*1.1. Microgeneration*

Microgeneration is a form of decentralized or distributed energy supply [8] where: energy generation serves in-situ demand (high degree of self-consumption); installations are deployed at lower-voltage distribution network level; and small-scale technologies are deployed including rooftop solar PV, small wind turbines, small hydro and domestic combined heat and power (CHP) [9]. Benefits include lower electricity bills, hedging against future electricity price rises, lower GHG emissions, reduced reliance on fossil fuels, reduced electrical losses on the electricity network and improved building energy rating (BER) [10].

Photovoltaics is the direct conversion of light into electricity at the atomic level by materials displaying a photoelectric e ffect causing them to absorb photons of light and release electrons. When these free electrons are captured, it results an electric current [11]. Semi-conductors are treated/doped to form a p-n junction such as in crystalline silicon cells by di ffusing phosphorous into the silicon and introducing a small quantity of boron, forming an electric field. When photons are absorbed by a PV cell, electrons under the influence of the field move out towards the surface. This flow or current is 'harnessed' by an external circuit with a load [12]. The electricity generated is direct current (DC), converted to alternating current (AC) using an inverter to synchronise with mains electricity [10]. Solar PV panels do not generate CO2 emissions during their operation; however, emissions are generated during the production of the solar panels and during their disposal. Solar PV systems can be connected to home for supplemental power, full power and backup supply (o ff-grid) or as a revenue generating power system [13].

Solar PV panels are installed in residential, commercial and industrial settings or as a stand-alone system for generation of electricity for feeding to the national grid. In 2017 very little renewable electricity in Ireland was produced from solar PV, with installed capacity of around 15.7 MW and around 11 gigawatt hours (GWh) of electricity generated equating to 0.1% of renewable electricity or 0.04% of electricity gross final consumption (GFC) [5]. Households currently account for approximately 1.0 megawatt (MW) of installed residential solar PV systems connected to the grid [5]. The Irish Government, in its climate action plan 2019, has indicated the solar PV system is expected to grow to 1.5 gigawatt (GW) of installed capacity by 2030 [14].
