Given all the ways in which humans are otherwise smarter and better educated than plants, you’d think we would have established a bit more of an advantage in our capacity to harvest the sun’s energy.
Without any access to higher education, plants routinely synthesize between 3 and 6 per cent of total solar radiation. Humans, meanwhile, use solar photovoltaic cells to record an average efficiency of 15 per cent – not bad, but hardly an overwhelming advantage.
And the plants, to be fair, had a head start.
Presumably unsatisfied with the current state of affairs vis-à-vis human-plant competition, researchers at the University of Cambridge claim to have discovered a way to extract solar energy at nearly 100 per cent efficiency.
The key, apparently, is in the study of particles known as ‘dark’ spin-triplet excitons.
In a press release filled with science that sounds like it was made up by Michael Bay to justify a bunch of on-screen explosions, lead author Maxim Tabachnyk exclaims, “The key to making a better solar cell is to be able to extract the electrons from these dark triplet excitons.”
Until now, solar cells have used the easy-to-manage single-spin “bright” excitons created by light photons. Their cousin, the dark triplet excitons, spin in such a way that it is difficult to harness their energy. So difficult, in fact, that it was previously thought impossible. This new breakthrough has smashed a hole through the theoretical solar efficiency ceiling.
One of the reasons why this is exciting is that the advantage of renewable energies has never been in their high efficiency.
Conventional solar cells operate at a high of nearly 45 per cent efficiency. Meanwhile, wind power achieves up to 40 per cent and has a theoretical limit of 59 per cent. What renewables lack in efficiency they make up for in, well, renewableness – there’s plenty of sun and wind available as inputs.
If solar PV can dramatically boost its efficiency level – especially to near 100 per cent – that has major implications for the push to displace oil and gas from the top of the energy pyramid. Oil power generation averages an efficiency level of 38 per cent, so it’s not like fossil fuels are untouchable in terms of their ability to turn energy into power without waste.
Photosynthesis requires excitons too, but only the single-spin kind. For now, plants will have to be content to trudge along at a frankly laughable 3 per cent efficiency. Or perhaps not – scientists around the world are currently working to increase plant photosynthesis efficiency in hopes that it will boost food production, aided by such donors as the Bill and Melinda Gates Foundation.
And so that eternal struggle for solar conversion bragging rights continues. Man vs. plant. Ultimately, the more effectively we can harness energy from the sun, the easier it will be to rely on that enduring source of heat and power over the next billion years or so.
The Earth has a lot more sun than it does oil, so it would be nice to be able to use more of it.
- A\J Editorial Board (19) A\J Editorial Board
- A\J Special Delivery (185) A\J Special Delivery
- Backstage at A\J (87) Backstage at A\J
- Current Events (216) Current Events
- EcoLogic (16) EcoLogic
- Food and Culture (29) Food and Culture
- Green Living (36) Green Living
- Made in Canada (23) Made in Canada
- Renewable Energy (59) Renewable Energy
- Shades of Green (15) Shades of Green
- Summer Reading Series (8) Summer Reading Series
- Sustainable A\J (58) Sustainable A\J
- The Green Student (19) The Green Student
- The Mouthful (14) The Mouthful
- The Wild Side (44) The Wild Side
- Think Global (21) Think Global
- Turtle Island Solidarity Journey 2018 (4) Turtle Island Solidarity Journey 2018
Popular on A\J
- It's Friday! In this week's #SummerStudentTakeover, we take a look at Canadian cottage culture with Mystaya Touw… https://t.co/oC0PQtjgwP — 4 days 17 hours ago
- The new Recap is up! There's no feature this week, but stay tuned - A\J's adventures in Louisiana are coming soon https://t.co/xg3gAaXyka — 1 week 16 hours ago
- A\J looks at how @ClimateActionWR is working to reduce Waterloo Region's emissions https://t.co/mADWfupWTn https://t.co/NH7grME2lW — 1 week 1 day ago