Net Zero: Powering our campus

Posted on: 6 July 2022 in Issue 2

Sustainable Liverpool caught up with Rachael Hanmer-Dwight, Carbon and Utilities Manager, to tell us more about how the University’s district network helps power the campus, and outlines why we need to decarbonise our energy supply.

Sustainable Liverpool: How big is the University’s carbon footprint?

Rachael Hanmer-Dwight: The University’s annual carbon footprint is 40,000 tonnes of CO2 per annum. This is what we refer to as our Scope 1 and 2 emissions, and how most organisations quantify their immediate carbon footprint.

Our emissions have plateaued at this 40,000 tonnes mark for the last five to 10 years, despite the expansion of the University, both physically in relation to our campus, and in terms of student numbers.

Nevertheless, we are still in the top ten emitters within the UK higher education sector. This is mostly because we are a research-intensive university, and we have a large estate, including our own Halls of Residence, which have increased in both size and capacity over the last decade.

Sustainable Liverpool: What are Scope 1, 2 or 3 emissions?

Rachael Hanmer-Dwight: Reportable carbon emissions are usually referred to as ‘scopes’. These can broadly be defined as follows:

Scope 1: Emissions from the direct combustion of fuels on campus, including any natural gas we use or from things like the university-owned vehicle fleet

Scope 2: Emissions associated with any electricity imported by the University

Scope 3: Emissions from indirect activities, such as waste disposal, water supply and wastewater treatment, staff and student travel, construction and the procurement supply chain

Sustainable Liverpool: What makes up the University’s Scope 1 and 2 emissions?

Rachael Hanmer-Dwight: The University’s annual carbon footprint of 40,000 tonnes can be roughly broken down as follows:

4,000 tonnes CO2 from electricity imported from the Grid

36,000 tonnes CO2 from natural gas imported from the Grid

100 tonnes CO2 from the petrol and diesel used in our University-owned vehicle fleet

Sustainable Liverpool: Why are we using so much gas?

Rachael Hanmer-Dwight: The vast majority of our scope 1 and 2 emissions are associated with our gas usage. The University has its own subsidiary energy company, ULEC (University of Liverpool Energy Company), which operates onsite energy systems, also known as a District Network. Our District Network is gas-based. So that’s why we import very little electricity and import a great deal of gas.

Sustainable Liverpool: Why do we have emissions from electricity if we are on a 100% renewable tariff?

Rachael Hanmer-Dwight: The University imports a small amount of electricity from the National Grid, in much the same way you receive electricity from the National Grid at home. We receive this electricity through a 100% renewables tariff, and we are supplied with a breakdown of which renewable sources the electricity was generated from.

For some internal reporting purposes, we can refer to this as zero carbon, and attribute zero emissions to it. However when reporting externally, for example in the annual HESA Estate Management Return, universities are required to use ‘average’ carbon factors for any electricity supplied through the Grid. This is regardless of whether the electricity has been sourced through fossil fuels or renewable sources. These carbon factors are published by the Government each year. Under these reporting schemes, we report 4,000 tonnes per annum against our renewable imported electricity.

Sustainable Liverpool: What is a district or heat network?

Rachael Hanmer-Dwight: A district network is a localised energy system which generates power and heat onsite, and provides this energy to a designated area. It’s also sometimes called a heat network because it captures the ‘waste heat’ from electricity generation and then circulates this heat to provide heating and hot water across its buildings.

The University operates one of the largest district networks in the HE sector, on our main city centre campus, using two onsite energy centres to generate power and heat and supply this across our estate. There is also a small district network and energy centre at the Greenbank residential site.

District networks are seen as a key pillar in the UK’s decarbonisation journey. The number of heat networks in the country is expected to grow, and they will be subject to significant scrutiny and standards to ensure they are low or zero carbon in their emissions.

Rachael Hanmer-Dwight from the University's Energy team discusses our Combined Heat and Power (CHP) Energy Centre and Heat Network with Clarke Energy

Sustainable Liverpool: How does a district network generate heat and power?

Rachael Hanmer-Dwight: Both of our district networks use Combined Heat and Power (CHP) engines, and large industrial style boilers. The CHP engines are fed with gas, imported from the National Grid, which then generate the electricity used in our buildings. The operational heat is captured and used to deliver heating and hot water across campus.

Large boilers also run on gas and provide back-up heating and hot water. These are used if the CHP engines fail, or in the depths of winter when heating demand increases.

The district network at Greenbank also uses thermal storage tanks. These store surplus hot water, which can then be used for heating and hot water on that site when required.

Sustainable Liverpool: How long have we been using District Networks and are they still fit for purpose?

Rachael Hanmer-Dwight: The University first built a district network over 30 years ago – in fact we were the first University in Europe to do so. Since then ULEC has invested over £30 million into building a resilient energy network, including the expansion of solar generation, and this is now classified as a ‘third generation’ network, using gas-fuelled CHP.

CHP technology was originally a low-carbon innovation because it ran predominantly on natural gas. Although gas is a fossil fuel, it was less carbon intensive than importing electricity from the National Grid. This is no longer the case due to the rapid decarbonisation of electricity, as more and more renewable generation sources have come into the mix, such as wind power. We are now investigating how we can transform and decarbonise our district networks so they can continue operating without being so heavily dependent on natural gas or fossil fuels.

Sustainable Liverpool: How are we going to decarbonise our district networks?

Rachael Hanmer-Dwight: The University is currently out to tender for a large-scale project focusing on the decarbonisation of our energy supply and operations. This major project has been in development for two years, and will require complex and extensive engineering investigations and assessments to determine what the University’s implementable plan will be. All technological and innovative options are on the table. The University’s priority is to decarbonise and ensure the resilience of its energy supply.

Whatever plan we develop, it must be manageable and help us achieve our 2035 Net Zero target. It may require adaptations to the central energy infrastructure across the district network, as well as energy technology and adaptations at building level.

For sites not served by our district networks, such as Leahurst and Ness, we need to investigate how they too can be decarbonised while continuing to use energy imported from the National Grid.

Sustainable Liverpool: Do we have any renewable generation onsite?

Rachael Hanmer-Dwight: We have a range of solar assets across our sites, mostly on our main campus and at Ness Gardens. These provide some solar power and thermal generation and contribute a small amount to the University’s total energy needs. We are continuing to explore where we could extend this as we move through our decarbonisation journey.

Sustainable Liverpool: Are we planning to reduce energy demand and improve energy efficiency?

Rachael Hanmer-Dwight: A second package of works is underway to assess the energy efficiency of the entire campus, and to develop a prioritised programme of energy measures and interventions that can be implemented across the estate. This and the decarbonisation project will support significant delivery of the University’s 2035 Net Zero Carbon commitment.

Find out more about our path to net zero here.

Rachael Hanmer-Dwight, Carbon and Utilities Manager