As an energy analyst/investor, I like to keep an eye on what the big picture is telling me about the future of energy investments. Spotting trends early can be the difference between making a winning investment and investing in a dying energy source.

We know that political and environmental observers would like to see the U.S. transition to "cleaner" fuel, but is it happening? Are we really giving up coal for natural gas, and what's with this renewable-energy talk?

To give us an idea where trends are headed, I have provided some interesting statistics from the Energy Information Agency (EIA), which publishes monthly data that can give us a great idea about where our energy is coming from and where the trends are headed.

These stats are for January to August 2011 compared with the same time frame in 2010.

  • Total U.S. energy consumption was up 0.3%.
  • Coal usage was down 2.8% and power generation usage of coal was down 3%.
  • Natural-gas usage was up 2%, with power generation usage up 2.5%.
  • Nuclear-power generation was down 2.7%.
  • Renewable-energy usage was up 14%.

The numbers seem to suggest that we are indeed transitioning our electrical generation away from coal and toward natural gas and renewable energy. So how do we invest with this information?

Money blowing in the breeze
Although solar power gets most of the headlines, mostly because of Solyndra and other government-backed failures, wind was the driver of renewable energy's growth this year. Solar power accounted for just 78 trillion Btus of energy in the first 8 months of 2011, while wind accounted for 773 trillion Btus of energy. That's more than biofuels and is quickly gaining on hydroelectric power as the No. 1 source of renewable energy.

On the flip side, coal was the biggest loser, but that doesn't mean Arch Coal (NYSE: ACI) or Patriot Coal (NYSE: PCX) are going belly-up any time soon. A slow transition away from coal in the U.S. is being countered by growing demand for coal in emerging markets like China. Since we have an abundance of coal here, that means major exports going forward. That'll soften the blow for miners and help railroads such as Union Pacific (NYSE: UNP), which transports coal.

Natural gas will probably continue its growth as a fuel source in the United States. Increasing supply from explorers such as Range Resources (NYSE: RRC) and Quicksilver Resources (NYSE: KWK) will continue to drive down the cost, and since natural gas burns cleaner than coal, it's a more desirable source of fuel. In the near term, natural gas is the biggest winner as a fuel for our electricity needs.

But don't miss out on the biggest shift happening in our energy infrastructure. Renewable energy, particularly wind and solar, will continue to make up a larger and larger portions of our energy picture as costs fall. Solar-module costs have fallen more than 20% since the beginning of the year, and with manufacturers such as SunPower (Nasdaq: SPWR) and First Solar (Nasdaq: FSLR) building massive power generation plants in the country's deserts, more of our energy will come from solar.

Take your pick
Do you want to invest in slowly dying energy sources such as nuclear power or even coal, or do you want to invest with natural gas or the fast-growing solar industry? I've made my pick and put my money down on solar.

What energy source are you investing in? Leave your thoughts in the comments section below.

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.