Schools Energy Retrofit Programme

Milton C of E Primary School was one of the first schools to participate in the programme and benefit from guaranteed energy savings. Following receipt of an Investment Grade Proposal (IGP), detailing potential measures and savings, a number of Energy Conservation Measures (ECMs) were installed across its three buildings in summer 2015.

One year after completion, the school has exceeded their performance guarantee, saving £16,000 on their energy bills.

Savings:

• £11,000 energy spend reduction per annum
• 26% savings on energy cost per annum
• 45 tonnes of CO₂ per annum saved

Value:

• £166,000
• Simple payback of 15 years

"This programme not only allows for the replacement of major items, but also creates a learning and working environment that is superb and energy efficient. The savings general will be used to ensure that Milton C of E Primary School continues to deliver the highest standard of education that the pupils deserve.”

David Lee, Chair of Governors, Milton C of E Primary School

Summary of Energy Conservation Measures (ECMs)

Solar PV Array: Installed 30kW CIGS Solar PV Array with Export Limitation on the large south-facing roof, which will generate an annual financial benefit of £4,689, saving 8.4 tonnes of carbon a year.

Lighting Upgrade: An LED upgrade across the three buildings will yield around £1,400 in savings every year. It will also provide 6.4 tonnes of carbon savings.

Building Automation: Controlling existing plant via Building Energy Management Systems (BEMS) and programmable thermostats will save the school in excess of £1,650 per year and around 9 tonnes of carbon.

Loft insulation: Improving loft insulation to current building standards will save a total of 2.7 tonnes of carbon and will free up more than £430 per annum in terms of saved heating cost.

Condensing Boilers: After careful consideration, it was agreed that all boiler plants would be replaced with modern condensing boilers, which will save more than 15 tonnes of carbon and more than £2,430 in heating costs.

Zoning: Zoning in different areas of the school will provide better heating control. This will enable the school to save an extra £190 in heating costs and contribute just over a tonne of carbon savings.

Insulation of heating components: By insulating the heating plant, the school will be saving in excess of £300 annually, which translates into approximately a further two tones of carbon savings per annum.

Soham Village College, a member of the Staploe Education Trust, is a large secondary academy set in a 40 acre site. Prior to the project the school consumed 2.4 million kWh of energy per annum at an annual energy cost in excess of £100,000. Much of the energy infrastructure on site was old and either inefficient or reaching the end of its lifecycle.

We invested £481,700 in upgrading the energy infrastructure at Soham Village College installing solar PV, LED lighting, replacing boilers that were at the end of their lives, and installing state of the art energy management systems across the site to enable optimised operation of heating. The school lease the equipment from the us, with lease costs being paid for from the savings in their energy bill. The lease terms give the school the option to buy the equipment at the end of the 15 year lease term at a pre-agreed residual value.

Summary of benefits:

• £481,700 capital investment
• 629,447 kWh energy saving per annum
• 31,531 energy savings & revenues
• 41,423 kWh of renewable energy generated per annum
• 179 tonnes CO₂ saving per annum

Summary of Energy Conservation Measures (ECMs)

Solar PV arrays: 50 kW solar PV was installed in two separate arrays. The installation uses polycrystalline solar modules with a power optimiser system to maintain optimal performance, even if part of the system is shaded. Around 70% of the electricity generated will be used on-site, saving nearly £3,000 per annum in electricity costs, with the surplus exported to the electricity grid. The installation will also generate £2,400 of revenue for the school from Feed in Tariff and Export tariff payments and save nearly 16 tonnes of carbon per annum.

Condensing boilers and calorifiers: The selected solution replaced seven old, inefficient boilers with six new high-efficiency condensing boilers. Two calorifiers were replaced with new units and emitter controls were fitted to electric hot water heaters. This will contribute 22 tonnes of carbon and £3,000 to the overall savings.

LED Lighting upgrade: A total of 1,114 luminaires using fluorescent, tungsten halogen and HID (metal halide or sodium) were replaced with LED luminaires. This will yield nearly £15,000 a year electricity savings and provide around 80 tonnes of carbon savings per annum, as well as significantly reducing ongoing maintenance costs.

Heating Ventilation and Air Conditioning system insulation: Installation of tailor made insulation jackets and pipework lagging across 10 boiler houses will save the college around £1,600 annually. This translates into a further 7.8 tonnes of carbon saved per annum.

Building automation: Priva BlueID Building Energy Management Systems (BEMS) were installed across all plant rooms, enabling the status and performance of all heating and hot water systems to be viewed and optimised via a web-enabled dashboard. This will save the college in excess of £4,400 per year along with nearly 33 tonnes of carbon.

Emitter controls: Programmable Room Thermostats were installed in 51 Fan Convector Unit heated zones, along with 98 Thermostatic Radiator Valves and integration of underfloor heating into BEMS control. This will yield nearly £2,200 a year savings and provide around 16 tonnes of carbon savings per annum.

Great Paxton Primary School had a previous annual energy spend of £11k per year and was guaranteed to save £7k per year (64% saving) with these new improvements.

Savings:

• £11,000 energy spend reduction per annum
• 62% savings on energy cost per annum
• 20 tonnes of CO₂ per annum saved

Value:

• £97,000
• Simple payback of 15 years

"It’s been a huge success. After one year we are cash positive and our electricity and gas bills have halved. We have generated income and reduced our carbon footprint, but most importantly, we have provided a better environment for our children to learn in. With the savings made we are in a position to provide more for our pupils.”

Lee Frost, Headteacher, Great Paxton Primary School

Summary of Energy Conservation Measures (ECMs)

Solar PV array: Installed a Solar PV Array, sized at just under 30kW on the south facing pitched roof, it generates an annual financial benefit of circa £4.4k, saving 7 tonnes of carbon a year.

Lighting upgrade: An LED upgrade across the three buildings yields around £835 in savings every year. It also provides 4.6 tonnes of carbon savings.

Building automation: Controlling existing boiler plant via Building Energy Management Systems (BEMS) saves the school in excess of £371 per year and around 2.3 tonnes of carbon.

Insulation : Improving loft insulation to current building standards and insulating the heating components within the heating system in the boiler room, this saves at least 3 tonnes of carbon and frees up more than £488 per annum in terms of saved heating cost.

Condensing boilers: After careful consideration, it was agreed that the boiler plant would be replaced with modern condensing boilers, which saves more than 5 tonnes of carbon and more than £867 in heating costs.

Comberton Village College Low Carbon Heat Network – Case Study

The County Council has been working in partnership with the Cam Academy Trust, and Bouygues Energies and Services to deliver a low carbon heat network (LCHN) at Comberton Village College following on from installation of energy efficiency measures (141 kW solar PV, LED lighting and controls upgrades). The project takes the secondary school completely off oil heating and replaces oil boilers, that were approaching the end of their life. As well as reducing carbon, the project will save the college around £931,000, over the 20 year equipment lifetime, compared to the cost of operating and maintaining oil heating.

• Capital Cost of the project £3.1 million
• Energy savings of 1,051,810 kWh pa
• Payback of 16 years
• Carbon saving 248 tonnes CO₂e pa

Ground source heat pumps (GSHP)

There are 2 GSHPs installed in the main Energy Centre which provide 705kW of heating to the school. These extract heat through a network of underground pipework linked to 60 boreholes, each 200 metres deep, in the college’s car parks.

Low Carbon Heat Network (LCHN)

The GSHPs in the main Energy Centre upgrade the temperature of the heat extracted from the boreholes to 65 degree centigrade and supply a network of pipes linked to 10 further plant rooms around the site. The network of pipes, some wall mounted and some buried in trenches, ensures that the water is recirculated and re heated.

A key element of the heat network is a 15,000 litre thermal store, essentially a large hot water tank, that stores heat from the heat pumps so that peaks in demand for heating can be smoothed. The Energy Centre also includes an electrode boiler to provide back-up heating in the event that one of the GSHPs is down for maintenance.

The LCHN will reduce carbon emissions from the college’s heating by 248 tonnes of CO₂e (a 70% reduction) in the first year. As the grid electricity used to drive the GSHPs is further decarbonised, this saving will increase to 344 tonnes (a 95% reduction) in year twenty.

We have a budget for providing finance for schools energy efficiency retrofit projects

1. Maintained Schools - A loan of typically 15 years. Up to 20 years can be considered for deeper retrofits involving boiler replacement
2. Academies - A Managed Services Agreement (MSA) where the academy lease the equipment from us, typically for 15 years. Option to purchase equipment at end of term at a pre-agreed residual value

In both cases:

• Interest on the capital is charged at public sector rates
• Loan / lease payments can be funded from project energy cost savings and revenues
• Interest rates are staggered to improve cashflow in early years of project

In order to ensure the project is performing as guaranteed, the Energy Performance Contractor assesses the performance of the energy conservation measures each year for the duration of the payback period.

Assessment includes routine adjustments for:

• solar irradiance (weather)
• heating degree days (weather)
• (If required) Non-routine adjustments are made for unforeseen changes in energy use e.g. :
• Increase or decrease in student numbers
• Change in site/plant operating hours

An Annual Reconciliation Report is provided in draft, reporting on performance versus the guarantees, ahead of a meeting. These reports are a contractual document required as part of the energy performance contract, and must be agreed by the school, EPC contractor and County Council.

If there is a shortfall in performance, the EPC contractor compensates the school, unless there have been offsetting over-performances in previous years

We understand that schools simply do not have capital of sufficient scale to pay for projects up front, so we have developed low-cost finance solutions to enable the up-front investment required. For maintained schools, we can offer a straightforward loan with interest rates below the market level. You use the loan to pay the service provider. Loan repayments are managed so that as much as possible, schools can see a positive cash flow through the contract period, with the value of the energy savings realised exceeding the cost of loan repayment. For low carbon heating projects, we can also apply for grant funding and provide capital contributions to make these, higher capital cost projects, affordable.

As the County Council is unable to offer a loan to academy schools, we have instead developed an ‘off-balance sheet’ solution. This works like an operating lease to deliver energy savings to your school.

Who is involved?

Cambridgeshire County Council selected an initial service provider from the Re:fit procurement framework for Energy Performance Contracting, in 2014. Since then, the Council has re-procured its Energy Services Provider, most recently in 2020. The current providers are Bouygues Energies & Services and SSE Energy Solutions.

Cambridgeshire County Council – we appoint the service provider and work closely with them to ensure schools are getting the quality service they need; we also provide financing to schools for the projects.

Bouygues Energies & Services and SSE Energy Solutions – are the service providers who conduct engineering surveys, develop business cases and project manage the installation. Bouygues and SSE can also provide Energy Performance Guarantees.

School – the client; will need to provide site information and access, make timely decisions about proceeding and are responsible for maintenance after installation.

Business cases assume existing infrastructure e.g. wiring, pipework, radiators, in good condition. A small provisional cost allowance is included for asbestos and other contingencies.

EPC contractor is responsible for Measuring & Verifying annual energy performance for the payback period

Energy savings are guaranteed for the duration of the payback with compensation payable in the event of an overall shortfall

School are strongly advised to maintain half hourly automated meter reading for gas meters. This enables accurate assessment of thermal performance and early identification of any issues

Some risks and responsibilities remain with school:

• Operation & Maintenance of equipment
• Energy price risk (eg. if energy unit costs are higher than predicted within the initial energy performance contract)
• Weather
• At handover, it is best if at least two members of staff are trained on new systems, in the event of staff changes, schools should obtain training from their servicing contractors