Photovoltaic power technology advances
SEIA's Shugar, who is also CEO of solar voltaic installer Solaria Corp., said the technology to make the crystalline silicon wafers used for photovoltaic cells has improved exponentially over the past few decades.
The silicon wafering process begins with solid ingots made of single-crystal or multi-crystalline silicon material.
Thirty years ago, blocks of silicon ingots were sliced into thin wafers by hand using expensive and inefficient diamond saws, much in the same way a butcher slices cold cuts. The relatively thick wafers were then used to make photovoltaic cells.
In the 1980s, the solar industry began using wire saws to cut the ingots into wafers. Each slice was 500 microns in thickness (a micron is 1/1,000 of a meter). Historically, every five years, silicon wafer production has seen a 50-micron reduction in thickness. Today, wire saws slice an entire block into wafers at the same time, each wafer being only 150 microns in thickness, Shugar said.
Because of cost reductions, Shugar said solar deployments have grown by 50% to 100% every year for the past 12 years.
"It really is a technology story at the end of the day," Shugar said.
Major challenges ahead
Even with the advances in technology, Google's Demasi said there are still major challenges ahead, not the least of which is the intermittent nature of renewable energy and delivery hurdles.
For example, "smart grids," or electrical grids that are controlled by computers and measure the amount of electricity going out to businesses as well as the surplus green power being sold back to a utility, are still in their infancy.
Demasi said getting utilities to play the middleman role and deliver the renewable product Google wants is not always possible because green power resources are still limited.
Coal-fired power plants are still the single largest producer of electricity for corporations, but that is changing, according to Hitt. Five years ago, coal-fired power plants produced 52% of the nation's industrial energy supply. Today, they produce just 30%, she said.
Renewable energy still makes up just 9.1% of the power produced in the U.S., according to the Energy Information Administration.
"The holy grail is a low-cost resource delivered to the end user by the utility but that's also scalable to a company's needs," Demasi said. "Our ambition is to be 100% green as we grow, but that's a daunting challenge...."