Wessex: Net zero by 2030 means challenging assumptions on investment

Wessex Water has pledged to take a “total carbon” approach to reaching net-zero emissions by 2030, stressing that water companies cannot shy away from tackling difficult-to-decarbonise areas.

Publishing its routemap as part of the industry-wide commitment to reach net zero by 2030, the South West-based water and sewerage company underlined the need to focus both on operational emissions and “embodied carbon” resulting from the materials, products and services it uses.

To that end, Wessex intends to build “whole-life carbon into our decision-making processes”. However, it emphasised that the innovative approaches needed to achieve this goal would require “challenging assumptions about the best ways to carry out investment for customers, communities, and the water environment”.

The routemap sets out broad actions Wessex will take to achieve net-zero operational emissions by 2030, as well as paving the way for net-zero total carbon emissions by 2040.

Its 2019/20 baseline stands at 117 kilotonnes of carbon dioxide equivalent. Around 65 per cent of this is related to energy use, 25 per cent from sewage and sludge process emissions and 10 per cent from transport.

The plan estimates that a business-as-usual approach would see these emissions cut by a third. Its strategy to find the remaining savings is focussed around three strands:

• Emissions avoidance by further reducing leakage and encouraging water efficiency; use of lower carbon transport and promoting low energy, nature-based solutions
• Optimisation measures to improve energy efficiency
• More renewable energy by increasing generation from biogas and new opportunities for wind and solar power, both as generator and end user

The routemap says offsetting emissions should be a “last resort” but may be necessary to hit the 2030 target. Through its subsidiary company EnTrade – an online platform for collaboration with farmers and landowners – Wessex is “looking at opportunities to play a part in the creation of markets for carbon reductions through the promotion of nature-based solutions”.

As well as switching to low-carbon transport options, including biomethane, the routemap points to continued opportunities for remote working to limit the need for travel.

The document highlights the difficulty of tackling treatment emissions and says action in this area will be informed by trials of monitoring solutions.

Wessex’s renewable energy credentials will be burnished by further biogas production, new solar and wind installations on its land and through the exploration of power purchase agreements with off-site renewable generators.

As well as setting out readily available options for the current decade, the routemap looks ahead to more innovative solutions, envisaging trials in the late 2020s/early 2030s. These include the integration of hydrogen generation with existing activities; alternative sewage treatment such anaerobic treatment processes and algae and the rollout of further measures to minimise use of potable water, such as water reuse and rainwater harvesting.

It also mentions the potential for technological carbon capture, including turning sewage sludge into biochar, a charcoal-like material widely recognised for its potential for greenhouse gas removal, via pyrolysis, gasification or hydrothermal carbonisation.

The company’s initial estimates suggest that a full-scale biochar unit at its Bristol sludge treatment centre could capture around 20 ktCO2e per annum. However, it would likely cost “tens of millions” to build and involve a major change in sludge management practices.

Chief executive Colin Skellett said: “There is no doubt we are in the midst of a climate crisis. Unless substantially reduced or removed, these gases will result in a level of global warming that will be catastrophic for humanity and most of the world’s remaining ecosystems. The climate is changing rapidly and the effects will become more severe unless we act now.

“It is critical that we focus our efforts on ways to neutralise our carbon footprint and are committed to achieving net zero operational carbon emissions by 2030. However, we must decarbonise all aspects of our work, and will work to achieve net zero total emissions by 2040 at the latest.”