Soleil Lofts: Residential virtual power plants have arrived
In September of 2019, Soleil Lofts, a unique luxury solar apartment complex located just outside of Salt Lake City, made its official debut.
What sets these apartments (also known as net zero homes) apart? Their ability to utilize clean energy and the fact that they are equipped with 5.3 megawatts of solar and 12.6 megawatts of state-of-the-art battery storage.
The lofts are more than just a residential apartment community - they are also the country’s largest residential virtual power plant (VPP).
SolarReviews had the chance to interview CEO of Auric Energy, Jess Phillips; one of the partners who took the revolutionary idea of the Soleil Lofts and turned it into a reality.
Why were the Soleil Lofts designed as net zero homes?
The Soleil Lofts are the product of a partnership between The Wasatch Group, Auric Energy, sonnen, and Rocky Mountain Power. The concept of building a solar apartment complex that could run on renewable energy and battery storage was created by The Wasatch Group, a Utah-based real estate development firm.
The Wasatch Group didn’t just decide to build the lofts in Herriman, Utah, at random. Because the town is located within a mountain valley, it becomes the perfect environment for emissions to build up.
The trapped emissions have the potential to create significant smog throughout the town. Because of this, Herriman was poised to be a great place for building zero-emission solar apartments.
To make the completion of the Soleil Lofts possible, The Wasatch Group called on Auric Energy. The two companies had previously worked together to install solar on Zion Bank Stadium - an undertaking that saw Auric Energy plan and design the solar and energy storage component.
Like the Zion Bank Stadium solar project, Auric headed the task of finding the right solar panels and the right battery system for the Soleil Lofts.
How are Soleil Lofts’ solar apartments powered?
All 22 buildings within the complex have been fitted with custom-made, 430-watt Solaria solar panels. But as it turned out, having the perfect solar panels was only half the battle.
The battery systems were going to be installed within the apartments themselves, meaning that Auric Energy needed to not only consider the batteries’ functions but also how they looked. The developers decided to install the sonnen ecoLinx battery in each of the 600 units.
“We looked at over a dozen different battery solutions. At the end of the day, sonnen’s longevity and safety were the two most critical value propositions,” Phillips said.
The batteries were purposely oversized in terms of what residents would need on a regular basis, in order to allow for abundant accessible power. The entire complex is all-electric, so the apartments will not rely on natural gas plants for stoves or heating. Their only power source is the sun!
What makes the Soleil Lofts a virtual power plant (VPP)?
Virtual power plants, also known as VPPs, take multiple independent energy sources from different locations (like the batteries in each apartment) and combine them into one power network.
VPPs are designed to relieve stress on the grid by distributing power from each independent resource during peak load times. They are controlled by cloud-based software, and unlike traditional residential batteries, the battery systems are accessible to the utility.
The relationship between the Soleil Lofts and local utility Rocky Mountain Power is what makes this particular solar apartment complex so unique, as Rocky Mountain Power will effectively manage the battery system as a VPP.
“Solar companies and utilities haven’t always gotten along,” explains Phillips, “but because we sat down with them and listened to their needs and goals, we were able to present this as a holistic solution.”
Rocky Mountain Power can deploy up to 50% of the combined power of all of the community’s batteries to offset the stress on the grid during peak hours. “When the demand for utility power goes up as everyone gets home from work, instead of firing up a fossil-fuel powered ‘peaker plant’ hundreds of miles away, Rocky Mountain Power has stored sunlight ready for instantaneous response,” according to Phillips.
This project will help Rocky Mountain Power determine how to best incorporate distributed generation systems into the grid for future projects, as well.
What are the benefits of a VPP as a Soleil Lofts tenant?
Residents can enjoy some peace of mind knowing they have backup storage in the event of a grid outage. If an outage does occur, the batteries can run anything within the apartments, thanks to the solar-plus-storage design.
Each unit can be powered indefinitely by solar, even if the grid goes out - and their batteries will continue to charge, as well. So whether the grid is out for an hour or a year, the Soleil Lofts still possess the power of the sun. Phillips quips, “Bring on the zombies! Soleil Lofts is ready for them!”
The solar panels will allow residents to see major savings on their electricity bills, as the units were built with energy efficiency in mind; the average electric bill is expected to be much lower than those at nearby and similar complexes. Plus, all of the units come with energy efficient appliances, enabling tenants to use even less electricity.
Throughout the community, there are 104 electric vehicle (EV) charging stations and over 70 solar carports. Phillips believes this is one of the best parts of being a member of the Soliel community:
“Living a net zero lifestyle isn’t easy, but it’s an attainable goal these days thanks to numerous technologies, like what's being implemented here. The best part, living in a sustainable way is now more convenient and economic when you choose to live at Soleil Lofts!”
Could residential virtual power plants become more common?
There is a potential setback for the future of VPPs like the Soleil Lofts. With the upcoming expiration of the federal tax credit, large solar projects like these might not be financially feasible anymore.
Phillips acknowledges that the federal tax credit had an impact on the project, stating: “I can say that the incentive allowed this ‘first of its kind project’ to happen now versus years from now, because of the tax credit.”
On the other hand, he also believes that projects like this are in fact possible without the incentive, so long as companies create effective working relationships with utilities. VPPs can also be created through existing renewable power generating sources, like solar panels and batteries.
Future construction projects are not the only avenue in which utilities can initiate a VPP. If utilities make the option available, people who have already installed solar-plus-storage can choose to participate in a VPP. This would allow utilities to enjoy the benefits of a VPP without having to rely on new construction projects.
Expect to see more VPPs like the Soleil Lofts around the country
New construction communities equipped with renewable energy systems are a great starting point for utilities to implement VPPs. Utilities nationwide have the unique opportunity to turn these community works in progress into VPPs, just like how Rocky Mountain Power has done with the Soleil Lofts.
And the fact that this project could be successfully implemented in a state like Utah, which has low average electricity costs ($0.105/kWh), bodes well for its adoption in higher-cost locations like Rhode Island ($0.22/kWh) and California ($0.19/kWh).
Particularly in California, there is huge potential for its adoption, especially in light of the upcoming requirement that solar systems in the state must be installed on all new construction beginning in 2020.
Utilities have been worried about the impact of renewable energy on the power grid for some time and VPPs have the potential to be the solution utilities have been searching for.
Soleil Lofts’ specialized design could serve as a model for other utilities in terms of how to successfully incorporate VPPs into the grid.
Author: Catherine Lane | SolarReviews Blog Author
Catherine is a researcher and content specialist at SolarReviews. She has strong interests in issues related to climate and sustainability which led her to pursue a degree in environmental science at Ramapo College of New Jersey.