green

Air source heat pumps: the next steps towards net zero

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Air source heat pump and air conditioning unit: the unglamorous side of our journey towards net zero

We seek to inspire and enable young people to make a positive difference – this is our purpose as a school. This means that they can make a positive difference to themselves, through the improvements in their learning, behaviour and attitude that they make every day. They can make a positive difference to our Academy, through their presence in our community and the contribution that they make. And they can go on to make a positive difference to the world, as a result of the education they have had at Churchill.

Making a positive difference is also something that we seek to do in the Academy’s environment, and our environmental impact. I have previously written about our net zero target and the steps we have already taken on that journey. More recently, we have completely replaced the heating system in the Performing Arts block (which also houses three art classrooms) to be run entirely off an air source heat pump, which was installed over the winter.

How a heat pump works (diagram from EDF)

An air source heat pump absorbs heat from the air around us and transfers that heat to the inside of the building. Outside air is drawn in over a network of tubes filled with refrigerant gas, which circulates at -28°c to extract heat energy from the air outside. This low temperature refrigerant means that the systems pulls heat from the air, even when the outside temperature is below freezing. The gas passes through a compressor which increases the pressure and temperature, causing it to change from a cold gas to a hot liquid. The compressed hot liquid passes into a heat exchanger, which provides heat to the system. The refrigerant then turns back into a cold gas and starts the cycle all over again.

We are using an air-to-air system, which means that it will also double as a cooling system in hot weather in the summer. This means that the rooms will be kept at a good working temperature all year round – all using low carbon technology.

Net Zero Grant: we’re not finished yet!

I’m also delighted to say that we have been successful in securing a grant from the Department for Net Zero and Energy Security – the Public Sector Decarbonisation Scheme. The grant, totalling £222,430, will allow us to replace gas boilers with air source heat pumps in the Sixth Form and around the Hive and Hall building. It will also pay for other improvements, such as double glazing and external wall insulation.

The work is all scheduled to be completed before September, which will mean that when we return for the new academic year there will be yet another building completely run from renewable energy sources – a further step towards our net zero target.

The project signifies the latest in a long line of energy efficiency and decarbonisation projects that we’ve been working on since 2015. Investments in point of use hot water heating, solar pv, boiler controls and LED lighting have supported a 70% reduction in CO2 emissions across our activity, and we remain committed to our ambition to be net zero carbon by 2030.

Of course, we welcome the grant funding to enable the next stage of our decarbonisation work to continue and look forward to taking another step forward on our sustainability journey. Our students are passionate about a greener future, and we’re striving to lead and deliver on this.

However, we know we have been fortunate with having funding allocated, as many other projects will not have been successful. And, without this grant, we simply couldn’t have afforded to do the work ourselves. As we’ve highlighted in the past, the ambition of school leaders is not always matched by the funding available for capital works or initiatives around decarbonisation. And with the increasing pressure on school budgets from many directions, including rising fuel costs, the question shifts from decarbonising for the good of the planet, to one of simple affordability. Because, the truth is, installing low carbon alternative technology is expensive! If the government is serious about a national move to net zero, it needs to be funded properly for all, and not just those fortunate few who are able to secure the grants.

Sustaining Sustainability

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This week Mrs Franklin (the Academy’s Sustainability and Marketing Manager) joined me to present to a national conference of School Business Leaders. We were asked to present our work on reducing the Academy’s carbon footprint towards our goal of net-zero by 2030, and we also took the opportunity to look more broadly at our sustainability priority.

Many of the things we spoke about in our presentation are captured in the blog post I wrote around the #COP26 summit in Glasgow last November – Going Green: Churchill and #COP26. We emphasised how important it is to us that sustainability is one of the five priorities in the Academy’s five-year strategic plan, and that sustainability is driven by our students – as we owe it to them to protect the planet they will grow up on. In fact, I will be judging the students’ Seeking Sustainability competition entries next week!

Solar PV array on the roof of the Athene Donald Building

Mrs Franklin was able to update the conference delegates on the impact of some of our carbon reduction work:

  • Reviewing our controls and boiler optimisation so that boilers are only on when they are absolutely needed has saved 22,000 kWh of energy
  • The replacement of our lighting with LED units has saved 150,000 kWh on electricity
  • The solar panels (or photovoltaic cells as they’re more properly called) which cover much of our roof space across the site can deliver up to 40% of the Academy’s electricity needs in peak summer weather
  • The introduction of point-of-use hot water heaters mean that our boilers can be completely switched off for long periods of time in warm weather, saving 300,000 kWh in gas

Finally, Mrs Franklin was able to present an updated carbon emissions chart which shows we have reduced our carbon footprint by 70% since 2015 – a further 20% reduction since the 2020 figures.

This presentation wasn’t all celebration however. As a school, we have picked almost all of the “low hanging fruit” in our battle to reduce our carbon footprint. The next stage of our journey to net zero involves the bigger challenge: reducing or removing our dependence on natural gas completely. As we look at heating and cooling solutions across the Academy’s estate, to replace our ageing gas boilers, we really want to find low-carbon solutions. Our Trustees last week commissioned work to explore how best to achieve this.

What we already know is that we will need additional funding to enable this work. We also know that the Department for Education is facing an estimated £11.4 billion bill just to bring the school building estate up to standard across the UK – and that’s before they begin to think about decarbonising that estate. And so, whilst we are grateful for the existence of the DfE’s Sustainability and climate change: a strategy for the education and children’s services systems – we feel that it doesn’t go far enough. If we are serious about net zero, we need to tackle the big ticket items which contribute to our carbon footprint: gas-fired heating systems, and emissions from transport. Whilst we can make progress on these issues ourselves, we’re going to need help if we’re going to solve them for good – and that means investment to back up the sentiments.

We know our students are ambitious for a greener future – and we owe it to them to deliver it.

Going Green: Churchill and #COP26

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The COP26 summit is an opportunity to change the world. Leaders are meeting in Glasgow to accelerate action towards the goals of the Paris Agreement and the UN Framework Convention on Climate Change. They will attempt to agree significant actions to reduce carbon emissions, control global warming, and save our planet for future generations. Whether they succeed or not, is out of our hands. But, at Churchill Academy & Sixth Form, we are committed to doing what we can to reduce our impact on the environment, and to improving the prospects of a greener future for our students and those that follow in their footsteps.

Our commitment

We’ve taken the Let’s Go Zero pledge, declaring our aim to become zero carbon by 2030. We know that schools can be the trailblazers for their community, responding to young people’s calls for action.  In fact, they can inspire whole communities to tackle the climate crisis. In the coming pivotal ‘climate decade,’ we will be part of Let’s Go Zero’s national network of schools and sustainability organisations, sharing information about how to reach zero carbon, and working with local councils and government to make it happen.  

Our ambition

In our aim to achieve net-zero carbon emissions by 2030, we will:

  • Recycle more waste material than we send to landfill
  • Achieve the decarbonisation of our heating system on site, reducing reliance on gas 
  • Re-invest financial savings from sustainability initiatives back into programmes that will deliver towards our carbon emission target

We will show Kindness to the environment, demonstrate Curiosity when looking at how to do things differently, and practice Determination to make a positive difference.

Here are some of the things we’ve already done:

The built environment

Over the past five years we have transformed the built environment of our Academy. In 2019 we finally demolished the original school building, the 1956 block which was latterly home to Tudor House, Science, IT and Business. The energy-inefficient, single-glazed, concrete building has been replaced by modern, well-insulated facilities including the Alan Turing Building and the Athene Donald Building. Both of these were built with sustainability in mind, not just in their construction methods but as sources of energy generation. The roofs of both blocks are completely covered in solar panels, as you can see in the shot of the Athene Donald Building below:

It’s not just the new builds, either. We have solar panels across the roofs of Performing Arts and Music as well, as you can see in the latest Google Maps satellite images of our site:

Source

We are currently halfway through the complete internal rebuild of the Stuart and Lancaster House building, home to languages and humanities. This includes ripping out and completely replacing all the heating, lighting and electrical systems to run as efficiently as possible, as well as ensuring the building is properly insulated and ventilated.

Hot water

A point-of-use water heater

This is the unglamorous part of decarbonisation! Previously, hot water for the site was provided by tanks, heated by boilers in big boiler room facilities for each separate block. This process was energy-inefficient and wasteful, as it heated large amounts of water whether it was needed or not. Over the past year we have been phasing out these hot water tanks and replacing them with point-of-use water heaters, which only heat water as it is needed. These heaters reduce wasted energy, and also free up spaces which previously housed tanks and boilers for storage. We will continue this work in the future.

Lighting

All of our new builds and refurbished facilities have been equipped with LED lighting, and over the past years we have been phasing out any remaining fluorescent tubes to replace them with energy-efficient units. They actually provide better quality light too! Many of our corridor lights are now linked to motion sensors as well, so they are not on unnecessarily, and the external lighting has been upgraded as well. Let there be light!

Recycling

We have always tried to recycle as much waste as possible, and this term we have increased the number of recycling bins on site to encourage pre-sorting of waste as it is thrown away.

The real battle, of course, is reducing the amount of waste we produce in the first place! There is much we can still do in this area, and students and staff are already moving forward with plans to use technology instead of paper, to reduce packaging waste, and to continue our battle against litter.

The green environment

We are lucky in our rural site, surrounded by trees, fields, orchards, and the Mendip Hills. We do all we can to preserve and enhance our green and pleasant site wherever possible. This includes a massive programme of tree planting across the site, including across our car parks and around the perimeter. We are also keen to encourage biodiversity, working with local partners to ensure the wildlife that shares our environment can continue to flourish.

Student Leadership

The student-led Green Team has been operating in the Sixth Form for the past five years. Previously they have introduced reusable and recyclable coffee cups for the Common Room, used the “no power hour” to highlight energy usage, and redeveloped the pond area next to the Sixth Form Centre. This year, the Green Team has great plans – and they’re going whole school, to bring main school students on board too. Look out for further updates later this year!

Energy and CO2 impact so far

Our CO2 monitoring graph, with future projections

The efforts above have already had a significant impact on our CO2 emissions, which have been cut by half in the past five years. We know there is more to do if we are to achieve our ambition to be an environmentally sustainable institution – in particular, reducing our reliance on gas, and continuing to improve the efficiency of our site. We’re proud of what we’ve achieved so far – but we’re just getting started.