In-House versus Outsourced Engineering Services: Page 7 of 7

Josh Weiner


SepiSolar ( is a turnkey system design and engineering firm, based in Fremont, California, that specializes in solar PV, energy storage and microgrids. As of January 2018, SepiSolar has designed more than 3,500 residential projects, 1,000 commercial projects and 200 energy storage projects. The company employs licensed civil, structural and electrical engineering professionals and is able to stamp projects in 49 states.

SP: Who are your typical customers, and what types of professional services does SepiSolar provide?

JW: We serve three major customer groups: small- to medium-size independent developers and EPC firms, solar EPCs or developers, and nonsolar developers. The first group consists primarily of companies with core competencies that lie somewhere outside solar design. They may have a compelling financing structure, sales skills or installation expertise but a knowledge gap on the design or engineering side of the business. SepiSolar fills that gap. The second group includes medium- to large-size companies, vertically integrated or not, with solar expertise. These companies are looking for an engineering-as-a-service provider that can support peak demand periods and accommodate the busier seasons. SepiSolar provides a quick, adaptable and flexible service that these companies can turn on or off without sacrificing quality or expending management resources. The third group includes architects, general contractors, governments or public entities, and financiers or owners who do not know much about solar at all. For instance, SepiSolar is working with the lead architect on the Smithsonian Institute’s Air and Space Museum, which is a multi-decade project with incredible complexity in building design, LEED certification and net-zero requirements. The name of the game here is to manage complexity on behalf of our customer to make the solar integration process as simple as possible.

SP: What is the value proposition of outsourcing design and engineering services to a third-party provider?

JW: The value proposition is gaining a vantage point that the customer wouldn’t otherwise have to navigate, maneuver and dodge the various technical obstacles that sometimes prevent the development of a particular solar project from moving forward. These requirements and many others vary and are often technical in nature, and they frequently cause added costs and delayed project timelines. Whether it’s a 1 kW or a 1 MW project, there are so many requirements that come into play. Our job is to master these requirements and leverage that experience for the benefit of our customers.

SP: Do any of your customers try to transition away from outsourcing their engineering needs and develop in-house engineering capabilities?

JW: Some customers have asked us if we can assist with the first project or two until they can get up to speed and can bring design and engineering in-house. This is completely fine by us because one of three things tend to happen. One, customers occasionally learn what they need to from us and go on to become industry leaders, in which case we take pride in helping them grow from zero to hero. Two, more frequently, customers fall in love with our quality of service and work us into their business model. Three, the customer never quite develops all the capabilities that we have, in which case it may take over a portion of the work but continue to use us to perform other portions of the work or provide design review services to ensure quality control.

Jordan Weisman

Project Manager and Owner
Sunbridge Solar

Founded in 2010, Sunbridge Solar ( serves the Portland, Oregon, metro area market, as well as Vancouver, Washington. The company has 10 employees. Its project portfolio is roughly 70% residential and 30% commercial.

SP: How does Sunbridge Solar meet its design and engineering needs?

JW: We perform basic technical drafting and electrical design activities in-house. These capabilities are sufficient for any residential or commercial PV projects in Oregon or Washington that conform to the checklist for prescriptive PV installations. These jurisdictions have policies in place that expedite permitting for standard projects, meaning conventional light-frame construction with appropriately spaced rafters or trusses. Projects that fall outside these criteria are nonprescriptive installations that require stamped engineering plans. About 30% of our projects are nonprescriptive and require PE-certified plan sets. Commercial projects in Oregon also require that an electrical engineer stamp the electrical drawings. Since it is prohibitively expensive for a small company like ours to have an engineer on staff, we outsource our engineering requirements to a number of firms. But roughly 70% of the time, we are able to permit projects in-house.

SP: To what extent does Sunbridge Solar use technology—such as module-level power electronics or solar design software—to reduce its reliance on design staff or professional engineers?

JW: Very little. Module-level power electronics is more of a selling point for customers than a means of reducing reliance on technical staff. We do utilize solar design software but mainly for generating proposals and production estimates.

SP: Does your company ever work with solar design service providers?

JW: Yes, we utilize solar design service providers for larger commercial projects. As our business transitions from residential to commercial projects, it is helpful to rely on an experienced team of designers to support and collaborate with us. These design service providers are able to conduct on-site visits, draft building and electrical plan sets, advise on the technicalities of interconnection and work with their selected engineer to deliver a final permit. Although this can be costly, it can also greatly reduce the project management time needed to get a commercial project off the ground. For a small business, this time savings can have a huge value. In effect, we are able to install larger projects while minimizing overhead, which has been vital to the growth and success of our business. I think our company would need to employ roughly 50 people before it would make sense to hire an in-house engineer.


David Brearley / SolarPro / Ashland, OR /

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