Energy Storage Design & Engineering

SepiSolar engineers are at the forefront of battery design, technologies, codes, utility policies, and permitting. Whether you’re installing energy storage for the first time or have years of experience, SepiSolar can support your energy storage project with a full suite of design and engineering services.

Whether lithium or flow batteries, grid-tied or off-grid, with or without fuel-based generators, SepiSolar offers complete permit-ready design packages and consulting services for your storage project.

Solar Plus Storage Permit Packages

SepiSolar designs energy storage systems that are tailored to your specific technology, application, and the requirements of local AHJs and your utility. Complete solar-plus-energy storage permit packages typically include:

  • Project description
  • Construction notes
  • Governing codes
  • Site plan
  • Site specifications
  • PV layout
  • Mounting & racking methods
  • Three-line electrical diagram
  • Electrical calculations
  • Electrical elevations
  • Parts List
  • Required Safety Placards

Other Solar-Plus-Storage and Energy Storage Services

SepiSolar designs energy storage systems for residential, commercial, industrial, agricultural, utility, and microgrids. Our services include:

  • Electrical single-line and three-line diagrams utility and permit processing
  • Battery storage system sizing and performance modeling
  • Solar PV-plus-storage system sizing optimization
  • Storage O&M and battery augmentation schedules
  • Stand-alone energy storage design for peak shaving, backup, UPS, and emergency applications
  • Load analysis, Degradation analysis, FTC compliance analysis
  • Designs for DC- or AC-coupled energy storage systems
  • Energy storage utility interconnection processing
  • Energy storage technology comparisons (e.g., lithium vs. flow batteries vs. flywheel vs. others)
  • Energy storage financial modeling for sales proposals: residential, commercial, industrial, utility
  • Electrical and structural PE stamps for all 50 states and jurisdictions
  • Processing for California SGIP and SOMAH solar-plus-storage applications

Solar-Plus-Storage Modeling Services

SepiSolar’s engineers have developed proprietary solar-plus-storage modeling tools for designing cost-effective systems for all energy storage applications, demand charge reduction, frequency regulation, spinning reserve, transmission support, and other applications. Learn more about SepiSolar’s Energy Storage Financial Modeling and Technical Consulting.

Energy Storage Technologies

SepiSolar engineers are energy storage technology and chemistry agnostic. We design solar-plus-storage systems for all battery chemistries and brands, including:

  • Lithium (Li-ION, LFP, NMC, NCA, etc.), including Tesla, Sonnen, LG, Panasonic’s Pika Energy, Sony, Enphase, StorEDGE, SimpliPhi, etc.
  • “True” flow batteries (vanadium, iron-chromium), including Avalon, Vionix, Primus, VRB, UET
  • “Hybrid” flow batteries (zinc-bromine, iron-iron, zinc-iron, etc.): ESS, Primus, etc.
  • Lead acid (advanced, traditional, etc.)
  • Nickel-cadmium
  • Flywheel (Amber Kinetics)
  • Other proprietary storage technologies


Using SepiSolar for designing and engineering Swell Energy’s solar-plus-storage systems was a no-brainer. Storage is complicated, so we wanted to work with a team of U.S.-based quality engineers who could speak ‘fluent storage’ and get out accurate plan sets quickly and with minimal AHJ revisions. If you’re looking for a quality design partner who knows how to get storage permit plans approved in California, trust the SepiSolar team.”

Andrew Meyer,
Co-Founder, Swell Energy

Solar Design PDF

Solar Design PDF

Get a free energy storage design consultation.

Get a free energy storage design consultation.


CA Small Business Enterprise

Certification ID:

Bidder/Supplier ID:

NAICS Codes:
541330 – Engineering services
541340 – Drafting services
541490 – Other specialized design services
541618 – Other management consulting services
541690 – Other scientific and technical consulting services
541990 – All other professional, scientific, and technical services

D-U-N-S number:

811024, 81101701, 81101516, 81101604, 43232614, 81101505

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