A few thoughts from a lurker with some RE background, offered FWIW.
I examined the question of 'reasonable max RE capacity' of Ireland using indigenous sources only - no biofuel imports, etc. This followed the general approach of 'Renewable Energy without the Hot Air' by David MacKay - I happen to like his style of thinking in that work.
So, Ireland has low population density, large dairy and beef industry, no nuclear power (by legal prohibition), high penetration of wind power by installed rated capacity, high incoming wave energy from the Atlantic; etc.
I examined 3 different mixes for the form of final energy consumed.
So, it turns out that, making 'reasonable' assumptions about max physical limits - land available, plant growth rates, construction constraints for RE installations, future RE technology rollout for wave and offshore wind, etc, the answer is 'Yes' - Ireland could become self sufficient through RE for all 3 major sectors of electricity, transport and heating - in theory. The main downsides? Kill all the cattle, and all trees grown for crops used for heating. Not pretty, if you're a dairy or beef farmer. Also, major reliance on offshore RE in deep, wild Atlantic waters.
So in my view, we must push for max electrification of energy systems, embrace smart flexible grid solutions, empower distribution grids to accept high intermittent RE penetration, and get very serious about energy efficiency.
And even then, still find a way to capture CO2 at atmospheric concentrations economically. (Maybe turn it into gypsum for building products?) 'Cos RE is all very well, but we still have to reverse the GCC juggernaut humanity has unleashed upon the planet...
Nothing like a challenge!