• Investment of ~US$4.4tn/yr needed to hit climate target by 2050: IRENA
• Solar powered evaporation could reduce emissions from desalination


IRENA urges massive investment in green energy to hit climate targets

How much will it cost to hit the International Panel on Climate Change’s stated target of limited global warming to 1.5C?

A new report from the International Renewable Energy Agency estimates it will cost US$131 trillion to meet those targets by 2050, an eye-watering US$4.4tn a year on average. That’s around 5% of global GDP in 2019.

Under that scenario around 90% of the world’s new electricity supplies by 2050 would need to be powered by renewables and decarbonisation technologies.

Current government policies would lead to around US$98tn of investment out to 2050, with IRENA stating around US$24tn would need to be redirected from investments in fossil fuels.

The Abu Dhabi based agency’s World Energy Transitions Outlook report has been prepared ahead of the UN’s COP26 climate dialogue in Glasgow later this year.

While IRENA says it is focused on technologies that are viable today, the public funding and policy areas are where its vision gets especially thorny.

Meeting these projections would require an almost two-fold increase in public finance for energy transition technologies and power supply from US$450bn in 2019 to US$780bn, and the phasing out of subsidies for fossil fuels with the adoption of incentives for decarbonising like carbon pricing – a particularly difficult proposition in mining and energy driven economies like Australia.

Renewables themselves would make up around a quarter of that mix, with energy storage and efficiency technologies requiring the same level of take up with hydrogen equating to about 12% of the global energy mix, something that would require a 16,666x rise in electrolyser capacity from 0.3GW currently to 5000GW by 2050.

Interestingly, IRENA sees a role for blue hydrogen consisting of natural gas with carbon capture and storage, making up a third of hydrogen supply with green hydrogen made from renewable sources accounting for two thirds.

Bioenergy would account for around 18% of the market while carbon capture and storage would also make up a significant portion of the energy investment mix.

Meeting these objectives would see a sharp rise in renewables sector jobs, according to IRENA, which currently make up about 20% of jobs in the global energy industry.

Under current policy settings 23 million jobs will be available in renewables by 2050. That would rise to 43 million under the proposed 1.5C scenario, around a third of all energy jobs, a figure based on the bullish projection that the total number of jobs in the energy industry will rise from 58 million globally to 122m by 2050.


Could solar power make desalination emissions free?

Researchers in Saudi Arabia are tapping the power of the sun to solve one of the world’s big sustainability issues, desalinated water.

According to the Yale School of the Environment, 300 million people worldwide now get their freshwater drinking supplies from approximately 16,000 desalination plants.

Around a fifth of the world’s total is produced in sandy and arid Saudi Arabia, which is also among the world’s largest oil producers meaning it has a bountiful supply of cheap fossil fuels to power its desalination industry.

That means the industry is not terribly emissions friendly, a problem for which researchers from King Abdullah University of Science and Technology believe they may have a solution.

Their PV-membrane distillation-evaporative crystallizer (or PME if you can’t handle that mouthful) has a solar panel which generates waste heat to power water evaporation, with heat generated at each stage used to help power the next.

Green energy IRENA
The solar desalination model developed by researchers in Saudi Arabia. Pic: Joule

Not only did this method reduce the heat of the solar panel, generating around 8% more energy, it also produced around double the amount of fresh water as previous methods of solar desalination and does not produce the toxic brines which are a by-product of the traditional desal process.

“Previous work mainly utilized the hydrophobic membrane with a high thickness to reduce the thermal conduction loss and our theoretical model found that the reducing the thickness of hydrophobic membrane can achieve a high desalination performance and low solar cell temperature simultaneously,” lead researcher Wenbin Wang told Physics World.

“We are currently scaling up this device and planning to build a photovoltaic farm that combines electricity generation and seawater desalination.”