Commercial solar installation in Chicago.

Array sizing inputs

How do you size a commercial solar array in Chicago?

Demand charges drive the math · DEMAND Demand is billed per kilowatt per month, set by the 15-minute stretch in the month when your use peaked. An array cuts demand only when it is producing during that stretch. Many commercial buildings peak in the afternoon on cooling load, and sun on the building is part of what creates that load, so peak demand and peak output often land together. As a rule of thumb, solar saves demand equal to about 10% of rated capacity: roughly 100 kW off a 1 MW system. Shading analysis before layout · SITE STUDY We run a shading analysis of the roof or lot first, tracking which shadows fall where and when, then draw the array around the result. Roof walls, rooftop units, elevator housings, and taller buildings next door all push panels off the spots that look best on a satellite image. You get the study attached to the layout, so you can see why each row sits where it sits. Roof, parking canopy, or open ground · ARRAY TYPE Rooftop arrays and parking canopy arrays both serve commercial sites, and one property can carry both. Old industrial land counts too: a brownfield in DePue, Illinois was rebuilt into a 27 MW solar project that sells its output to local utilities. We walk the roof and the lot before recommending a mix.

PROJECT PLANNING

Should your Chicago building own the solar array or buy the power?

Own the array outright · CAPITAL You put up the capital, keep the production, and carry the upkeep. Ownership is one of the structures a solar business case weighs, next to leases and power purchase agreements. Flux can hold the upkeep scope after handover so the array does not go unwatched. Lease or power purchase agreement · THIRD PARTY A renewable energy firm builds, owns, operates, and maintains the system while you host it and buy the output. You avoid the upfront capital cost. Energy savings performance contracts and energy-as-a-service agreements work the same way, with the firm keeping ownership. State policy decides third-party ownership · ELIGIBILITY Third-party ownership with the site owner as the power buyer is allowed only in certain states. We confirm the current Illinois policy before we build a side-by-side comparison, so you are not pricing a structure you cannot sign. Who maintains it after year one · UPKEEP Under third-party ownership, the firm that owns the array operates and maintains it. If you own it, that work is yours to schedule, and Flux can run it: panel cleaning, inverter checks, roof penetration inspections, and a written log of each visit.

Bid package contents

What should a commercial solar bid in Chicago include?

• Twelve months of electric bills with the demand lines, so the array is sized against your real peak instead of square footage. - A shading analysis of the roof or lot, dated and attached to the bid, not promised for later. - Proof of commercial-scale solar work: three or more years designing, engineering, and installing commercial solar systems, plus past jobs on commercial, industrial, or utility-scale projects. That standard is self-certified across the industry, so ask for the job list behind it. - One Department of Buildings inspection request, booked as an appointment for a set date, with the on-site contact named. The department otherwise works first-come, first-served, and a duplicate request does not move you up. - Written exclusions in plain words: what the price does not cover, such as roof repairs found during layout.