Residential solar PV, the roll-outs, and the optimisations

Solar photovoltaic (PV), particularly residential solar PV systems, are playing a growing role in the move to a renewable energy future. It is a key component in the move to reduce global greenhouse gas emissions, it's effectiveness or perceived effectiveness will depend on how it is deployed and utilised. This review examines various deployment strategies for residential solar PV, identifying key factors affecting the roll-out of these systems and the effectiveness of different optimisation methods or strategies during and post-deployment. It highlights the interests of multiple stakeholders, including grid operators, utilities, policymakers, and consumers, and examines how these interests shape the optimisation goals for residential solar PV systems. The review explores the impact of policies such as subsidies, feed-in tariffs, and peer effects on the installation and self-consumption rates. In addition, it discusses the role of electricity consumption patterns, forecasting, technology, rebound effects, data visibility, and demand response in maximising the benefits of residential solar PV. The findings of the literature shows the importance of policymakers understanding the implications of their strategies so that they can avoid repeating mistakes from other jurisdictions. It highlights the crucial relationships between policy, technology, and end consumer behaviour in optimising residential solar PV. It also offers insights into how the different optimisation objectives (such as cost savings, carbon reduction, or grid stability) shape optimisation strategies. Direct cash incentives and net metering/export tariffs are identified as the most effective methods for increasing solar PV installation rates, though they must be carefully chosen as studies have shown significant amounts (67%) were shown to have no impact on growth rates. Further research indicates $1/W rebate can have an increase in installs between 47% and 62%. Most recently Ireland's FiT introduction coincided with a 200% growth rate in 2 years. While Feed-in-Tariffs (FiTs) have been effective in accelerating solar PV deployment, they can reduce self-consumption rates. Countries like Germany have adjusted FiT rates to encourage storage system adoption, thus promoting self-consumption. This review paper highlights the importance of aligning deployment incentives with optimisation strategies to achieve system level outcomes.