Solar Powered Schools: The Montessori Place
A break with the past - moving away from fossil fuels and towards a low-carbon future
The Montessori School group is an independent teaching facility that takes a holistic approach to education, providing children with an understanding of their place within nature and how their own wellbeing is intrinsically linked with the natural world.
In 2016 the Montessori Place School purchased a large site for a new school in the Sussex countryside, situated in Uckfield near Lewes.
The site consists of three main buildings which were constructed in the 19th Century and required a great deal of renovation work to bring them in line with modern energy efficiency standards. The main building for example had unfilled cavity walls and an uninsulated roof.
Furthermore, there was no connection to the mains gas. All of the buildings on the site were reliant upon Liquid Petroleum Gas (LPG) to provide heating and hot water. This type of fuel is not only expensive and vulnerable to volatile price fluctuations, but it also contributes to climate change and a deterioration of local air quality.
BHESCo were engaged to identify the most cost-effective and environmentally sustainable alternative to using the liquid gas, in addition to project managing a variety of improvements to the energy efficiency of the building.
Identifying the best outcome for the school
To identify the most cost-effective and suitable solution for the energy needs of the new school, BHESCo’s project management team first completed a deep survey of the existing property.
We analysed the data to calculate the anticipated annual energy demand of the school, and used this as a benchmark to measure and compare the reduction in demand that we could expect from installing different types of energy saving technologies.
At the same time, BHESCo engaged a variety of solar panel installers to submit designs and forecasts for the potential electrical generation capacity from rooftop solar PV.
In this way we were able to make conclusions about which combination of technologies would best meet the power requirements of the school, as well as being able to provide upfront cost and future savings projections. Our goal was to reduce the amount of energy required by the property, and to meet as much of this requirement as feasibly possible via on-site renewable micro-generation.
PHASE 1: Designing an integrated solar powered heating and lighting system
The final design proposed by BHESCo incorporated a range of energy saving and energy generating technologies that would work in synergy to deliver the most cost-effective and environmentally sustainable solution possible for the Montessori Place.
A 105 panel roof-mounted solar photovoltaic (PV) array was installed on two of the buildings, which will have a combined generation capacity of 27kW of electricity.
For this project BHESCo partnered with Solar Advanced Systems to undertake the solar PV installation. In addition to the panels, it was decided to install a SolarEdge Inverter for each of the separate systems, enabling BHESCo to remotely monitor the performance of the technology.
Keeping students and teachers warm with an air source heat pump and underfloor heating combination
With no mains gas connection to the site, all of the buildings relied on Liquid Petroleum Gas (LPG) for heating provision. LPG is a highly polluting fossil fuel and using this as a heat source was anathema to the environmental values of the school.
To meet their heating demand in a financially and environmentally sustainable way, BHESCo recommended that the Montessori Place install an air source heat pump for their heat and hot water needs.
IBD Distribution were engaged to install a 7kW Daikin air source heat pump, which is able to draw power directly from the solar PV system.
To deliver the heat throughout the building we decided to install an Envirotube underfloor heating system, separated into four distinct zones (classroom, lobby, bathroom, and kitchen). Each zone has its own programmable digital thermostat, allowing individual zones to be set to specific temperatures.
Reducing energy demand and costs through energy efficiency measures
The relatively old age of the property presented a great opportunity to achieve significant gains by improving the thermal and energy efficiency.
AJ Taylor Electrical were engaged to upgrade the existing lighting system, which mainly comprised halogen and compact fluorescent fittings, with energy efficient LEDs (Light Emitting Diodes). In total, over 100 lighting fixtures were replaced, which we estimate will save the school a remarkable £1,338 per year.
In addition to improving the lighting, BHESCo suggested that the Montessori Place could make big improvements to the thermal efficiency of the property by installing insulating materials.
Upon BHESCo’s recommendation, Earthwool insulation was installed in the loft up to a uniform depth of 300mm. Furthermore, Titan Insulation were engaged to install ‘Springvale Platinum Eco Bonded Bead’ cavity wall insulation for all external walls.
Annual Savings To The Montessori Place School - PHASE 1
PHASE 2 - Replacing the oil fired boiler with a ground source heat pump
Following the success of Phase One delivery, the Montessori Place commissioned BHESCo to design an alternative heating solution to replace the oil fired boiler on which they relied for the main building.
After a detailed analysis of the heat load requirements BHESCo concluded that the school could meet its heating demands with a ground source heat pump.
The grounds of the school provided sufficient space in which to develop a series of boreholes that could be connected to a heat pump, and a survey from Nicholls Boreholes concluded that the site was suitable.
The existing oil boiler at the school was replaced with an 87kW ground source heat pump which will provide efficient operation, extracting heat from deep underground through a series of 120 metre deep boreholes into the ground.
This high quality, efficient heat pump will provide up to 5kW of heat for every 1kW of electrical input.
The heat pump, buffer tank and hot water cylinder are positioned in the existing boiler room following some internal modifications. The school currently uses approximately 170,000 kWh per year for heating and hot water and consumption is expected to increase to around 232,000kWh as more of the building will be utilised.
By installing a renewable heating system the carbon emissions from the school will be significantly reduced. Heating using oil with the extended building usage would emit 57.4 tonnes of carbon dioxide per year. Using an efficient heat pump is estimated to reduce this to 11.4 Tonnes – a reduction of 46 Tonnes per annum. (the equivalent of planting 761 trees, or taking 10 cars off the road).
All boreholes and pipework are buried underground and the land above can continue to be used as a garden / pathways around the school.
We estimate that replacing the oil fired boiler with a ground source heat pump will carbon emissions by over 1,000 tonnes during the lifetime of the system.
Delivering greater financial benefit by capitalising on subsidy support mechanisms
The combination of energy generating and energy efficiency measures that were installed for this project will enable the Montessori Place School to enjoy a significant reduction in their annual energy costs, in addition to achieving a meaningful decrease in their environmental impact.
One of the key factors which made this community energy project so economically appealing was its eligibility for both the solar power ‘Feed-In-Tariff’ and ‘Export Tariff’ and the ‘Renewable Heat Incentive’.
The Feed-In-Tariff was a subsidy support mechanism introduced in 2010 which compensated solar panel owners for the renewable electricity that was generated on-site. Once a solar PV system had been installed and registered with the industry regulator, the system owner could receive periodic payments for 20 years. Unfortunately, the Feed-In-Tariff scheme was closed in April 2019 for new applicants.
The Export Tariff rewards solar electricity producers for any excess electricity that they export to the national grid. This scheme was remodelled as the ‘Smart Export Guarantee’ in January 2020, when it became a legal obligation for larger energy companies to offer competitive prices for the energy the buy from solar producers.
The Renewable Heat Incentive (RHI) is a similar support mechanism which provides a financial subsidy for renewable heat generation.
Air source heat pumps work by extracting latent heat from the outside air and increasing the temperature under pressure for use inside a property. For this reason, the heat that is generated is ‘renewable’, and so the air source heat pump at the Montessori Place is eligible for the Renewable Heat Incentive.
Added together, we expect these three subsidy mechanisms to add up to a combined value of £34,062 over the period 2016 – 2031.
Delivering improvements at no upfront cost through BHESCo's 'Pay As You Save' finance initiative
As with the majority of BHESCo’s community energy projects, all of the energy performance improvements included as part this project were installed at no upfront cost through our innovative ‘Pay As You Save‘ financing.
The cost of the various technologies, and the corresponding labour costs involved, were met through a community share offer.
Investors were invited to become shareholder members of Brighton and Hove Energy Services Co-operative in return for a 3% annual return on their investment.
The energy efficiency and energy generating technologies will deliver immediate cost savings to the school. A portion of these savings is then used to repay the initial cost of the project to BHESCo on a monthly basis, plus an additional 5% which is passed on to our shareholders as annual interest.
After a number of years, the upfront cost is repaid in its entirety to BHESCo, and the school becomes the owner of the equipment able to enjoy 100% of the savings for its remaining operational lifetime.
Energy Saving and Energy Generating Equipment Installed
27kW solar PV
300mm loft Insulation
106 LED lamps
7kW air source
87kW ground source
13 x 120m boreholes
Environmental Impact Reduction
We expect the energy generation and efficiency measures installed for this project to reduce carbon emissions by 1,191 tonnes during the operational lifetime of the equipment, which is equivalent to: