In the case of drinking water, desalination is already cheap enough that we're talking pennies a day. Even a typical American usage of 100 gal/day is around $0

In the case of drinking water, desalination is already cheap enough that we're talking pennies a day. Even a typical American usage of 100 gal/day is around $0.15 at market energy rates [1] and is still under $0.50/day with solar. [1] http://www.window.state.tx.us/specialrpt/water/gamechangers/desalination.php http://www.window.state.tx.us/specialrpt/water/gamechangers/... gives $489 per acre-foot.