University of Ulster

The Centre for Sustainable Technologies (CST) is a strong dynamic research group with a wide range of internationally recognised activities including Advanced Glazing, Heat Pumps, Energy Storage, Biomass & Bioenergy, Techno-Economic Simulation of Power Generation, Solar Thermal and Solar PV. CST publishes extensively in international journals and has attracted research funding in excess of £5.5 million. It has secured a further £3 million in infrastructural supporting funding to provide state-of-the-art laboratory facilities.

This investment has seen the laboratories equipped with extensive computing facilities and data analysis and acquisition equipment. Specialist glazing laboratory facilities include high specification, high vacuum ovens, large-scale calorimeter/durability test facilities and a water/air permeability test facility. Vacuum glazing consists of two sheets of glass hermetically sealed around their periphery with a vacuum gap between the glass sheets.

CST’s Laboratory facility illustrating its external solar testing facilities

An array of tiny support pillars, typically 0.3 to 0.5 mm in diameter, are used to separate the glass panes and to prevent them from touching due to atmospheric pressure. Low emittance coatings are used on one or both of the internal glass surfaces to reduce radiative heat transfer from the inside to the outside of the glazing. The University of Ulster has developed and patented a novel sealing technique for the fabrication of vacuum glazing at low temperatures and have fabricated glazing with a mid-pane U-values down to 0.86 Wm-2K-1 for a 0.4m by 0.4m sample employing hard low-e coatings.

Solar technology

In support of solar activities, an indoor solar simulator is provided. External experiments are carried out on a south-facing roof with easy access and are serviced to accommodate solar thermal and PV environmental testing. A number of patents are being developed for partially evacuated concentrating solar thermal systems currently under development by Ulster. Photovoltaic systems have been integrated onto the laboratory and contribute 11.8 kW of electricity during peak operation. The performance of a number of PV and solar thermal systems has been monitored on domestic and public buildings. Research has developed a number of concentration systems to enhance the performance of PV modules by up to 75% leading to more power for less cost.

Funding has also been secured to construct a new downdraft gasifier, engine and generator to deliver up to 25kW of electricity and 100kW of heat to the University while undergoing tests of various biomass fuels and fuel preparation techniques. Current research is based on studying the production of several types of biomass and investigating their behaviour in thermal conversion processes. The conversion processes are being studied and optimised in order to generate renewable energy more efficiently. Computer modelling is used to design and maximise the efficiency of the thermal processes, and to identify the ideal specifications of biomass fuels for different processes. System studies evaluate the performance, cost, and socioeconomic benefits of the full range of bio-energy systems considered. Other projects include investigation of better burner technology for the combustion of biomass and investigating effects of biomass-derived gases on the performance of fuel cells.

Cost-effective systems

Heat pumps are increasingly popular and research is focused on more efficient and cost-effective systems. Current projects include the development of high temperature air-source heat pumps for domestic retrofit and the development of a combined compressor/expander unit to improve efficiency. Air-source heat pumps have an advantage in the moderate maritime climate of Ireland with its relatively warm winter conditions and avoid the expensive ground source installation. High temperature air-source systems with a seasonal coefficient of performance (heating) of over 3.0 have been developed and tested with the advantage that they can be retrofitted directly into existing wet radiator systems traditionally heated by a boiler.

Energy storage in phase change materials (PCMs) allows very high energy densities to be achieved at well-defined temperatures. Studies showing improvements in cooling of spaces through enhanced chilled beam ceilings and energy storage up to 65°C for heating applications have been carried out. Also modelling of PCMs integrated into building wall elements to create the effect of thermal mass has illustrated reduced cooling demands.

Techno-economic assessments of carbon capture systems and their associated cleaner coal combustion systems have been carried out utilising “ECLIPSE”, a unique and powerful process simulator developed by the University and used in evaluating many future power plant projects within the European Union and United Kingdom.

Thus CST at the University of Ulster is able to bring forward a timely series of innovations capable of meeting a sustainable energy agenda.

W: www.ulster.ac.uk