EGEB: Scientists develop ‘true’ bifacial solar cells with 29% power output

In today’s Electrek Green Energy Brief (EGEB):

• Scientists in Australia claim they’ve developed “true” bifacial solar cells.
• A Tennessee utility-scale solar farm will be the first in the US to be financed by corporate carbon offsets.
• UnderstandSolar is a free service that links you to top-rated solar installers in your region for personalized solar estimates. Tesla now offers price matching, so it’s important to shop for the best quotes. Click here to learn more and get your quotes. — *ad.

‘True’ bifacial solar cells

Bifacial solar cells aren’t new, but scientists at the Australian National University (ANU) in Canberra claim that they’ve developed what principal investigator Dr. Kean Chern Fong says is “a true bifacial solar cell, as it has nearly symmetrical power generation capacity on both surfaces of the device.” Fong said:

Bifacial solar cells are becoming increasingly important in the roll out of solar farms and are expected to have a market share of over 50% in the next five years.

And chief investigator Dr. Marco Ernst said:

This is a world record for selectively laser-doped solar cells and among the highest efficiency bifacial solar cells.

The team used a technique it calls “laser doping,” which uses lasers to locally increase electrical conductivity:

This allowed the research team to achieve a front conversion efficiency of 24.3% and a rear conversion efficiency of 23.4%, representing a bifacial factor of 96.3%.

This performance represents an effective power output of approximately 29%, well exceeding the performance of the best single-sided silicon solar cell. 

Of course, weather and geography will have a large impact on the efficiency of ANU’s bifacial solar cells. An ideal climate would be desert with little vegetation, such as a 125MW solar project in Oman, whose developer claims is the largest single-unit solar farm using bifacial modules in the world.

Read more: JPMorgan Chase leads with the world’s largest bifacial solar rooftop — and lending to fossil-fuel companies, more

Carbon offset solar farm

Corporate carbon offset schemes enable companies to invest in environmental projects in order to balance out their own carbon footprints. And on Thursday, a 1-megawatt solar farm will break ground in Jackson, Tennessee, that will be able to power 200 homes. Its owner, Clearloop, says it will be the first utility-scale solar farm in the US that is 100% financed by corporate carbon offsets.

Clearloop partners with brands, companies, and individuals to expand access to clean energy and generate long-term opportunities in economically distressed communities across the US. Former governor Phil Bredesen (D-TN) is one of the company founders.

Solar provided a meager 0.56% of Tennessee’s electricity as of first quarter 2021, so even 1 MW is cause for celebration. The US Energy Information Administration (EIA) provides Tennessee’s bigger solar picture:

By early 2021, utility-scale solar power sites with a combined generating capacity of 182 megawatts were operating in the state.

The state’s largest, a 53-megawatt solar farm, came online in December 2018. A new 150-megawatt solar farm is scheduled to begin operating in the state at the end of 2021. In 2020, about one-fourth of Tennessee’s solar power generation came from customer-sited, small-scale (less than 1 megawatt each) solar PV installations that are located mostly on residential and business rooftops.

Tennessee is projected to install 1,740 MW of solar over the next five years.

Photo: Eric Byler/The Australian National University