Converting retired coal plants to hydrogen (blue and green) producers and peaking generators seems a good option. Some coal plants could be forced out of the market earlier than their technical lifetime given the uptake of both large scale and distributed renewable energy. They could reuse their core parts and transmission infrastructure for brownfield hydrogen plants.
One of the common ways to capture wave energy, is via a point-absorber which harvests energy from the up and down movement of waves. Australia's RMIT has designed a point-absorber with a novel counter-rotating dual turbine. The design can apparently deliver twice the efficiency of other currently available point-absorber wave technologies. https://www.rmit.edu.au/news/all-news/2021/aug/wave-energy-technology
One solution to power outages is the notion of power storage, instead of real time usage. The notion of energy storage can either be at utility scale, which includes all energy storages at the side of the utility provider, or energy storage can include behind the meter storage, which is all measures taken by households and industry to store energy or ultimately remote power systems which are supplied to remote areas that are not typically connected to the grid. Israeli companies are the leaders in innovation concerning energy storage, with expertise in hydrogen as well as mobile energy units. https://israeltrade.org.au/2021/09/23/the-future-of-storage-energy/