Chris Soler

1.5 acres is about 300 by 200 feet. To get 700 feet of drop,it would have to,be a cliff like Niagra falls. Somehow I think you have a much smaller drop. To get an approximation of hydro power you multiply the the gpm by the feet of fall and divide by 10 to,get the watts of continuous output with a 50% efficient hydro turbine. You can design the turbine to produce a high voltage and go long distances and use a mppt solar controller to drop  to battery voltage. Ive installed a dozen systems that combine the solar panels and hydro into one controller to keep,the batteries charged. Chris

I've installed 7 of these systems. If the tubes are warm to the touch then the vacuum has failed. Usually the tube has a silver color at the bottom which is a oxygen absorption chemical. If the silver is gone the tube has failed. The tube will collect solar energy but will radiate it back out as soon as the temperature gets much higher than the outside air temperature. My system has a copper heat pipe and no water inside that plugs into the manafold  at the top. You loosen the connection at the bottom of each tube and wiggle and rotate and pull down to get the tube out of the  manifold. With my system you don't have to drain the water to replace the tubes. I don't know what is in your system so,if water comes out as you start to,remove a tube then you will have to drain the water. Chris