Solar reader

[EowynCarter]

it seams bookeen made a partnership to make some solar power e-reader.
Idea is interesting. (Thinking about it, no one did that already ?)

http://blog.bookeen.com/sunpartner-t...rgy-e-readers/

Sunpartner Technologies is a high-tech engineering company specializing in Solar NETs (New Energy Technologies). Since 2008, they’ve been developing the transparent PV component Wysips® that seamlessly integrates into any surface, transforming it into a solar panel.

So, over the screen ? What impact on readability ?

[Calenorn]

It's an interesting idea.

If you don't want to wait, you can try one of these:

http://www.amazon.com/gp/product/B00...?ie=UTF8&psc=1

It's a sturdy solar panel that charges its own battery. Once that's done you can charge an ereader (or phone) several times.

With this and a good ebook library, my reader and I can go completely off the grid for a very long time!

[GeoffR]

I think it makes more sense to have a seperate solar panel rather than one integrated into the reader: that way you can sit in the shade and read while the solar panel is in the sun charging; you can use the energy collected by the panel to charge a range of different devices (radio, torch, camera, etc.) not just the ereader; and you can have the solar panel attached to your bicycle, backpack etc. while on the move during the day to power your ereader and other devices when you stop for the night.

[EowynCarter]

Originally Posted by GeoffR

I think it makes more sense to have a seperate solar panel rather than one integrated into the reader: that way you can sit in the shade and read while the solar panel is in the sun charging; you can use the energy collected by the panel to charge a range of different devices (radio, torch, camera, etc.) not just the ereader; and you can have the solar panel attached to your bicycle, backpack etc. while on the move during the day to power your ereader and other devices when you stop for the night.

Depends on your uses / need.

I have an USB battery. But, I'm rarely away from a power plug for a long time.
I don't need the battery unless i actually forget to charge. So it's just : here's one device i won't have to worry about.

Someone traveling a lot and having a bunch of devices, external battery might make more sense indeed.

[Ken Maltby]

A typical location within the U.S. gets an annual average of 5 full-sun-equivalent hours per day. This means that the 1000 W/m² solar flux reaching the ground when the sun is straight overhead is effectively available for 5 hours each day. Each square meter of panel is therefore exposed to 5 kWh of solar energy per day. At 15% efficiency, our square meter captures and delivers 0.75 kWh of energy, per day. - See more at: http://physics.ucsd.edu/do-the-math/....PEa5WPfb.dpuf

That is based on average annual data, you can't count on that for any given day. Your device probably has no surface that is a square meter in size. 750w sounds like a lot, but that is for all day's collection. Lets say that you had 1/5th of a square meter of collection area, that would give you 150w per day (when/if you had 5 hours of full sun that day) Now to collect your solar power you need batteries, none of which are 100% efficient. Say - Li-ion at 80%, (which is one reason I believe that this scale of devices are one of the few examples where "Solar Power" makes any sense.) 80% at charging = 120w into the battery, then 80% at discharging = 96w per day, with it pointed directly at the sun, all day.

I couldn't find how much power the device consumes per hour of use/page turn, or such.

Luck;
Ken

[theducks]

I could see having a Solar charge device cover (w/optional 'tank' battery)
about 24insq of solar cells
The charge flap should be arranged so charging can happen even if the device is covered (origami cover anyone ) or the charge the optional 'tank' battery if seperated

[FizzyWater]

Okay, here's where I admit my ignorance....but can "solar panels" also be used under indoor lighting? I used to have a "solar powered" calculator that worked with any light source, not just the sun.

[Apache]

Solar watches work with any light source.
Apache

[jhowell]

I haven't been able to locate a data sheet for Sunpartner Technologies Wysips® Crystal, but this page and this document indicate that the photovoltaic surface is 0.5mm thick, 90% transparent and produces 5mW-peak/cm².

Solar cells are measured assuming full direct sunlight of 1000W/m², i.e. 100mW/cm². So the Wysips is about 5% efficient. That is better than I expected for an almost transparent screen.

A 6" e-reader screen is about 100cm², so the peak output with full direct sunlight would be 0.5W. Indoor lighting would provide a small fraction of this power.

[Calenorn]

Originally Posted by FizzyWater

Okay, here's where I admit my ignorance....but can "solar panels" also be used under indoor lighting? I used to have a "solar powered" calculator that worked with any light source, not just the sun.

The battery I linked to above shows by indicator light that it is charging when placed under BRIGHT indoor lighting. I haven't tested how long it would have to stay that way for a full charge.

The bottom line question is, can the solar panel capture enough energy to make up for the amount that an e-ink reader will use during the same amount of time?

[GERGE]

Something like this makes a lot more sense to me, I think I will research a bit and then buy one.

http://www.amazon.com/Universal-Port...=solar+charger

[Tarana]

My BIL and his friends already use a separate solar charger that charges their phones when they are up at the cabin (no electrical hookup). Solar chargers wear out before the units do, so I don't actually see any advantage here. It does make sense if you live in a 3rd world country where there is limited access to any electricity. I do think the number of people who live in the US who would need a solar powered ereader would be fairly limited. My sister fried her solar powered calculator when she left it out to get rays when she was in Wyoming last summer. Heat is an issue.

[jhowell]

Direct sunlight has illuminance of about 50,000 lux. A typical indoor home or office is around 500 lux, or about 1% of the light power. So a 6" Wysips panel that produces 500mW in full sun would only produce 5mW indoors.

I don't know about the Bookeen e-reader, but according to this teardown, the battery in the Kindle Voyage has a capacity of 5Wh. Amazon claims a Voyage charge is good for 6 weeks of reading at 1/2 hour per day (21 hours total) with wireless off. Given the 5Wh battery this indicates an average power consumption of 240mW.

Using a Wysips panel would charge the Voyage about 10% per hour in full sunlight when off or 5% per hour when reading. It would only charge about 1% per day indoors even with the device left off.

I mostly read indoors, so for me this technology wouldn't be worth the added cost. I would much prefer wireless charging so that I could have a charging mat on my nightstand to charge overnight after I finish reading in bed without any need to attach a charging cable.

[auspex]

Originally Posted by Ken Maltby

A typical location within the U.S. gets an annual average of 5 full-sun-equivalent hours per day. This means that the 1000 W/m² solar flux reaching the ground when the sun is straight overhead is effectively available for 5 hours each day. Each square meter of panel is therefore exposed to 5 kWh of solar energy per day. At 15% efficiency, our square meter captures and delivers 0.75 kWh of energy, per day. - See more at: http://physics.ucsd.edu/do-the-math/....PEa5WPfb.dpuf

Please try to keep your units straight. You're right that you should be talking in kWh. Talking about 750w per day is meaningless.

To put your numbers in perspective, I used to run my entire house on 3kWh per day. That included all my lighting, a laptop and satellite modem, stereo, fans for my heating system, but rarely TV (and fridge, oven and hot water were all gas).

As jhowell said, a Wysips panel could charge an e-reader around 10% in one hour of full sunlight. Well, I read a lot, and on an e-reader that's already been in use for two years (these batteries only tend to have about a three-year life span when used in phones—I'm not sure what the much slower discharge rates of an e-reader will do to their lifespan), I get more than a week out of a charge. So, I'd basically need to get about an hour of sunlight every day to make it worthwhile. otoh, I don't read it much outdoors!

[Phogg]

Originally Posted by auspex

Please try to keep your units straight. You're right that you should be talking in kWh. Talking about 750w per day is meaningless.

To put your numbers in perspective, I used to run my entire house on 3kWh per day. That included all my lighting, a laptop and satellite modem, stereo, fans for my heating system, but rarely TV (and fridge, oven and hot water were all gas).

As jhowell said, a Wysips panel could charge an e-reader around 10% in one hour of full sunlight. Well, I read a lot, and on an e-reader that's already been in use for two years (these batteries only tend to have about a three-year life span when used in phones—I'm not sure what the much slower discharge rates of an e-reader will do to their lifespan), I get more than a week out of a charge. So, I'd basically need to get about an hour of sunlight every day to make it worthwhile. otoh, I don't read it much outdoors!

More like seven hours sunlight per week, not necessarily continuous.
and not necessarily whilst reading.

Lying on the kitchen table in a sunbeam next to your car keys while you are doing the laundry or vacuuming could fit part of the bill. or sitting on the dashboard while you are driving.

If there are charging cells on the bezel I suspect clear TPU cases will be popular for this reader.