Question: Can anyone suggest an alternative to energy from a battery?

I'd like a system to replace my deep cycle leisure battery, I currently use [this](http://www.halfords.com/webapp/wcs/stores/servlet/product_storeId_10001_catalogId_10151_productId_264265_langId_-1_categoryId_165475) 110 AH leisure battery with a 1200W inverter. 
I run my computer, lighting and sound system off it while I'm "out in the sticks", It works just perfect, there's more than enough energy to get a couple of days usage between charges, I just wanted to know if there's a greener way of storing the energy - instead of using ye olde plastic box full of acid and corroding metal. 

I'm not interested in using a diesel or petrol generator, I'm looking for something a bit cleaner and greener than that, was thinking about the possibility of running a dynamo off a bottle of pressurized gas or air? - I'd probably need an unfeasibly large tank for this tho! 

Cheers Chiphackers :)

Answer: 
How about solar power?
One alterna-power answer might be fuel cells. A more old-fashioned and commonly available one would be a generator running off some liquid fuel (probably diesel). You might still want a buffer battery for that, of course, but you might be able to get rid of the inverter in some cases.