climate crisis Renate Egan

We Can Still Make Solar Panels Even Better and Cheaper

Andreas Gucklhorn/Unsplash, CC BY-SA
By Renate Egan / The Conversation

The cost of turning sunlight into electricity has fallen more than 90% over the last decade. Solar is now the cheapest form of newly built energy generation.

Job done? Not quite. Right now, solar works well at cost-competitive prices and can help us cut emissions significantly. But with less than 5% of the world’s electricity delivered by solar, we are just at the start.

The solar panels of 2022 are like the chunky mobile phones of the 1990s. Much more is possible with the same underlying technology.

Australia is likely to play a key role in global progress. For decades, we’ve been at the forefront of solar technology development and deployment. We’ve held the performance record for silicon solar cells for 30 of the last 40 years. We now have more solar deployed per capita than any other OECD country, meeting close to 15% of our electricity needs. More than 80% of the world’s new solar panels rely on the PERC cell, a technology developed in Australia.

So what’s next for solar? Hundreds of researchers across Australia are focused on two goals: cutting costs even further and generating the most electricity possible out of incoming sunlight.

Why does solar need to improve?

Solar has the potential to transform our industries, transport and the way we live – if we push the technology as far as it can go.

Ultra-cheap electricity unlocks huge possibilities, from turning water into green hydrogen to serve as energy storage or to use in industrial processes, through to electrifying transport, energy systems and everything else we use fossil fuels for.

Last year, Australia’s renewable energy agency laid out its vision for ultra low-cost solar. The goal is ambitious but achievable.

By 2030, the agency wants commercial solar cells to hit 30% efficiency, up from 22% today. It wants large scale full system costs (panels, inverters and transmission) to fall by 50% to 30 cents per watt.

It will take intensive research. More than 250 Australian researchers are working towards these goals at the Australian Centre for Advanced Photovoltaics, a collaboration between six universities and the CSIRO.

solar panels
Silicon has more to give – with a few new materials layered on top. Michael Wilson/Unsplash, CC BY

Can silicon really keep on giving?

Solar cells convert sunlight into electricity with no moving parts. When sunlight hits silicon – the material commonly used in solar cells – its energy frees up an electron able to move within the material, just as electrons move in wires or batteries.

The solar panels on your roof probably began as desert sand, melted down to silica, refined into silicon and refined again to form 99.999% pure polysilicon. For decades, this versatile material has been at the heart of solar’s success. Importantly, it’s scaleable – from the size of a pin head to arrays covering square kilometres.

But to get the absolute maximum out of sunlight falling on these panels, we need to go beyond silicon. We can’t reach efficiencies of 30% with silicon alone.

Meet the tandem cell – a solar sandwich. Because silicon can only absorb a maximum of 34% of visible light, researchers are focused on adding layers of other materials to capture different wavelengths of light.

Perovskites are one option. This family of materials can be printed or coated from a liquid source, making them cheap to process. When we stack this material atop silicon, we see a major jump in the solar cell efficiency.

While promising, there are still problems to iron out – specifically, ensuring perovskites can last the 20 plus years we’ve come to expect from silicon panels.

Perovskite crystals
Perovskites are abundant and useful – but the trick is making them last. Shutterstock

Researchers are also looking at other materials, such as polymers and chalcogenides, a group of common minerals including sulfides which have shown promise in thin, flexible solar cells.

Any new material must not only work well at converting sunlight to electrons, but be abundant in the earth’s crust, available at low cost and stable enough to ensure long lifetimes. Chalcogenides, for example, are made of common elements such as copper, tin, zinc and sulphur.

If we can get to 30% efficiency, it would pay enormous dividends. The costs of establishing a large solar farm would be slashed. With more efficient solar cells, you need fewer panels and less land for the same power output.

It would also make fossil fuels even less competitive. Coal-fired power and car engines are around 33–35% efficient, meaning most of the energy embodied in fossil fuels is actually lost as heat and noise. You also have to pay to continuously supply the fuel. Solar and wind come at no cost once you’ve established the plant.

How can we cut costs further?

At present, the cost of power from new solar in Australia is A$50 per megawatt hour. (Black coal is around $100/Mwh.) That’s according to the CSIRO’s 2021–22 assessment of energy costs.

By 2030, our renewable energy agency wants to slash that to just $15/Mwh, or 1.5 cents per kilowatt hour. Solar energy at this cost – coupled with storage – would deliver low-cost, reliable power 24/7.

Costs will come down as we increase efficiency of the solar cells, as the modules last longer, and as we come up with more cost effective ways to manufacture and deploy the solar technologies.

Ultra-low-cost solar electricity will be transformative, allowing Australia to build new capability in current and emerging industries, such as turning hydrogen and ammonia into fuel sources, the green processing of steel and aluminium and even the processing of silicon itself, so we can make more solar panels.

Even with today’s technology, demand for solar is expected to double and double again in the next ten years. That means there will also be a need to figure out how the solar industry can grow sustainably – and how to recycle solar panels as early solar panels reach the end of their useful lifetimes and need renewing.

Australian innovation kickstarted the solar boom. As climate change intensifies – and the need for clean, locally produced energy grows – the sun-drenched country may once again be able to help speed up the world’s transition away from fossil fuels. The Conversation

Renate Egan, Professor, UNSW Lead, Australian Centre of Advanced Photovoltaics, UNSW Sydney


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13 comments

  1. Please tell me how you are going to get the suitable silicon substitute while remaining an enemy of both Russia and China, the main source of the materials you want.

  2. The issue isn’t whether we can manufacture solar panels or any other manufactured product. The issue is the costs to the rest of the world’s species for a high energy industrial civilization that we have. Plundering the world and plundering the labor power of us, to mine, smelt, refine, fabricate, deliver and dispose of these products is and has been incredibly destructive to the wider environment and to the many species who have no say in the destruction of their habitat. If we were a truly communist society in which we, the working class, had total control of the means of production I would hope that we might choose to reorder our priorities to mitigate the effects we have on other species. As it is the components of solar panels and all the other equipment to deliver the tiny amount of electricity are environmentally costly. The first issue is to remove the means of production from the small group of capitalists who care nothing about us or the world but only their disgusting profit.

    1. Whether Capitalist or Communist – the issue is the same , sourcing. mining and processing the raw materials – that’s the cause of the planet’s degradation – and up to this point, there really is no environmentally “sustainable” way to do that …

      You cannot have infinite growth on a finite planet – so it seems to me the answer is to reduce our energy requirements – how much of the stuff we use energy for do we really NEED and how much is used for sustaining a particular “lifestyle”

  3. I like that pv is used to heat water via a DC heating element vs. the older method of heavy plumbing and pumping, at least to a preheater tank. My favorite solar device is using mirrors to heat a target to turn a turbine generator, the industrialists want to supersize for profit and control reasons(don’t want any independent wage-slaves) or to waste tax $$ if they can’t. I would prefer batteries be an elevated tank of water, pump up during sunlight, release downward to turn generator as needed. Perhaps I watched too many Flintstones cartoons with the friendly animals mobilizing household gadgets, or because I like the tinkerers who make crazy contraptions, or there’s some other reason/excuse.

  4. solar production creates massive amounts of toxic byproducts conveniently ignored. panels typically must be replaced after 2 decades. they do not generate enough electricity for industry. even in climates like Australia their use is limited and expensive—panels being only 1 component required

  5. I was fine for the first few paragraphs. But then you started saying “we” and talking about Australia. I’d prefer that you say “we” and talk about humans.

  6. Seems that I will be adding comments aligned to those above.
    This article read like an advertising blurb.

    Sand mining – not just for the silicon, but also for the concrete foundations required for solar farms – destroys ecosystems and the lives of those animals and plants that live in those in those ecosystems.
    All in the name of maintaining an unsustainable economy and lifestyle.
    Yet, the continuance of infinite growth on a finite planet underpins much of the so-called green/renewable industry.

    Chris Hedges interviewed Derrick Jensen and Lierre Keith upon their release of ‘Bright Green Lies, How the Environmental Movement Lost Its Way and What We Can Do About It.’

    https://www.ecowatch.com/sand-mining-climate-crisis-2651083582.html
    https://www.greenfacts.org/en/sand-extraction/l-2/index.htm

  7. The article reads as one big advert for Australian efforts and borders on verbal breast-beating.

    While I don’t think any of the numbers quoted (I checked them against their source here: https://iea-pvps.org/wp-content/uploads/2022/01/IEA-PVPS-Trends-report-2021-4.pdf ) are exactly wrong, I believe they are seriously misleading.

    This report states that: “In just a few years, Australia has reached the highest installed PV capacity per inhabitant with 810 W/cap. Germany is second with 648 W/cap. Japan ties with the Netherlands in third position with 571 W/cap. Belgium comes in at the 5th place with 523 W/cap,
    followed by Italy (365 W/cap). Switzerland and Malta come next
    with respectively 343 and 324 W/cap. Greece and Korea are
    closing the top 10 with 316 and 306 W/cap.”

    Ok, Australia in the lead with 810 W/cap in solar, Germany second with 648 W/cap. Great huh? Or perhaps not?

    Australia generates only about 29% from renewable sources: https://www.energy.gov.au/publications/australian-energy-statistics-table-o-electricity-generation-fuel-type-2020-21-and-2021

    From this website:

    “Renewable sources contributed an estimated 77,716 GWh, making up 29% of Australia’s total electricity generation, up 5 percentage points on the share in 2020.

    The largest source of renewable generation was solar (12% of total generation) followed by wind (10%) and hydro (6%).

    Fossil fuel sources contributed 189,737 GWh (71%) of total electricity generation in 2021, down 5 percentage points on 2020.

    Coal accounted for the majority of electricity generation, at 51% of total generation in 2021.”

    Hmm, so Australia is 51% coal-powered and has 29% renewables. And wond power has a share of 10% versus PV 12%. Now if the article’s objective were to drum up funds for Australian PV research, I could understand it. But isn’t this Australian PV jig a bit overhyped?

    Take the example of Germany: https://www.cleanenergywire.org/factsheets/germanys-energy-consumption-and-power-mix-charts

    It states that Germany generated 46.4% of its electricity from renewable sources. Those renewables split up into 19.5% from onshore wind, from offshore wind 4.3%, and from PV 8.8% and 27.9% from coal (including lignite).

    Can anyone explain to me why Australia might be seen as a model for renewable energy? As I see it, it’s only PV where Australia is ahead (small wonder given the disproportional amount of sunshine Australia gets) and it’s heavily behind on turning away from coal.

    Last but not least, the breathless narrative about PV misses one crucial point: PV is incapable of replacing conventional sources of energy generation in most of the world. The reason being that its production is so strongly peaked during summer daylight hours (specifically from 10 to 16). You get no PV power at night and almost none during winter. Which leaves a glaring gap.

    Battery storage is a sine-qua-non in order to be able to rely om PV on a 24-hr basis and other sources (e.g. wind) are needed for winter periods.

    Improved batteries (not an active Australian research area) are needed to make renewables more usable, not a rather marginal increase of 22% to 30% conversion efficiency. Unfortunately Australia’s competitive position compared to established battery manufacturing countries can only be characterised as weak.

  8. @rosemerry

    When you write: “Please tell me how you are going to get the suitable silicon substitute while remaining an enemy of both Russia and China, the main source of the materials you want.”, you’re being completely silly right?

    I don’t know if anyone ever told you, but sand (silicon dioxide; SiO2) is the basis of silicon production. Problem is the extreme purity you need for PV cells. That requires energy-intensive and involved chemical industries.

    You’d be right in pointing out that China, which buys boatloads of coal from Australia and where pollution and siting of expansive chemical plants is never a problem, is out in from where silicon production is concerned.

    Your argument basically runs like: “We need China as a source of silicon because unlike us they have no problems at all about pollution and energy use.”. True as far as convenience goes, wrong in all other respects.

  9. @ Richard Hirst

    Good to see you’re awake to the need for sustainable production.

    Perhaps you’ll also note that Capitalist enterprises (steered and aided by judicious taxation and environmental regulation on part of national governments) are way out in front where sustainable production is involved. The underperformers simply cease to exist. This works extremely well, in marked contrast to e.g. “Communist” ways of controlling production, as convincingly demonstraded by the USSR and Mao.

    You might also have heard that coordinating global prooduction capacity is an undertaking of colossal complexity. Rest assured though that we have found an excellent way to effect optimal coordination. You may have heard of it, it’s known as the Market Mechanism where the main performance indicator is Price / Performance. This has been shown to work extremely effectively.

    The only problem so far has been to incorporate so-called external effects (i.e. drawbacks of a production process that can be offloaded to others than the consumers) of goods. If you’d like to make yourself useful, contribute to a sensible system of taxes that properly reflect those external costs.

  10. Government taxes will never catch up with externalized costs. First, because capitalists keep finding new ways to externalize costs. And second, because capitalists buy off the politicians.

    And the “market mechanism” is a beautiful idea, as long as you keep your eyes tightly shut and don’t look at the evidence. The truth of the matter is this: The market doesn’t make you rich for selling a better product. Rather, the market makes you rich for persuading other people that you are selling a better product. That’s why companies spend more on marketing than on research and development. Instead of the “market mechanism,” think of the “incentive mechanism” — 1 Tim 6:10.

  11. @SH

    […]
    “You cannot have infinite growth on a finite planet ”

    True, but completely irrelevant. Nobody asks for ‘infinite’.

    ” – so it seems to me the answer is to reduce our energy requirements – how much of the stuff we use energy for do we really NEED and how much is used for sustaining a particular “lifestyle”

    Yes and no. Totally depends on what you mean. Do you mean household energy consumption per capita? If so, point to the US. Do you include industry? If so, point to China.

    If you’re tired of pointing at people, try some articles, like e.g. this one (it’s dated but still insightful): https://www.aceee.org/files/proceedings/2008/data/papers/8_24.pdf

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