It's easy to see the appeal of this business: In general, the payback period for saving electricity is much quicker than for investing in alternative energy generation. Typically, the costs associated with reducing electricity usage are recovered within three to four years; whereas the payback period for a solar or wind plant is more typically seven to eight years.

JCI's battery division also has a green sheen. Its new lithium ion batteries (developed in conjunction with partner Saft) should become a key supplier to the nascent electric and hybrid vehicle markets.

Of course, the company still makes money on legacy products. For example, JCI's traditional car battery business controls roughly one-third of the market for after-market batteries. That's a nice recurring business, as a typical car will go through at least three to four batteries in its lifetime. Johnson also makes a range of other auto interior products such as seats, door panels and electronics.

But the most important thing to know about Johnson Controls can't be found among its customers or its products. Instead, it is the company's cost structure, which has shed so much weight in recent years that the company is considered to be the leanest in its field. During the past two years, the company has closed 31 plants, pared its workforce by about -12% and can still make a profit, even if the economy slumps again.

Analysts think JCI can generate roughly $34 billion in sales this year, up a solid +19% from last year, but still about $4 billion below fiscal (September) 2008 levels. Once the economy gets back on its feet and sales move back toward the $40 billion mark, those cots cuts should yield record profits.

Action to Take --> Johnson Controls has typically traded for between seven and 20 times forward earnings. Right now, the forward multiple is much closer to the low end of that range. Assuming shares trade up to the mid-point of that range, or 13 times projected earnings, and if the fiscal 2011 EPS forecast of $2.42 is to be believed, then shares should rise back up to the upper $30s. That's +50% above current levels. When sales claw back to the $40 billion mark, perhaps in fiscal 2012, per share profits should exceed $3. Not bad for a $26 stock.