Thanks Heehaw:
I am not looking for something with usable light so much as something to mark the location of the driveway which is about about 400 feet in length, is semi-eliptical and has a centre island flower garden towards one end. I don't care if they don't stay on all night but I would like them to stay on from dusk until midnight. At this time of the year in our part of the world, that is about 7 hours, with not much more daylight hours to recharge the cells. I think I will need about 30 units and I am thinking of mounting them on 3 inch pipe, probably thickwall PVC, three feet into the ground and three feet above ground, something that won't rust or need painting and can be easily repaired or replaced if damaged. I know they will be a nuisance to mow around. The ones I have seen tend to run about $US500 to$US800 each which is why I haven't done anything as yet. So far I have chosen not to go the traditional trenching route as it presents a number of problems including boring under the existing driveway in at least three locations.