Edinburgh Napier University

  This study has been undertaken to research the impact of shading on a large scale solar PV site at 56° latitude north, this is the first site in the UK at this latitude, consisting of 2500 solar panels across a 5 acres. As solar altitude decreases obstacles and blockages become more of a hindrance and careful planning is required to ensure the amount of shading on the panel surface is kept to a minimum. The impacts of shading on the Edinburgh College Solar Meadow, from obstacles along the Southern and Eastern edges have been investigated.
The accuracy and applicability of existing methods of solar resource modelling and solar photovoltaic (PV) module performance are investigated in the case of the ground array installation. The principal derived quantities consist of slope irradiation, cell temperature and cell efficiency. Experimental data was collected on site through both automated and manual measurements for comparison with the calculated quantities for both triangulation and quality assurance. The impact of shading has been analysed and the effect on energy delivery captured throughout the year. The research undertook detailed modelling in order to compare and evaluate the data obtained with further comparisons made between a number of modelling tools and other forms of output associated with the solar farm directly.
The site was expected to generate 560,000 kWh across the year with no impact from shading, based on the installers assumptions. Results indicate that the models used to compare and contrast slope irradiation, cell temperature and cell efficiency are accurate and within the expected range as per manufacturer specifications. The results also show that shading impacts the energy generation with a significant reduction in the winter months with respect to the available energy at the site by as much as 50%. Being the first study of its kind, at high latitude in the UK, to show the importance of accurate shade modelling at higher latitudes the findings show greater consideration is required at concept stages when taking account of solar obstacles. Shading has reduced the overall output, of this particular array, by 136,859 kWh across the year studied.