After Solar Impulse flight, solar power is getting its day in the sun

By helping to propel an airplane around the world recently, solar power took what some would consider a quantum leap into the future — one that includes less use of fossil fuels.

The flight of Solar Impulse 2, which this week completed a 25,000 mile journey across Europe, Asia and North America, captured the public's imagination and raised a tantalizing question that has long been the source of mere speculation. If the sun can play a role in aerial circumnavigation, can it live up to its billing as a large-scale energy source?

The answer, according to some, appears to be yes.

After years riddled with false starts and high-profile failures, it appears the sun is indeed beginning to shine on solar power, as even oil and other fossil fuel intensive companies ratchet up their investment in sustainable energy. A recent study by Columbia University's Center on Global Energy Policy said worldwide government spending on clean energy topped $10 billion per year as of 2015.

Numerous plans are already underway to bolster the power and reach of sustainable energy — the largest being China's $50 trillion plan to create a global electricity network that will curb carbon emissions.

The idea of a global energy grid — long considered a holy grail of sorts by conservationists — has been bandied about for years. In fact, a number of alternative energy initiatives are underway, given new impetus by last year's global climate accord as well as trends that favor the use of renewables. At last year's climate accord in Paris, 20 countries pledged to double their investment in clean energy within five years.

In the current environment, "it's less about making additional technological breakthroughs, but about taking what's out there and pairing it up" with existing initiatives, Ulrich Spiesshofer, president and CEO of ABB told CNBC in a recent interview. ABB's solar division was one of the companies that contributed to Solar Impulse 2's flight around the world.

Moves to improve solar efficiency — including concentrated solar power, a method that allows sun rays to be stored for use even at night — have the potential to produce "a paradigm shift," Spiesshofer said.

The former management consultant added that it was possible to "decouple growth" from activities that frequently create a Hobson's choice between economic feasibility and safeguarding the environment.

"Renewable power generation is becoming very much attractive economically and is effective," Spiesshofer told CNBC. "The combination of solar with hydro power and [increased storage capacity] is really starting to change the world," he said.

According to industry watchers, several macro trends are heightening expectations for solar power. One in particular has been the growing use by public utilities, which were incentivized by recent regulatory changes to use cleaner energy to generate electricity.

Last year, utility grid operators comprised the largest source of new U.S. solar capacity, according to information from the Solar Electric Power Association.

Vincent De Vito, a partner at Bowditch & Dewey and a former Energy Department official, said that "there is an uptick in solar projects primarily driven by utilities investment in the space," in part because nuclear plants have either been taken offline, or new construction has stalled.

It's created an opportunity for renewables in general, and a favorable environment for solar power in particular. After years of being dogged by volatile solar input prices and bankruptcies like SunEdison, which led to questions about the sector's viability, retail and commercial demand is on the rise.

"We're nowhere near a tipping point, but it's a growing market and there's activity there," DeVito told CNBC.

Meanwhile, investments in projects such as concentrated solar power (CSP) mean that thermal energy can be stored and used to produce electricity at any time — even at night or during inclement weather.

Harnessing the power of the sun when it's not shining is what Spiesshofer said was "the biggest challenge in solar: to provide predictable, decarbonized baseload supply. It's one of the biggest challenges of mankind."

The CEO expressed particular excitement about constructing a global network for electric power generation, with solar as the linchpin. With lots of preparatory work and grid modernization at the national level, a global grid can potentially deliver the sun's rays from one country to the rest of the world.

"The estimated cost of this effort is high," Spiesshofer said. "However, the benefits and financial [return] could be sufficient to make it economically feasible. The first proposed steps for digitization of the existing grid, addition of renewables and addition of storage are already in progress."

In theory, a global grid would wrap the world in a net of high voltage direct current systems, which are already in existence. The devil, however, would be in the details: A system of paying for network use would need to be established across countries, as well as a uniform standard of safety and security — no easy feat in a world riveted by instability and terrorism.

Still, Spiesshofer expressed optimism, especially in light of the leaps and bounds of the sector's growth.

"It's demonstrated what people thought a few years ago was unthinkable," he said.