My best investment return ever
The highest investment return I have ever achieved was not on a stock, bond or business investment.
It was to replace my home thermostat.
My home was built in 1977. Almost exactly 30 years later, in March 2007, I updated to a modern programmable digital thermostat, which cost $40 plus a half hour of installation time, using only a screwdriver.
In the first 8 weeks, our gas use fell by more than half compared to last year, despite colder weather this year. The savings are at least $150. Summer air conditioning results remain to be measured, but the implication is we will save between $500 and $1500 in the first year, on a $40 investment.
This can happen because programmable thermostats are flexible. By day, you want the temperature at 67 degrees, but at night, no one cares if it falls to 62. That 5-degree change causes a nonlinear reduction in energy use — depending on outside temperature, it can be the difference between running the heater 10% of the time or 100% of the time at night.
Whether you value energy conservation or frugality, this is an astonishing result. The implication is that, if you have an old house, you can save more energy with a $40 thermostat upgrade than by buying a $20,000 Toyota Prius.