SunGreen Systems​



Facility Type

  1. Manufacturing Facility
  2. Commercial Office Building
  3. Light Industrial Building​


Solar + storage, Reduce peak demand, Shift time-of-use rates, Increase market opportunity

Commercial Operation Dates

2019 – 2020

Energy Storage System Size​

  1. 1554 kW / 3108 kWh
  2. 222 kW / 444 kWh​
  3. 112 kW / 223 kWh​

Annual Net Savings

  1. $340,000 / year ​
  2. $120,000 / year ​​
  3. $185,000 / year​

Partnering with Stem to Deliver Higher Value Solar + Storage Solutions to Customers ​

Southern California-based SunGreen Systems offers commercial solar PV, energy storage, LED lighting, and cool roof systems. With roots in real estate development, the 10-year-old firm has the knowledge and experience to handle large commercial solar + storage construction projects.

​​Over the last few years, SunGreen has focused on solar super structures on parking garages. SunGreen recently installed a 400 kW full coverage solar parking garage at 1901 Main St in Irvine, CA and they are currently completing a 1 MW full coverage solar parking garage system for the Kelemen Company at the Atrium building in Irvine. To deliver more value to customers at lower costs, SunGreen continues to seek out new technologies and strategies, partnering with industry-leading firms such as Stem.


SunGreen built its stellar reputation by providing highly efficient solutions, including solar, LEDs, and cool roofs to enable customers to reduce their need for expensive power from utility companies. Today, however, changes in the utility industry can mean that expensive, on-peak rates don’t align with the sunniest part of the day when solar is most effective. 

In Southern California, for example, Southern California Edison (SCE) and San Diego Gas & Electric (SDG&E) are shifting their time-of-use (TOU) rates, with on-peak charges occurring in the late afternoon and evening instead of midday. This shift means less savings for companies with a standalone solar system that must switch back to utility power in the evenings. 

A solar + storage strategy is the answer. Solar + storage enables solar customers to collect and store solar energy during the day—taking advantage of the lower day-time utility rates—then switch to their stored solar energy in the evenings when utility rates spike. 

“A solar + storage strategy enables our customers to maximize their savings and protects the value of their investment in solar, even as the utility industry continues to experience major shifts,” said Alex Deeter, Sales and Marketing Engineer at SunGreen Systems. “Storage is also a huge competitive differentiator for us. It enables us to expand our offerings and reach a broader market.” 

A solar + storage strategy also delivers improved economics for SunGreen because the increased savings enjoyed by customers translates into higher revenue for SunGreen under the terms of the company’s purchase agreements. 


When SunGreen recognized that storage had become a key differentiator, it needed a storage partner that would support the most effective go-to-market strategy. 

“Our customers are increasingly sophisticated, and they understand the value of a solar + storage strategy,” said Deeter. “We needed a storage partner that was easy for us to work with and that allowed us to present a single, comprehensive proposal with obvious benefits for customers. Stem has been ideal.” Having worked successfully with Stem as a referral partner—and with a solid understanding of the advantages of Stem’s Athena AI to effectively manage and optimize battery usage—SunGreen moved toward a more formal solar + storage partnership with Stem. 

As a turnkey energy storage provider, Stem supports SunGreen throughout the project lifecycle, including system procurement, permitting and interconnection advising, operations, maintenance, and performance guarantees. One of the key benefits for SunGreen is battery procurement certainty and savings versus the need for SunGreen to go directly to battery manufacturers. Stem can negotiate a better price on batteries and then warehouse the batteries to ensure on-time delivery to job sites. This significantly reduces procurement and delivery complexity for SunGreen and ensures a better customer experience. 

“The advanced capabilities of Stem’s Athena AI means our customers can realize a sufficient savings to offset the additional cost of the storage system,” said Deeter. “This has allowed us to offer significant additional value in our proposals without a net increase in our customers’ long-term costs.” 


SunGreen’s Stem-powered solar + storage strategy has led to accelerated uptake by customers. The company closed three solar + storage projects in the first three months after formalizing the partnership. Project payback for customers has improved by 6 to 12 months compared to standalone solar projects, while the increased customer savings has resulted in higher SunGreen revenues. “We are extremely excited about our solar + storage strategy and working with SunGreen on new projects,” added Christy Martell, Stem’s Director of Partnerships. “For example, we are looking forward to partnering with SunGreen on new resiliency and backup applications to ensure their customers derive even greater benefits from their deployments.” 

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