The United States has gone from a non-factor in oil and gas production 15 years ago to a world leader in crude oil refining and the largest producer of oil and natural gas. That in itself is revolutionary as the U.S.’ position will only continue to grow and create new opportunities.

But we want to dig deeper to find the real money-making opportunities. Oil may not be next gen, but how we get it is.

Miners realized there was still oil left in the depths of their wells, and wanted a better way to get every last drop out of them. Hydraulic fracturing – or fracking – was then developed as a method of injecting a high-pressure sand mixture into shale rock and causing the oil to flow out to the top of the well.

Fracking became popular a few years ago and it made a lot of people a lot of money along the way. It then fell off with the drop in oil prices, but I’m here to tell you that it’s back – and in a big way. Not just because our administration is pouring money into this field, but because the way we’re getting oil out of the ground continues to improve.

Take a look at the graph below:

As you can see, fracking has become so popular that it has overtaken conventional means of oil production. If you’re the old Wall Street, you probably just look at the stodgy old drillers, refiners and producers. I’m taking a different approach. For my money, I’m going with the company that supplies the sand used in fracking. Think back to the gold rush – you don’t want to pay the miners themselves, but the pick and axe suppliers that make it all happen!

As more U.S. oil and natural gas producers build new rigs, demand for sand only continues to grow and Hi-Crush Partners (HCLP) is there to fill the need. As the second-largest sand company in the United States, this stock is one of my favorite ways to play the energy revolution. I’m also a fan of U.S. Silica Holdings (SLCA), which produces whole grain commercial silica products used as fracturing sand. This is another industry-leading company that is aiming to turn rising sand volumes into profits.

There’s another element to fracking that leads right into another of my next-gen energy niches. The sand compound used in fracking requires water, and while that may not sound like a big deal, the fact is that water is quickly becoming a scarce commodity.

The world’s water usage has long been a source of concern. For decades, people have been using fresh water faster than nature can replace it. This has contributed to hunger, disease, conflict and migration in some regions. It’s scary to think about, but two-thirds of humanity currently live in zones that experience water scarcity at least one month a year. Last year, the World Economic Forum’s annual survey of opinion leaders identified water crises as the top global risk over the next decade, so this is clearly a serious problem that will need to be addressed in the coming years.

As more attention is brought to water scarcity and its value to new energy developments, innovative investment opportunities are rising to the surface. One company I like is Xylem (XYL), a manufacturer of water and wastewater solutions that works with natural gas and utility companies. The stock has been a favorite of mine since President Trump was elected and as the infrastructure spending deal comes closer to fruition, the stock should continue to benefit.

Both of these niche themes are ones I’ll be keeping a close eye on as the technology for new energy continues to develop. In my next article, I’ll shift from how energy is harnessed to how it’s being made better for the environment. Stay tuned!