Have you ever tried to argue a point that your counterpart simply doesn't understand?

This is how I often feel when arguing the bullish case for renewable energy. Though I must admit, it's getting easier.

For all the times my take on renewable energy has been met with responses like, "It will never work. . . renewable energy won't make a dent in supply," I simply think to myself, "How can it never work if it's already working?"

If renewables can't make a dent, why are they being installed faster than any other energy technology, producing more energy now in the U.S. than even nuclear?

And why have billionaires like Bill Gates and Warren Buffett already invested willfully in clean technologies. . . and gone on to profit handsomely? Quite frankly, if you haven't yet invested in renewable energy or at least come to the realization that it's worth pursuing, if only for the profits. . . you take your place among those to which I once referred as silly readers.

And I'll spend no further time trying to convince you.

But for those interested in making some of the easiest money around, I've got to tell you. . .

Renewable Energy is Booming

For starters, renewable energy captured more venture capital in the third quarter than both the biotech or software industries. This is the first time that's ever happened.

So the smart early money has already developed a healthy appetite for this sector. Venture capitalists poured $1.2 billion into cleantech last quarter, with the bulk of the money going to solar, biofuels, and smart grid technologies.

And the momentum doesn't stop there, it continues on down the chain. . . to public markets to steel in the ground. Every cleantech sector is reporting stellar growth.

The U.S. Geothermal Energy Association reported this month that their namesake sector has installed capacity of more than 3 GW. That will double in the next few years to more than 7.1 GW as new projects come online in California and Nevada.

And global solar capacity will do even better. With about 19.5 gigs already installed, capacity is slated to surge 1,037% in the next decade to well over 220 GW. . . led by the United States and China.

Solar stocks could see gains of equal percentage. Some — like the two I talked about last week — have surged more than 200% already this year. . . during a recession. . . and with every naysayer with a keyboard writing about a solar glut!

And the less-talked-about smart grid will be an $8 billion per year market, starting this year. Stocks in that sector have doubled this year, too.