Development and finance
Environmental and social impact: two authorizations prepared from the start
A generation project has to show two things before it is built: that its effect on the environment is prevented and mitigated, and that the communities in its area of influence were identified and taken into account. They are two separate processes, before two separate authorities, and lenders review both.
Environmental impact statement (MIA)
Before SEMARNATMexico's General Law of Ecological Balance and Environmental Protection (LGEEPA) requires prior environmental impact authorization from SEMARNAT for electricity industry works and for gas pipelines, in the cases set by its Regulations (LGEEPA art. 28, secs. I and II).
The MIA describes the project and its site, identifies impacts on soil, water, flora, fauna and air, and proposes measures to prevent, mitigate or offset them. The authorization sets the conditions for building and operating.
A ground-mounted solar park, a cogeneration plant and a gas pipeline have different impacts; the MIA is prepared alongside the design, not afterwards.
When not to start here
- If the site is not yet secured: the MIA is prepared for a specific site.
- If the design can still change a lot: a major change forces the assessment to be revisited.
- If the project sits in a protected natural area or a coastal ecosystem: check first whether the site is viable.
Social impact
Energy Sector Social Impact Statement (MISSE)
Before the Ministry of EnergyWho files it
Those developing electricity infrastructure projects, before SENER (LSE art. 136).
What it contains
Project stages and area of influence, communities and peoples in that area, positive and negative social impacts, and measures in a social management plan (art. 136).
How it is prepared
With a participatory approach, a gender perspective and respect for human rights (art. 136).
Exemptions
Among others, plants that need no permit, and expansions or maintenance with no significant social impact (art. 137).
Decision period
SENER decides within no more than 90 calendar days; it may approve, approve with conditions or deny (art. 139).
Rules
"Disposiciones Administrativas de Carácter General sobre la Manifestación de Impacto Social del Sector Energético", SENER, DOF 16-Feb-2026.
Electricity Sector Law (LSE), DOF 18-Mar-2025, arts. 136, 137 and 139; LGEEPA art. 28.
Emissions and the grid factor
The official referenceTo estimate the emissions avoided by a project that displaces grid power, the reference is the National Electric System emission factor published by SEMARNAT and the CRE.
Any figure of avoided tonnes must come with its method: the generated energy that actually displaces grid power, multiplied by the factor in force for the reporting year.
0.444tCO2e/MWh
National grid emission factor
Year 2024, in force for 2026 reporting. SEMARNAT-CRE notices of 28-Feb-2025 and 29-May-2026.
Frequently asked questions
Does a solar park need an MIA?
The electricity industry is among the works that require SEMARNAT environmental impact authorization, in the cases set by the LGEEPA Regulations (art. 28 sec. II). It is reviewed case by case, by site and size.
Are the MIA and the MISSE the same?
No. The MIA assesses environmental impact before SEMARNAT; the MISSE assesses social impact before SENER. They are separate processes and a project may need both.
How long does SENER take to decide on the MISSE?
The law gives it no more than 90 calendar days (LSE art. 139).
Do you publish the CO2 avoided by your plants?
Not yet. When we do, it will use the official factor of 0.444 tCO2e/MWh and a method note.
Review a project
Location, technology and size: that tells us which assessments it needs.
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