Should Ireland Fuel Its Power Stations With Wood Shipped From Australia?

Should Ireland Fuel Its Power Stations With Wood Shipped From Australia?

In Ireland, there has recently been some controversy over a proposal to transition a number of the country’s dirtiest power stations away from burning peat bogs, which emits even more carbon than coal. Instead, the plan is to burn “biomass” – that is, wood. However, because Ireland has relatively little forestry, there is not enough wood available to meet demand. That’s why Bord na Mona, a semi-state body that manages several peat burning power plants, proposed to source the wood from Australia.

This angered conservation groups, who pointed to the very high carbon footprint of hauling timber all the way from the other side of the world, just to burn it for electricity. And over the summer Irish planning authorities refused permission for one peat-burning power plant in County Offaly to be converted to biomass, putting the plans on hold.

Burning Australian wood in Ireland does indeed sound daft, at first. But the true carbon footprint isn’t always as straightforward as it would seem at first glance (just look at how, for example, cutting plastic packaging can sometimes lead to more food spoiling and thus higher carbon emissions, or how cotton or paper bags can sometimes work out worse than a plastic bag). Therefore, since Bord Na Mona has been slow to release details on the potential carbon emissions, I thought it would be useful to try and estimate them myself.

First I want to clear up one thing: burning trees doesn’t necessarily count as emissions. Though trees are made of carbon, if at least one is planted for every one cut down then the overall amount of carbon in the atmosphere should remain roughly neutral.

There are many other sources of carbon emissions related to forestry though, including land use changes, forest management or processing of the wood after harvest. But in this particular case, the main source of carbon emissions would be transport.

Calculating the footprint

To make the calculations simple, let’s assume a shipment of exactly 1,000 tonnes of logs from Australia to Ireland, a distance of about 21,000km by sea. We’ll also assume another 500km by lorry to and from the port. The carbon footprint of a cargo ship depends on the type of ship, fuel used, route, speed, and so on, but for a bulk carrier it works out to about 8 grams of CO₂ per km per tonne of cargo.

Should Ireland Fuel Its Power Stations With Wood Shipped From Australia? Carbon emissions by transport method. International Chamber of Shipping, https://www.ics-shipping.org/docs/co2

For trucks it varies between 40 to 90 grams, but 55 grams per km per tonne would be a reasonable estimate. Do the maths and that works out at 168 tonnes of CO₂ emitted by the ship, and 27.5 tonnes by truck, giving a combined total of 195.5 tonnes of CO₂.

Whether these emissions are worthwhile depends on how much energy the timber contains, and that depends on the type of wood and its moisture content (wood absorbs water, making it heavier and less energy dense). A fast growing and moderately wet hardwood such as eucalyptus has an energy content of 3,500 kilowatt hours per tonne. We then have to assume the power plant will lose around 70% of all that energy (mostly as heat) when burning it to make electricity.

What this means is 1,000 tonnes of eucalyptus will yield around 1.05m kilowatt hours of electricity (the full calculation is at the end of the article). And when you take the total carbon emitted in transporting those logs to Ireland, and divide it by that total electricity generated, you get a carbon footprint of 186 grams of CO₂ per kilowatt hour.

It is worth emphasising that there is considerable sensitivity in these estimates. If any of the key variables change – if the distance to port increases, if we use a different type of wood with less moisture, and so on – it can have a big impact.

By comparison, the carbon footprint of importing biomass from North America to the UK has been estimated at 122 gCO₂/kWh. One 2014 study found that a more conventional biomass operation using locally sourced timber would have a footprint of 30 gCO₂/kWh, compared to 34 gCO₂/kWh for wind and 50 gCO₂/kWh for solar.

Should Ireland Fuel Its Power Stations With Wood Shipped From Australia? The carbon footprint of electricity from selected sources. Nugent & Sovacool, 2014

(Almost) anything is better than peat

So hauling biomass such a long distance doesn’t look like a great idea. However, the carbon footprint of peat is at least 1,100 gCO₂/kWh, nearly five times higher, and coal is very similar. And even these figures ignore the enormous environmental destruction that comes from peat extraction or coal mining.

Should Ireland Fuel Its Power Stations With Wood Shipped From Australia? An industrial peat harvester. James T M Towill, CC BY-SA

So the critics certainly have a point – bringing wood from Australia is indeed considerably worse than any other renewable option. But it’s still better than burning peat and destroying more of Ireland’s diminishing bog lands. Yes, the country could develop other sources of biomass such as agricultural or municipal waste, or fast-growing crops like willow or hemp. But factories take time to build and trees or crops take time to grow, and nobody is going to develop such resources if demand for the fuel simply isn’t there.

This is the reality of sustainability: we are often faced with trade offs between least worst options. In fact, Ireland will soon face an even bigger decision. Moneypoint, a coal burning power station and the country’s single largest source of carbon emissions, will hit the end of its service life in 2025 and there is a big question mark about what’s going to replace it.

Ultimately, there is no perfect solution to climate change. If there was, we’d have already implemented it. Options need to be carefully evaluated, for the devil is truly in the detail and small tweaks to a process can potentially lead to big changes in carbon emissions. This also shows the importance of long-term planning. After all, had the unsustainable nature of peat burning been acknowledged decades ago, we’d not be in this situation.


The full calculation:

Total generated from 1,000 tonnes of eucalyptus logs: 1,000 tonnes x 3,500 kilowatt hours per tonne = 3,500,000 kwh x 0.3 (because the other 70% is lost and not converted to electricity) = 1,050,000 kwh

Transport emissions: 195.5 tonnes of CO2 are emitted in transporting 1,000 tonnes of logs from Australia to Ireland, or 195,500,000 grams.

Divide the carbon emissions by the generated electricity to get a carbon footprint of 186 gCO2/kWh (195,500,000 / 1,050,000 = 186)The Conversation

About The Author

Dylan Ryan, Lecturer in Mechanical & Energy Engineering, Edinburgh Napier University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

books_causes

enafarzh-CNzh-TWdanltlfifrdeiwhihuiditjakomsnofaplptruesswsvthtrukurvi

follow InnerSelf on

facebook-icontwitter-iconrss-icon

 Get The Latest By Email

{emailcloak=off}

EVIDENCE

Racing Ice Loss Strips Greenland Of Mass
Racing Ice Loss Strips Greenland Of Mass
by Tim Radford
Greenland is shrinking, losing ice seven times faster than a generation ago. Scientists have taken a new and ominous…
Americans Are Worried About Climate Change, But Underestimate How Serious It Is
Americans Are Worried About Climate Change, But Underestimate How Serious It Is
by Bobby Duffy
The world is often better and getting better than people think. Murder rates, deaths from terrorism and extreme poverty…
Fossil Fuel Production Plans Could Push Earth off a Climate Cliff
by The Real News Network
The United Nations is beginning its climate summit in Madrid.
UN Report Warns Only Rapid and Transformational Action Can Stave Off Global Climate Disaster
UN Report Warns Only Rapid and Transformational Action Can Stave Off Global Climate Disaster
by Jake Johnson
Failure to heed these warnings and take drastic action to reverse emissions means we will continue to witness deadly…
Hothouse Earth: Here's What The Science Actually Says
Hothouse Earth: Here's What The Science Actually Says
by Richard Betts
A new scientific paper proposing a scenario of unstoppable climate change has gone viral, thanks to its evocative…
'4°C Of Global Warming Is Optimal' – Even Nobel Prize Winners Are Getting Things Catastrophically Wrong
'4°C Of Global Warming Is Optimal' – Even Nobel Prize Winners Are Getting Things Catastrophically Wrong
by Steve Keen
William Nordhaus was awarded the 2018 Nobel Prize in Economics for “integrating climate change into long-run…
Did Scientists Get Climate Change Wrong?
by Sabine Hossenfelder
Interview with Prof Tim Palmer from the University of Oxford.
How Climate Change Affects Wildfires
by NBC News
NYU environmental studies professor David Kanter explains how climate change is creating the perfect conditions for…

LATEST VIDEOS

Fossil Fuel Production Plans Could Push Earth off a Climate Cliff
by The Real News Network
The United Nations is beginning its climate summit in Madrid.
Big Rail Spends More on Denying Climate Change than Big Oil
by The Real News Network
A new study concludes that rail is the industry that's injected the most money into climate change denial propaganda…
Did Scientists Get Climate Change Wrong?
by Sabine Hossenfelder
Interview with Prof Tim Palmer from the University of Oxford.
The New Normal: Climate Change Poses Challenges For Minnesota Farmers
by KMSP-TV Minneapolis-St. Paul
Spring brought a deluge of rain in southern Minnesota and it never seemed to stop.
Report: Today's Kids' Health Will Be Imperiled by Climate Change
by VOA News
An international report from researchers at 35 institutions says climate change will threaten the health and quality of…
How Supercharged Trash Gas Could Produce More Green Energy
by InnerSelf Staff
Synthetic compounds called “siloxanes” from everyday products like shampoo and motor oil are finding their way into…
300 Million Face Severe Risk of Climate-Fueled Coastal Flooding by 2050
by Democracy Now!
As a shocking new report finds that many coastal cities will be flooded by rising sea levels by 2050, Chile’s President…
Climate Warning: California Continues To Burn, Data Estimates Of Global Flooding
by MSNBC
Ben Strauss, CEO and Chief Scientist of Climate Central joins MTP Daily to discuss alarming new information about…

LATEST ARTICLES

The Earth Needs Multiple Methods For Removing CO2 From The Air To Avert Worst Of Climate Change
The Earth Needs Multiple Methods For Removing CO2 From The Air To Avert Worst Of Climate Change
by David Goldberg
Many climate researchers like myself believe government needs to advance technology that will actually suck carbon…
The Emissions Due To Electricity Loss On The Power Grid Is A Lot
The Emissions Due To Electricity Loss On The Power Grid Is A Lot
by Sarah Marie Jordaan and Kavita Surana
When it comes to strategies for slowing the effects of climate change, the idea of reducing wasted energy rarely gets a…
Ultra-fast Computers Could Avert Global Disaster
Ultra-fast Computers Could Avert Global Disaster
by Tim Radford
The world can be saved. It needs global co-operation, careful research and the building of ultra-fast computers.
Politicians Not Markets Slow New Energy Dawn
Politicians Not Markets Slow New Energy Dawn
by Paul Brown
It is politicians, not economists, who stand in the way of wider adoption of cheap renewable energies across the world.
Racing Ice Loss Strips Greenland Of Mass
Racing Ice Loss Strips Greenland Of Mass
by Tim Radford
Greenland is shrinking, losing ice seven times faster than a generation ago. Scientists have taken a new and ominous…
Lessons From The Hockey Rink Could Help Ontario Tackle Climate Change
Lessons From The Hockey Rink Could Help Ontario Tackle Climate Change
by Jennifer Lynes and Dan Murray
The Auditor General of Ontario’s recent report found the province’s current climate change plan is not based on “sound…
Climate Change Threatens A Scary Number Of Plant Species
Climate Change Threatens A Scary Number Of Plant Species
by InnerSelf Staff
Almost 40% of global land plant species are very rare, and these species are most at risk for extinction as the climate…
How Drought Is Affecting Water Supply In Australia’s Capital Cities
How Drought Is Affecting Water Supply In Australia’s Capital Cities
by Ian Wright and Jason Reynolds
The level of water stored by Australia’s capital cities has steadily fallen over the last six years. They are now…