Evidence on Wind Farm Performance Decline in the UK

Onshore wind farms in the UK have aged at about the same rate as other kinds of power station. The average wind farm has an annual load factor of about 28% when first commissioned, which declines by about 0.4 percentage points per year. After 15 years, the load factor would have fallen to 23%. This ageing does not appear to have made developers replace their farms early. Forty out of the first forty-five wind farms commissioned in the UK were still operating at this age; four had been repowered. Taking this deterioration into account raises the levelised cost of electricity by around 9% over a 24-year lifespan, discounting at 10 per cent a year. This is a summary of the peer-reviewed paper “How does wind farm performance decline with age?” published in Renewable Energy, vol. 65, pp 775-786, which is available to download from http://tinyurl.com/wind-decline

Guest Editorial: Nutrition in toddlers

No Abstrac

Summary of Wind Farm Performance Decline in the UK

This note provides a summary of the paper “How does wind farm performance decline with age?” Renewable Energy, vol. 65, pp 775-786, which is available to download from tinyurl.com/wind-decline

“Prosumage” and the British electricity market

Domestic electricity consumers with PV panels have become known as “prosumers”; some of them also have energy storage and we have named the combination “prosumage”. T he challenges of renewable intermittency could be offset by storing power, and m any engineering st udies consider the role and value of storage which is properly integrated into the ‘smart grid’. Such a system with holistic optimal control may fail to materialise for regulatory, economic, or behavioural reasons. We therefore model the impact of naïve prosumage: households which use storage only to maximise self- consumption of PV, with no consideration of the wider system. We find it is neither economic for arbitrage nor particularly beneficial for shaving peaks and filling troughs in national net demand. The extreme case of renewable self -sufficiency, becoming completely independent of the grid, is still prohibitively expensive in Britain and Germany, and even in a country like Spain with a much better solar resource

A guide to performing skin-prick testing in practice: tips and tricks of the trade

Atopy can manifest in childhood as infantile eczema (atopic dermatitis), allergic rhinitis and asthma. In practice, it is critical to identify the offending allergen in atopic individuals. This will not only influence therapeutic interventions, but may also have a significant impact on the individual’s quality of life. The most common clinical test for allergy detection is the introduction of an allergen directly into the skin in the form of a skin-prick test. Skin-prick testing is recommended in the diagnostic workup for allergies because it is reliable, safe, convenient, inexpensive, minimally invasive, and has the advantage of multiple allergen testing in one, 15- to 20-minute, test. Skin-prick testing can be performed from birth onwards. Although there is a small risk of developing anaphylaxis, the test remains safe to perform in a consultation room or at the patient’s bedside. Worldwide, a skin-prick test remains the test of choice for allergy because of its convenience and cost-effectiveness. A globally accepted guideline for skin-prick testing is still lacking and would be beneficial to both patient and physician.Keywords: allergy, indications, contraindications, cut-off points, measurement

Asthma control - Practical suggestions for practicing doctors in family practice

Many surveys of asthma care suggest that only 5% of asthmatics are meeting the ‘Goals of asthma management' as set out in the Global Initiative for Asthma (GINA) guidelines. Despite the availability of useful asthma therapies and treatment strategies, the morbidity from asthma has remained significant. This review includes practical suggestions on optimal asthma control for the family practitioner. South African Family Practice Vol. 50 (2) 2008: pp. 26-3

Searching (the) FIRST radio arcs near ACO clusters

Gravitational lensing (GL) of distant radio sources by galaxy clusters should produce radio arc(let)s. We extracted radio sources from the FIRST survey near Abell cluster cores and found their radio position angles to be uniformly distributed with respect to the cluster centres. This result holds even when we restrict the sample to the richest or most centrally condensed clusters, and to sources with high S/N and large axial ratio. Our failure to detect GL with statistical methods may be due to poor cluster centre positions. We did not find convincing candidates for arcs either. Our result agrees with theoretical estimates predicting that surveys much deeper than FIRST are required to detect the effect. This is in apparent conflict with the detection of such an effect claimed by Bagchi & Kapahi (1995).Comment: 6 pages; 8 figures and 1 style file are included; to appear in Proc. "Observational Cosmology with the New Radio Surveys", eds. M. Bremer, N. Jackson & I. Perez-Fournon, Kluwer Acad. Pres