I agree with you on all you've said. I guess the power used in charging up big batteries still accounts for same as the one used in running the device. It only saves you energy in that the sun/electric supply is not always there-you can save for use later. I always say it is better to conserve energy than to produce it. In my country, only those that use electricity on prepaid meters tend to conserve it. People on postpaid where a fixed amount of bill comes per month tend to leave their light bulbs on during the day. This is something those on prepaid are very much aware of. In terms of water, we often use water from boreholes, the public pipe-borne water system is something you see being used carelessly, it's not hard to see running faucets and waste of such water. These are things we should put into consideration to reduce the energy dissipated in making the utility work.