There's a broad trend in the utility world towards so-called Time-Of-Use (TOU) pricing. Rather than a tiered rate (electricity gets more expensive the more you

There's a broad trend in the utility world towards so-called Time-Of-Use (TOU) pricing. Rather than a tiered rate (electricity gets more expensive the more you use it in a month), electricity has different prices at different times of day. A major problem utilities face is the so-called duck-curve. As people come home at night and start turning on appliances, electricity demand surges. In solar-heavy places, this corresponds with the sun going down and all the solar capacity going offline. To meet this spike in demand, utilities need to fire up new power plants ("peaker plants"). Now, these are huge capital investments that stay idle for most of the day just to turn on to meet end-of-day requirements. Not ideal. So in comes TOU pricing -- make electricity more expensive during these demand surges. TOU pricing is already an option in a lot of places. It's popular if you have an electric car (you're going to use more electricity so tiered pricing is more expensive... instead, you can have an incentive to charge your car during the middle of the night at times of lowest demand). And TOU pricing is becoming more common in markets with heavy solar penetration (to combat the duck curve problem). So, what would a home battery offer? Effectively allows you to load-shift around TOU pricing. Even if you don't have solar on your roof, if you live in an area with heavy solar penetration, TOU pricing makes electricity cheap during the day... charge your battery during cheap times and use it when you come home and electricity is expensive. Whether the numbers makes sense depends on your market and consumption patterns, but as far as broad trends go, TOU is creating an incentive for batteries even on grid-connected houses.