Last fall, I wrote about Wal-Mart's (NYSE:WMT) bright idea to launch a massive in-store campaign to educate customers about the benefits of replacing older incandescent light bulbs with their newer, more energy-efficient counterparts commonly known as compact fluorescent lights (CFLs). At the time, I noted that while the CFLs cost six times as much as regular incandescent bulbs, they were estimated to pay for themselves in as little as five months because they use just 25% of the energy that an ordinary bulb gobbles up.

I was impressed enough with this economic argument to immediately replace all of the bulbs in my home with General Electric's (NYSE:GE) "Spiral" CFL. In total, I spent a few weekend hours replacing about 30 bulbs.

I did all of this back in September, so I have now presumably recovered more than my initial upfront cost. These 30 bulbs are now putting me in the black to the tune of $150 a year. This modest act got me to researching how else being green could put me even further into the black.

Easy money, little sacrifice
Perhaps not surprisingly, there are a number of other simple actions that you and I can do to help protect both the environment and our pocketbooks. For instance, turning down the home thermostat by a measly 1 degree will save the average person about $45 a year. Lowering the thermostat on the water heater to 120 degrees will save an additional $24. Easy money for little sacrifice.

If you seal and insulate your home ducts, the average savings has been estimated to be $310 a year. If you drive a lot, reducing your average speed from 75 mph to 65 mph on the freeway will save you another $123.

The total of these modest actions amounts to $652. It's not a huge amount of money, but neither is it trivial. Here, then, is my Foolish idea.

The Environmental Reinvestment Plan
Why not reinvest these savings to do some further good for the environment and your own economic well-being? For example, the savings could be used to replace an older air conditioner or refrigerator with a newer, more energy-efficient model. Or you could squirrel away the savings for a few years and then put a nice down payment on a more energy-efficient automobile, such as a Ford (NYSE:F) Escape Hybrid or a Toyota (NYSE:TM) Prius. If the upgrade increases your fuel efficiency by just 15 miles per gallon, the switch would save the average driver $400 annually.

If none of these options interests you, there is always the possibility of investing in a solar-power company, such as Motley Fool Rule Breakers recommendation Suntech Power (NYSE:STP), or in a company like Zoltek (NASDAQ:ZOLT), which will benefit from the expansion of wind power. Alternatively, the money could be directed toward a mutual fund or ETF that focuses on investing in clean-tech companies, such as PowerShares WilderHill Clean Energy Fund (AMEX:PBW).

Being green is not only the right thing to do for the environment; it's also the smart thing to do for your own financial well-being.

Interested in reading more about clean-tech power? Check out these articles:

PowerShares WilderHill Clean Energy and Suntech Power are recommendations of Motley Fool Rule Breakers, where we keep an eye on the market's most impressive innovators. Interested? Try out the service free for 30 days.

Wal-Mart is a Motley Fool Inside Value pick.

Fool contributor Jack Uldrich also recommends placing a plastic bottle filled with water in your toilet tank, to reduce the amount of water you use when you flush -- otherwise, you are literally flushing money down the toilet. He owns stock in GE and Suntech Power. The Fool has a strict disclosure policy.

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.