Last week, French oil and gas giant Total spent an attention-grabbing $1.4 billion for a majority stake in U.S. solar company SunPower. Your inner conspiracy theorist may immediately consider the move as part of some oil industry plot to buy up alternative energy companies and then crush them. But the real reason behind Total’s purchase is that it cares deeply about the environment. Just kidding. It’s because the company thinks solar is going to make lots of money.

Like BP, Chevron, and almost every other oil company, Total is coming around to the idea that investing heavily in clean energy technology is a smart business and marketing move. Total has long been a leader in this sector; the company first got involved in solar energy in 1983, before it was cool. It’s not as if the oil industry is hard up for cash, but it is realizing that having control over all of our energy supply puts it in a much more powerful position than just having control over our declining oil supply. Chevron says as much on its website:

With forecasters predicting that the world’s energy demand could

increase as much as 50 percent in the next 30 years, the world will need

all the energy that can be produced from every potential source. To meet that kind of demand, the world will need to produce every

molecule of energy, from every available source. And while oil, natural

gas and coal are expected to provide over 80 percent of the world’s

energy for the near future, next-generation renewables, such as

biofuels, solar and wind power may play a key role in meeting the

world’s energy needs.

Even taking into account the other renewable energy deals that oil companies have recently been involved in–BrightSource Energy has taken cash from BP and Chevron, for example–the Total investment is a huge one. SunPower and Total hope to become one of the world’s top three solar energy companies over the next decade, according to the Wall Street Journal.

Naturally, other solar companies are beyond excited to have the oil industry’s piles of cash behind their products. “Total’s acquisition of a majority stake in SunPower is a significant endorsement for the solar

PV industry and demonstrates the growing importance of this industry

within the broader energy sector,” said Russ Kanjorski, vice president

of marketing at Abound Solar, in an emailed statement. “With leading multinationals, such as Total and General Electric, making major investments in solar PV manufacturing, the future looks very bright for the industry as a whole.”

This isn’t to say that everyone who owns a renewable energy company should start gearing up to pitch to the BPs and Exxons of the world–Shell is whittling down its biofuel portfolio as it realizes what will and won’t make money–but oil companies are clearly willing to spend big bucks to maintain their energy dominance. As long as companies like Total use their clean powers for good, we won’t complain (about that part of their business, at least).

For the people who just can’t get behind a gas company making an above-board investment in a renewable energy company, don’t forget this moment from electric car history, when Chevron buys an innovative battery company to destroy it: