The carbon footprint of every solar project, avoided against embodied
pvSpline sets the emissions the solar energy displaces on the grid against the emissions embedded in making, carrying and disposing of the equipment, over the life of the project, and gives the carbon payback time.
Avoided emissions, against the right grid
The avoided CO₂ is the energy produced times the carbon intensity of the grid it displaces. Give the country’s two-letter code and the run looks its intensity up in a table built from open references: Ember’s yearly electricity data, the IPCC’s direct-emission medians and, for France, ADEME’s Base Carbone. Or type the figure from your own source.
Operational or life-cycle
An operational figure counts combustion only; a life-cycle figure adds the fuel chain upstream and the building of the power plants. Declare which convention your intensity follows, and with no figure typed, the run takes the country’s figure in that convention.
Embodied emissions, component by component
Modules, structure, wiring, inverter, battery, transport and end of life each carry an intensity that scales with the system’s power, energy or capacity. Each starts on a published default; type the figure from your supplier’s environmental product declaration (EPD) where you have one. Replacing the inverter or the battery during the project counts its footprint twice, and recycling can earn a credit at the end of life.
The balance over the project’s life
The balance runs over the same horizon as the financial projection. The results chart it year by year and cumulatively, and give the carbon payback time and the lifetime balance, which the report prints for SFDR, CSRD or GRESB reporting.
In a tender, the modules’ ECS
For a CRE tender, the simplified carbon assessment is another figure: the modules’ certified footprint per kWp, checked against the ceiling the tender family sets. The dossier productible gives the verdict.
A carbon balance in four steps
- On the Project tab, tick Carbon footprint enabled on the CARBON FOOTPRINT card.
- Enter the site’s Country code, or the grid’s carbon intensity, and its accounting mode.
- Replace the component defaults with your suppliers’ EPD figures where you have them.
- Run the simulation and read the carbon payback and the lifetime balance in the results.
Questions
What if I leave the country blank?
With no country and no figure, the run falls back on 400 g of CO₂ per kWh, many times the French grid’s intensity, so a French site’s avoided CO₂ would come out heavily overstated. Always give the country code or the figure.
Does it work for an off-grid or pumping project?
Yes, for every system type. Where there is no financial card, the horizon of the balance sits on the carbon card itself.
What about thin-film modules?
Set the module footprint to the technology’s own figure: the default is a crystalline-silicon reference.
The fastest way to judge a simulation tool is to run it on a project you already know.