Converting energy into anything that can be stored long time is an absolute waste. * The best option is storing it as potential energy for water, i.e. using a

Converting energy into anything that can be stored long time is an absolute waste. * The best option is storing it as potential energy for water, i.e. using a pump and a dam. That's 90% efficient, except, we can't exactly build dams everywhere. * Power to gas to power has a dreadful 10% efficiency ratio, and it also requires energy to make. So, you use a ton of energy to store very little energy. * Conversion to hydrogen has the same problems. Best we can do 25%. What do you do when you only have a tiny bit of excess energy? The process takes a constant amount of energy in, so you need a constant power source. Nuclear reactors, ideally. Storing nuclear waste isn't hard. France is building a storage place that will handle all our nuclear waste produced until 2080, safely for hundreds of years. The project cost 25 billion euros, and that includes looking for potential places, running tests, and everything else involved in new things. Future projets would be much cheaper. Considering the country is subsidizing renewables to the tune of 70 billion, it costs us one third of the price for a solution of literally a lifetime. That's also taking into account that, ultimately, very little of the nuclear waste is truly oh-shit-oh-shit dangerous. With a simple phone call, you can most likely go visit a low activity waste storage location, which is 90% of the waste we produce, and you can just go dance on storage tanks. Radioactivity is basically nil. Additionally, waste is only waste because we can't use it. Look at projects like Superphénix and breeder reactors, and suddenly you've got all this stored "waste" able to produce much more energy.