Knowledge library
Practical guides grounded in current regulation and project delivery experience: rooftop self-consumption rules, the zero-capex ESCO model, EPC scope, cost and payback analysis, and battery storage.
01 · Solar knowledge
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.
02 · Investment models
How the solar ESCO model works: an investor funds the rooftop system, the company buys on-site power below the grid tariff. Eligibility, contract structure, risks and the clauses to negotiate.
03 · EPC services
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.
04 · Investment analysis
The cost structure of a rooftop solar project, what moves the cost per kWp, and how to calculate payback and levelised cost of electricity (LCOE) from simulated yield and grid tariffs.
05 · Energy storage
What BESS does in a factory: peak shaving, shifting solar generation, backup during outages and supporting power purchase contracts. How to size power and energy, choose cell technology and meet safety requirements.
06 · Working principle
Animated explanation of how solar power is generated: the photovoltaic effect inside the cell, DC current from the modules, the inverter converting DC to grid-synchronous AC, how energy reaches on-site loads and the grid, and what drives real yield.
07 · Electrical basics
Animated comparison of single-phase and three-phase supply: 220 V versus 380 V in Vietnam, conductor count, suitable capacity, how to choose a single- or three-phase inverter, and phase imbalance issues when connecting solar.
08 · Equipment selection
How to select solar equipment brands on verifiable criteria: IEC certification, efficiency, warranty terms, degradation and local service. Why Orca Energy favours JA Solar modules and Sungrow inverters on commercial rooftop projects in Vietnam.
09 · Investment cost
What goes into the cost of a 100 kWp rooftop solar system for a factory, how much energy it produces in Vietnam, how savings are calculated and which variables actually drive the payback period.
10 · Grid connection engineering
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.
11 · Operations & maintenance
A practical guide to operating and maintaining rooftop solar: monthly, quarterly and annual task lists, tracking performance ratio, finding faulty modules with thermography, and the KPIs worth putting in an O&M contract.
12 · Equipment
Comparison of solar inverter types – string, central, hybrid and micro-inverters: operating principle, pros and cons, the datasheet parameters that matter, and how to choose by project size and roof geometry.
13 · Industrial parks
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.
14 · Permitting
The connection agreement process for self-consumption rooftop solar with the Vietnamese utility: preparation steps, the technical documents to have ready, commissioning, and the mistakes that get applications sent back.
15 · Policy
What Directive 10/CT-TTg and Official Letter 7404/BCT-DL say about electricity saving and self-production, self-consumption rooftop solar: targets, priority groups, deadlines and what it means for factories.
16 · Procedure
How to install self-production, self-consumption rooftop solar in Vietnam under Decree 58/2025/ND-CP: building conditions, notification versus development registration, grid connection and the rules on surplus electricity.
17 · Policy
What is already in force under Decree 58/2025 for household self-consumption rooftop solar, what remains a draft decision at MOIT, and how a household should calculate real savings.
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.
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