Short answer
A solar EPC project runs through eleven stages: site survey and feasibility, detailed engineering, energy-yield analysis, procurement, civil and structural works, AC and DC works, module mounting structure installation, substation and transmission-line works, testing and commissioning, grid synchronization support, and operation and maintenance.
The eleven stages
| Stage | Typical output |
|---|---|
| 1. Site survey and feasibility assessment | Site data and a view on whether the project is technically viable |
| 2. Detailed engineering and plant design | Layout, electrical design and construction drawings |
| 3. Energy-yield and system-loss analysis | A generation estimate with stated assumptions |
| 4. Procurement | Ordered and delivered modules, inverters and balance-of-system equipment |
| 5. Civil and structural works | Foundations, site works and structural construction |
| 6. AC and DC works | Installed and connected DC and AC electrical systems |
| 7. Module mounting structure installation | Structures installed, ready to carry modules |
| 8. Substation and transmission-line works | The plant's connection to the grid |
| 9. Testing and commissioning | Test records and an operating plant |
| 10. Grid synchronization support | A plant synchronized with the grid |
| 11. Operation and maintenance | Ongoing plant care aimed at long-term performance |
Stages overlap in practice. Procurement starts while engineering is finishing, and civil and structural work begins before all equipment arrives. The list below explains each stage. The same sequence appears on the EPC capabilities page.
Planning and design (stages 1 to 3)
Site survey and feasibility
The survey records what the site is actually like: boundaries, levels, soil, access, nearby infrastructure and the route to the grid. Feasibility uses that data to test whether the project works technically before money is committed to design and equipment.
Detailed engineering and plant design
Engineering produces the layout, the electrical design, the structural design and the documents needed to build the plant. Good engineering anticipates construction problems on paper, where they are cheap to fix.
Energy-yield and system-loss analysis
This analysis estimates how much energy the designed plant should generate, after losses from temperature, soiling, shading, wiring and equipment. Ask for the assumptions as well as the result, because the result is only as good as its inputs.
Procure and build (stages 4 to 8)
Procurement
Procurement covers modules, inverters and balance-of-system equipment such as cables, transformers and switchgear. It should follow the engineering design, with datasheets, inspection and a delivery plan that fits the construction schedule.
Civil and structural works
Site preparation, foundations, drainage, roads and structural construction form the base for everything that follows.
AC and DC works
DC works connect modules into strings and carry power to the inverters. AC works carry power from the inverters through transformers and switchgear toward the grid. Both need careful installation, labelling and testing.
Module mounting structure installation
Mounting structures hold the modules at the designed tilt and withstand wind and ground conditions. Their alignment affects how smoothly module installation goes.
Substation and transmission-line works
Depending on the connection point, the plant may need its own substation and a transmission line to the grid substation. These works connect the plant to the grid and are designed together with the rest of the plant.
Commission and operate (stages 9 to 11)
Testing and commissioning
Before the plant exports power, installed equipment is tested, protection settings are verified and records are kept. Commissioning brings the plant into operation.
Grid synchronization support
Synchronizing with the grid is coordinated with the utility. Support from the EPC team helps the plant meet the connection requirements and start exporting.
Operation and maintenance
A plant is operated and maintained for decades. Operation and maintenance support is aimed at long-term plant performance, and it is easier to organise when planned before commissioning, using the knowledge of the team that built the plant.
How the lifecycle applies to different projects
All stages apply to large ground-mounted plants. A commercial or industrial rooftop project uses most of them at a smaller scale, usually without substation and transmission-line works. Operation and maintenance can also be a standalone need for plants that are already running.
Common questions
- What does EPC stand for in solar?
- Engineering, procurement and construction. An EPC contractor designs the plant, buys the equipment and builds it, usually including testing and commissioning.
- Does Solaris provide testing and commissioning and grid synchronization support?
- Yes. Testing and commissioning, and grid synchronization support, are part of the EPC capabilities Solaris lists.
- Is operation and maintenance part of EPC?
- It is the final stage of the EPC lifecycle that Solaris lists, although some owners contract operation and maintenance separately.