Biomass and Its role in the energy transition ETC

BIOMASS AND ITS ROLE IN THE ENERGY TRANSITION

IE's Steven Gislam spoke to the Energy Transitions Commission's Lord Adair Turner and lead author Meera Atreya about biomass, and how it can help reach net-zero.

In June, IE spoke to the Energy Transitions Commission (ETC) co-chair Lord Adair Turner to find out about the first two of five reports being published this year on how the world can transition to net-zero – one on electrification, the other on green hydrogen. In July, the ETC released its third report, ‘Bioresources Within a Net-Zero Emissions Economy: Making a Sustainable Approach Possible’, in which it sets out how the rapidly increasing demand for bioresources could outstrip sustainable supply.

We caught up with Lord Turner along with the report’s lead author, Dr. Meera Atreya, to learn more about the role that bioresources can play in the transition.

“We'd been developing an overall view of the technologies required to decarbonise the economy,” explained Turner. “About a year ago, we took a step back and looked at all these technologies. That way, we could work out the relative balance, and see where the limits are on how much and how fast you could build. That led to the five reports we’re publishing this year.”

“This report is different in tone to the last two. The ‘Making Clean Electrification Possible’ and the ‘Making a Hydrogen

Economy Possible’ reports, essentially say ‘build, build, build, as fast as you can’. There are no mineral constraints, there are no resource constraints, and there aren't, except at the margins, serious local environmental impacts.

“This report has a different tone. It says, ‘be careful of overbuilding because you can create adverse consequences. There are inherently constrained supplies. You have to work out what those are and live within those limits.”

Bioresources are organic materials made from biological sources, such as plant biomass. Biomass can be directly burned for heat or converted to gaseous fuels and renewable liquids via several processes.

The European Commission’s Joint Research Centre found that in 2016 energy from biomass accounted for 59% of the EU’s renewable energy consumption, and 10% of total energy consumption.

However, as the ETC report points out, “not all biomass is ‘good’ biomass”. This statement is more than simply a soundbite. It cuts to the heart of the sustainability issues connected with biomass production, of which, according to Turner, there are two main elements.

The first of these relates to situations where biomass production directly competes with food production. An example of this would be when land for palm oil plantations in Indonesia, the world’s largest palm oil producer, began directly competing with land used for food production. Also, these massive plantations can have a detrimental effect on local biodiversity.

The second element to consider is landuse change, such as deforestation. “If a piece of tropical forest is burned down and then used for biomass production, while the biomass production from that point on may have a good carbon balance, it'll take centuries before it offsets that one-off carbon release from clearing the forest in the first place,” said Turner.

There is also an important distinction to be made, says Dr Atreya, between forms of biomass that require dedicated land use and those that come from waste and residual sources, of which she outlined three main types – agricultural residues, forestry residues, and municipal and industrial wastes.

“Biomass in the waste and residues category, which doesn’t require dedicated land use, is synergistically created by industries such as forestry and agriculture. You’re creating timber or food, but some of the branches, husks, and other leftover biomass can also be used for materials and energy.

“There can be a role for land use dedicated to biomass production, but the focus needs to be on land that isn't already being used for human habitation or biodiversity, such as protected forests or natural lands. There really isn’t much land available that isn’t already playing an important role,” she added.

Ranking actual types of bioresources on the ‘good to bad’ scale, Lord Turner places palm oil, rapeseed, and soybean biodiesel as on the bad end vs fossil fuel. Better are other ‘first-generation' biofuels such as bioethanol from sugar cane,

sugar beet and to a lesser extent corn. But bioethanol with the lowest global warming potential comes from ‘second generation’ biomass such as straw, husks, forest residues and so on from non-dedicated land, or from switchgrass or short rotation coppice grown on dedicated land.

“The crucial thing is, as far as possible, not using biomass from dedicated land, but waste and residues. And then within dedicated land, you've got to ask what would be the alternative use of that land? And if that use was anything to do with tropical forest, don't touch it,” he said.

Given that biomass is a finite resource, the next logical question to ask would be about allocation. With different industrial sectors, all having vastly different material and energy requirements and all at differing points along the road to net-zero, there must be an ideal way of putting this resource to use.

The main priority, according to the ETC, would be to use it as a material – the increased use of timber in housing, cellulose fibres in clothing, and as a feedstock for plastics, are just a few examples.

Lord Turner argues, however, that beyond material uses there are “two, maybe three contenders trade-offs”.

“As a fuel, focus biomass use on aviation simply because we don't have a better alternative. Shipping has better alternatives in ammonia or methanol, road transport has better alternatives in either battery or hydrogen. Eventually, synthetic fuels may beat biofuels in aviation, but for the moment that seems like a higher priority use.

“The other high priority use is where you can use it to produce negative emissions because you are attaching it to carbon capture and storage, for example in a power station. So, basically, only use it for combustion without CCS in an environment where there are no alternatives. Where you can use it with CCS, then it may be valuable as a route to creating negative emissions.”

While the use of biomass, especially as a fuel may not be ideal, the fundamental point of the ETC report is that it should be prioritised for materials uses and used sparingly, particularly for energy uses as a stopgap while better technologies are being developed.

It is said that necessity is the mother of invention. With new technologies and improvements to existing technologies coming thick and fast, any breakthrough technologies are more likely to reduce the demand for biomass, rather than unleash new ways of producing it.

“To give an example,” Turner says, ending on a note of optimism, “we assume that longdistance aviation needs biofuels or synthetic fuels, but when somebody comes up with a battery which is six times as energy-dense as it is today, you are extending the range of electric flight. Also, the cheaper solar PV and batteries get, the less you need biomass.

“We tend to think that we need either fossil fuels or biomass to produce intense industrial heat, but people are working on the issues of how to electrify high-temperature heat production. So, there's a series of technologies, which suggest that bioenergy is not needed. And then there are biotechnologies, which will reduce the amount of land needed to produce food and fibre.

“So the good news is that through a combination of those, we may be able this century to release a significant amount of land back to the natural environment and that includes reforestation.” n

Lord Adair Turner, co-chair of the Energy Transitions Commission