve got a ‘real’ ultra mobile solution in my hands. Vodafone have given me a second SIM card for the UMPC and with the built in HSDPA modem I’m online with broadband speeds within seconds of turning the UMPC on. This is how it should be!
May/071
Choosing the Solar UMPC
Its decision time on the UMPC and I think I’ve just about come to my conclusion – The Samsung Q1b HSDPA. Its not perfect but it covers the important requirement of efficiency very well. Maybe in a few more months there will be better options but right now I need to focus on one device and start testing and getting used to it.
Let me take you through the reasoning though. You might be thinking about the same thing yourself so I’ll list my requirements and then go through the options.
Requirements.
- Power efficient. Obviously. I’m looking for sub 10W average power drain for a total power budget of under 60W per day. (More on the power-budget in another post.)
- Lightweight. All UMPCs are lightweight. This shouldn’t be a problem.
- Bright screen. Some are better than others and when you’re outside, this can make a huge difference. Put it this way, I’d rather be sitting on the terrace of a cafe rather than inside on my own!
- Keyboard. I’m going to be doing a lot of typing so this is going to be an important requirement. Nearly all built-in keyboards are nothing more than thumbboards. I will have to consider external keyboards
- Protective case. A slip case isn’t going to be enough. I need a very good protective case. Preferably rugged.
- Ruggedness. 8 days on the road is going to be tough on a UMPC. I’m concerned about dust and the hard drive.
- Bluetooth connectivity (for data through mobile phone). There are other connectivity options including connecting a mobile phone via USB and getting a UMPC with built in 3G data modem.
- SD card slot for digital camera images.
- Extended battery. Generally the batteries with UMPCs are around 20-30W/hr types. an extended battery is going to make charging easier.
- Reliable. A proven track record is important.
- Cost effective. Upper limit is around 1500 Euro for all UMPC equipment.
I have already chosen VIA as the platform I will use. Intel is powerful but can start to sap power very quickly is not used carefully. One stray process and you can eat 15W in an hour. I don’t want that to happen. AMD is another option and there are some nice low power solutions around. The only problem is that the processing power of the AMD solutions is limited. I have edited a couple of movies on an AMD platform and it was a long process. I can not afford to leave the PC for one hour crunching videos and sapping energy.
VIA have been on the UMPC scene since the Origami launch in March 2006 and the core of their solution is the C7-M ULV CPU. Its available in 1, 1.2 and 1.5Ghz versions but until recently, only the 1Ghz versions have appeared in UMPCs. Amtek (OEM), Samsung and Uren are really the only manufacturers that already have VIA-based UMPCs on the market and although there are three more available this month, they are new, untested and not available for immediate delivery.
The T700 was the first VIA-based UMPC. Its a basic device compared to some of the UMPCs we’re seeing today with a simple style, no SD and no web cam. It has proven to be a solid device though. It has an extended battery and there are bump cases available for it. Its also good value. You can pick up branded versions for under $800. The big problem with the Amtek T700 though is its average battery life. 11-12W drain is normal. It is also lacking the SD card slot required.
The second option is the Q1b from Samsung. This is the VIA version of the Q1, another UMPCs released as part of the Origami project from Microsoft. Its a slightly more attractive design and comes with a 280nits screen. Brighter than the T700. Again there’s no mouse and no SD card slot but bump cases and even a specially made Samsung organiser pack with keyboard is available. In fact, I’m using one to type this right now and its a very very nice keyboard. The other major advantage of the Q1b is its battery life. It can average well below 10W and is even reported to run in a battery saving mode with low-backlight for 4 hours. That’s about 8W average drain. Again, its a good value buy although its not available in its basic form in Europe because Samsung introduced it here in Germany with a built in HSDPA modem, bigger disk and more memory. Potentially a great advantage but the price is quite a bit more than the T700 is available for. It would stretch the budget when taking into consideration the keyboard and protective cover.
Finally, there’s the Uren V1. Unfortunately this one is very quickly out of the running because it’s not available at outside Asia. Its also a car-focused UMPC. The most difficult thing about the Uren though, is that no-one has really written any reports about it in English. Its certainly not a UMPC that I’ve been able to get hold of and test so at this stage it goes straight to the bottom of the list.
So there you have three UMPCs. One looks like good value and capable. The other looks like its perfect for the job but expensive and the other is out-of-reach. I mentioned a budget of 1500 Euro for the UMPC. This includes the cost of protective cover, keyboard and extended battery. When I add up the costs of the Q1B HSDPA, the organiser pack (with the wonderful keyboard) and an extended battery I come to just under 1500 Euro. Phew! I’ve even got some spare change for a USB-SD adaptor. The Q1B HSDPA it is then and as you might have seen on UMPCportal.com, I have already taken delivery of one. Unfortunately it had a faulty USB port so its gone back but the short time I spent with it was really nice. The HSDPA modem is going to be a great advantage and I’ve already transferred the data portion of my Vodafone tariff to a new SIM card. No messing with Bluetooth or cables and no worrying about keeping the mobile phone charged. If the phone dies there’s always skype!