While our phones and tablets gulp down electricity like it is going out of fashion, e-ink ebook readers take a more leisurely approach, only sipping power when the page reloads. This is great for battery life - but ultimately you still need to plug in occasionally.
Though perhaps Bookeen and SunPartner Technologies have just changed that. At Mobile World Congress, the two companies have announced what they say is the first solar cover for ereaders using Wysips Graphics technology. Simply put, your book could simply recharge while you carry it around.
The way it works is that the casing is covered with a printed optical network, which combines with solar modules - and which enables the ereader to recharging using the same photovoltaic effect that full size panels use. An hour in good light conditions (which they define as 25000 lux or more) is apparently enough power to give your ereader a whole day of extra battery life. Nice.
At the moment, the technology is exclusive to Bookeen ereaders (sorry Amazon fans), but don't be surprised if the technology finds its way on to Kindles of the future too.