Analysis work to refine fabric energy efficiency assumptions for use in developing the Sixth Carbon Budget

The Climate Change Committee (CCC) commissioned University College London to review and update the cost and savings assumptions related to energy efficiency measures in homes, including an increased focus on in-use performance. The updated assumptions incorporate in-use measured data from the National Energy Efficiency Data-framework (NEED) alongside the latest evidence published by Government on the costs of measures. Over 150 datasets, studies and published reports were considered in total. The resulting assumptions were used as an input to Element Energy’s analysis ‘Development of trajectories for residential heat decarbonisation to inform the Sixth Carbon Budget’, focusing on existing home

Wave-driven flow over shallow reefs

Long-term (1 month) observations of waves and currents over a natural reef are presented which show a strong correlation between offshore rms incident wave height and cross-reef currents at subtidal frequencies. The energy spectrum of the cross-reef currents shows a significant peak at twice the semidiurnal tidal frequency, while the spectrum of sea surface elevation over the reef flat shows no corresponding peak. Furthermore, experimental results reported by Gourlay (1993) show setup over the reef occurs in the absence of a beach, and the cross-reef transport decreases with an increase in the sea surface slope across the reef flat due to an increase in setup at the top of the reef face. Analytic solutions for flow forced by wave breaking over an idealized reef explain the above features of cross-reef flows in the absence of a beach. Through the surf zone on the reef face the cross-reef gradient in the radiation stress due to wave breaking is partitioned between balancing an offshore pressure gradient associated with setup over the reef and forcing a mean flow across the reef. Over the reef flat, where the depth is constant, there is no forcing due to wave breaking and the flow is driven by a pressure gradient which results from the setup through the surf zone. The magnitude of the setup through the surf zone is such that the transport across the reef flat matches the transport through the surf zone which is forced by the gradient in the radiation stress. Solutions are presented for general reef geometry, defined by the reef width and slope of the seaward reef face, and incident wave forcing, defined by the depth at the breakpoint and the depth of water over the reef. As the depth over the reef goes to zero, the solutions converge to the plane beach solutions described by Longuet-Higgins and Stewart (1964), wave setup is maximized, and the cross-reef transport is zero. In other cases the relative magnitudes of the setup and the cross-reef transport depend on the geometry of the reef and the incident wave forcing

Modelling and monitoring tools to evaluate the Urban Heat Island's contribution to the risk of indoor overheating

The growth of cit ies increases urban surface areas and anthropogenic heat generation, causing an Urban Heat Island (UHI) effect. In the UK , UHI effects may cause positive (winter) and negative (summer) health , comfort and energy consumption consequences . With the increasing focus on climate change - related heat exposure and consequent increased mortality risk, there is a need to better investigate the UHI during hot seasons. This paper reviews the current literature regarding UHI characterisation using monitoring, modelling, and remote sensing approaches, their limitations, and applications in building simulation and population heat exposure models . Ongoing and future research is briefly introduced in which downscaling techniques are proposed that provide higher temporal and spatial information to assess and locate heat - associated health risk in London