Kicking the Diesel Habit, With Glass Solar Cells

Access to renewable energy is increasing globally, and yet the market for diesel generators continues to grow across all sectors, including commercial and industrial users. Solving this conundrum is imperative if the global economy is to electrify and decarbonize. One solution may lie in a new glass solar cell under development by a team of researchers from South Africa and Belgium.

Why diesel?

Energy users turn to diesel generators for three basic reasons: accessibility, reliability and cost.

Despite the impact on greenhouse gas emissions,  demand for diesel generators is rising as global demand for electricity increases.

Small scale solar-plus-storage systems are beginning to cut into the diesel generator market in areas without grid access. They also help fulfill demand for backup power. However, the up-front cost of solar-plus-storage can still be relatively high. That factor helps explain why the global diesel generator market was poised for a five-year growth spurt as of 2017.

The upward trajectory is continuing into 2019. Somewhat ironically, greenhouse gas emissions and the impacts of climate change may be partly responsible for the increased demand.

Last spring, Market Research Future observed that “the diesel generator market has gained significant traction due to the amplified occurrence of natural disasters globally,” with demand is especially strong in the power station and data center sectors.

Why solar cells?

The problem of electricity access is more acute in some areas than others, according to EIA:

“Around 84 percent of those without electricity access reside in rural areas and more than 95 percent of those living without electricity are in countries in sub-Saharan Africa and developing Asia. While still far from complete, progress in providing electrification in urban areas has outpaced that in rural areas two to one since 2000.”

Part of the urban-rural divide is due to the expense of building new transmission lines to serve relatively small pockets of population.

Service to remote energy users is an area where small scale, distributed solar energy could provide a distinct advantage over diesel generators.

Compared to solar, diesel is at a disadvantage in remote areas where the cost of fuel transportation piles on to higher costs for servicing and repair.

Solar entrepreneurs are beginning to grasp the opportunities in the off-grid market in Africa and elsewhere, though that still leaves diesel stakeholders with plenty of room to grow.

Glass solar cells to the rescue

The new glass solar cell research could help provide solar stakeholders with an edge, by enabling solar cells to serve double duty as windows.

That’s a win-win for energy consumers. Glass windows (such as the one shown above at the Bejar Market in Salamanca, Spain, which Onyx Solar designed) allow daylight into rooms, helping to reduce the use of electricity during peak daytime hours. Having a window that also produces electricity is icing on the cake.

Ideally, the overall effect on the bottom line is to absorb part of the cost of solar cells into the energy profile of a building. That would help property owners and other stakeholders calculate the potential for significant, long term savings compared to diesel generators.

The long road to transparent solar cells

The new solar research comes from scientists based at the University of the Free State in South Africa, and Ghent University in Belgium. Ghent University describes the motivation in terms of the diesel generator conundrum:

“The research is driven by the UFS and was prompted by ever-rising electricity prices and growing demand for electricity production. South Africa lives with constant power outages which leaves people stuck in lifts and facing chaos on the roads as traffic lights cut out. Many people who can afford them now rely on generators.”

The challenge is to develop materials that are efficient at converting solar energy without blocking too much light from passing through.

To solve the puzzle, the research team is developing glass made with light-collecting materials, which zero in on the invisible, ultraviolet and infrared ends of the light spectrum. The workhorse parts of the new solar cell are concentrated along the sides.

Solar cells on the go

The new approach enables ample light to pass through, but the devil is in the details. The research team is still working on the right combination of materials. They foresee an R&D period of about 10 years before a market-ready product emerges from the laboratory.

When it does, the impact could be game changing. In addition to windows for buildings, the new solar cell could be used in billions of smart phones and tablets around the world.

The research team also anticipates incorporating the new solar cell into durable materials that could replace metal roofs. That would provide another “cool roof” option to help improve energy efficiency in buildings, as well as creating another opportunity for site electricity generation.

In addition, auto manufacturers like Toyota are already experimenting with solar-equipped cars, and solar-integrated body parts could provide another option.

If ten years seems too long to wait, take heart. Other research teams have also been busy at work on solar cells that could be integrated into buildings, mobile devices, and autos. That includes a team at the U.S. Department of Energy’s National Renewable Energy Laboratory, where work on a “switchable” solar cell is progressing.

Image credit: Onyx Solar