Amy Simpkins is an expert in the economics of energy systems and is CEO of Golden, Colorado-based muGrid Analytics, which provides custom modeling, analysis, and dispatch strategy for solar and solar-plus-storage projects across the US and around the world.
Installing solar without battery storage can absolutely be worth it. Generally speaking, solar stands on its own economically. Solar is a mature technology with relatively straightforward economic outcomes — energy usage is offset by kWh generated. Though most solar developers will say that they assume zero demand charge reduction from pure solar, it is also likely that you’ll see a modest amount of demand reduction, provided that your peak usage happens when the sun is out.
Adding battery storage to solar can save even more money than solar alone, but solar alone is generally economical in and of itself, so the answer to the original question is yes, solar is generally economically viable on its own.
The economics of adding battery storage to solar are complex. This complexity is primarily due to the fact that your savings are dependent on smart usage – charging and discharging – of the battery. Batteries aren’t as simple as solar in that you can just plug them in and they save money. They have to be strategically used and commanded to work when its most advantageous. This requires a thoughtful dispatching strategy that can only be developed with some serious math.
Furthermore, time shifting energy and peak shaving with batteries for economic reasons is a nascent use case for battery storage. As such, the capital expenditures for battery storage can be high, and their economic viability is highly dependent upon your specific load profile and the prevailing rate tariff from the utility that sets the “rules” of the economic “game” you are playing. This means that batteries are economically viable for some customers in some rate tariff environments and not for others. So while the question of “is solar worth it?” is generally a simple “yes,” the question of “is battery storage worth it?” is a more complex “it depends.”