Seoul is bringing next-generation solar technology into the city that can generate more electricity from the same area than conventional panels. The city will run a pilot program applying tandem solar technology, which stacks different types of solar cells to boost generation efficiency, at parking lots and aging solar installations to verify performance. The test is drawing attention as a possible way to increase solar output in dense urban areas where installation space is scarce.
The Seoul Metropolitan Government, Seoul Energy Corp. and Hanwha Solutions' Qcells division signed an agreement on the 21st to demonstrate and expand the use of new solar technology. Under the agreement, the three parties will verify the generation performance, durability and on-site applicability of perovskite-based tandem solar cells and draw up plans to expand their use.
Tandem solar technology stacks solar cells with different properties vertically, allowing light that conventional silicon cells cannot absorb to be converted into electricity. Its theoretical efficiency limit is about 44%, roughly 1.5 times the 29% of conventional silicon solar cells. That figure is theoretical, however, and actual generation performance must be confirmed through the demonstration.
The demonstration will center on parking lot canopies and solar installations that have been in operation for more than 15 years. At parking lots, tandem panels and commercially available conventional panels will be operated under identical conditions to compare output and performance. The project will also analyze generation efficiency and the degree of performance degradation under varying temperatures, solar radiation levels and seasonal changes.
Aging solar installations will be replaced with tandem panels to measure gains in output and operational stability. Based on the results, the city plans to examine whether existing facilities can be converted to high-efficiency equipment.
Seoul has installed a cumulative 504 megawatts of solar capacity to date. Annual generation stands at about 589 gigawatt-hours, enough to supply roughly 160,000 households of four. The city plans to use the demonstration results in shaping policies and regulations for deploying high-efficiency solar power on building rooftops, parking lots and public facilities.
Under the agreement, Seoul will oversee the project while Seoul Energy Corp. provides demonstration sites and operates the equipment. Hanwha Qcells will supply solar modules along with design and construction expertise.
"Because space for installing solar panels is limited in urban areas, high-efficiency technology that produces more electricity from the same space is important," said Yoon Jae-sam, head of Seoul's Climate and Environment Headquarters. "Through this demonstration, we will thoroughly verify the generation performance and on-site applicability of tandem solar cells and develop a deployment model suited to Seoul's conditions."