The parable of the frog and boiling water is hundreds of years old. It has been used throughout history as a metaphor for circumstances in life when people are unable to see gradual change around them.
Pool Pump, Tracking Array - Gallery
Leeson 3/4 HP DC motor, ETA Adapter, 1.5 HP pool pump that circulates 26,000 gallons per day in a 14 ft. by 28 ft. pool. Located at Lane & Ursula Garretts' home in Scottsdale, AZ. The PV Powered pool pumping system has paid for itself more than 3 times over, since installed in 1980.
660 Watts of PV power that runs the pool pump shown in the previous picture. ZomeWorks Tracker with 6 AstroPower modules. Considerably less expensive now, systems of this type, are giving 20% or more tax-free return on the installed cost.