Category Archives: green economy

is bioenergy a viable future option?

I haven’t investigated this issue before, and my general uninformed view as I begin this post is that producing fuel somehow from plants when we’re already having problems with over-use of land, and maintaining biodiversity, seems like a solution which will likely cause further problems downstream.

This general view I’ve found well expressed in an article published in The Guardian and on the World Resources Institute website in late January 2015, nearly seven years ago now. Were the authors correct then, and has anything changed since?

The 2015 article argues for solar energy as a more efficient use of sunlight, which, essentially is what bioenergy also uses. However, there are problems with getting energy generated from the sun, in, say, the Sahara Desert, to regions of high demand in Europe. And there may be ways of harnessing bioenergy without excessive land use. An article published in Nature Sustainability at the beginning of this year (2021) suggests, in its abstract, that:

growing perennial grasses on recently abandoned cropland is a near-term strategy for gradual bioenergy deployment with reduced risks for food security and the environment

The full article is behind a pay-wall, and I’m poor and cheap, but the authors appear to be arguing that a fair amount of bioenergy potential, measured in exajoules (that’s a ginormous number of joules) can be tapped from abandoned cropland, and from increasing areas of potential cropland, without affecting biodiversity or utilising essential water resources.

None of this suggests that bioenergy has major potential for an immediate future that looks increasingly dire. Saul Griffith, an Australian scientist, inventor and entrepreneur, spoke on the Climate One podcast (Electrify Everything, Oct 29 2021) about the situation.

There’ll be some geothermal; there’ll be some biofuels for some applications; there’ll be some hydroelectricity. But wind and solar are now proven to be the cheapest generators of electricity in the world.

The International Energy Agency (IEA) has an article from earlier this year about bioenergy, land, and the net-zero-emissions-by-2050 target. This is a new area for me, so I was interested in the quoted fact that, currently, some 40% of bioenergy supply (about 25 exajoules) is from solid biomass (wood, and waste materials). This is a traditional use, mostly for cooking, ‘which is inefficient, often linked to deforestation, and whose pollution was responsible for 2.5 million premature deaths in 2020’. The aim is to reduce this type of fuel to zero by 2030 – which does sound optimistic.

The plan, or hope, is to transfer to and control a sustainable bioenergy supply as part of a transformed energy economy. This energy, IEA reckons, will be divided into solid bioenergy, biogas, liquid biofuels and bioenergy with carbon capture and storage. We’re talking 2050 here, and the IEA article writes about it in the present tense (a bit weird – for example ‘by 2050 almost half of liquid biofuel use is for aviation’). It projects that around 5% of our energy generation will come from bio, and that it will be ‘an important source of low-emissions flexibility to complement variable generation from solar PV and wind’. It will also be used in the paper and cement industries, to meet high temperature heat requirements not easily electrified, and in the early future to 2030 it will be used to replace ‘dirty’ biomass – for example, improved stoves. The IEA also appears to be talking up carbon capture and storage (CCS, or BECCS if you unite it with bioenergy), that somewhat vague technology which has yet to prove itself. I’ll have to write about that in future, to comprehend the process and to see if any progress has been made.

The IEA projects that the 2050 bioenergy supply (that 5% of total) will amount to around 100 exajoules. In its optimistic scenario, 60% of this supply will come from ‘sustainable waste streams’ which don’t require land use, compared to 20% currently. The idea appears to be that we will have come much closer to solving the current waste problem – from plastics to clothing  and various recyclables. Sorting and utilising will presumably be much more efficient, perhaps using advanced AI. There is also much talk of ‘advanced’ biofuels, presumably more efficient and energy dense. 

The controversial issue of utilising food crops and land for bioenergy is addressed, with a scenario that involves increased usage up to 2030, then gradually reducing to zero by 2050. Short-rotation woody crops (which are generally more productive of bioenergy) on marginal lands will largely replace them.

This emphasis on reclaimed land for bioenergy-producing short-rotation woodland makes me wonder about something outside of the IEA’s purview – the other life that such woodland might sustain, or not, as the case may be. What sort of birdlife, for example, would be attracted to such human-designed forests? A forest without birdlife would be an empty place indeed, but how would any bird fit into this human scenario? The IEA’s narrow focus thus becomes problematic when biodiversity issues are raised, but intercommunication on these issues should allow such woodland to be sustainable from a biodiversity perspective. 

 Another interesting usage in this IEA projection is the term ‘advanced’ . There will be ‘advanced’ biofuels by 2050, as well as ‘advanced’ short-rotation woody crops, and other such advances. In some respects, this is a reasonable assumption, but unforeseen consequences are unseen, after all. Still, the IEA are intent on collaboration with other stakeholders, including presumably spokespeople for those without a voice, such as all non-human species. Quite a large and varied sector. 

An article on ResearchGate from two years ago, ‘The Future of Bioenergy”, argues that land-intensive bioenergy may have uses in the short-term but is not a viable long-term option, due largely to the promise of other technologies. It quotes an earlier IEA study that finds that bioenergy has become an increasingly significant part of the current energy mix, a situation that’s likely to pertain for some time, but not so much for the long term. It also questions the viability of BECCS, which was promoted in an earlier IPCC paper. The problem with bioenergy, it seems, is that it may not be, and is unlikely to be, as green as its proven alternatives. There are, of course, major problems in applying green energy to aviation and to some heavy industries, and some current methods of biofuel production are hardly less harmful than those for conventional fuels. Land use is also an issue fraught with unforeseeables. But of course, researchers will continue their research, and new breakthroughs are always possible. Something to keep an eye on.

References

https://www.nature.com/articles/s41893-020-00680-5

https://www.climateone.org/audio/electrify-everything

https://www.iea.org/articles/what-does-net-zero-emissions-by-2050-mean-for-bioenergy-and-land-use

https://www.researchgate.net/publication/336740381_The_Future_of_Bioenergy

a hydrogen energy industry in South Australia?

an artist’s impression of SA’s hydrogen power project

I recently received in the mail a brochure outlining SA Labor’s hydrogen energy jobs plan, ahead of the state election in March 2022. The conservatives are currently in power here. The plan involves building ‘a 200MW hydrogen fuelled power station to provide firming capacity in the South Australian Electricity Market’.

So, what does a ‘hydrogen fuelled power station’ entail, what is ‘firming capacity’ and what does 200MW mean?

A presumably USA site called energy.gov tells me this:

Hydrogen is a clean fuel that, when consumed in a fuel cell, produces only water. Hydrogen can be produced from a variety of domestic resources, such as natural gas, nuclear power, biomass, and renewable power like solar and wind. These qualities make it an attractive fuel option for transportation and electricity generation applications. It can be used in cars, in houses, for portable power, and in many more applications. Hydrogen is an energy carrier that can be used to store, move, and deliver energy produced from other sources.

This raises more questions than answers, for me. I can understand that hydrogen is a clean fuel – after all, it’s the major constituent, molecularly speaking, of water, which is pretty clean stuff. But what exactly is meant by ‘clean’ here? Do they mean ‘carbon neutral’, one of today’s buzz terms? Presumably so, and obviously hydrogen doesn’t contain carbon. Next question, what exactly is a fuel cell? Wikipedia explains:

fuel cell is an electrochemical cell that converts the chemical energy of a fuel (often hydrogen) and an oxidizing agent (often oxygen) into electricity through a pair of redox reactions. Fuel cells are different from most batteries in requiring a continuous source of fuel and oxygen (usually from air) to sustain the chemical reaction, whereas in a battery the chemical energy usually comes from metals and their ions or oxides that are commonly already present in the battery, except in flow batteries. Fuel cells can produce electricity continuously for as long as fuel and oxygen are supplied.

So the planned 200 megawatt power station will use the chemical energy of hydrogen, and oxygen as an oxidising agent, to produce electricity through a pair of redox reactions. Paraphrasing another website, the electricity is produced by combining hydrogen and oxygen atoms. This causes a reaction across an electrochemical cell, which produces water, electricity, and some heat. The same website tells me that, as of October 2020, there were 161 fuel cells operating in the US with, in total, 250 megawatts of capacity. The planned SA power station will have 200 megawatts, so does that make it a gigantic fuel cell, or a fuel cell collective? In any case, it sounds ambitious. The process of extracting the hydrogen is called electrolysis, and the devices used are called electrolysers, which will be powered by solar energy. Excess solar will no longer need to be switched off remotely during times of low demand.

There’s no doubt that the fortunes of hydrogen as a clean fuel are on the rise. It’s also being considered more and more as a storage system to provide firming capacity – to firm up supply that intermittent power sources – solar and wind – can’t always provide. The completed facility should be able to store 3600 tonnes of hydrogen, amounting to about two months of supply. There are export opportunities too, with all this excess supply. Japan and South Korea are two likely markets.

While it may seem like all this depends on Labor winning state government, the local libs are not entirely averse to the idea. It has already installed the nation’s largest hydrogen electrolyser (small, though, at 1.25 MW) at the Tonsley technology hub, and the SA Energy Minister has been talking up the idea of a hydrogen revolution. The $11.4 million electrolyser, a kind of proof of concept, extracts hydrogen gas from water at a rate of up to 480 kgs per day.

The difference between the libs and labor it seems is really about who pays for the infrastructure. Unsurprisingly, the libs are looking to the private sector, while Labor’s plans are for a government-owned facility, with the emphasis on jobs. Their brochure on the planned power station and ancillary developments is called the ‘hydrogen jobs plan’. According to SA’s Labor leader, Peter Malinauskas, up to 300 jobs will be created in constructing the hydrogen plant, at least 10,000 jobs will be ‘unlocked from the $20bn pipeline of renewable projects in South Australia’ (presumably not all hydrogen-related, but thrown in for good measure) and 900+ jobs will be created through development of a hydrogen export industry. He’s being a tad optimistic, needless to say.

But hydrogen really is in the air these days (well, sort of, in the form of water vapour). A recent New Scientist article, ‘The hydrogen games’, reports that Japan is hoping that its coming Olympic and Paralympic Games (which others are hoping will be cancelled) will be a showcase for its plan to become a ‘hydrogen society’ over the next few decades. And this plan is definitely good news for Australia.

Japan has pledged to achieve net-zero greenhouse gas emissions by 2050. However, this is likely impossible to achieve by solar or other established renewables. There just isn’t enough available areas for large scale solar or wind, in spite of floating solar plants on its lakes and offshore wind farms in planning. This is a problem for its hydrogen plans too, as it currently needs to produce the hydrogen from natural gas. It hopes that future technology will make green hydrogen from local renewables possible, but meanwhile it’s looking to overseas imports, notably from Australia, ‘which has ample sunshine, wind and empty space that make it perfect for producing this fuel’. Unfortunately we also have an ample supply of empty heads in our federal government, which might get in the way of this plan. And the Carbon Club, as exposed by Marian Wilkinson in her book of that name, continues to be as cashed-up and almost thuggishly influential as ever here. The success of the South Australian plan, Labor or Liberal, and the growing global interest in hydrogen as an energy source – France and Germany are also spending big on hydrogen – may be what will finally weaken the grip of the fossil fuel industry on a country seen by everyone else as potentially the best-placed to take financial advantage of the green resources economy.

References

Hydrogen Jobs Plan: powering new jobs & industry (South Australian Labor brochure)

https://www.energy.gov/eere/fuelcells/hydrogen-fuel-basics

https://en.wikipedia.org/wiki/Fuel_cell

https://www.eia.gov/energyexplained/hydrogen/use-of-hydrogen.php

‘The hydrogen games’, New Scientist No 3336 May 2021 pp18-19

Marian Wilkinson: The Carbon Club: How a network of influential climate sceptics, politicians and business leaders fought to control Australia’s climate policy, 2020

https://www.abc.net.au/news/2021-03-23/hydrogen-power-play-in-sa-as-labor-announces-gas-plant-project/100022842