BY STEPHANIE STEINBERG
Daily Staff Reporter
Published April 13, 2009
Solar cells are among the most well-known alternative sources of energy. But Engineering Prof. Max Shtein is working to bring solar technology into more homes by making solar cells more conducive to daily life — like weaving them into textiles.
Shtein said this change will allow people to consume energy in eco-friendly ways when using everyday products.
“Going to the store and buying clothes, for example, is a lot more familiar to a lot more people than installing a solar cell on the roof of their house,” he said.
Shtein, an assistant professor of materials science and engineering, and a team of researchers are developing a system to create solar cells out of fibers that can be woven into textiles.
“Most of those textiles are actually dyed using organic dyes where the molecular structure is very similar to the structure of the molecules we would use to make organic-based solar cells,” Shtein said.
Shtein has brainstormed many uses for his discovery including carbon fiber airplanes with solar cells interwoven into the plane’s structure and coats and tents made out of solar cell fibers. He said a tent that can effectively generate electricity from the power of the sun can solve many of the problems caused by natural disasters.
“There’s a lot of instances where you have disaster relief kind of shelters, where you want to be able to generate electricity for people to communicate, for people to purify water, to read, to do things they need to do,” Shtein said.
The solar cells applied to the fibers are very thin and add no thickness to the material. Shtein said he discovered that bundles of fibers in a textile absorb more light, making the textile more efficient at collecting energy than a regular, flat solar cell.
Solar panels are one of the most common means of obtaining solar energy. Through the use of photovoltaics, solar cells convert sunlight into electricity.
Though solar panels provide a way to capture light energy, University scientists are working on new and improved methods to harvest energy from the sun.
“The sun is a terrific energy resource for humanity in general,” said Stephen Maldonado, an assistant professor of chemistry. “The output of power that reaches the earth from the sun is several times as much energy as people use every year.”
Maldonado and his team of researchers are studying and designing systems that convert solar energy into chemical bond energy, which can be used to make electricity.
“We work with materials that are similar to what’s found in photovoltaics or the solar panels you see on people’s houses,” Maldonado said, “but those typically operate for solar to electrical energy conversion, and we’re much more interested in making systems that mimic photosynthesis in plants.”
One of the disadvantages of solar cells is that the generated electricity must be consumed immediately because it cannot be stored for long periods of time.
Maldonado said plants are good at converting solar energy into chemical bond energy for making chemical fuels. Using plants as a model, the research team hopes to devise a system that can store solar energy in chemical bonds for long-term storage — similar to how energy is currently stored in gasoline and fossil fuels.
United Solar Ovonic — based out of Rochester Hills, Mich. — is the largest producer of flexible solar cells in the United States. Flexible solar panels are sometimes more useful than regular solar panels because they can be applied to curved surfaces like dome-shaped stadiums.
On average, United Solar Ovonic sells three to four solar panels a week to customers in Michigan.
United Solar Ovonic Sales Engineer George Zaharopoulos said the company has seen an increase in sales since President Barack Obama passed the stimulus package, which included tax incentives for renewable energy investors.
“People are more persuaded to use solar because they get reimbursements and rebates from their state,” he said.
According to a survey conducted by AltaTerra Research Network last November, solar energy installation is on the rise. Results from the survey showed a 52 percent growth rate of newly installed solar energy each year until 2012.
Geological Sciences Prof. Joel Blum believes there are major advantages to alternate energy sources.
Blum teaches GEOSCI 344 Sustainability & Fossil Energy: Options & Consequences at Camp Davis, the University’s Rocky Mountain field station near Jackson, Wyo. The course — which educates students about the scientific and environmental issues related to sustainable and traditional fossil energy sources — will be offered for the first time this summer.
While Blum is an advocate for using renewable forms of energy, he said Michigan is one of the worst places in America to capture solar energy.
“Michigan is a very cloudy place,” Blum said. “It doesn’t mean that it’s not feasible and shouldn’t be done, but it makes much more sense in sunny places like the Western United States where you have much, much, much greater annual solar radiation than you have in a place like Michigan.”
Despite Michigan’s cloudiness, the University decided to install solar panels on the roof of the Dana Building when it was renovated in 2004.
Bill Verge, the associate director of Utilities and Plant Engineering at the University, said the University installed solar energy collectors in an effort to become more environmentally friendly and reduce greenhouse gas emissions.
“I’m a firm believer in the fact that global warming is occurring and that we have to move away from fossil fuels,” Verge said. “And I think that solar energy is one of the best opportunities, even in the state of Michigan.”
Helaine Hunscher, program coordinator of the Center for Sustainable Systems in the School of Natural Resources and Environment, wrote in an e-mail interview that the solar panels on the Dana Building don’t generate enough electricity to sustain the entire building. The angle of the sun and cloud conditions affect the photovoltaic output of the solar panels, and the power demand of the Dana Building varies by occupancy and the use of equipment and lights.
However, the system has shown positive results, Hunscher wrote in the e-mail.
“In 2005, the solar panels generated 35,000 KWh (kilowatt-hours) of energy which is enough to light a 100-Watt bulb for about 40 years,” Hunscher wrote.
She added that on a sunny day in May 2005, the panels met 23 percent of the power demand of the building.
Although the solar panels are not providing an immediate reduction in utility costs, Verge said the University will see a payback in cost reductions in 15 to 20 years.
She added that the main value of the technology is to use it for educational purposes by involving students from the School of Natural Resources and Environment in monitoring the system and evaluating its effectiveness.
In spring 2008, the University also installed a solar collector on the top of the University’s Central Power Plant that helps heat water in Central Campus facilities. The collector is the first of its kind to be installed in the United States and can heat water up to more than 200 degrees Fahrenheit. Its estimated 25-year lifespan will offset the costs from future fuel increases.
Verge said the University is looking into installing more alternate energy sources like solar panels and solar collectors down the road.
“However, the price needs to come down quite a bit before we can utilize it in a large scale,” he said.
Another group on campus is investing in solar energy — not for powering a building, but for running a car.
The University’s Solar Car Team is the largest student project on campus. Involving about 100 students from different schools on campus, the team works together to build a car to race in competitions held every two years.
This year’s car is as tall and long as a normal car and can reach a top speed of 87 miles per hour. The one main difference from a regular car is its six square meters of solar cells on the roof, which are used to charge the vehicle’s lithium ion batteries. Additionally, the car is only 600 pounds — driver included.
Engineering senior Steven Hechtman is the project manager of the Solar Car Team. He said while solar energy is useful for charging the car’s batteries, the amount of energy obtained from the sun is very limiting.
“Our solar cells only pull in as much power as you use for a hair dryer,” he said. “So if you compare it with the horsepower of a regular car, there’s not enough energy coming from the sun to power a real heavy vehicle.”
Hechtman said the next generation of consumer cars will probably include solar cells on the roof — citing the next Toyota Prius as a vehicle that will use solar energy to charge a certain percentage of its battery.
However, he said it’s unlikely there will ever be a car that runs solely off the power of the sun.
“If you want a car that’s the size of a normal car, the weight of a normal car, with all the features of a normal car, there’s no way you can power it completely by the sun,” he said.
Even though solar energy may never be able to generate enough power to fully run vehicles, it has the potential to greatly reduce fossil fuel consumption around the world.
Moreover, the developments made by University researchers shows that solar energy could provide at least a part of the solution Michigan’s economic troubles.
Shtein and Maldonado agree that a concerted effort to produce solar cells in Michigan could have a huge impact on the state’s economic situation.
Shtein said Michigan is well-suited for large-scale production because of the automotive industry.
“You have a highly trained work force, you have very good manufacturing capacity and here people know how to scale things up,” Shtein said. “In solar cells a big problem is scale up. We’re not making enough of them fast enough.”
Maldonado said if researchers can create an alternative energy resource that’s more uniformly distributed, they could potentially restructure the way society operates.
“If that technology can be developed here within the state of Michigan and cultivated here, that would give Michigan an insight in terms of being a major player in that sort of energy redesigning,” Maldonado said.
He added: “Getting involved in solar energy is really a sort of hot ticket item that could really have a lot of financial gain if it’s done right.”