Depending on the solar system, the home, and the homeowner’s expectations for their system, project installations may include what are termed “adders.” Adders are items and related costs beyond the basic panels, inverters, racking package. Some adders are operational, or necessary, for the solar system to be able to operate, while others are optional features.

Examples of operational adders would be roofs constructed with tile or some non-traditional material, or an electrical panel that needs to be upgraded to accommodate the energy load of the solar system. Here, additional costs will need to be accounted for to install the solar system.

Examples of optional adders would be a solar panel upgrade, battery system, or something else not required for basic operation of the solar system.


  • Be sure to take note of potential adders from the very beginning of the sales process! Adders that are not identified until after funding has been secured can result in reduced sales commissions, out-of-pocket costs for the homeowner, or the need to revisit funding approval, and ultimately increase the potential of a contract's delay or cancelation.

  • The table below represents examples of common adders and ranges in pricing. Adders are market specific, so build in adequate adder pricing into your projects, and definitely consult your sales support representative to ensure adders costing is accurate for the specific state and local jurisdiction.

If an adder price is marked with an asterisk (*), the price will automatically be calculated in the app once it is selected. All other adders must be added manually by the salesperson in the app’s “Add-on (included in ITC)” adder line on the financing screen. Reference 'Building a Proposal in the App - Part IV, Selecting Financing' for instructions on populating the ITC adder line.




Small Size system < 5kW

Adder accounts for fixed cost associated with system installation

$.40/ Watt*

Main Panel Upgrade

Potentially necessary in older homes or when home has 100 amp Main Service Panel and solar system is larger than 5 kW


Sub panel Upgrade

Potentially necessary when main panel requires additional room to add circuits


Move Vent Pipe

Non-combustion vents only

$200 each

Metal roof

Corrugated or standing seam

$.10/ Watt*

Flat Tile roof

Cement & walkable tiles without breaking

$.10/ Watt*

Hard Spanish Tile

“S” shape

Cement & walkable without breaking

$.10/ Watt*

Soft Spanish Tile

“S” shape

Clay, ceramic, breakable

Quantify costing with Clean.Tech rep

Steep roof > 35°

Steeper than 45º may be disqualified

$.20/ Watt

Flat roof < 5º

Chemically bonded

$.15/ Watt

Travel Adder

Potentially incurred when installations require extenuating drive times and related milage or lodging

Quantify costing with Clean.Tech rep

Ground Mount, Substructure

Trenching not included

$.50-$.55/ Watt*

Ground Mount Trenching, Conduit, and Wiring

Linear distance from array to service panel, avoiding obstructions

$150 flat fee plus

$15/ Linear Foot

* When selected, the cost is added automatically in the app.

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