The sonnenCore battery qualifies for an upfront incentive of almost $2,000 through Rocky Mountain Power’s Wattsmart battery program. Image source: sonnen
Homeowners across the United States are affected more than ever by frequent, prolonged power outages thanks to changes in climate and increased electricity demand that utility companies just can’t meet. In response, more and more people are looking to take energy into their own hands by utilizing solar battery storage to keep their lights on when the grid is down.
It’s not just homeowners seeing the benefits of home energy storage, though. Utilities are starting to realize that distributed storage can be a useful tool for the entire grid, not just individual homeowners. As a result, utilities are looking to pay their customers to install batteries and participate in what are called “virtual power plants” - a network of customer-owned batteries that utilities can use when they can’t meet demand on their own.
Utah's Rocky Mountain Power (RMP) is one of those utilities. In 2019, RMP spearheaded the nation's first residential virtual power plant project with the Soliel Lofts - a luxury apartment community that includes a battery in every unit that RMP can use when there is stress on the grid. A year later, RMP expanded this idea to all of its customers with the Wattsmart battery program.
Wattsmart participants who install qualified energy storage equipment can receive both upfront and ongoing incentive payments in exchange for giving RMP access to the energy stored within their battery. But how exactly does the program work, and are the incentive payments worth it? Let’s find out.
Rocky Mountain Power’s Wattsmart battery program at a glance:
- The Wattsmart battery program is a four-year program in which participants give Rocky Mountain Power permission to use the energy stored in solar batteries installed at their home or business in exchange for upfront and ongoing incentive payments.
- The upfront Wattsmart incentive is equal to $400 per kW of energy storage installed.
- The ongoing annual participation incentive is equal to $15 per kW.
- Sonnen and SolarEdge brand batteries are currently the only batteries eligible for the program.
- The program terms and conditions are vague and subject to change at any time, so participants must be comfortable with the possibility of earning less money than they initially thought.
What is Rocky Mountain Power’s Wattsmart battery program?
Simply put, when you sign up for the Wattsmart battery program, RMP is paying you for the ability to use the energy you have stored in your battery when the utility is struggling to meet power demands. This allows RMP to offer more reliable service to all of their customers by assisting with meeting energy demand and decreasing the number of potential power outages.
What's in it for you? The incentive payments lower the upfront cost of installing the battery, allowing you to have a source of backup power during a power outage, and it can maximize the amount of green energy you use to power your home.
How often will RMP use your battery? How much energy will be used?
The details of this program are pretty fuzzy. There are no set guidelines anywhere in the program terms of how often RMP will use your battery. The only indication is in the program website’s FAQ section, where it states that RMP could be using your battery daily.
RMP also doesn't have a clear limit on how much power it'll leave in your battery. Similar battery programs launched by other utilities, like PG&E and Green Mountain Power, let you choose how much of your battery power you give the utility access to, so you can ensure you have a certain amount left in case of a power outage.
RMP doesn’t give you this ability and doesn’t have a clear limit on how much power they will leave in your battery after they use it. One part of the website says it’ll leave at least 10% charged, while another part says 20%. This means you could end up not having enough energy in your battery if there’s a grid outage, which isn’t ideal.
How much is the Wattsmart battery incentive worth?
The Wattsmart program has a four-year initial term, with an annual renewal option after year four. During the program's first year, you will earn a one-time upfront enrollment incentive, equal to $400 per kilowatt installed. So, if you installed a battery with a 7 kW power rating, your enrollment incentive would be worth $2,800.
7 kW x $400 per kW enrollment incentive rate = $2,800
For the remaining three years of the program, you will earn an annual bill credit called the participation incentive. The participation incentive is equal to $15 per kW installed. Using the same 7 kW battery as before, your annual participation incentive would be worth $105 each year.
7 kW x $15 per kW participation incentive rate = $105 per year
Over the initial four-year term, a 7 kW battery would earn $3,115 from the Wattsmart program. Because RMP requires batteries to be paired with solar panels to participate in Wattsmart, you can also take advantage of the 30% federal solar tax credit to reduce the upfront cost of installing a battery even further.
Important note: The Wattsmart Battery program incentives can change at any time, so you’re not guaranteed to get the current rates listed. For example, if you apply for the program right now when the participation incentive rate is $15, but they drop it to $10 per kW next year, you would be credited at the new lower incentive rate, despite signing up for the program when the rate was higher. This means you can’t guarantee a certain amount of savings with the program.
What batteries qualify for the Wattsmart battery program?
Currently, sonnen batteries and the SolarEdge Home Battery are the only batteries that can participate in the program. This limits what batteries you can install in your home if you want to participate in the Wattsmart program, but, sonnen and SolarEdge are high-quality brands.
The following table outlines the prices of some of the eligible battery models, and what Wattsmart battery incentives they would qualify for:
| Battery model | Price* | Power rating | Enrollment incentive | Participation incentive per year |
| sonnenCore | $9,500 | 4.8 kW | $1,920 | $72 |
| Eco 10 | $24,000 | 7 kW | $2,800 | $105 |
| EcoLinx 12 | $33,000 | 7 kW | $2,800 | $105 |
| SolarEdge Home Battery | $9,000 | 5 kW | $2,000 | $75 |
*Price estimates before installation costs and incentives.
Is the Wattsmart battery program right for you?
The Wattsmart battery program might not be for everyone. Rocky Mountain Power says the best people fit for the program are "customers who are early adopters of technology, energy conscious and want to make a positive impact on the environment with renewable energy". If these are things you're passionate about, this is a great way to be a part of a new program.
As for everyone else, it can still be worthwhile, as long as you are comfortable with giving RMP almost unlimited access to your battery for four years. It is a good opportunity to save a bit on the upfront cost of a battery and potentially have backup power during a grid outage.
But remember, RMP can deplete your battery down to 10%- 20% charge whenever they want, meaning the company might not leave you enough power to actually hold you over during an outage. You also have to be okay with the possibility that incentive rates and program terms could change at any time. So if you don't like the uncertainty that comes with Wattsmart, it might not be right for you.
Whether or not you should participate in Wattsmart depends on what matters most to you. If helping the grid and the environment are worthwhile investments in your eyes, go for it! If you're super concerned about having access to backup power and limiting the amount of energy you use from the utility, maybe opt out. To get started on figuring out if Wattsmart is the best option for you, use our solar and battery calculator. You can get an estimate of how much a battery impacts your investment in solar.
Jen Merithew
Written Content Manager
Catherine is the Written Content Manager at SolarReviews, where she has been at the forefront of researching and reporting on the solar industry since 2019.