Solar Energy power is the conversion of energy from sunlight into electricity, either directly using photovoltaics (PV), indirectly using concentrated solar power, or a combination.
Concentrated solar power systems use lenses or mirrors and tracking systems to focus a large area of sunlight into a small beam.
Photovoltaic cells convert light into an electric current using the photovoltaic effect.
This article is about how Beth Parks uses a bucket of water to improve solar cell efficiency.
Solar cells offer a clean source of energy, with so many benefits on our environment but the efficiency of a fixed solar system is limited: The sun moves, but solar cells do not.
Beth Parks has designed an astonishingly simple way to overcome this limitation using a bucket of water. As she will describe at the 2019 APS March Meeting, she developed a frame that holds the solar cell with a bucket suspended on either end.
By controlling the leak of water from one of the buckets, the solar cell shifts, tracking the arc of the sun throughout the day.
“In Uganda today, between 20 to 25 percent of people don’t have access to electricity,” said Parks, an associate professor at Colgate University. “One solar cell supplies enough energy to power lights and charge cell phones and also radios. This is a huge quality-of-life improvement.”
While solar panels offer a clean source of energy, they are typically mounted on a fixed frame and only optimally oriented toward the sun during specific hours of the day.
Although, there are available micro-controller based solar tracking systems, they are quite expensive to construct.
Beth Parks previously saw a design for a frame that would allow the solar panel to track the sun using hanging weights. But the design had not been tested to see how it actually performed. Nor had it been optimized for affordability to ensure commercial viability and adoption.
During her year on a Fulbright fellowship in Uganda, she worked with students at the Mbarara University of Science and Technology to design a frame using metal tubing that a local welder could easily obtain and assemble.
“We have created a frame using inexpensive materials that allows the solar panels to track the arc of the sun throughout the day,” Parks said. “This approach could make solar energy more affordable to households and small businesses in the developing world.”
In her design, a bucket of rocks is placed on the west side of the frame and a bucket of water is placed on the east side. Using a controlled leak from the water bucket, the weight shifts and the panel slowly rotates from east to west throughout the day.
Parks and her team tested the design on 20 random days in Uganda. The solar cell on the movable frame captured 30 percent more sunlight than the stationary solar cell at the same location.
“If this frame is adopted, it has the potential to create a small industry for the local community,” Parks said.
According to Beth Parks, the cost of the system:
The solar panel
The battery
The charger and the frame—is about 10 percent less than a comparable rooftop solar energy system.
This astonishingly simple, inexpensive and ingenious method could increase solar energy captured for people in developing countries, as well as remote regions that are off the grid.
Credits: Beth Parks, Techxplore
