Prepare the inverter specification, quantity and US destination before you ask for factory quotes.

Question-led planner

On grid solar inverter manufacturers: questions before the inquiry

Use this planner when the array will operate grid-tied. It collects configuration, interface and approval questions. It does not size the array or approve a factory.

Build a Sourcing Brief

Fields still blank until you fill them

  • Grid-tied string, central or microinverter path
  • Rated AC power and DC input range
  • MPPT channels and phase
  • Grid voltage and communication protocol
  • Monitoring and rapid-shutdown dependencies, if any

Evidence to attach to the quoted model

  1. Datasheet that states grid-following or grid-forming behaviour and the standard cited.
  2. Drawing that shows AC and DC terminations you can match to the one-line.
  3. Listing or test record whose model string matches the quote, when you require one.
  4. Commissioning boundary: what the factory includes and what stays with your installer.

Family literature that never names the model remains a brochure. Put it aside until the factory links the file to the item.

Decisions this planner leaves open

String cabinet or module-level

Fewer cabinets can simplify an unshaded grid-tied block. Module-level devices can change shade behaviour and monitoring granularity. Write which constraint dominates. Do not let a supplier erase the other column.

Headline price or delivered scope

A smaller unit price can be the right commercial result when cables, freight, taxes and warranty match. If those differ, the lower number is not yet a decision. Ask both factories to restate the missing column.

Efficiency number

Record the percentage only with its test basis and the model it belongs to. A peak figure without the standard is a note, not a ranking key.

Approvals outside sourcing

Utility interconnection, local electrical review and structural checks are not closed by sending this form. List them as open so nobody reads silence as consent.

On-grid equipment still needs the destination voltage and phase your site uses. Export limits, power-factor settings and protective functions belong in the question list when the utility has already published them. If the utility has not, say so.

A grid-forming inverter claim is a specification to verify, not a default for every grid-tied package. Many grid-tied units are grid-following. Ask the factory which behaviour the quoted firmware provides and which standard the manual cites.

Use a worksheet with requested value, quoted value, document revision and reviewer decision for rated power in kW, voltage in V, current in A, MPPT range, enclosure rating and operating temperature in °C. Check the model and firmware identifiers against the datasheet and project one-line. Resolve deviations in writing before coordinating a sample; any energized verification needs a qualified reviewer, an agreed method and recorded acceptance criteria.

If your budget favors acquisition cost, ask which gateway, cable and warranty services are excluded. If you prefer a premium or mid-range proposal, ask for those same line items rather than accepting a tier label as proof. Compare the whole-order total in one currency and state who pays for samples, testing and freight. Leave unknown costs open until a supplier confirms them.

The Department of Energy inverter and grid-services primer is a public vocabulary source for these questions. It is not a product approval and it is not a substitute for the proposed-item datasheet. Pair it with your own inquiry cards and the matching steps. The longer narrative sits in the procurement brief.

Send the on-grid question list

Copy the blanks you could not answer. Add quantity, US destination and, if you wish, a budget range with currency and a per-unit or whole-order note.

Request Factory Quotes