Clayesmore School Solar PV

Wattcraft provided feasibility, concept development, technical specification and owner’s engineer services for rooftop PV installations at Clayesmore School.


The following services were provided:

  • Energy Savings Opportunity Scheme (ESOS) compliant energy assessment of potential for energy efficiency measures.

  • Assessment of potential for renewable energy and other energy supply measures, including combined heat and power (CHP) and heat pumps.

  • Sitewide rooftop PV options assessment, feasibility, concept development and technical specification for 28kW and 163kW rooftop PV arrays.

  • Owner’s engineer services during project delivery, dealing with technical and economic matters arising, representing the client to ensure that the project was delivered in accordance with the specification and with adherence to contracted costs.

    The first stage of the work was the energy assessment, including energy efficiency measures and sustainable energy supply measures. Wattcraft recommends following the Energy Hierarchy, prioritising assessment of opportunities for avoidance of energy consumption and assessment of energy efficiency before assessment of renewable energy generation potential and this approach was put into practice on this project. There is an environmental case for this, but also an economic case.

    The economics of rooftop PV in the UK are generally dependent on using a significant proportion of the electricity generated on site. The sizing of PV on this project was carried out in conjunction with the assessment of electricity demand further to the introduction of energy efficiency measures. Annual and diurnal electricity demand profiles were developed, against which the PV generation profile for the proposed arrays was compared in order to determine the economic case for PV.

    A range of potential PV modules with different efficiencies was considered and whilst high-efficiency modules, such as monocrystalline, give a greater annual yield where available roof area is a constraining factor, the selected PV was polycrystalline, with the economics of the time giving this a more favourable overall return on investment.

    Clayesmore School was subject to the requirements of the Government ESOS scheme and so the energy efficiency component of the assessment had to be compliant with the requirements of ESOS. You can find out more about ESOS here.

Clayesmore School Rooftop PV arrays

Clayesmore School Rooftop PV arrays