The Growing Appetite for Solar Power

The world has now installed one terawatt of solar power. As many as three billion solar panels have been placed on solar farms, fields, as well as on rooftops of homes and buildings, on warehouses and shopping centres.

Looking at solar on a regional basis, the biggest contributors with greater than 100 gigawatts (GW) include China, the EU, and the US. The US was last to reach the goal, but it is building fast. Together, the three regions have half the world’s installed solar power.

Australia’s total installed solar power sits at just over 25 GW, with at least 13 GW installed on home rooftops. It’s a total that lags behind the biggest solar players, but on a per capita basis Australia has the highest solar capacity, at close to 1kW per person. It’s one of Australia’s carbon emission reduction bright spots.

But where Australia is slightly ahead, the world is just getting started. The International Renewable Energy Agency (IRENA) said last month that the world will need 5.2 terawatts (TW) of solar power generation capacity by 2030 and 14 TW by 2050, if we are to limit global average temperature rises this century to 1.5 degrees Celsius.

That amount is the entire world’s installed solar multiplied by five within eight years and then almost tripled again in the following twenty years -- all for a chance to keep warming to only a slight catastrophe.

Solar production in 2022 is estimated at around 200GW, less than half of IRENA’s requirement at 450GW, but still a high watermark for overall production.

Chinese Supremacy in Solar

So, who’s making solar? Over 90 per cent of solar panels in Australia are made in China and that is a story told around the world. Around three-quarters of the world’s solar cells and modules are made in Chinese factories, along with the entire upstream supply chain, including polysilicon production for silicon wafers, involving large-scale mining.

Ninety-five per cent of conventional panels are made in China. Ten manufacturers comprise 90 per cent of the global market for panels: four of the top five are in China. 

The world's largest panel provider in 2021 was Longi, winning by a small margin over Trina Solar. The rest of the top five were JA Solar, JinkoSolar, all Chinese-headquartered manufacturers, and Canadian Solar, headquartered in Canada. Ranked fifth, it has most of its manufacturing in China as well. Longi, Trina, Jinko, and Canadian Solar are all listed companies.

Vietnam and Malaysia represent the only real country-scale competition. The EU’s former manufacturing base was largely lost to cut-throat pricing. US companies make about 1 per cent of supply, with the biggest being Nasdaq-listed First Solar. (First Solar’s thin-film solar products don’t rely on the global polysilicon supply chain.)

Australia has just one commercial supplier, Tindo Solar, which currently makes 60 MW a year, a fraction of a percentage point of global solar output.

Significant efforts are being made by India with its Production Linked Incentive (PLI) scheme, the EU via various post-pandemic “recovery and resilience plans”, and the US via the Solar Energy Manufacturing for America Act to foster more domestic manufacturing.

Silver Shines in New Cells

A key shift in solar manufacturing is a switch to n-type solar cells. Technology details aside, they promise small but significant advantages in efficiency and reliability over efficiency-capped p-type solar modules which currently dominate mass solar production.

The biggest players are rapidly shifting production to the newest n-type manufacturing technologies, which is expected to take the largest share of production before 2025. A winner in the new production method is silver -- or at least silver mining companies.

Silver in specialized pastes is used for contacts and plating due to its conduction and long-term reliability. One alarming figure is that n-type technologies may double the silver of current p-type solar cells - or more. One estimate suggests that PV manufacturing currently uses 8% of the world's annual silver supply, and has a growing appetite. An unlikely trajectory of manufacturing growth and use of current n-type production methods suggests PV would require the entire annual silver supply some time before 2050. Naturally, significant R&D is going into reducing the need to use silver, including majority copper pastes, with less silver.

New Solar Applications

Solar is also popping up in more applications. Building-integrated PV in glass is being produced by more of the Top 5 solar manufacturers, and is being pitched at new buildings in sun-drenched cities. Developers are attempting to offset the energy demands of new buildings while retaining the popular all-glass exteriors. While not quite BIPV, Collins Square Tower in Melbourne added solar at the top of its sky scrapers to offset building demand, while Cbus Property said last year it was adding a "solar skin" to its $1 billion commercial office tower in Melbourne CBD as well. Combining both looks like a future outcome for new buildings.

In cars, an old-but-new idea in EVs is seeing panels being installed on car roofs and trucks via vehicle-integrated PV, or VIPV. One outcome of this is that car makers prefer ultra-high efficiency solar panels, with more advanced materials. One type here is gallium arsenide panels, which are currently used in satellites and in space craft for their high efficiencies, where cost per panel is less important. The growing EV space and VIPV may see a rise in the niche solar production method as it goes onto more vehicles.

One example of this is in the latest Hyundai Sonata. Hyundai offers an upgrade to a solar panel on the roof for $US1,100. Calculations point to a 9 per cent improvement in overall fuel efficiency, based on adding 1,000 miles (1,600km) of "free" range per year. Mercedes and Toyota also have models in development or already currently available. 

And in terms of EVs that are designed with a solar-first approach, Dutch start-up auto manufacturer Atlas Technologies has focused its Lightyear auto to soak up as much sun as possible, with fellow start-up Sono Motors and its Sion auto working on a similar idea.

Solar production and the supply chain giga-complex is set to continue to increase, with China unlikely to lose its dominant role. Associated equipment such as solar trackers, inverters, glass, backsheets are all part of the equation as well.

On a grander economic basis some estimates are that solar manufacturing is about one-quarter of the total solar industry. Most jobs and money are in deployment, installation, engineering, and operation and maintenance expertise. Along with increasing utilisation of batteries for long-term storage, the sector is investing billions of dollars at breakneck speed.