(FORTUNE Magazine) – Here's a novel advertising strategy--pitch your least important product and ignore your most important one. That's what British Petroleum is doing in a U.S. billboard campaign emphasizing the company's investments in renewables. One ad reads SOLAR, NATURAL GAS, WIND, HYDROGEN. AND OH YES, OIL. Another: WE BELIEVE IN ALTERNATIVE ENERGY. LIKE SOLAR AND CAPPUCCINO. The billboards, and seven others like them, all note it's a start and carry the tag line beyond petroleum.

Well, please: If the world's second-largest oil company is beyond petroleum, FORTUNE is beyond words.

In the past six years BP has invested more than $200 million in solar power, building an 18% market share. That sounds impressive. By comparison, though, it invested $8.5 billion in exploration and production of fossil fuels in 2001 alone. If BP put its advertising mouth where its money was, its ads would be featuring oil rigs in the Gulf of Mexico, where it will invest $15 billion over the next ten years.

BP does have a portfolio of green energy, and on another billboard, as well as in TV ads, it touts its goal of making solar power a billion-dollar business by 2007 (up from $240 million last year). But considering that BP is already a $174 billion company, $1 billion is mere lunch money. All told, BP generates enough wind and solar power (77 megawatts) to keep Boise lit for a year. And oh, yes, BP also produced 3.4 billion barrels of oil equivalent (a figure that combines oil and natural gas) in 2001. Exactly how much is that? Enough to satisfy all of America's oil needs for six months.

In short, renewables make up a trivial portion of what BP does. Does that make BP evil? No. It makes it--gasp!--an oil company. And a good one: BP is widely respected as an employer, investor, and corporate citizen. It lowered the sulfur content in its oil before it was forced to do so and does good-guy things such as sponsoring the reintroduction of bald eagles to New York City. Still, an ad campaign that manages to mention solar energy five times and the O-word only once, and in a backhanded manner, just begs for skepticism.

BP's regional president, Bob Malone, says the billboards are meant to address environmental concerns of the U.S. public and to demonstrate that the company is thinking creatively about the future of energy. "The oil business has a negative reputation," he says. "We are trying to say that there are different kinds of oil companies." As for being "beyond petroleum," the company's slogan since mid-2000, Malone concedes that BP is decades away.

Somehow that didn't make the billboard.