Professor Sarah Mc Cormack

Summary

Determining the Parameters for Luminescent Spectral shifting Devices at Windows that Enable Energy-efficient Enhancement of Daylight, Particularly its Circadian Entrainment Luminance, in Low-daylight Conditions and Poorly-daylit Locations Light in the short wavelength range is effective in maintaining the human circadian clock. At particular times of the day in specific locations away from windows deeper in buildings the natural penetration of daylight may not provide sufficient circadian luminance to maintain healthily synchronized biorhythms. Luminescent lightshelves are a wholly new concept that have the potential to concentrate low intensity sunlight, modify its colour and project that light deep into a room. This research will bring this concept into reality. It will examine what set of properties, characteristics and design for luminescent shelves enables the delivery of desired daylight properties into a room where low daylight would otherwise prevail in a predetermined manner Providing daylight concentration and appropriate spectral shifting enables daylight to be projected deep into poorly daylit spaces, as well as being able to potentially provide lighting conditions that maintain biorhythmic health. This can be accomplished without incurring, the energy use associated with achieving this with artificial lighting. It also obviates the need for the output complex controls associated with accomplishing this with artificial lighting as natural temporal variations in solar illuminance directly produce corresponding temporal variations in the, intensified and spectrally modified, output illuminance.

Funding Agency

Velux Stiftung

Project Type

Research

Person Months

12

Summary

The Government's White Paper on Energy has set a series of challenging targets for the energy sector for 2020, with 33% of electricity to be generated from renewable sources . While the focus has been on wind energy and biomass, solar energy and photovoltaics (the conversion of solar energy directly into electricity) can play a contributing part. For Ireland where over 90% of our energy is imported1, Photovoltaics (PV) offers the prospect of local electricity supply security. In the short-term, the installation of PV on household, commercial and light industrial buildings can reduce peak electricity demand and improve energy supply security; In the long-term, PV can contribute to energy supply security by reducing reliance on depleting fossil fuels, by increasing the use of indigenous resources and by diversifying fuel sources. In Ireland due to our climate, there is the misconception that PV technology does not work however as long as there is sunlight, electricity will be produced; and while the output is reduced in cloudy conditions the technology still produces electricity. There is no detailed monitoring of PV installations in Ireland therefore there are no reliable data to illustrate the technologies performance in Irish conditions. This proposal aims to address this using the expertise in DIT in the Dublin Energy Lab and by collaborating with the International Centre of Excellence the European Commission Director General Joint Research Centre, (JRC), Ispra, Italy. A test facility will be established to determine the performance of different types of PV systems and to optimise system design.

Funding Agency

HEA

Programme

Strand III

Project Type

Research

Person Months

24

Summary

Transpired air collectors utilize solar thermal energy to heat cold outside air for use in many space heating and industrial process heat contexts (e.g. solar dryers, heating of maintenance hangars). This technology provides an effective means for substituting renewable energy sources for fossil fuel consumption, particularly in cold climates. However, potential applications of solar energy for air heating in Ireland have not been viable economically to date due to: (i) high initial installed system capital costs, (ii) low solar energy conversion efficiencies, (iii) low outlet temperatures and thus small ensuing solar fractions, (i.e. proportion of the total heating energy requirement met by solar energy) and (iv) inadequately addressed design for effective building and systems integration. The student will investigate transpired air-heating solar energy collectors with the main aim of the project to optimise a new generic form of collector in terms of solar fraction and life-cycle cost. A prototype will be developed, modeled and optimized and the student will take advantage of further funding offered by DIT to progress the project into advanced PhD research.

Funding Agency

HEA

Programme

Strand 1

Project Type

Research

Person Months

2

Summary

Photovoltaics (PV) convert solar energy directly into electricity and integrating PV into buildings is now recognised widely as the most cost-effective form of grid-connected PV power generation in industrialised countries. However, the cost of PV must be reduced to allow wide-scale implementation and one technique is by substitution of PV material by lower cost concentrating systems. This proposal addresses this and describes the use of laser dyes as well as nano-scale Quantum Dot technology in a novel, non-imaging, non-tracking luminescent solar concentrator (LSC), to concentrate both direct and diffuse solar radiation onto a PV cell leading to (i) smaller PV areas being required per unit electrical output, (ii) higher efficiency conversion of solar energy to electricity ensuing and (iii) significant electricity generation in cloudy and winter conditions as diffuse insolation is concentrated. Objectives: . To investigate different laser dyes and nanomaterials such as quantum dots (QDs) and nano rods for use in a luminescent solar concentrator (LSC) . To investigate different carrier materials for use in a LSC . To develop and validate a ray trace model for the LSC . To fabricate a number of novel LSC systems such as stacked, liquid and thin film

Funding Agency

HEA

Programme

Strand 1

Project Type

Research

Person Months

2

Summary

Buildings play a significant role in the global energy balance. Typically they account for 20-30% of the total primary energy requirements of industrialised countries, approximately 40% in the EU and 46% in Ireland. Photovoltaics (PV) convert solar energy directly into electricity and integrating PV into buildings is now recognised widely as the most cost effective form of grid connected PV power generation. These heat dissipation techniques are required as only ~16% of the solar energy incident on a PV device is converted to electricity; the remaining insolation absorbed is transformed into heat. For crystalline silicon solar cells the associated elevation of PV temperature reduces solar to electrical energy conversion efficiency by 0.4-0.5%K-1. The most common approach uses a duct behind the PV module or its mounting system which allows natural convection and wind induced air-flow from the back of the PV panel. Accrual of airborne dust in inlet grilles and on duct surfaces ultimately causes a reduced rate of heat transfer from the PV. This proposal will investigate the use of phase change materials (PCM) as a novel method to regulate the rise in BIPV temperature as these PCMs absorb a large amount of energy as latent heat at a constant phase transition temperature. Depending on ambient conditions, a PV/PCM system may enable the PV to operate near its characterising temperature and thus with good solar to electrical conversion efficiency.

Funding Agency

HEA

Programme

Strand 1

Person Months

3