Photo: Creative Commons

MIT professor develops game-changing solar technology

BOSTON — Imagine your phone could power itself.

That may seem like sci-fi, but the technology to do such a thing already exists. And the man who created the organic LED display, which brings life to the media we consume every day, is the one responsible for it.

Vladimir Bulovic, an engineering professor at MIT, launched the start-up Ubiquitous Energy in 2011 to commercialize transparent solar technology. Windows will begin to power vehicles and buildings for a variety of personal and commercial applications as early as 2020.

Joshua Qualls | Vladimir Bulovic poses for a portrait.

“It is just different than what you would ever imagine solar cell to be,” said Bulovic, also director of MIT.nano. “And a lot of my own thinking about technology in general is about how do you make it human-centric.”

To this point, solar technology has been far from human-centric. It aids us, but it serves broader energy needs. This will change with Bulovic’s work at the cutting edge, offering new solutions to age-old problems.

Bulovic developed the transparent solar technology based on his work with OLEDs, which he created more than 20 years ago. OLED technology was difficult to commercialize, but now it’s truly ubiquitous — it’s in nearly all smart devices and televisions being produced today.

Innovations to existing technology take a while to develop. OLED was in development for about a decade before it became affordable enough to deploy in consumer products, and the technology behind transparent solar cells will likely take as long.

“There is actually a reason why certain things succeed and certain things fail,” Bulovic said.

Bulovic can print 100 meters of transparent cells in about 10 minutes, and he estimates it would take just a few years to print all the cells he would need to power the planet. Although it could solve many energy problems, there may be consequences.

“This can have dramatic effects on the social infrastructure of the world,” Bulovic said. “If all of us had all the energy we want, what would that truly mean?”

The solar cells will have a colossal impact, but are dimensionally tiny. At only half a micron thick, they are thinner than an average human hair.

Being so small, transparent solar cells aren’t as efficient as normal solar cells. However, this technology can be applied to more surfaces and easily hidden from view. What’s more, it’s able to bend and flex unlike traditional cells.

“The solar cell of tomorrow is nothing like the solar cell of today,” Bulovic said.

What brought us to this point?

Massachusetts is more energy conscious than most states, and the Boston area is at the forefront of adopting “green” energy solutions, along with other major U.S. cities.

The increasing renewable resources in Massachusetts have launched a revolution in net electricity generation.

Ten years ago, all utility-scale renewable energy sources in the state came from hydroelectric and biomass facilities.

But after many solar informational resources went online in 2008, things began to change.

By 2017, nearly one-sixth of the state's net generation was produced with renewable energy.

Within that, three-fifths was provided by solar photovoltaic (PV) power.

In 2017, Massachusetts was ranked seventh in the nation in solar PV, with an installed generating capacity of almost 2,000 megawatts.

In addition, Massachusetts is seventh among all states in the amount of producing electricity with solar PV.

Data visualizations by Zicong Zhang

The Massachusetts Department of Energy Resources (DOER) is cooperating with electric utilities to build the most energy-efficient state in the nation. Together with Eversource, National Grid and Unitil, they have launched the Solar Massachusetts Renewable Target (SMART) Program. This long-term sustainable solar incentive program will boost the development of solar PV technology in the state by producing about 1,600 megawatts of solar generating capacity.

As Massachusetts’ capital city, Boston invested the largest amount of money into building solar PV systems in the state. According to the Production Tracking System (PTS) Solar Photovoltaic Report from Massachusetts Clean Energy Center, the total cost of design fees from solar PV systems in Boston is over $153 million over the last 18 years. This amount makes up about 2 percent of the grand total of the state.

Today, more and more people are building their own solar PV system to save money long term. According to the Open PV Project from data.gov, the residential install type is ranked the highest, making up about 45 percent of total solar PV systems purchases.

From Cambridge, Bulovic is optimistic about where his technology will lead not just the state of Massachusetts.

“As an inventor, you're not looking at solely financial gain — especially if you are an academic,” he says. “Our job is impact. Our job is to deliver impact to the world.”

Strengthening an aging technology

Under the leadership of Northeastern University mechanical and industrial engineering professor Kai-Tak Wan, doctoral candidate Scott Julien, 35, and three other engineers created a method for quantifying the strength and longevity of adhesion on solar modules.

Julien said the industry lacked tests for that, but the engineers created a way to measure the strength of the solar panel’s glue through their research.

Traditional solar panels have five layers: a glass surface, blue silicone solar cells and a plastic backsheet, with layers of rubber glue between them.

Solar installations per year in Massachusetts

Joshua Qualls | Source: Massachusetts Clean Energy Center

Understanding the strength of this glue is imperative to prolonging the life of the panel, Julien said. If the glue gives way, the panel becomes a safety hazard.

An array of solar panels can produce up to 1,000 volts; when a solar panel’s adhesion starts to crack, water can seep in and create dangerous conditions.

“Put it outside long enough, it's going to start to crack and break down,” Julien said. “It’s enough to really be a safety concern for people in the industry.”

Julian’s team has retrieved decades-old solar panels from around the world, as far as Thailand, to see how the adhesion survives and whether the panels are still safe to use after an extended period of time.

“The worst thing (for a solar panel) is actually clouds,” said Wan, the faculty research adviser. “(The panel) will all cool down quite quickly. When the cloud moves on, the panel will suddenly go back to a high temperature.”

He said if the glue protecting the panels is not strong enough to withstand temperature shifts and condensation, the efficiency of converting the stored energy to electricity can be reduced.

The research, funded by the U.S. Department of Energy and the National Institute of Standards in Technology, will conclude this summer. The adhesion-strength measuring method will be shared with these investors, who will then be able to share it with the solar technology industry.

Wan and Julien, who have been researching together for over a decade, have never conducted funded research in solar technology before, but are already seeing the importance of the work.

Moving forward, Wan hopes that solar technology research will receive more funding, allowing panels to become more accessible for everyday consumers.

“We need this kind of research,” Wan said, noting one of the most important things that can be done is to keep costs low and create reliable technology. “We don’t want to pollute our environment. We want to replace all those fossil fuels with solar panels, wind power and things like that.”