Grid EPC Contract

PV design & inverter selection

There are many daunting questions and many different answers. It is not as simple as some EPC contractors make you believe.

Do you make it with high voltage modules or low voltage modules? Do you want 10 x 100 KW per MW or 2 x 500 KW per MW of inverter? Which voltage range do you choose? How many in series and how many in parallel? Which make of inverter suits the temperature range and hence the voltage range? What will be the extremes that the design can take from a voltage and current perspective, and what are the possibilities of that in the chosen location? On the inverter side – modularity and efficiency curves based on temperature conditions come into play as well.

Electrical design

Line losses, wiring selection, weathering patterns for wiring – this again is very involved. What kind of junctions, where and how the entire wiring is circuited again has design complexities and considerations.

Structure design

It is not simple “fix it at degrees equal to latitude” thing. Some companies who have experience elsewhere in the world have reported that good structure design can improve productivity by as much 10% while reducing capital costs. This is an experience thing, and not purely a theoretical calculation.

Civil design

Again, the longevity can be greatly affected by this. As an example, there could be possibility of rain logging in the site, and we may need to raise the panels up. But, if there are maintenance issues when water is filled in the site – we may still need access for the panels – hence there may be a need for platforms that ensure access to the panels. This is just one example. There are so many other considerations that a good civil design can identify and provide for.

Evacuation design

There are strict norms with which EB will accept the power, and design has to ensure that all those conditions will be met at all scenarios. Specialist consultants are needed for this, and not any other electrical contractor.

Maintenance and monitoring design

Once you build the plant, it needs to be constantly monitored for optimized performance and hence a good ROI. Cost-benefit needs to be analysed with respect to the best-in-class monitoring solution.

Commissioning

Project Management

Orchestrating all the pieces to come in place, as well as making sure that the engineering specifications are met during execution – is a very complex task, and one that requires organized and structured people.

Government Liaisoning

Networks, ability to get work done, ability to get paperwork done are skill sets needed for this.
Team for execution: Major players in this phase are:

• PV Panel supplier
• Inverter supplier
• Electrical contractor
• Evacuation contractor (different from electrical)
• Civil contractor including foundations
• Structural designer and contractor (different from civil)