whare do you live in the USA????
and If it were really worth all the trouble you would see
Solar Panels all over the country....and you dont..
you wont get a pay back on this and if you were to
put garden hoses on your roof.it would have a bad smell
and taste when it finally made it to your faucet..
if you live somewhere that you could get passive heat
to heat your home...from an air type soalr panel
then it might be would be worth your time to actually BUILD some
soalr panels that you would sit on the south faceing side of your home
and would gather HEAT in both the summer and winter......
Here is a cheap idea for you.....
I know of some old man that actually made solar panels
out of alluminum beer cans...
he built a wood frame......
then he put a reflective sheet of 4x8 insulation as a backing
then he cut the tops and bottoms out of alluminum beer cans
painted them black. ...and lined them up in a row from top to bottom
then he makd a mainfild on the bottom and one on the top....
then he covered and selaed off the box with tempered glass.
faceing the panel on the south side of his home....
the air came in the bottom mainfold piped in from his lower floor and flowed
through the panel and came out
the top "hot as hell" and was pumped into his living room....
he did that CHEAP and is about along
the same lines ad your garden hose theory.......
and you would have fun drinking the beer....to get the cans.
thats an added bonus.
good luck have fun...