The potential application of residential solar thermal cooling in the UK and the role of thermal energy storage technologies.

As the UK Building Regulations demand better insulatedand more airtight new buildings, a potential cooling requirement is emerging in new build dwellings in the UK, leading to an increase in the market for domestic air conditioning systems in this country.At the same time, current strategies at a European and National level are starting to focus on the use of renewableand low carbon energy sources, aiming at energy security and reduction of carbon emissions.Solar thermal cooling in small scale residential applicationsis of particular interest due to the major electrical energy supply problems experienced in many countries related to the demand for cooling in summer. Only recently have such small scale systems become commerciallyavailable and it is still a relatively expensive technology. The performance of these systems depends strongly on the local climate, the COP of the cooling system and the holistic design of the plant and buildings.Either absorption refrigeration or desiccant coolingcan be used in solar cooling applications.Solar cooling is normally designed to cover a certain percentage of the demand (30%-60%) and an auxiliary fossil fuelled system is therefore required to drive the Thermally Activated Cooling Systems (TACS) the periodswhen there is insufficient solar energy.This paper explores the potential cooling demand in a dwelling in the UK and the use of Thermal Energy Storage(TES) systems to increase the solar fraction available.The paper uses the ECOTECT (see Ecotect) building modelling software to model a particular dwelling, drawn from generic regional UK housing stock information(Rhodes et al., 2007) as a Case Study to illustratethe papers aims. A scenario to simulate realistic hourly patterns of occupancy and internal gains due to appliances and lighting is described. The cooling requirementand the collector area required to meet this demand are calculated. The role of the TES in relation to the solar fraction of the system is investigated. The limitations of the software used for this simulation are also discussed along with the reliability of the results.