Amazon (NASDAQ:AMZN) and Apple (NASDAQ:AAPL) lead the list of U.S. commercial solar installation, according to “Solar Means Business,” a newly released report by the Solar Energy Industries Association (SEIA).

Apple tops the list, with 393 megawatts (MW) installed in the last three years, and Amazon comes in second, with 330 MW installed. Target (NYSE:TGT), Walmart (NYSE:WMT) and Alphabet (NASDAQ:GOOG, NASDAQ:GOOGL) are also in the top 10.

Moreover, according to the study, 2018 ranks as the second-largest year for commercial solar installations, with 1,144 MW installed. And the biggest news SEIA shared is that “more than half of all corporate solar capacity has been installed in the last three years.”

Clearly, the solar industry is gaining momentum. And that momentum is building at the exact same moment that global demand for solar power is about to go parabolic.

I’ve been studying and investing in the solar market for several years now. And as far as I see it, two catalysts are fueling the solar boom.

First, I’ll show you these three profit triggers — and then I’ll show you how to profit from them.

Solar Profit Trigger No. 1: Falling Costs, Rising Efficiency

The cost of solar-power installations has been plummeting — in both the residential and utility-scale markets. In many parts of the world, solar power is still more expensive than conventional power-generation technologies, but the gap is closing very rapidly.

According to the SEIA report, U.S. solar costs have fallen by 65% over the last decade. In 2009, on average, installing a solar panel cost $8.50 per watt. Now its costs just a little less than $3.

Meanwhile, solar-panel efficiency has skyrocketed over the past decade or so.

In 1954, when Bell Labs invented the first useful silicon solar panel, they were about 6% efficient. We didn’t achieve 20% efficiency until the mid-2010s, less than five years ago. Today, manufacturers are making panels with 30% efficiency.

And they’ve reached 45% efficiency in the lab.

Solar Profit Trigger No. 2: The Big Boys Step In

Further, the true cost comparison between solar power and other technologies involves more than just dollars and cents. Clearly, the toxic emissions that spew from coal-fired plants impose a cost on the planet that solar panels do not.

That’s why India and China — the two most populous, and two of the most polluted, countries on the planet — are ramping up their solar-power capacity.

Both of these countries have devoted themselves to solar power, like teenagers to tattoos, and both countries have laid out ambitious plans to expand their solar footprints.

Of course, sinking costs, rising efficiency and the burgeoning demand for solar power from China and India are not the only reasons to expect global demand to soar over the next several years…

Solar Profit Trigger No. 3: The X Factor

A powerful new “X factor” has entered the solar energy market — and it has the potential to supercharge demand.

That X factor is energy storage (aka batteries).

Until recently, solar-power installations lacked the ability to store energy. They were simply use-it-or-lose-it power generators. Energy storage technologies were too expensive to be viable additions to solar-power facilities.

But this old story is changing rapidly. Energy storage has arrived – and its arrival could be a very big deal for the solar industry.

In the “olden days” of 2015, a company like Target would contract with a solar company to install solar panels on the roofs of its superstores. Once installed, the panels would deliver daytime electricity to supplement the electricity Target pulled from the regional power grid.

But now, when Target installs new rooftop panels, it often also installs a battery system to store the excess energy it doesn’t use immediately.

In 2017, Target kicked off its solar-storage project at its store in Kailua-Kona, on the big island of Hawaii’s east coast. There it installed a 910-kilowatt solar system from SunPower (NASDAQ:SPWR) that included a 250-kilowatt energy storage component.

This may have been the first time a Target store had added energy storage to solar — but it won’t be the last.

By the end of this year, Target expects to install rooftop solar systems on more than 500 store locations. And by 2030, the company plans to meet 100% of its energy needs from renewable sources.

Utilities are also embracing energy storage. Increasingly, they are opting to add new generating capacity by building energy-plus-storage facilities, rather than gas- or coal-fired power plants.

Last year, for example, the Arizona Public Service committed to deploying 850 megawatts (MW) of energy storage over the next six years. Along the same lines, NextEra Energy Inc. (NYSE:NEE) announced plans to deploy a 409 MW solar-plus-storage solution at Florida Power & Light Co., replacing two gas-fired power plants.

Looking globally, the deployment of battery-based energy storage solutions (BESS) is ramping up quickly. According to JPMorgan, the cumulative installed base of BESS will soar 100-fold between now and 2030.

The bottom line: Solar is big – and getting bigger.

A $4 Trillion Opportunity

At the end of 2018, the world’s installed capacity of solar-power generation totaled nearly half a billion megawatts — accounting for more than 7% of the globe’s power capacity.

But new capacity installations are on track to soar 25% this year, according to Bloomberg New Energy Finance, and to nearly double by 2021.

Many forecasts anticipate an equally spectacular growth trajectory. According to the International Energy Agency’s (IEA) “Sustainable Development Scenario,” solar-power capacity will soar fivefold between now and 2025, accounting for a whopping 38% of global power generation.

Looking further out, the IEA anticipates a 13-fold increase in solar-power capacity by 2040, at which point this renewable source would be providing two-thirds of the world’s power needs.

The IEA anticipates global spending on solar power to total $4 trillion over the next two decades — or about $180 billion per year.

If investment of this magnitude were to occur, solar power would become the world’s primary electricity source by 2040.

But you don’t have to wait 20 years to profit on this trend.

There are a lot of companies out there that are jumping on the solar bandwagon, and there is clearly a lot of investing potential here.

But it’s all about finding the right companies that offer significant long-term potential.

That’s why I’ve just released a special “all solar” edition of my brand-new newsletter – Fry’s Investment Report.

In it, I share two recommendations to get investors in on this technology’s profit ground floor.

To learn more, I strongly suggest you go here to find out how to join Fry’s Investment Report.

Eric Fry is thhttps://orders.investorplace.com/chain?cid=MKT410381&eid=MKT419624&encryptedSnaid=&snaid=&step=starte resident expert on global investment trends at InvestorPlace. And he and his members have been experiencing much success when it comes to solar over the past year or so. In late October 2018, Eric recommended buying some call options on a solar-focused exchange-traded fund. By late January, that ETF had soared more than 30%. (Over the same time frame, the S&P 500 Index advanced just 3%.) The way Eric played it, readers who followed his advice ended up making 203% on their entire position – in just a smidgeon over three months. And in early October 2018, Eric suggested they get in on a certain solar stock’s call options. Since then, the stock has skyrocketed more than 75%. They’ve closed out the first third of that option trade for 168% gains… and the second third for gains of 282%. And they’re still sitting on 200%+ gains with the final third of that trade. To learn how to join them, go here.