Apple sure has come a long way since the Mac Classic. Last summer Apple surpassed oil giant Exxon in becoming the largest company in the world.

As they say, with great power comes great responsibility. Luckily, Apple wants that power to be solar. 

At least, that's the case when it comes to its facility in North Carolina, where the tech king announced earlier this week an ambitious plan to build the largest on-site "end-user-owned" solar-energy system in the country for its massive data center in the city of Maiden. The project would span 100 acres, clocking in at 20 megawatts, or 42 million kilowatt-hours annually.

Most big projects like these generate energy that's sold to utilities. But this would be an enormous localized closed system, generated and used by the same entity.

The icing on the cake is Apple's five-megawatt fuel cell farm that will use gasses captured from biomass. This is scheduled to open later this year next to the data center. As a result of all this, the U.S. Green Building Council has certified the facility LEED Platinum, its top award -- something unheard of for a data center of this magnitude.

"We know of no other data center of comparable size that has achieved this level of LEED certification," Apple said in its report.

In the tech world, data centers, the backbones of online support and data, are notoriously energy-hungry buildings that take up a lot of land. Their energy use dwarfs office buildings of the same size. Estimates say data centers account for about 2 percent of the country's total electricity use. Big players like Apple, Google, and Microsoft all have campaigns to increase the efficiency of these giant, but necessary, facilities.

It's nice that Apple is taking such vast steps in this realm. But a quick glance at the company as an emitter of carbon suggests that there are other areas that can also use improving. The company believes it was responsible for more than 23 million metric tons of greenhouse gas emissions in 2011. That's a lot of tons! Sixty-one percent of that comes from manufacturing while Apple facilities only account for 2 percent.

However, "though our revenue has grown, our greenhouse gas emissions per dollar of revenue have decreased by 15.4 percent since 2008," the company states.

Read more about Apple's plan for its North Carolina data center here.

-- Brian Foley/ image: apple.com