The corporate world is not known for its cleanliness. But amid the dirty dealings of megacorporations, these three businesses are managing to rely 100% on renewable energy. Here's how Intel (INTC -1.79%), Green Mountain Coffee Roasters (GMCR.DL), and Nokia (NOK 3.60%) are the cleanest companies around.

1. Intel

Source: Intel. Solar panels at Arizona Intel campus.

Not only does Intel source 100% of its electricity use from renewable sources; it also uses more clean energy in absolute terms than any other company. With an annual usage of 3,100,850,000 kWh, Intel is the undisputed leader in renewable energy use.

Intel purchases some of its power from a third-party renewable-energy credit provider, but it also buys clean electricity straight from utilities, and even produces some of its own. Its cocktail of clean power includes biogas, biomass, small-scale hydro, solar, and wind. 

Producing computer chips takes a lot of power, and Intel's commitment to 100% renewable energy is so large-scale that it could affect the entire renewables industry. "Intel's renewable energy efforts are meant to spur the market and make renewables cheaper and more accessible, in turn helping to reduce the overall carbon emissions from electric generation," said Brian Krzanich, senior vice president and general manager of Manufacturing and Supply Chain for Intel. "Intel's REC [renewable energy credit] purchases, support for solar installations and other clean energy investments will continue to be priorities for us as we search for effective sustainability opportunities around the globe."

2. Green Mountain Coffee Roasters

Source: Green Mountain Coffee Roasters, Inc .

Green isn't just the first word in this company's name -- it's a selling point for each cup of Green Mountain Coffee Roasters' delicious brew.

The company's solar and wind investments more than offset the company's energy use -- Green Mountain currently purchases or produces enough renewable energy to account for 120% of its annual 46,013,376 kWh consumption.

Over the next two years, the coffee roaster is getting increasingly serious about its efficiency. Green Mountain is installing sub-meters and other monitoring devices to find energy savings "sweet spots" across its supply chain. The company has created its own energy cost-per-sales metric, which dropped 17% from fiscal 2011 to fiscal 2012.

3. Nokia
Nokia defies normal telecom statistics by using a whopping 53,284,535 kWh of renewable energy annually. The company created its first climate strategy in 2006 and has been increasingly focused on energy efficiency in the years since. Between 2000 and 2010, Nokia halved the greenhouse gas footprint of its phones and hopes to reduce it by an additional 15% by 2015.

In 2012, the company generated 2,500,000 kWh of renewable energy onsite, from fuel cells in California to biogas in Chennai.

And it's not electricity alone where Nokia goes green. The company has implemented a variety of environmental initiatives at its facilities around the globe.

While telecom companies like Nokia have a lot to gain from consuming clean energy themselves, their products have the potential to create a much more environmentally efficient world. With 1.3 billion Nokia users around the globe, Nokia users cut their own energy consumption by picking up their phones instead of piling into cars or onto planes.

Go green to make green?
Relying on renewables for 100% of energy use may seem like an expensive habit. But for Intel, Green Mountain Coffee Roasters, and Nokia, it's the new normal. These companies market themselves on their environmental initiatives, and efficiency programs continue to help each corporation hang on to more of its cash. These companies are leaders -- and their complete commitment should continue to pay off in the years to come.