Net Zero

Welcome to Net Zero: The Energy Efficiency Podcast, episode 4, the podcast that brings you a mix of energy efficiency news, products and tips all year round. We’re interested in profiling people and products involved in promoting energy efficiency habits, products and information, so please do get in touch if you have something to contribute.

This week: net zero, tenants’ rights to energy efficiency works in their homes, and district heating. But before we get on with our advertised features, at the end of last week the UK press was reporting the National Grid’s prediction that zero carbon energy sources will provide more than half the UK’s energy in 2019.

Coal-fired power is declining, replaced by clean sources of power such as wind, solar, hydro and nuclear. So far this year coal-fired power has generated only 3% of power, whereas renewable eneergy has leapt from generating just 2% to 20%. This comes on the back of Britain’s longest stretch of coal-free power generation recently, equivalent, according to a Guardian article, to preventing 5m tonnes of CO2 being release into the atmosphere, the equivalent of a staggering 12bn miles driven in a car.

The government plans to phase out all coal-fired power generation in just six years from now, so the Natinal Grid has the job of ensuring other sources can replace it. It is spending over £1bn a year to adapt the grid for all renewables.

Net Zero

Carbon capture technology at a coal mine

Net zero is in the news every day just now it seems – so what is it? According to the LSE’s Grantham Institute on climate change and the environment, net zero refers to emissions produced and emissions removed from the atmosphere. This can be achieved by reducing the emissions, extracting carbon, or a bit of both. The Grantham Institute draws a distinction between net zero, and gross-zero:

“In contrast to a gross-zero target, which would reduce emissions from all sources uniformly to zero, a net-zero emissions target is more realistic because it allows for some residual emissions.”

Trees

There are many permutations of how to achieve net zero. Simple tree-planting can help as trees absorb carbon dioxide. A positive knock-on from this is increased habitat for creatures of all sorts and an enhanced landscape, but this is a slow process. An article from Left Foot Forward claims that tree planting alone could deal with a third of greenhouse gas reductions needed in the next decade. This is the subject of political pressure for increased funding and government attention. Encouragingly, the CCC recommended a huge programme of reforestation and peat moorland restoration in its recent report on net zero.

Carbon capture

Technology has a huge role to play, most prominently carbon capture and storage. This in theory permits the continued burning of fossil fuels. The carbon is compressed to a liquid state then pumped deep underground into now-empty coal mines, gas reservoirs and so on. This system can capture up to 90% of carbon released from burning fossil fuels in electricity generation and some industrial processes.

Direct Air Capture removes CO2 directly from the air, converting the oxygen and storing the carbon. This type of system is used in sealed environments such as submarines and space craft, but it’s difficult to make economical at scale. As usual, there is the need to make a business case for developing technologies, creating a market for so-called ‘negative emissions’. An article on Business Green suggests that this can be achieved through a government-run system or regulated market.

Offsetting

Emissions cannot be removed completely. The CCC estimates 130 million tonnes of carbon dioxide-equivalent will still be emitted even with current technologies maximised, mainly from industry, aviation and shipping, and agriculture. Offsetting seems to be the only way to deal with these, at the moment. The Grantham Institute explains th