Tuesday, January 26, 2016

[biofuelwatch] Good blog article about biogas from maize in the UK


More Maize Madness: Far from being a climate change panacea, producing Biogas helps intensify its consequences

Tackling climate change is one of the most pressing and urgent things facing humanity, alongside (and related to) the 6th Global Extinction crisis. Some suggest that tackling Climate Change trumps all other considerations.

One of the biggest consequences of climate change facing the UK is severe flooding due to increasingly intense rainfall.

But flooding is exacerbated by unsustainable types of land-use. Maize is one of the most unsustainable and environmentally damaging crops it is possible to grow in the UK.

maize field flooded

Somerset Levels Maize field, flooded.

One of the reasons for this is that Maize is harvested so late in the season that the ground is too wet to do anything with, after the harvest. So fields are left either with stubble over winter, or rough-ploughed. This field is in the Somerset Levels, the scene of intense flooding two years ago.

Maize harvesting involves a forage harvester driving up and down over the field and tractors and trailers driving alongside collecting the maize harvest. So all the traffic across the field compacts the soil which leads to water running straight off the compacted surface – akin to a tarmac-ed car park.

It is therefore somewhat ironic that the NFU are pushing for much more Maize to be grown – to supposedly help alleviate climate change. Maize for biogas, they say, will help mitigate climate change by replacing fossil-fuel derived natural gas with biogas, produced by fermenting maize. the NFU would like to see well over 200,000ha of land converted to grow biogas Maize. I've previously criticized the maths underpinning the idea that growing biogas Maize actually saves any carbon at all; and the ridiculous double subsidies that support its production. What I hadn't appreciated then was how much maize is needed to fuel these Anaerobic Digester (AD) plants.

We have an AD plant on the outskirts of Dorchester at Rainbarrow Farm, next to Prince Charles' model village of Poundbury. In fact the plant is partly owned by Prince Charles via his Duchy of Cornwall. I imagine Duchy farms in the area (for there are many) also grow the maize to fuel the plant. I was a bit surprised, last Autumn, to see tractor with trailers full of Maize trundling through the streets of Dorchester on their way to the digester.

Anaerobic Digestion can in theory turn all sorts of green waste into environmentally friendly biogas. But in the case of Rainbarrow Farm, two thirds of the plant's feedstock is maize – that's 26000 tonnes of maize. If that sounds a lot, that's because it is a lot. Maize is highly intensive crop, producing around 50 tonnes per hectare of farmland. That means over 500ha (1200 acres) of farmland is needed, just to supply one small AD plant. Still, you might think that's worth all the environmental damage, increasing the risk of flooding, destroying the wildlife (and fishing) quality of rivers by filling them with polluted sediment. After all, what's more important than tackling climate change?

The only problem is this: apart from the fact that growing maize to produce biogas has a much bigger carbon footprint than anyone in the industry likes to admit, this AD plant creates enough gas for around 2000 houses per year. With 200,000 households in Dorset, we would need to be growing 500,000ha of maize to supply them with gas.

That's twice the area of Dorset.

Meanwhile the NFU continues to push for landowners to be paid for the loss of crops when floodwater is stored on farmland, following the successful case last week. This would presumably include loss of Maize crops grown for biogas, on land that had formerly been permanent pasture. Pasture which, until it had been converted into Maize, had been very good at holding and storing flood water, without any damage to the grass crop. As Private Eye would say, Trebles all round.



Posted by: biofuelwatch@ymail.com


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Biofuels are a wide range of fuels which are in some way derived from biomass.

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