Both BP (BP -2.04%) and ExxonMobil (XOM -1.26%) have released their outlooks that predict what the future holds for energy over the next 30 years. Each of them holds a premier status as one of the world's largest integrated energy companies. That means that when their management teams publish their thoughts on how they view the energy landscape in the coming decades, it's a good idea to listen closely.

BP and ExxonMobil have some particularly interesting things to say about the state of renewable sources of energy. While it's obvious to assume members of Big Oil, including BP, ExxonMobil, and also Chevron (CVX -1.21%) will lean heavily on oil, the future also has some big things in store for renewable forms of energy as well.

Interestingly, BP and ExxonMobil each agree that energy demand is only set to rise going forward, due to population growth and rising standards of living, especially in the emerging markets. In response, they're both pursuing energy savings initiatives that should boost productivity by reducing emissions and costs. However, they're taking different approaches to the subject of renewable energy.

BP is pulling back on its renewables investments, and as a result, is at risk of falling behind its Big Oil brethren. Here's where each company stands when it comes to renewables.

BP has some commitment issues
BP and ExxonMobil both acknowledge that the future is likely to see energy demand increase significantly. BP expects global energy demand to rise 41% between now and 2035, while ExxonMobil states global energy demand should rise 35% by 2040.

Fortunately, BP plans to get in front of this with a series of energy-saving initiatives. In recent years, it's redesigned its chemicals plants to cut down on waste, while simultaneously increasing production. In addition, BP has targeted efficiency opportunities in its refining business. For example, it's developing new technologies in China to produce oil from hydrocarbon sources other than oil.

ExxonMobil and Chevron have done the same. ExxonMobil expects the use of renewables will increase by 150% by 2040, led by wind and hydroelectric power. And, since 2000, ExxonMobil's Global Energy Management System has allowed the company to pinpoint and effectively act on several energy-saving initiatives specifically in its downstream and chemicals businesses.

However, BP is also effectively ending its renewables investments for the foreseeable future. After plowing more than $8 billion into renewable sources since 2005, the company announced it won't set another target for future spending. Essentially, BP believes its massive investments are now self-sustaining, and will take a wait-and-see approach before devoting additional resources to renewables.

Chevron investing in geothermal
One area not looked into by BP and ExxonMobil is geothermal energy, where Chevron is taking a leadership position. It launched a subsidiary known as Chevron Energy Solutions Co. to pilot the company's efforts toward reducing emissions, and has been extremely effective in upgrading facilities and incorporating renewables into the broader business.

For example, in recent years Chevron has supplemented its growth in Indonesia and the Philippines with geothermal energy. Chevron now prides itself on being one of the world's leading geothermal producers, and currently supplies 890 megawatts of electricity capacity in Indonesia and the Philippines, which is enough to serve millions of customers.

The Foolish conclusion
Big Oil's renewables programs aren't likely to pay big rewards in the short run. However, the integrated majors fully acknowledge the need for making these investments now. As global populations soar and energy demand ramps up in emerging economies, oil alone isn't going to do the job. It's going to take a much more diversified approach, and each of them are building out their portfolios to include renewables across the globe. In addition, they're pursuing energy efficiency initiatives to reduce emissions and costs.

BP seems to be taking a much more cautious approach to its renewables investments, however, which may put the company at risk of falling behind. It's done a lot to create efficiency improvements that will help boost profitability. Still, ExxonMobil and Chevron seem to be leading Big Oil in investing in renewables for the future.