# What is the embodied carbon of rooftop solar panels per kWp for Scope 3?

Canonical: https://senseible.earth/answers/solar-panel-embodied-carbon-per-kwp

There is no single figure. Crystalline silicon modules carry several hundred kilograms of CO2e per kWp, and more when made on a coal heavy grid. Use the module maker's EPD if you can get one. Report the whole amount in Scope 3 Category 2, capital goods, in the year you buy the system.

## Where the figure should come from, best first

1. An EPD or product carbon footprint for the exact module, which states kg CO2e per module or per kWp. Divide by the module's rated watts if needed.
2. The manufacturer's declared footprint, for example from a tender or a low carbon module label.
3. A published life cycle range for crystalline silicon, such as the IEA PVPS Task 12 life cycle studies, with the manufacturing country stated.
4. A spend-based estimate on the EPC value, labelled, as a last resort.

## What to include in the boundary

A module figure covers only the panels. A rooftop system also has inverters, mounting structure, cables and, for ground mounted plants, foundations. Steel or aluminium structures can add a meaningful share. Say whether your figure is module only or the full system.

## Which year it lands in

The Scope 3 Standard puts the full cradle to gate emissions of capital goods in Category 2 in the year of acquisition. You do not spread them over the plant's life the way the accounts depreciate it. A large solar purchase can therefore make one year's Scope 3 jump; explain it in the report rather than smoothing it.

## When it is not your Category 2

- Under a RESCO or OPEX model the developer owns the plant, so the panels are its capital goods, not yours. You buy electricity.
- Solar bought by a landlord for a building you rent is the landlord's capital good.

## Worked example: a 500 kWp rooftop plant

- Assumed embodied carbon: 0.6 t CO2e per kWp (illustrative; replace with the module EPD)
- 500 kWp x 0.6 = 300 t CO2e in Category 2 in the purchase year
- Assumed yield: 1,400 kWh per kWp a year, so 500 x 1,400 = 700,000 kWh a year
- Grid electricity avoided: 700,000 x 0.710 = 497,000 kg, about 497 t CO2 a year less location-based Scope 2

The 0.6 t and 1,400 kWh figures are labelled assumptions for the arithmetic, not published values for any product or site.

## What Senseible does here

Senseible reads the solar EPC or module invoice into the capital goods line of the supplier evidence trail, kept with its HSN code and a SHA-256 fingerprint; the embodied figure comes from the module EPD or your labelled estimate. After commissioning, the lower grid kWh on your electricity bills shows up as lower Scope 2.

- [How to count a new machine in Scope 3](https://senseible.earth/answers/how-to-count-a-new-machine-in-scope-3)
- [Rooftop solar and net metering in Scope 2](https://senseible.earth/answers/rooftop-solar-net-metering-scope-2)
- [RESCO solar: who claims Scope 2](https://senseible.earth/answers/resco-opex-solar-who-claims-scope-2)
- [How to read GWP on an EPD](https://senseible.earth/answers/how-to-read-gwp-on-an-epd)

Sources: [IEA PVPS Task 12, Life Cycle Inventories and Life Cycle Assessments of Photovoltaic Systems](https://www.iea.org), [GHG Protocol Corporate Value Chain (Scope 3) Standard, Category 2](https://ghgprotocol.org/corporate-value-chain-scope-3-standard)

Last reviewed 2026-10-17. Module footprints vary widely with manufacturing location and year; prefer a current module EPD over any range.