Emissions and energy calculation methodologies Avoided metric tons of carbon dioxide equivalent (MTCO e) 昀椀gures were derived from 2 actual kilowatt-hour (kWh) production of our deployed microinverter 昀氀eet from Enphase’s inception through December 31, 2023 as recorded in our Enlighten™ monitoring database, including a gross up factor of 1.2 to account for deployed systems which are not monitored in the Enlighten database. The conversion of kWh production to carbon dioxide equivalent 昀椀gures was made using the U.S. EPA Greenhouse Gas Equivalencies calculator. The 2023 GHG emissions inventory follows the GHG Protocol Corporate Standard, covering Scope 1, Scope 2, and certain Scope 3 categories. All emissions were calculated using an operational control and location-based method for electricity and heat consumption across all leased facilities globally. We forgo market products to reduce emissions, so the reported location-based 昀椀gures are equivalent to market-based emissions 昀椀gures. Note that heat consumption was only gathered for facilities located in North America. Electricity consumption for European o昀케ce locations was estimated by square foot using data from the U.S. Commercial Buildings Energy Consumption Survey (CBECS), representing two percent of energy consumption reported. Electricity and heat consumption were converted to MTCO e using emission factor data provided in the Emissions Factors for 2 Greenhouse Gas Inventories provided by the U.S. EPA (eGRID2021) for U.S. locations and the Emissions Factors 2021 data set from the International Energy Agency (IEA) for international locations. Emissions calculations cover those attributable to carbon dioxide (CO ), nitrous oxide (N O), and methane (CH ) resulting from electricity generation, heat 2 2 4 generation, and transmission and distribution losses. Emissions are converted to CO e by 2 multiplying by their global warming potential (GWP), referencing default factors provided by the Intergovernmental Panel on Climate Change (IPCC). Hydro昀氀uorocarbons (HFCs), per昀氀uorocarbons (PFCs), sulphur hexa昀氀uoride (SF), and nitrogen tri昀氀uoride (NF ) gases 3 are excluded from our inventory, as facilities under our operational control do not produce signi昀椀cant amounts of these GHGs. The data supporting Scope 3 disclosures was provided by our third-party travel agency, contract manufacturers, and internal logistics team, covering purchased goods and services (category 1), upstream transportation and distribution (category 4), business commuting (category 6), and downstream transportation and distribution (category 9). Emissions attributable to contract manufacturing were made using supplier-speci昀椀c data, covering Scope 1 and Scope 2 of manufacturing activity at eight manufacturing sites, representing substantially all of total contract manufacturing spend in 2023. The emissions disclosed represent only that fraction of activity attributable to the manufacture of Enphase products. 84