I totally agree. Diversification is always a good idea and it seems that there are some options. But I think thermal storage is only a large scale option and quite "centralized". Maybe large amounts of small scale storage like batteries could also be some kind of safety net. Assumed that in the future every car and every household will have a battery, then, with the right infrastructure, this can be used as a decentralized balancing mechanism.
In the article a company named Gelion is mentioned... do you have further information on this? I can't find a website... just a few other articles saying that there "might" be "something revolutionary".