The climatological relationships between wind and solar energy supply in Britain

We use reanalysis data to investigate the daily co-variability of wind and solar irradiance in Britain, and its implications for renewable energy supply balancing. The joint distribution of daily-mean wind speeds and irradiances shows that irradiance has a much stronger seasonal cycle than wind, due to the rotational tilt of the Earth. Irradiance is weakly anticorrelated with wind speed throughout the year ($-0.4 \lesssim \rho \lesssim -0.2$): there is a weak tendency for windy days to be cloudier. This is particularly true in Atlantic-facing regions (western Scotland, south-west England). The east coast of Britain has the weakest anticorrelation, particularly in winter, primarily associated with a relative increase in the frequency of clear-but-windy days. We also consider the variability in total power output from onshore wind turbines and solar photovoltaic panels. In all months, daily variability in total power is always reduced by incorporating solar capacity. The scenario with the least seasonal variability is approximately 70%-solar to 30%-wind. This work emphasises the importance of considering the full distribution of daily behaviour rather than relying on long-term average relationships or correlations. In particular, the anticorrelation between wind and solar power in Britain cannot solely be relied upon to produce a well-balanced energy supply.Comment: 19 pages, 19 figures, accepted for publication in Renewable Energy. Text updated to match accepted version (one footnote added, some references corrected

Using the Twentieth Century Reanalysis to assess climate variability for the European wind industry

We characterise the long-term variability of European near-surface wind speeds using 142 years of data from the Twentieth Century Reanalysis (20CR), and consider the potential of such long-baseline climate data sets for wind energy applications. The low resolution of the 20CR would severely restrict its use on its own for wind farm site-screening. We therefore perform a simple statistical calibration to link it to the higher-resolution ERA-Interim data set (ERAI), such that the adjusted 20CR data has the same wind speed distribution at each location as ERAI during their common period. Using this corrected 20CR data set, wind speeds and variability are characterised in terms of the long-term mean, standard deviation, and corresponding trends. Many regions of interest show extremely weak trends on century timescales, but contain large multidecadal variability. Since reanalyses such as ERAI are often used to provide the background climatology for wind farm site assessments, but contain only a few decades of data, our results can be used as a way of incorporating decadal-scale wind climate variability into such studies, allowing investment risks for wind farms to be reduced.Comment: 18 pages, plus 4 page supplementary information included here as Appendix D. This is the authors' corrected version, matching the content of the version accepted by Theoretical and Applied Climatolog

Letter From Hazel Thornton to Editors of the Pennsylvania Dutchman, March 13, 1950

A handwritten letter from Hazel Thornton addressed to the editors of the Pennsylvania Dutchman, dated March 13, 1950. Within, Hazel describes her artworks which deal with depictions of Amish life and requests a subscription to the Pennsylvania Dutchman.https://digitalcommons.ursinus.edu/shoemaker_documents/1054/thumbnail.jp

The relationship between wind power, electricity demand and winter weather patterns in Great Britain

Wind power generation in Great Britain has increased markedly in recent years. However due to its intermittency its ability to provide power during periods of high electricity demand has been questioned. Here we characterise the winter relationship between electricity demand and the availability of wind power. Although a wide range of wind power capacity factors is seen for a given demand, the average capacity factor reduces by a third between low and high demand. However, during the highest demand average wind power increases again, due to strengthening easterly winds. The nature of the weather patterns affecting Great Britain are responsible for this relationship. High demand is driven by a range of high pressure weather types, each giving cold conditions, but variable wind power availability. Offshore wind power is sustained at higher levels and offers a more secure supply compared to that onshore. However, during high demand periods in Great Britain neighbouring countries may struggle to provide additional capacity due to concurrent low temperatures and low wind power availability

Skilful seasonal prediction of winter gas demand

In Britain, residential properties are predominantly heated using gas central heating systems. Ensuring a reliable supply of gas is therefore vital in protecting vulnerable sections of society from the adverse effects of cold weather. Ahead of the winter, the grid operator makes a prediction of gas demand to better anticipate possible conditions. Seasonal weather forecasts are not currently used to inform this demand prediction. Here we assess whether seasonal weather forecasts can skilfully predict the weather-driven component of both winter mean gas demand and the number of extreme gas demand days over the winter period. We find that both the mean and the number of extreme days are predicted with some skill from early November using seasonal forecasts of the large-scale atmospheric circulation (r > 0.5). Although temperature is most strongly correlated with gas demand, the more skilful prediction of the atmospheric circulation means it is a better predictor of demand. If seasonal weather forecasts are incorporated into pre-winter gas demand planning, they could help improve the security of gas supplies and reduce the impacts associated with extreme demand events

Overdetection in breast cancer screening: Development and preliminary evaluation of a decision aid

Objective: To develop, pilot and refine a decision aid (ahead of a randomised trial evaluation) for women around age 50 facing their initial decision about whether to undergo mammography screening. Design: Two-stage mixed-method pilot study including qualitative interviews (n=15) and a randomised comparison using a quantitative survey (n=34). Setting: New South Wales, Australia. Participants: Women aged 43–59 years with no personal history of breast cancer. Interventions: The decision aid provides evidence-based information about important outcomes of mammography screening over 20 years (breast cancer mortality reduction, overdetection and false positives) compared with no screening. The information is presented in a short booklet for women, combining text and visual formats. A control version produced for the purposes of comparison omits the overdetection-related content. Outcomes: Comprehension of key decision aid content and acceptability of the materials. Results: Most women considered the decision aid clear and helpful and would recommend it to others. Nonetheless, the piloting process raised important issues that we tried to address in iterative revisions. Some participants found it hard to understand overdetection and why it is of concern, while there was often confusion about the distinction between overdetection and false positives. In a screening context, encountering balanced information rather than persuasion appears to be contrary to people’s expectations, but women appreciated the opportunity to become better informed. Conclusions: The concept of overdetection is complex and new to the public. This study highlights some key challenges for communicating about this issue. It is important to clarify that overdetection differs from false positives in terms of its more serious consequences (overtreatment and associated harms). Screening decision aids also must clearly explain their purpose of facilitating informed choice. A staged approach to development and piloting of decision aids is recommended to further improve understanding of overdetection and support informed decision-making about screening.National Health and Medical Research Counci

Walking the tightrope: communicating overdiagnosis in modern healthcare

Overdiagnosis and overtreatment have serious implications for individuals, healthcare systems, and society,1 2 and effective strategies are urgently needed to help the public, clinicians, and policy makers address this problem. Communication about overdiagnosis has been highlighted as essential for moving forward but presents several challenges, such as the potential to confuse the public, undermine trust, and adversely affect people who already have a diagnosis. Various communication based strategies offer real promise; we describe what is known and what we need to know to communicate effectively and safely about overdiagnosis and overtreatment. Key messages: Overdiagnosis provides no benefits to patients and is a challenge to the sustainability of modern healthcare systems Communication based strategies could help reduce overdiagnosis and its negative impact on individuals and health systems Mass media education, shared decision making, terminology changes for disease states, and deliberative methods (juries) all have potential as effective communication strategiesKJMcC is supported by a National Health and Medical Research Council (NHMRC) career development fellowship (1029241), JJ is supported by an NHMRC early career fellowship (1037028), and. JW is supported by a career development fellowship from Cancer Research UK (C7492/A17219)