Well I would likely start with something like this...
http://www.ebay.com/itm/Universal-H...800?pt=LH_DefaultDomain_0&hash=item4d035cee78
And then devise a latching system that will work within the movement of that device... It doesn't say what the stroke is, so it's kind hard to get into many details...
That actuator can either slide a bolt type latch or even just pull up a hook type latch...
Once you get that part done, then it's just a matter of making a 24 hour clock that will trigger it once a day... Lots of options here from a total DIY design to hacking an over the counter alarm clock or timer... Hacking an over the counter clock will take a little bit more circuitry, as you would need to convert what is likely a multiple repeating alarm signal into a single shot to activate the actuator...
For the battery, since this is low current drain a 12V motorcycle or garden tractor battery would work well... They will have plenty of juice to run the actuator and plenty of reserve power as well... If you want to have solar charging those little dashboard solar chargers will likely be enough to keep the battery topped off for this circuit... But it might be just as easy to bring the battery in once a week and top it off with a regular car charger...
The question now is do you want to go at designing your own 24 hour timer or kit bashing/hacking something over the counter?