Has anyone tried of know if it is possible to run an FW aquarium off a small panel.
This has come up before. It comes down to pure math; you need to figure out how much power your tank is drawing and then size the panel.
Filters are easy, they are fairly low powered (Aquaclear HOB's for example are around 9w for an AC70; Canisters are around 35w on average). Lighting CAN be low powered, as long as you're not trying to do high light plants; you could easily run a T5HO bulb for a reasonable power draw (many of my 40gallon tanks use 24watt T5HO).
Heaters, unfortunately, are the killer.
Let's look at cost. Canadian Tire has 15w panels on sale right now for $99.00 and a 120w panel for $1099.00. You could pick up two of the 15w panels to run a filter and basic lights. You'd need the 120w panel to even pretend to heat your water, and even then you might not have enough power to heat anything but a very small tank.
Flat Solar panels are still inefficient, to get the most out of them you would have to build them on to a tracking system with a photocell (perhaps you still own a large satellite dish?). Not to mention the cost of batteries etc. I doubt anyone has ever gotten sustained 15w out of a small panel.
Terry
Thanks for the info, just something that came into my head today.