Priya. Theo. Twenty-three people. One niche.

Priya — co-founder

ELECTRICAL ENGINEER

Priya Achterberg grew up in Davis. UC Davis electrical engineering 2006, Stanford MS in Electrical Engineering / Energy Systems 2008. Her thesis was on microinverter topology for partial-shading conditions in residential PV. She joined SunPower in 2008 as a residential systems engineer, working out of San Jose; she was on the team that designed SunPower's first integrated PV-on-roof product (which never reached market) in 2011-2012.

She joined Tesla Energy in 2014, two years before the Solar Roof launched. She was on the launch team. She was on the 2016 Buffalo plant tour with Elon when Tesla and Panasonic unveiled the prototype. She managed Tesla's Northern California Solar Roof installer-certification program from 2016 through her departure in 2017.

She left Tesla because the Sacramento Valley footprint was thin. Tesla had certified two installers in the entire region in 2017, and neither was investing in real installation depth. Priya wanted to install Solar Roof at scale. She and Theo started Helios in November 2017.

Priya holds California General Contractor License B-1 (#1102841), California C-46 Solar Contractor License (#1102841-46), NABCEP PV Installation Professional certification, and is the named principal on Helios's Tesla, GAF Energy, and SunStyle installer agreements. She is married to Joost Achterberg, a pediatric neurologist at UC Davis Medical Center. They have two children — Tara (10) and Suresh (7).

She writes the quarterly Helios Bulletin. She runs the office. She still goes on most site audits.

Theo — co-founder

NABCEP PV INSTALLATION PROFESSIONAL

Theo Ramaswamy grew up in San Luis Obispo. Cal Poly San Luis Obispo construction management 2009. He spent five years at GAF Materials Corporation as a residential rep on the California Central Coast from 2011 to 2016, covering San Luis Obispo, Santa Barbara, and Ventura counties. In 2015 he was pulled onto the GAF Energy team during the development of what would become Timberline Solar, working with the launch product team through the prototype phase and field testing in 2015-2016.

He left GAF in 2016 to take his NABCEP PV Installation Professional certification and a year of independent contracting before partnering with Priya in late 2017. He runs the field side of Helios — every install is foremaned by Theo, by Marcus Delgado, or by Hana Park. No subcontractors.

Theo holds NABCEP PV Installation Professional certification, GAF Master Elite Solar installer status, CertainTeed solar specialist certification, and Tesla Certified Installer credentials. He is married to Megan Ramaswamy, a high school chemistry teacher in Sacramento. They have three children — Ravi (8), Indira (6), and Asher (3).

Theo lives on the roof. If you book a site audit, he is the one most likely to show up. He is also the one most likely to call you back at 6:47am to ask a follow-up question about your second-story dormer.

Our two crew leads.

Marcus Delgado joined Helios in 2018 as our first hire. He is Tesla Certified Installer, GAF Energy Authorized Installer, and one of two crew leads on every project. He grew up in Sacramento, came up through framing carpentry, and moved into integrated PV after a year of bolt-on solar installation work that he describes as "watching people void roof warranties one stanchion at a time."

Hana Park joined Helios in 2020. NABCEP PV Installation Associate, GAF Master Elite Solar, SunStyle Certified Installer (the only crew lead in Northern California with all three manufacturer credentials). She came from a small Bay Area solar firm that closed in 2019. She runs the SunStyle installs and most of the architect-led modern projects.

Twenty-three people on the payroll.

Helios is a 23-person firm. The composition is intentional. There are 2 co-founders (Priya and Theo), 2 crew leads (Marcus and Hana), 12 certified installers (all NABCEP Associate or PV Installation Professional, all Tesla-certified or GAF-certified or both), 3 estimators who do site audits and HelioScope modeling, 2 permit-and-interconnection specialists who handle all PG&E paperwork and county permit submissions, 1 office manager, and 1 warehouse manager. No subcontractors. No day labor. No commission salespeople.

The firm has grown carefully. We hired our 5th employee in 2019, our 10th in 2021, our 15th in 2023, and have stabilized at 23 in 2025. Growth past this point is not a strategy — depth on the existing systems is. We would rather install 24 more Tesla Solar Roofs next year than expand into bolt-on solar, asphalt re-roofing, or commercial work.

Why we install three systems and only three.

Manufacturer certification is real work. Tesla Solar Roof requires a multi-day training, a field installation under direct manufacturer supervision, an ongoing annual audit, and a per-install QA review on the first dozen installs. GAF Master Elite Solar requires a comparable training-plus-audit cycle. SunStyle Certified Installer requires manufacturer-led training in Lausanne or at SunStyle's Boston office.

Most California solar installers do not bother with any of this. They install bolt-on rack-and-rail panels, which have no manufacturer-certification gate — anyone with a C-46 license can install them. The certification gate is the barrier we use to define what we do. Tesla, GAF Energy, and SunStyle are the only three roof-integrated PV products on the California market with full manufacturer certification programs. We hold all three. That is the entire business.

There is no sub-niche of bare asphalt re-roofing. There is no commercial division. There is no battery-only installation arm. Helios installs roof-integrated solar. We have done so 184 times since 2017.