The exhibition floor seems virtually endless

The exhibition floor seems virtually endless. With 600 vendors and almost 18,000 visitors, the size of the solar power trade show in Las Vegas gives you an idea of just how big the American solar industry is becoming.

In 2015 it was worth almost $23 billion US. And according to the Solar Energy Industries Association, it's expected to double in 2016.

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One of the trends driving that growth has been the falling cost of solar energy. The price of installing solar has dropped by more than 70 per cent over the last 10 years. And according to Hugh Bromley, who analyzes the industry for Bloomberg New Energy Finance, it's expected to fall even further.

"The technology's evolutionary, not revolutionary, but the costs are being pushed down year on year," Bromley says. "And in fact, you see oversupply in the amount of solar equipment produced, which means you can source equipment quite cheaply."

A solution for high cost of installation

The cost that still remains relatively high is for installing solar panels on rooftops. But thanks to new technology - from placemat-thin solar panels to innovative engineering - installation is getting cheaper, too.

Neil Goldberg, CEO of Smash Solar, lifts a solar panel at his booth and reveals the rivets underneath. "We've developed a system where you just take a module, you put it on the roof ... no structure to build, you just bolt it down."

Goldberg's system has done away with a costly metal framework. "This is attached with the same glue that hangs glass off the sides of skyscrapers, so it's never coming off," Goldberg says.

A second major trend builds on interest in finding ways to recharge electric cars without using fossil fuels.

In the trade show parking lot, Michael Kung of King Solarman demonstrates a solar panel on wheels that's hooked up to a Tesla automobile.

Solar charging in the employee lot

He crawls under the panel and points at a battery underneath. "Sun is pretty bright right now. We're charging and storing the power in the battery. And from the battery, we have power from the inverter that charges the car."

He says you can spot these solar stations charging cars in parking lots at companies like Google, Apple, Tesla and UPS.

"You come to the office, your electrical vehicle is maybe one-third or half empty," Kung says. "So you just park in the parking lot, in afternoon or lunchtime, your car is fully charged." He pauses, lifts his hands towards the sky. "Is free!"

The third major trend doesn't directly involve solar panels.

"A lot of the exciting developments happening at the moment are around the software side," Bromley says. "How do you integrate solar and storage systems into your environment? What app do you have that shows you how much solar energy you're producing, how much is that saving you?"

Apps track the solar advantage

Coming soon: Apps that tell you when you can make the most money selling power back to the grid.

Andrew Krulewitz has spent hours extolling the virtues of Geli software to interested passersby.

"It lets homeowners take greater control of their energy," Krulewitz says in his polished pitch. "They can see what they're using, where it's coming from, whether it's coming from the grid, solar, battery, and they can decide what to do with it."

But it's the software that his company is developing that shows where the industry is heading.

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"What our software will allow for, is when the grid operator - the utility - says, 'We could really use support from all these residential solar systems,' the homeowner will get an alert on their phone saying, 'Do you want to participate in this grid service, yes or no?'" Krulewitz says. "And if they say 'yes,' the utility is now starting to compensate homeowners for excess energy that they sell at a very specific point in time."

This year marked the installation of the millionth solar system in the U.S. That took 40 years from the inception of a solar industry. Installing the next million is expected to take just two.