Domestic fridge-freezer load aggregation to support ancillary services

Grid operators and electricity retailers in Ireland manage peak demand, power system balancing and grid congestion by offering relevant incentives to consumers to reduce or shift their load. The need for active consumers in the home using smart appliances has never been greater, due to increased variable renewable generation and grid constraints. In this paper an aggregated model of a single compressor fridge-freezer population is developed. A price control strategy is examined to quantify and value demand response savings during a representative winter and summer week for Ireland in 2020. The results show an average reduction in fridge-freezer operating cost of 8.2% during winter and significantly lower during summer in Ireland. A peak reduction of at least 68% of the average winter refrigeration load is achieved consistently during the week analysed using a staggering control mode. An analysis of the current ancillary service payments confirms that these are insufficient to ensure widespread uptake by the small consumer, and new mechanisms need to be developed to make becoming an active consumer attractive. Demand response is proposed as a new ancillary service called ramping capability, as the need for this service will increase with more renewable energy penetration on the power system.

Providing psychological services for people with diabetes

Previous research and service development guidelines have highlighted the importance of psychological issues in diabetes care, and both people with diabetes and diabetes professionals recognise the need for specialist psychological input. This article outlines the development of a service delivery model for psychological services in diabetes care, based on a patient needs assessment and the advice of diabetes professionals. This involved an assessment of the psychological needs of people with diabetes within an urban Health Trust in Northern Ireland, and the collation of the views of local diabetes professionals. Questionnaires to assess for depression, anxiety, binge eating behaviour and diabetes-specific worries were completed by 300 people with diabetes. The participants were accessed through both primary and secondary care diabetes teams. As expected, a high level of psychological distress relative to population norms was illustrated by the patient needs assessment. Particularly high levels of binge eating behaviour were reported, and levels of distress were higher for community-managed patients than for hospital-managed patients. The diabetes professionals unanimously agreed that there is a need for specialist psychological input and contributed to the service delivery model which is outlined in this article.