TerraSol Energies is a rapidly growing commercial and residential solar EPC company serving the greater Philadelphia and Delaware Valley region. As we scale our project portfolio and in-house installation capabilities, we are seeking an experienced Lead Solar Designer to anchor our engineering department. This is a hands-on leadership role: you will be the primary technical authority responsible for designing, calculating, and producing complete engineering drawing sets for our projects — working collaboratively with our senior management team, project managers, and field crews to deliver high-quality, permit-ready packages on time.

The ideal candidate combines formal engineering credentials with deep practical experience in commercial photovoltaic systems, is comfortable translating design concepts into accurate construction documents, and takes pride in the precision and completeness of their deliverables. This position is office-based in Chadds Ford, PA with periodic field visits to active project sites.

KEY RESPONSIBILITIES

Engineering Design & Drawing Production

• Develop and maintain complete engineering drawing sets for commercial and residential solar PV projects, including site plans, single-line diagrams (SLDs), three-line diagrams, plan-view layouts, roof/ground-mount structural layouts, equipment schedules, and labeling plans.
• Produce permit-ready drawing packages that meet AHJ (Authority Having Jurisdiction), utility, and NEC code requirements.
• Design systems using industry-standard CAD software (AutoCAD and/or PVComplete/Helioscope preferred); develop and maintain reusable drawing templates to improve team efficiency.
• Incorporate equipment specifications — inverters, combiners, disconnects, conduit runs, grounding systems — accurately and completely into drawing sets.

Electrical System Engineering & Calculations

• Perform all requisite power systems calculations, including wire sizing, conduit fill, voltage drop (feeder and branch circuits), short-circuit analysis, ground fault protection, and load flow.
• Size AC and DC conductors, overcurrent protection devices, and disconnects per NEC Articles 690, 705, and applicable sections; document calculations in a clear, auditable format.
• Evaluate interconnection configurations (utility-side, load-side, and behind-the-meter) and prepare interconnection application support packages for utilities (PPL, PECO, Delmarva Power, and others in the service territory).
• Conduct production modeling using PVWatts, Helioscope, or equivalent tools to support proposals, interconnection submittals, and performance guarantees.

Collaboration & Project Support

• Work closely with senior management and estimating team to incorporate design concepts and system configurations into accurate, buildable designs from early project stages through final permit issuance.
• Partner with project managers to ensure engineering deliverables align with project schedules; proactively communicate design issues or schedule risks.
• Provide technical review and redlines on subcontractor submittals, shop drawings, and equipment cut sheets.
• Respond to AHJ plan check comments; revise and resubmit drawing packages as needed to achieve permit approval.

Field Visits & Construction Support

• Conduct site visits during pre-construction for field verification (roof condition, structural assessment, electrical infrastructure, utility meter and service entrance evaluation).
• Provide construction-phase engineering support: RFI responses, field condition clarifications, as-built drawing updates, and commissioning verification.
• Collaborate with installation crews to resolve field discrepancies between drawings and existing conditions.

Quality, Compliance & Continuous Improvement

• Maintain engineering standards, drawing templates, calculation worksheets, and a library of pre-approved equipment details to improve speed and consistency across projects.
• Stay current on NEC code cycles, OSHA requirements, utility interconnection rules, and state/local incentive programs (PA, NJ, DE) relevant to TSE's project pipeline.
• Participate in post-project reviews to capture lessons learned and refine standard designs.

• Bachelor's degree in Electrical Engineering, Electrical Engineering Technology, or a closely related field; OR equivalent demonstrated experience in solar EPC engineering.
• Minimum 3–5 years of hands-on solar PV design experience, with a track record of commercial projects (100 kW and above).
• Demonstrated proficiency in electrical system calculations: wire sizing, voltage drop, conduit fill, short-circuit analysis, and load flow in PV applications.
• Working knowledge of NEC Article 690, Article 705, and applicable commercial electrical code requirements.
• Experience with interconnection applications and utility coordination within PJM territory (PPL, PECO, Delmarva, JCP&L, or similar utilities strongly preferred).
• Proficiency in AutoCAD or equivalent CAD drafting platform; ability to produce precise, professional-quality drawing sets independently.
• Familiarity with PVWatts, Helioscope, or comparable solar design and production modeling tools.
• Strong analytical skills; ability to manage multiple projects and deadlines simultaneously with a high attention to detail.
• Effective communication skills — able to present technical information clearly to non-technical stakeholders, AHJs, and utility representatives.
• Valid driver's license and ability to conduct field visits at commercial project sites in the Philadelphia/Delaware Valley region.

About TerraSol Energies, Inc.

TerraSol Energies was founded in 2009 with one goal: deliver smart solar energy solutions designed to maximize your investment — without the impersonal experience of big national solar companies. We’re based in Chadds Ford, PA, and have spent 15+ years building a reputation as the tri-state area’s trusted solar installer. We’ve completed hundreds of residential and commercial installations across Pennsylvania, New Jersey, Delaware, and Maryland — and we’ve done it as a family-owned, family-operated business that treats every project like it’s our own. Our certified team handles everything from start to finish, system design, permitting, installation, and long-term maintenance. So you never have to deal with multiple vendors or wonder what happens after your panels go up. We’re with you for the lifetime of your system.

Connections working at TerraSol Energies, Inc.