Document Type

Theses, Ph.D


Available under a Creative Commons Attribution Non-Commercial Share Alike 4.0 International Licence



Publication Details

Successfully submitted for the award of Doctor of Philosophy (Ph.D) to the Technological University Dublin, May, 2011.


The aim of this research is to investigate the techno-economic and environmental performance of domestic scale grid-connected photovoltaic (PV) and forced circulation solar water heating (SWH) systems in Ireland; and propose a new feed-in tariff designed using a large sample of high resolution electricity demand data in order to provide credible information for informed policy formulation. Detailed field trials of experimental installations of a 1.72 kWp grid-connected PV and two SWH systems (with 4 m2 flat plate and 3 m2 heat pipe evacuated tube collectors) were undertaken to collect data. The energy, economic and environmental performances of the systems was evaluated. Energy balance models for the systems were developed and validated using performance data. Drawing upon system performance data, the implications for policy formulation in Ireland were discussed. Results from the economic analysis on six commercially available sizes of gridconnected PV systems and the two SWH systems equipped with different types of auxiliary heating systems revealed that they are not yet economically viable in Ireland under the existing support policies and assumptions considered. However, projecting current system costs into the future using technology learning rates and market data revealed that some of the systems become economically viable at a later stage under different scenarios. Alternative policies were explored and a new feed-in tariff was designed that guarantees 50% market penetration for domestic scale PV system sizes. Grid parity between retail and wholesale electricity prices was projected to occur in 2023 and 2025 respectively under the best scenarios. A look at the marginal abatement costs for the PV and SWH systems show that on a purely economic basis, it does not make sense to promote investment in domestic-scale PV systems in Ireland now, since Ireland would have very little impact on the technology learning curves and thus system costs being a small market. However, existing policy support for solar thermal systems should be sustained since it improves the economic viability of SWH systems.