Lithium-ion batteries have revolutionized the realm of energy storage, primarily due to their superior energy density compared to other competing technologies. This section is your guide to how batteries work, the different types of batteries, and why it's a good idea to add one or more batteries to your solar. The AES Lawai Solar Project in Kauai, Hawaii has a 100 megawatt-hour battery energy storage system paired with a solar photovoltaic system. Sometimes two is better than one. Coupling solar energy and storage technologies is one such case. For this guide, we focus on lithium-based systems, which dominate over 90% of the market. Solar panels generate electricity only when the sun is. There are multiple models of batteries capable of storing solar energy; each has advantages and disadvantages. Understanding the differences between the 4 leading solutions available in the market will be key to.