Methane-trapped GreenShed – the climate-friendly future of beef farming?

As the government embarks on the path to net zero, beef production has come under closest media scrutiny within the livestock sector.

Livestock’s carbon footprint is a moot point for many, with inflated figures of two-pence and misinformation leading to a broader question about sustainability.

To shed a little light, agriculture is responsible for about 10% of the UK’s greenhouse gas emissions, according to Scotland Rural College (SRUC). Roughly 41% of that comes from beef, mostly in the form of methane.

Cattle, as ruminants, are defined by their unique digestive system, which produces methane during the fermentation process in their intestines, allowing them to digest foods that humans cannot eat.

Looking at carbon emissions from a broader perspective, an increasing number of organizations are making the shift toward greater environmental sustainability through efforts to offset carbon emissions, but few are actually changing their practices.

In an effort to directly address beef’s carbon footprint, researchers at SRUC have developed a shed that operates in a circular farming system and captures direct methane emissions from shelter cattle.

See also: Aberdeenshire farms modified hydrolysis reduces diesel use by 20%

How it works?

The so-called GreenShed will target the intensive side of the beef finishing segment, and as far as livestock is concerned, it will look and function like any other segment.

“We don’t change the production process,” says Dr. Carol Ann Dothy. “There is a huge environmental benefit from grazing, so we don’t want to take the cattle out of the weeds and put them in a barn.”

“But we have a chance with the completion of the livestock because they are already sheltered. We are trying to seize this opportunity and help the industry where possible.”

With Galebreaker as the technical partner on the project, the shed will be fitted with a curtain type design that will allow it to be closed – not completely, but just enough to create a slight negative pressure.

This ensures that no air leaks inside, so that the methane gas captured can be drawn directly from the livestock using a fan.

The energy needed for GreenShed will be provided by a combination of rooftop solar panels and waste burning in an anaerobic digestion unit.

This would form part of a more circular method of cultivation, in which heat from an anaerobic digester is used in a vertical tunnel to produce butter lettuce for restaurants.

Although a demonstration shed will be built from scratch, the system is designed to be modified to fit almost any existing farm building.

Who finances it?

There are 24 projects competing for funding through the Direct Air Capture and Greenhouse Gas Removal Program, which is managed through the Department of Business, Energy and Industrial Strategy (BEIS).

If successful in winning funding, GreenShed will advance to Phase Two, starting in April and including building a prototype for display.

The three-year project will allow researchers to validate their models for financial performance, technical performance, supply chains, and the effectiveness of reducing greenhouse gases.

The shed will be built at the SRUC Beef and Sheep Research Centre, which is located at the foot of the Pentland Hills outside Edinburgh.

It operates mostly as a 1,000-hectare commercial farm, with facilities already in place to capture and measure the methane gas produced by livestock.

The subject of the test is a herd of 400-strong suckling beef cattle spanning two breeding seasons, providing year-round stock to a home inside the shed.

They graze a mix of highlands, lowlands and hills, and once housed, they will be spotted for luxury, seeing how the model blends into the wider business.

Costs

The anaerobic digestion unit is the most expensive part of the construction, but the total price is still unknown.

“Until we build it, we can’t give an exact number,” says John Farquhar, one of the lead researchers on the project.

Conservative estimates for the worst range from £300,000 to £500,000, but that really depends on what the farmer actually has on the site. If they have an ad unit, you can take away half the price.”

Operating, maintenance and component servicing expenses would also add around £10,000 to £20,000 to that figure, along with the small labor cost the vertical tunnel gets.

Those prices are relative, of course, and a recent SRUC study of consumer behavior found that buyers were willing to pay more for low-carbon products.

“There is a reasonable margin that we think consumers are willing to pay for, and there is a clear shift from the source towards the environmental features associated with the products,” says Dr. Dothy.

With that in mind, economic modeling of GreenShed factors at a premium of 20p/kg for beef – which equates to a seven-year payback period for farmers without an anaerobic digester unit.

Those who already have an ad unit on the site can expect to break even in about three years.

The final result

While the project is still in its early stages and results are yet to be seen, GreenShed presents an exciting opportunity to produce environmentally sustainable beef, going a step further than simply offsetting carbon.

Given a large number of variables, the shed will aim to capture between 60% and 100% of methane emissions from livestock while they are housed – something that we hope will equate to a 30% reduction in their overall carbon footprint.

Cornish builds kit to convert mud emissions into fuel

© Banaman

GreenShed is not the first innovation designed to capture and convert livestock emissions into potentially beneficial assets.

Bennamann designed a new type of covered mud bunker that collects methane as it bubbles from the top of the liquid.

Once there is enough gas over the lake, a processing truck is brought in to convert it into clean, compressed gas or liquid methane fuel that can be used to power combustion engines.

Lake Bennamann costs about twice as much as conventional landbank construction and 30% more than stored above ground, but the company says the value of the fuel produced means the investment must pay off within four to six years, depending on the size of the farm.

For those who already have a quality shop, there is a modified gas-capture canopy that can be positioned over the top with minimal modifications.

The company’s engineers are also working on technology to capture methane from waste forage and solid fertilizer.

This involves adding water to the material and leaving it for a few days while it forms a slurry, which can then be drawn into a covered lake, where the gas can be captured. The remaining fibrous material can be spread as a soil conditioner or pasteurized for use as bedding.

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