I suspect the whole 'needs a hill' and amount if land taken becomes a problem as this cant be taken for granted as available. There are other solutions that see

I suspect the whole 'needs a hill' and amount if land taken becomes a problem as this cant be taken for granted as available. There are other solutions that seem effective and take so much space. Maybe something like this? http://www.gravitybattery.info/ http://www.gravitybattery.info/