A decade may not seem like a remarkably long time to have been in business, but it certainly is in the world of rooftop solar. In an industry known for its ups and downs, residential solar installer Sunrun hit the commendable milestone last week of 10 years in operation.

Executive Chairman and co-founder Ed Fenster and CEO and co-founder Lynn Jurich launched Sunrun in 2007 from an attic in San Francisco and signed the company’s first customers from a booth at a county fair. Since then, Sunrun says it has built more than $2.5 billion in solar systems, saved customers more than $150 million on their energy bills and generated more than 2.4 billion kilowatt-hours of clean energy.

With more than 3,000 employees serving more than 134,000 families in 22 states (and counting), Sunrun claims it’s now the leading home solar company in the country.

“We’ve come a long way in just 10 years and are just getting started,” said Jurich, in a statement.

Over the years, as technology and policy have evolved, so has Sunrun’s business model. Sunrun is no longer just a residential solar installer -- it now fashions itself as “the nation’s largest dedicated residential solar,storageand energy services company.” The decision to rebrand and launch the “Sunrun Brilliant Home” logo last December underscored the transition from pure-play solar company to a more comprehensive energy solution provider.

Then in June, Sunrun hired Audrey Lee as vice president of grid services -- yet another sign the company is expanding its presence at the grid edge. Lee, who holds a doctorate, previously served as vice president of analytics and design at Advanced Microgrid Solutions. She also worked with the U.S. Department of Energy, the California Public Utilities Commission, and the Massachusetts Department of Energy Resources to develop regulatory structures that promote energy innovation.

Lee’s job is to figure out how behind-the-meter solar and energy storage can be leveraged as grid assets. She will oversee a new partnership with National Grid, and work with other utilities and energy partners at the wholesale level to learn how distributed energy resources (DERs) can meet the needs of the grid more efficiently.

I recently caught up with Lee at GTM’s Grid Edge World Forum to discuss her new role and Sunrun’s new grid services initiatives. Questions and answers have been edited for readability and flow.

GTM: Talk a little more about your background and your new role at Sunrun.

LEE: I started out in government, so I have a policy background…and was really involved in demand response and energy storage and smart grid. Then I joined Advanced Microgrid Solutions, where I focused more on the commercial and industrial side -- thinking about how behind-the-meter energy storage could be leveraged as a grid service, and working with utilities and with the energy markets to do that. Sunrun is a really great next step for me in expanding that to the residential sector.

As our grid is evolving, you really need all of the different resources on the grid to work together and be coordinated. You need those markets to be transparent and the market signals to be clear to all the participants. I'm really looking forward to harnessing all of the solar and now the storage that Sunrun has installed, and plans to install, and integrate that into the grid so that it provides either capacity or ancillary services.

GTM: Sunrun has deployed around 1,000 BrightBox energy storage systems to date, largely in Hawaii where there is a self-supply tariff. What is the value proposition for customers in more dynamic markets like California? Is the appeal mostly backup power? Or is rate arbitrage driving customer interest?

LEE: I think you're right -- the backup and the reliability and resiliency are very attractive to customers, but also the time-of-use rates, which made arbitrage possible for residential customers. Then I think the world is an oyster in the future in terms of demand response programs that energy storage could participate in at the wholesale level. We are working with CAISO (the California Independent System Operator) on ESDER, the energy storage distributed energy resources stakeholder initiative, and holding meetings with the PUC, and looking to really expand the role of distributed energy resources. We are very optimistic about the role of residential storage in participating in the grid.

GTM: Where do you think residential energy storage will offer the most value -- at the distribution level or at the wholesale level?

LEE: I think it will be both. I mean, honestly, we're all working it out right now, right? There are so many stakeholder meetings with utilities and with aggregators and with policymakers to figure out what the role [of energy storage] is. How do existing structures, like the way utilities rate-base their assets, evolve? And how do they procure DERs? The great thing about storage paired with solar is that it's so flexible; it can provide all these different kinds of grid services. I feel like the technology is there; it's really up to us to figure out the regulatory framework and the market framework to leverage that technology.

Storage could play at the very local level on a circuit, on a feeder line to resolve backflow or voltage issues, or at a substation level to defer distribution upgrades or substation upgrades. [It can help with] local reliability and system reliability, and it’s a matter of aggregators working with utilities to pull that all together to make it work. [At the wholesale level] we're still figuring out the roles and responsibilities, the rules, and the market signals to do that.

GTM: How fast are things progressing at the wholesale level? We know there is an ongoing discussion about opening up wholesale markets to energy storage and distributed energy resources at the Federal Energy Regulatory Commission. Meanwhile, PJM has already established a frequency regulation market and became the largest market for energy storage. California also has rules that allow DERs to participate at the wholesale level. But when I spoke to CAISO earlier this year, representatives mentioned that the software and communications side of aggregating DERs still needed more work, so that the grid operator could be sure they would respond when needed.

LEE: I think from a technology perspective, it's new, so of course the CAISO [is cautious]. They're in charge of reliability for the grid; they need to be very conservative about this stuff. So it's a matter of doing projects together, showing them the data and getting everybody comfortable with this. And there's no better way than to actually try it out and prove it to the utility, as a distribution operator, and prove it to the CAISO that it can be done.

I know that a lot of utilities have pilots and are working with various partners on that. We don't have anything to announce at this point, but working with utilities to demonstrate [how DERs can operate in wholesale markets] is definitely something that we're very interested in. […] There is a great role for an aggregator like Sunrun to orchestrate what the storage does and coordinate, cooperate with the utility and the CAISO on this.

GTM: Do you think a Sunrun or another third party will play the DER aggregator in wholesale markets? Or will the utility?

LEE: I think it's going to be a mixture depending on the territory and the regulatory framework. I think Sunrun has a relationship with the customer -- we set up the contract with the customer and we know how that resource is used. […] And so I think we want to maintain Sunrun's relationship with the customer and then coordinate with the utility. If the utility were to manage thousands and thousands of systems, I imagine it would be a headache for them, so I think that it's going require cooperation and partnership with the utility. We want to make sure that the utility gets what it wants in terms of awareness and monitoring of what's going on with the assets, so they can depend on it for grid services.

GTM: This is an interesting time for DERs. On the one hand, there are discussions taking place around the country about the need to preserve net metering and favorable policies for rooftop solar. On the other, there's a transition to more time- and location-based rates taking place, which may be less appealing to rooftop solar, but help to support storage and the broader grid edge transformation we’ve been discussing. How would you characterize the way DER policies are taking shape in the U.S.?

LEE: At the end of the day, at Sunrun we want clean, renewable energy. We also want to reduce costs to customers. And I think those are the goals for a lot of regulatory commissions and utilities as well, so I think we all agree on that endgame, and it's a matter of deciding what the technology toolbox to make that happen is, and what are the right price signals to incentivize clean energy and reliable energy.

That's why we have this partnership with National Grid, because I think we are really able to leverage each other's strengths in doing that. National Grid is the grid operator in the U.K., so they really understand energy markets and transmission systems, and then of course they have their regulated side on the East Coast [of the U.S.] running a distribution company. And then Sunrun...has the relationship with the customer and the distributed energy experience, so we think that partnership really allows us to tackle this big problem and figure out how to make it work.

GTM: Yes, so Sunrun partnered with National Grid in January. We know the partnership includes a joint marketing agreement to accelerate solar adoption in New York state, a collaborative pilot to explore how DERs can be aggregated and used to help balance the grid, and a $100 million direct investment by National Grid in approximately 200 megawatts of residential solar assets across all of Sunrun’s markets. Where does progress on that partnership stand today?

LEE: The joint marketing is off the ground and their investment in us is starting to pan out. In terms of the grid services, we’re just starting to figure that out. […] We're trying to figure out where it makes sense to deploy solar-plus-storage and grid services.

[National Grid] is bringing in their expertise on the distribution, transmission and wholesale market side, and we're bringing in our experience on the customer side. […] It’s my job to get some good projects in the ground and then announce them to you.

GTM: How important do you think it is that solar companies like Sunrun lead in the grid services space? Other companies could take on that role. But the CEO of Cypress Creek, for instance, believes solar companies (large-scale, in his case) must lead on energy storage or get left behind.

LEE: Sunrun is really proactive and stepping up as a solar company to figure all of this out. And I think it's very important, because Sunrun touches so many customers. You need to bring ratepayers with you -- they're the customers and you need to make them part of the solution. Sunrun has that great relationship with the customer and is able to do that. I'm not saying Sunrun's going to solve everything, it's not going to operate the grid completely…but I think Sunrun's really stepping up.

GTM: How is Sunrun marketing to DER customers today? Has the process changed now that energy storage is involved?

LEE: Sunrun has come a long way in making the process of educating the customer and selling solar so efficient. And so I think adding on storage to the platform that they have already created is a small step. That platform is the operations, the people, the sales team and the installers, but it's also the software platform and making it really simple for the customer to understand what their electricity consumption is, what their rooftop solar is producing and how it's benefiting them. Because people don't think about electricity all the time -- you've got to make it interesting to them and important to them.

Also, as a solar customer myself, I want to know that my solar company is going be around, and I think Sunrun has really demonstrated that, and the same thing with storage. There's more involvement because there's more control required and more active participation from that storage into the grid, so customers want to know that there's a strong company backing that installation.

Sunrun has been around for 10 years, and that's no small thing.

GTM: Tesla recently gave up on door-to-door sales and shifted its marketing practice online. Does Sunrun also sell online right now?

LEE: We do both, but at some point there will be a human-to-human, face-to-face interaction. We can lead-generate through online [platforms], but at some point we're going to send someone out to make sure the home is suitable. [...] I think that co-marketing is a growth area for us with partnerships like with National Grid.

GTM: We’ve talked about rooftop solar and residential energy storage. Can you also describe the role you see Sunrun playing in home energy management?

LEE: I mean, it makes sense; we already have that customer relationship in their home, in terms of solar, so it’s a really small step to do storage and to do home energy management.

I think Lynn and Ed have great ambitions to continue to be one of the premier, best home energy management companies in the country. I couldn't speak specifically to the different parts of that [strategy], but we certainly are a home energy management company at this point.

GTM: How do you think Sunrun will reach the next level of customers? Some of the mature solar markets have recently started to slow. Will grid services start to open up new opportunities?

LEE: Sunrun recently doubled its total available market by going into other states -- New Mexico, Rhode Island, Texas, Vermont, Wisconsin, Washington, D.C., and Florida. We also re-entered Nevada and expanded operations in Pennsylvania. So it seems like there's a ton of room to grow, and of course, from my perspective, we would want to grow with energy services in those markets as well.

GTM: Do you think more work still needs to be done for a rooftop solar company like Sunrun to convince utilities that you’re both on the same team?

LEE: Yeah. […] I really want to sit down at the table with utilities and figure out, “What are your problems? How can we help solve them? What's the best way for us to work together?" Our solar-plus-storage resources are here for the grid, we want to be compensated fairly for them, of course, and operate in a very fair and transparent market, but really, there's value in this technology. We just need to figure out how to set up the rules and work together.