Renewable energy firm Aora has designed a hybrid biogas-solar structure that can power homes in off-grid scenarios such as in rural environments and small villages. The structure, which looms up over the ground like a giant flower bud, will be installed at two university locations in Ethiopia, under an academic partnership between Arizona State University LightWorks, and Ethiopia’s Addis Ababa Science and Technology University (AASTU) and Adama Science and Technology University (ASTU).
The ‘solar tulip’ structure utilizes solar energy during the day, and runs on biogas or biofuel at night or during cloudy or stormy days. The tulip can generate 100 kW of electricity, and it generates another 170 kW of thermal power, which can be used for heating applications.
The solar component of the tulip utilizes a group of mirrors that concentrate sunlight onto the ‘bud’ of the tulip in order to heat compressed air to over 1,000 Celsius (1,800 degrees Fahrenheit), which drives a small gas turbine. The mirrors constantly track the sun throughout the day, adjusting their angles for reflecting the sunlight onto the tulip. “This allows the tulip system to leverage every bit of available energy,” Aora said. Each tulip requires less than an acre of land, and can generate enough to power and heat between 60 and 80 homes, the company claims.
Aora believes the tulip is ideal for off-grid applications, offering a stable power supply 24 hours a day by supplementing its solar energy harvesting with electricity generated ideally by biogas such as animal waste or vegetative substrates. The tulip can also generate electricity from natural gas and diesel fuel.
“The tulip has several benefits which make it uniquely suited for Africa,” the company said. It is modular, takes up little space compared to other solar installations, and uses very little water, making it ideal for dry climates. “Once the community grows and outstrips supply, a second unit can be easily added,” it said. “Additionally, the installation time is very short at 6 months, meaning returns on investment can begin almost immediately. Most of the components can also be manufactured in-country, helping to create employment opportunities.”
The academic partnership is part of Ethiopia’s “Climate Resilient Green Economy Strategy,” which Ethiopia adopted in 2011. The goal is to transform Ethiopia into a carbon-neutral economy by 2025, while helping the country to strengthen its middle class. The partnership with Aora will aide in the development of renewable energy curricula at the universities, and will see two of Aora’s solar tulips erected — one at each university.