Scientists at the Australian National University (ANU) in Canberra have created the world’s first “truly bifacial solar cell”. These panels are dual sided, with both the front and the back of the solar module capable of generating power. Place a mirror behind these cells, and incoming sunlight can be absorbed twice.
“When deployed on a conventional solar farm, a bifacial cell absorbs direct incoming light, while also taking advantage of ground reflection, which can contribute up to additional 30 per cent power generation” said Dr Kean Chern Fong of the ANU team.
Using an innovative ‘Laser Doping’ process, ANU researchers have increased front and rear energy conversion efficiency considerably, giving them a 96.3% increase in generation capacity. According to ANU, their bifacial cells have an overall power output of 29%, which far exceeds that of typical one-sided cells.
Bifacial solar cells are nothing new, like many energy efficiency technologies its roots can be traced back to the 1960s satellite technology. Top level manufacturers like Canadian Solar offer 400W panels that can provide 30% additional output from the back.
The Chinese are reported to have used bifacial solar cells in their 2.2GW Solar Park in Qinghai which remains one of the largest solar installations in the world. Their added efficiency is often coupled with tracking racks which rotate with the angle of the sun. Bifacial panels have the advantage of requiring less degrees of movement. In doing so the complexity of the tracker can be reduced, requiring far less equipment and achieving a 5% energy efficiency increase on top of massive cost savings.
Arctech Solar, the world’s 4th largest tracker exporter, predicts that their new designs will increase the number of economically viable solar projects. They anticipate a healthy growth of exports prior to their IPO offering on the Chinese stock exchange expected next year.
The major hurdle to these projects is what will be reflecting the light back into the panel. Soil and weather conditions play a huge role in determining how much energy is available for the back half of the cell to absorb.
The economics of these bifacial solar parks vary wildly based on the individual conditions of the project. Very few locations have the sun, soil, and weather conditions that allow for optimal generation year round. Bifacial solar providers are known to claim their panels will increase output by 25% or more, but those cases are far and few between.
Suitable climates are typically arid desert lands, devoid of vegetation and Not in My Backyard (NMBY) residents. One company well equipped to work in the desert is Sterling and Wilson Solar Solutions (SWSS). They were awarded a $99 million contract to construct 194MW of bifacial solar cells in the U.S., similar to their 125MW project in Oman, which claims to be the largest single unit bifacial solar park in the world.
Creating a lower Levelized Cost of Energy for solar panels is the main objective of many utility scale manufacturers. JinkoSolar applied bifacial technology to their newly acclaimed 182mm wafer line, which boasts the lowest LCOE of any solar panel on the market. Their bifacial tech increases capacity by 3% over the next competitor.
Energy authorities across the U.S. are installing bifacial solar panels alongside tracking technology to combat land constraints. Invenergy opened its 100th solar facility, Southern Oak Solar Park in rural Mitchell County Georgia, equipping the county with 160MW of clean energy. Construction employed 400 people and is expected to inject $12 million into the local economy. Renewable Energy Systems (RES) provided the engineering support and oversaw construction of the facility.
The energy transition is heating up, with new technology driving up energy efficiency and reducing costs. Bifacial solar modules are just a sign of things to come.