Grid connection for rooftop solar: process and documents
Permitting
Most schedule slippage on rooftop solar projects happens in paperwork, not construction. This guide summarises the typical process with the utility for self-consumption systems and the documents worth preparing upfront to avoid repeated resubmission.
In this guide
01
The legal basis to read first
Self-consumption rooftop solar currently follows Decree 58/2025/ND-CP detailing the Electricity Law on renewable and new energy development, together with guidance from the Ministry of Industry and Trade and the internal procedures of the regional utility.
- Decide the arrangement: grid-connected or off-grid, and whether surplus export is registered or the system runs zero export.
- Check the building's compliance on investment, construction, land, environment, safety and fire protection.
- Identify the voltage level and intended connection point, which determines who processes the application.
- Contact the local utility for the forms and document list applicable in that area.
Regulatory information is reference material as of the update date; forms and detailed requirements can differ between regional power corporations.
02
Typical process
- Step 1: survey, size the system to the load and prepare a preliminary connection scheme.
- Step 2: submit the connection agreement request with technical documentation to the utility.
- Step 3: receive the connection agreement and finalise design against the technical requirements stated in it.
- Step 4: construct, test equipment and complete as-built documentation and test records.
- Step 5: commissioning, metering installation or adjustment, and energisation.
03
Technical documents to prepare
- Single-line diagram, connection scheme to the metering point and protection device layout.
- Datasheets and quality certificates for modules and inverters per the applicable standards.
- Capacity calculations, yield simulation and export limitation configuration records (for zero export).
- Roof structural documentation, safe work method statements and related fire protection paperwork.
- Test records, meter calibration certificates and as-built documentation after construction.
04
Why applications get sent back
- Registered capacity not matching the design or the equipment actually installed.
- No evidence of the anti-export configuration when the application declares no surplus export.
- Protection scheme missing isolation, reverse power and anti-islanding functions.
- Building construction and fire protection files not updated for the new rooftop installation.
Frequently asked questions
How long does the connection process take?
It depends on the connection voltage level, the quality of the submission and the workload of the regional utility; the most effective way to shorten it is to submit a complete technical package the first time.
Does an off-grid system need any approvals?
A standalone system with no grid connection still has to comply with the building's construction, electrical safety and fire protection requirements, even though no connection agreement with the utility is needed.
Who normally prepares the application?
For factory projects the EPC contractor usually prepares the technical package and deals with the utility on the owner's behalf, while the owner provides the building's legal documentation and signs the agreements.
Related guides
Solar knowledge
Commercial rooftop solar in Vietnam: rules and delivery
A complete guide to industrial rooftop solar in Vietnam: self-production and self-consumption rules under Decree 58/2025/ND-CP, sizing against the load curve, realistic yields and the EPC delivery process.
Grid connection engineering
What is zero export, and when should a factory use it?
How zero export (export limitation) works on self-consumption rooftop solar: control principle, required equipment, the yield you trade away, and when zero export beats registering surplus export.
EPC services
Solar EPC: scope of work and how to select a contractor
What a solar EPC contractor delivers: the E–P–C scope, the process from survey to commissioning and O&M, selection criteria and the contract risks that matter most.
Industrial parks
Solar for industrial parks: how to do it properly
How to deliver solar inside an industrial park: rooftop solar on leased factory buildings, ESCO models across multiple tenants, agreements with the park infrastructure owner, permitting and fire safety, plus renewable supply through DPPA.
Sources
- Decree 58/2025/ND-CP on renewable energy development – Vietnam national legal database
- Vietnam Electricity (EVN)
- Ministry of Industry and Trade (moit.gov.vn)
This guide compiles reference information from legal documents and official sources; it is not legal advice. Technical and financial ranges are industry reference values — project decisions require a site-specific survey.
Need a solar plan for your plant?
Orca Energy surveys the roof, analyses the load profile, simulates yield and builds the financial case for all three routes: self-investment, ESCO and renewable purchase through DPPA.
0867 831 368•solar@orcaenergy.vn
Request a consultation