Potential and Impact of Incorporating Roof Photovoltaic to Enhance Environmental Sustainability of Historic English Churches in the United Kingdom

The Church of England (CofE) is responding to climate change by taking measures to reduce their CO2 footprint under its flagship programme -'Shrinking the Footprint', to facilitate the CO2 emission reduction target of 80 % by 2050. Meeting this target will require both energy efficiency measures and zero carbon energy generation of which solar PV technology is a frontrunner as it has a substantially lower CO2 footprint than grid's electricity, with no moving parts, low maintenance and a long service life. Conventional church roofs built along the East-West axis offer the ideal pitches and orientation for collecting solar energy. However, within the CofE's vast estate of over 15,000 church buildings, 78 % of these buildings are listed and hence care must be taken to protect the building fabric. With this context in mind, this study identifies the benefits and concerns associated with the application of rooftop solar PV on historic English Churches and evaluates viable technologies currently available. The specific design and procedural requirements have been investigated and the process map of the implementation methodology established and illustrated through a case study of an existing church. Results showed that rooftop solar PV system has the potential to reduce the GHG emissions substantially, ranging between 75 %–84 % for electricity and between 20 %–27 % for gas based on the current demand and the choice of technology option. Findings on the issues, design options and life cycle environmental impacts are analysed with discussion and recommendation of future adaptation at a national level

Construction of Line Densities for Parallel Coordinate Plots

The graphical representation of high dimensional data may be accomplished by using the parallel coordinate plotting system. In such a representation points in Euclidian n-space are mapped into line segments in Euclidian 2-space by a projective transformation. This representation preserves much of the geometric structure found in hyperspace but not easily representable by other methods. In large data set applications, the graphical displays may be heavily overplotted like ordinary scatterplots yielding uninterpretable displays. In this paper, we suggest replacing the raw data display with a density plot. In order to define densities for lines sensibly, we introduce the notion of line densities and develop their basic construction. We illustrate with theoretical parallel coordinate density plots for the normal and the uniform cases. Finally we illustrate sample density plots with 4-dimensional spheres