Ferrius Energy guides cite OSHA, NFPA, NEC, the IRS, NREL, Lawrence Berkeley National Laboratory, and state energy offices and utility commissions such as Massachusetts DOER and DPU. Pages that depend on incentive programs or tax rules carry a "Last reviewed" month, and are revised when a regulation, tariff, or IRS notice changes. Nothing on this site is tax or legal advice; confirm your position with your own advisors.
Commercial Solar Resources, Guides and Tools
This is the Ferrius Energy library for commercial property owners, CFOs, developers, and investors evaluating solar and battery storage: cost and return guides, incentive and tax explainers, procurement checklists, and calculators. Every guide cites primary sources and carries a review date, because incentive programs and federal tax rules change.
Last reviewed: September 2026.
Cost and returns
Incentives and tax
Buying and building
Calculators for a first-pass investment case
Commercial Solar ROI Calculator
Net cost after the Section 48E credit and depreciation, simple payback, 25-year NPV, and IRR from your own inputs.
Battery demand charge estimate
Model peak shaving and demand response revenue with our engineers using your 15-minute interval data.
Solar farm land screening
Acreage, slope, wetlands, and distance to three-phase distribution decide whether a parcel is worth studying.