They are expensive and inefficient. Solar panels need to develop a lot before they can provide the average man on the street with enough energy to supplement a worthwhile portion of his energy intake. Mind you, the average man is pretty inefficient. Cars, lighting, heating, cooling. We sap up energy like there’s no need to think about tomorrow. I’m sure the average person could cut their energy usage by 90% if they had the skills, time, money and resources to do it. At that point, solar power might be a more interesting proposition.

Mobile computing is one of the areas that is already cutting its energy requirements buy huge amounts. Where notebook PCs can take 20-30W, ultra mobile PCs are taking 10W and in 2008 when we start to see dedicated ultra low power, ultra mobile computing devices, that power requirement is going to get slashed down to the sub 5W level. Intel is talking about sub 4W and VIA have just launched the 3.5W Mobile-ITX board. Of course, the reason for this is not because of energy conservation, its because of heat, size and weight. Mobile devices need to be small and light. Small devices can only dissipate a certain amount of heat and light devices can only contain a certain amount of battery. The last thing we want is a UMPC melting through the bottom of our bag!

One nice side-effect of all this drive for tiny, light devices is that solar energy starts to cash-in. Smaller energy requirements means smaller solar panels which means lower costs and higher mobility. Right now, today, if you took the best solar technology and made a fold-out sun-shade for a UMPC of about 20x20cm, you would be able to power the UMPC non-stop during sunshine. Its true. The best solar tech is reaching 40% efficiency in the lab and at that rate a 20x20cm panel would provide up to 40W of power. Unfortunately, this is lab-tech at the moment and good quality, mass produced solar panels are down at the 15% efficiency level. Also add in the fact that many places don’t get much sun and you can see why its not really possible today.

But lets take the Reware Juice Bag as a good example of a useable bit of solar tech. It can provide up to 7W of power from a 20x30cm panel stitched into the backpack. That’s about 25W of stored energy per sunny day if you take into account losses on storage. Today, that would give you about 2-3 hours UMPC usage but with a 5W UMPC, you’re looking at 5 hours usage. Drop down to 3W (2010 perhaps) and 8 hours of battery life starts to get really useful. Lets assume that by 2010 the efficiency of Solar panels in increased by 50% and you’ve got full-day power from a panel that’s the size of a UMPC.

OK, its not 100% practical for everyone to be sitting outside looking for sun but it would work for a lot of people. And its just one example. How about taking the same calculation and scaling it up to a classroom full of UMPCs. You could power a full class of 30 with a few square meters of solar panel. Costs would be sub $1000 and if you compare it to 30 normal PC’s taking 150W per hour for 4 hours per day. (30 x 150 x 5 = 1.8KW) you are not only helping the environment but you’re reducing your air-con costs, noise and starting to get to the point where you save significant amounts of money. For a university that has 2000 PC’s deployed, well I don’t need to show the calculation do I.

After the solar-ump tour is finished I’m going to be following solar tech very closely on this blog and will continue to promote the marriage of ultra mobile PCs and solar tech. I don’t see the battery companies shifting towards more efficient battery technology so as solar energy starts to become a really interesting business opportunity we might start to see solar being integrated into specialist UMPCs for long-term outdoor usage. At some point in the future, when the calculations look attractive to the bean counters of this world, investment money will come pouring in to the mass market and the whole thing could take off in a very short time span. I predict, with excitement,  that within 2 years we’re going to see solar accessories for UMPCs. Within 3 years we’ll see specialist UMPCs with integrated solar panels. I’m hoping that in ten years time, the extended battery will be a thing of the past.

I’m quite lucky to have been able to test a lot of UMPCs out over the last year. Most have been good in their own target markets but only some have been good for me. One of my favorites, the Kohjinsha SA1, an AMD based device is also one of the most-power efficient too and I took it to CeBIT this year where I used it exclusively for 5 days. It worked well and it demonstrated to me how much I might use a PC in one day. During the daytimes I was able to get by with a single charge – 4 hours. In the evening I was using it for another 2 hours, minimum! OK. CeBIT was a worst-case scenario. There was breaking news all over the place and there was one point where I was walking to a meeting with Intel and trying to edit and post a news entry at the same time. I don’t expect to be doing that on the bike! I do expect to be stopping 2-3 times per day for 30-60 minutes at a time though. Primarily to update my location, photos and geotags and to make quick reports here and also to work on any news that’s breaking. In the evening I expect to do a small amount of video editing, uploading and maybe a longer post, chat, IM etc etc. 2 hours is what i’ll give myself in the evening depending on the forecast for the next day.

At 9W drain (hopefully less in evening with low backlight and careful control of HSDPA and WiFi) that’s about 36W per day.

In addition to the UMPC I will have:

Mobile Phone. This is a Nokia 6380 with the 3.3v 900mah battery. 3watts. I will use this as my email and quick blog news checker using the gmail java app and the opera mini browser with bloglines mobile. These are combinations of applications that I’ve found very efficient and there’s really no need to turn on the UMPC to read email and RSS text. I can even do short emails on the phone too. If something interesting comes up then i’ll take the UMPC out of hibernate and do further reading, research or even email or blog. If I throw an hour or so of MP3 or FM radio in, I estimate that one charge per day on the 6280 will see me through. That will take about 5W of power from the power bank or I might be able to charge it in the early/late part of the day when the suns power falls below 70%.

Camera. This takes 4 x AA batteries. I use 2300mah 1.2v rechargeable batteries that should (if I use the camera carefully) last up to two days. That’s again, 5W per day. Charging will have to come from the solar panel during the day. Hopefully this can be done for an hour earlier or later in the day. Testing and research into different types of chargers needed. Smaller capacity batteries could also be useful.

GPS logger. This takes 2 x AA batteries every 15 hours. I hope that 2 batteries lasts me 2 days so that’s 2.5W per day. I will take a Bluetooth GPS device in case the logger fails. I think it lasts 10 hours on a 3W battery and can be charged from a USB port so its much the same in terms of power.

Lamp. This will be a very efficient LED lamp. Its possible to get ones that are solar powered or hand-cranked. I expect this to be a negligible drain. I will even take a few candles just in case. Bear in mind that it will be light until 2200 and will get light again at 0500. I don’t expect to be awake much during these hours!

Finally, something I haven’t mentioned yet, a backup PC. Well its more of a web tablet really. Its the Nokia N800 and it will run for 3-5 hours on a 5W battery. That’s very efficient and could serve as an email tool, IM tool and, at a pinch, blogging tool (although i’ll have to look into a mini keyboard solution for it.) This will only be used if the worst happens. I.e. I run out of power or the main UMPC breaks. Otherwise I won’t use it and it will stay packed away.

Total daily usage:

UMPC: 36W

Mobile Phone: 5W

AA batteries for camera: 5W

AA batteries for GPS logger: 2.5W

Total daily power usage: 48.5W

In the previous post I estimated I could average 48W solar power collection and storage per day. Bingo! Now, did I forget anything?

The other luxury I will give myself is a fully charged set of batteries before I go. I don’t think its unreasonable as anyone in their right mind would ensure that their batteries were charged before they went. Here’s the battery power that I will take with me:

• Powerbank: 56W
• Extended battery: 60W
• 2nd extended battery. Empty 
• 8xAA batteries for rotating through camera. 20W
• 4xAA batteries for rotating through GPS. 10W
• Phone charged. 3.5W
• Emergency UMPC charged. 5W

Total starting power: about 150W.

In theory, that lot will give me a 1 day buffer which means at some point in the tour, I can have a day of bad weather and continue as normal.

I will talk to select solar next week to see what they think of my estimates and if they give it the thumbs-up Ill start real testing – assuming the sun comes out!