Renewable expansion- can it keep up with demand?

Energy demand may have fallen during the COVID-19 shut down, but if the global economy gets back to something like its earlier level, it will rise again. Indeed, as before, it may rise faster than renewables can expand, so that carbon emissions will also keep rising. That certainly was the pattern in some sectors before COVID 19. But it is not the complete story- in some cases, demand had been falling, for example for electricity in some countries. And obviously it could do more, with proper support for energy efficiency measures. That too would help cut emissions.

Overall global CO2 levels had in fact  stabilized, with coal use being squeezed out in some (but not all) areas and renewable continuing to expand. REN21’s 2019 Renewable Energy Status Report noted, that modern renewables had expanded their share in final energy consumption by an average of 4.5% over the last ten years, whereas global energy demand had only risen by 1.5%.  However, although growing, the total renewable share was still only around 26% of power (11% of all energy) and squeezing coal out has been proving to be hard in some countries, with demand still rising. It’s a race against climate disaster.

Some are pessimistic about the outcome, pointing to the hidden life-cycle environmental costs of renewables.  In a recent critique, Prof. William Rees from the University of British Columbia says that ‘wind/solar energy is not really renewable. In practice, the life expectancy of a wind turbine may be less than 15 years. Solar panels may last a few years longer but with declining efficiency, so both turbines and panels have to be replaced regularly at great financial, energy and environmental cost. Consider that building a typical wind turbine requires 817 energy-intensive tonnes of steel, 2,270 tonnes of concrete and 41 tonnes of non-recyclable plastic.’

The same line is taken in the new controversial full length documentary film from Michael Moore and Jeff Gibbs, which I will be reviewing shortly. Its analysis has been widely challenged as dated and flawed. But, for now, suffice it to say that, while it is true that it takes energy to build wind turbines and the materials for them, modern devices can generate up to 80 times more power output over their lifetimes than is needed to make them. That’s far better than for nuclear plants – which typically only have a 15:1 Energy Return on Energy Invested ratio, and that will fall as reserves of uranium deplete and lower grade ores have to be used in an energy intensive mining and fuel fabrication process. So, in terms of low carbon energy supply, renewables are by far the best option. 

Nevertheless, as the Rees critique and the new film both note, renewables will also need rare earth metals. Rees says ‘World demand for rare-earth elements - and Earth-destroying mining and refining- would rise 300% to 1,000% by 2050 just to meet the Paris goals.’ Actually, it is not clear whether renewables would necessarily use more of these materials than would be needed if we simply replaced old obsolete plants with fossil/nuclear plants. However, while in either case there could be worrying impacts, materials recycling and substitution may help avoid or reduce them, and investing in energy efficiency would reduce the need for new supply capacity of whatever sort, and therefore the need for rare materials.  

Even so, there could be problems ahead. The Rees critique ends up by noting that ‘ironically, the mining, transportation, refining and manufacturing of material inputs to the green energy solution would be powered mainly by fossil fuels, and we’d still have to replace all the machinery and equipment currently running on oil and gas with their electricity-powered equivalents, also using fossil fuel.’   Construction of the first wave of renewable energy technologies (or indeed nuclear plants) does inevitably need fossil fuel, but, subsequently, renewables can begin to supply the energy needed to build the next generation of renewables, in bootstrap mode. Arguably, the fossil reserves should be ring-fenced for the initial phase of this replacement process, not just be used to generate power for no longer terms gain. The emissions produced from their use for this purpose could perhaps be offset by carbon sequestration via new forest plantations. So there may be some solutions.

A renewable future?

The Moore/Gibbs film claims that renewables can’t help cut net emissions: despite their widespread deployment, emissions have not fallen. The Rees critique similarly claims that ‘even if the energy transition were occurring as advertised, it would not necessarily be reflected in declining CO2 emissions’. While that may have been the case so far, since demand is also rising, the pattern seems to be changing, and hopefully, if demand can be cut and coal squeezed out, we can do better in future with the renewables’ already low energy and carbon debts falling as the technology improves.  There is of course plenty of room for debate about how we might get demand down, ranging from more or less radical technical fixes of various kinds, to draconian social constraints, including punitive energy pricing and even an end to economic growth.  I have explored some of them (and the issues raised above) in my forthcoming book ‘Can renewable energy deliver?’  No spoilers, but continued material growth on a planet with finite resources and carrying capacity is not backed! However, it is suggested that renewables can allow for some energy-use growth while avoiding emissions, and that perhaps the most urgent issue is- can renewable expand fast enough to limit climate change to survivable levels. Some say they they cant  and that we will need alternative or additional approaches – nuclear and/or fossil CCS .

However, with wind and solar power output growing ‘at an annual average of 20.8% and 50.2%, respectively, over the past decade’, as costs fall, and new nuclear and CCS pretty much stalled, it may be best just to help renewables (and energy saving) pick up pace even more. That surely makes more sense than diverting resources to arguably dubious high tech and high cost long shots like nuclear and CCS.  They are still being promoted hard, as in the UK Energy System Catapult’s ‘Innovating to Net Zero’ report, which includes a 2050 scenario with 30 GW of nuclear and major industrial CCS and BECCS projects.  Not an approach that the FIRES study seemed to hold out much hope for, as I reported earlier.

In the post-pandemic context, money will be tighter, so better use will have to be made of it. In 2019, renewable capacity reached over 2.5 TW globally, expanding by 7.6% and accounting for 72% of new energy projects. With costs falling, that seems to be the best way to go, and in my next post I look at a new EU 100% renewable scenario, which show how it might be done.