How to Make Natural Gas Greener
In discussing the challenges and opportunities facing gas, particularly regarding the environmental concerns, in light of the benefits of switching from coal to gas, Nigel Brandon, Director, Sustainable Gas Institute, Imperial College London, notes the trend of growing gas demand, which he calls a “good thing.”
He offers, “If we're switching out from higher carbon fuels into gas, then we also gain benefits in terms of other pollutant emissions of burning gas rather than coal, but of course it's still not a zero carbon fuel and we will also need to bear in mind the carbon intensity of gas going forward.”
Citing the political, social, cultural debate over climate change, Prof. Brandon shows a graph of the various probabilities of staying below a specific equilibrium temperature increase, considering how much CO2 is in the atmosphere. “Of course this is about risk, not just about absolutes,” he says.
According to him, governments have committed to a temperature rise of 2 degrees C, “and the probability of remaining within that goes down as our CO2 goes up.
“If we say we want a 90% probability of remaining within that, we need to keep to 350 ppm CO2, which is virtually impossible now.”
There is debate, he says, about the “carbon bubble” which sets a global budget for the amount of carbon that can be emitted from 2000-2050. Mr. Brandon's diagram shows a small, opaque circle to depict the carbon already burnt, and a somewhat larger circle representing what remains to be burnt – both add up to 886 gigatons of CO2.
Next to those spheres are three representing global fossil fuel reserves: a huge one for coal (around 2,000 tons) and smaller ones for oil and gas – just under 3,000 gigatons of CO2.
More recent analysis from University College in London published in Nature, he reports, revisited this analysis and relaxed the target to 50% probability of remaining within the 2 degree limit gives a budget of 1,100 gigatons. “They concluded in their paper that, for the world to maintain this limit, we could not afford to burn more than half the gas, one-third of the oil and 20% of the coal – quite a statement,” says Prof. Brandon, who adds that this affects how these assets are valorized.
What difference does greening gas make to technology developments? He shows a complicated diagram depicting the merit of heating and powering homes using fuel cell micro CHP unit – a very efficient generator. “You put natural gas into your house and you make your own electricity for 50% efficiency. You capture the heat, being that you're using about 90% of the value of the fuel usefully.”
It is, he says, about the most efficient technology conceived to power homes and by using it in a home it is possible to save 1.2 tons of CO2, not to mention 25% savings on energy costs for someone in the UK; the carbon benefit does not exist compared to nuclear energy provided consumers in France, he adds.
Being able to take carbon out of the gas network, according to Prof. Brandon, would result in being able to maintain a carbon benefit.
As a result policymakers, he explains, are being dissuaded from supporting energy efficiency measures to use gas for heating for fear of the “lock-in.” They believe in pursuing low carbon electricity.
But to deal with consumption peaks during winter months, he contends that the electric power infrastructure would need to be doubled, for example, in the UK, a significant investment.
He offers, “It's likely, therefore, that what we need is a system which is going to balance low carbon electricity – in other words, renewables and nuclear – against gas. The question is, what does that actually look like?”
Grappling with how energy systems should evolve considering sustainability, security and economic targets might be a real mandate for the greening of gas, he says.
High quality, transparent and robust analysis is necessary. “Sadly, industry isn't always best placed to do that, not only in terms of the skill set but in terms of public perception,” he opines.
Academia, however, can overcome those obstacles, but requires robust and up-to-date data in terms of cost, technology performance, etc., which are in the domain of industry. This, he says, points out the need for collaboration between the two.
With that in mind, Prof. Brandon explains that the Sustainable Gas Institute is a new research hub founded by BG Group and Imperial College, engaged with a wide range of partners. While focused on research, he says, “It's very much aimed at defining the innovative technologies that will be needed for gas to play its role to the benefit of the system as a whole in a low carbon world.”
Among the research “spokes” is one at the University of Sao Paulo on gas innovation; on carbon capture storage and use in the gas production/ distribution chain; and on energy efficiency, focused on the gas production side of the supply chain.
The hub, he adds, is focused on two main things: white papers – evidence-led, transparent, robust high quality pieces of work that address contentious issues relevant to natural gas; 2)
Of the organization's white papers, he says, “The first one we've chosen to work on is fugitive methane emissions and the gas supply chain. We've talked about the carbon benefits of gas compared to coal, but methane is, of course, a very significant global greenhouse gas – far more than CO2 – so if methane leaks and gets out into the environment, it makes a big difference to climate change impact of natural gas. There's a lot of contentious debate about what the numbers are.”
Secondly, he reports, the hub is trying to develop a simulation tool of a global energy system to be able to determine the role that gas might play, including the aspects of engineering and technology.
“It's a tool that allows you to look at the synergies between gas and other energy carriers,” he explains, “so you can ask 'what if' questions. Policymakers and other stakeholders, because it will be open source, will be able to see the basis on which the outputs and decisions are made, whereas today most of these models are hidden inside of a black box.”
Technology-rich, it should help them determine what to emphasize.
Strategic questions are being asked about natural gas, observes Prof. Brandon, who asks, “Is natural gas just a transition fuel? Or, actually, is it just a destination fuel? And if it is a destination fuel, how does one explain to stakeholders, policymakers and investors what the potential in the long-term is for the gas industry?”
A partnership between academia and industry can show gas the way forward, concludes Prof. Nigel Brandon.
-Drew Leifheit