Storing solar energy cheaply and efficiently is a key component for the future of renewable energy. Even though lithium ion batteries are great for solar power, they can still be costly and, depending on the chemistry, there can be safety concerns. There are ways we can store solar energy more directly though … and one of those is heat. For instance, concentrated solar energy plants can use that heat for producing electricity, cement, steel, green hydrogen, or anything else that needs high temperatures. Or for storing that thermal energy for days. A recent breakthrough could allow us to store solar energy directly into a liquid for up to 18 years. How's it work? And could this be a viable path forward for solar energy storage? Let's see if we can come to a decision on this.