The tricky nature of design and construction overlap in solar projects

Design

Solar PV facilities have ever increasing pressure on construction timelines.  In theory they are fairly simple design and construct projects, and one of the major benefits of these facilities is that they can come online in a relatively short space of time, and start generating revenue quickly.

So standard processes and procedures used within the engineering sector may be put under increasing pressure, in order to realise an early commercial operation date.

In an ideal world, the facility design is carried out upfront.  Site investigations are conducted, studies are done, calculations are calculated and all of these feed into the design process.  Design docs are developed, and bundled up into neat and ordered packages, which are handed over to the owner for review and comment.  Once everyone has had their turn to check that the design is in good order, and fully compliant with standards and specs, equipment is procured, and construction management documentation, such as work method statements, are developed.  Controlled.  Organised.  And compliant.

The reality of these projects is vastly different.  Certain things are known from contract negotiation – which modules, mounting system and inverters will be used, what is the overall facility capacity, where are the roads going to be located.  Designs will also be nicked from previous projects, to save time and cost, altered and amended based on local conditions.  Everyone will be watching the procurement of long-lead items with a keen eye along with any other activity under the project’s critical path.

So it’s likely that the design will be put together in clumps and blobs.  Loosely bundled documents, with vague references to geotechnical reports and flood studies, will come through in a piecemeal fashion.  Often before it’s been reviewed internally by the contractor.  There is enormous pressure on the Owner to carry out their reviews and issue comments with no delay, as everyone’s watching the clock.  But this way of submitting documentation is onerous on an owner’s engineer.  It’s difficult to plan and allocate resources when you’re not sure when documents are going to come through.  It can be hard to keep the same people on the job, which means more time spent by your engineers getting up to speed with the contract specs.  And it can mean multiple iterations of your log of comments.  It chaotic, pressured and not a whole lot of fun.

So some things that are important:

  • When documents come through, the contractor should highlight any specific aspects of the design which may have an impact on the overall project schedule.  For instance, tracker system design, which needs to be reviewed against local standards may be important as equipment needs to be ordered.
  • The document register becomes an incredibly important tool.  It should be tracking what the latest version of the document is, what the changes were in this revision, when it was issued and what the current status is (issued for review, approval, construction etc)
  • Document control in general becomes incredibly important.
  • The document management system should be easy to use.  If you need to go into the system to download small bundles of documents frequently, then it needs to be easy to navigate and docs need to be easy to download.  Access should be easy to secure, so that people on the design review team can search for documents themselves.
  • Transmittals should include a list of documents included, along with the location of the document on the document management system, or direct links to the documents.
  • Construction documentation, such as inspection and test plans and work method statements, should be developed in parallel, so that when the design is agreed, the ITPs and WMSs are ready, and there is no delay to construction.
  • For very time constrained reviews, it may be appropriate to focus solely on the observations of non-compliance with either local standards or the contract specs.  Design preferences may need to be dropped.  This is for the owner to decide.  They are paying for the product and it is ultimately their decision as to whether they are going for a gold standard project, or a project that finishes on time.
  • The contract should transfer all design risk to the contractor.  If the owner comes across any non-compliance at any point, the contractor should be required to fix it.  Increased pressure on the design phase should not relieve the contractor of their obligations to deliver a compliant project.
  • The contractor should be fully in control of construction quality.  So that the owner can see that the facility is being built to spec, and that accelerated works have not resulted in a poor quality product.

It’s difficult.  There are competing pressures, multiple activities taking place at the same time, and all parties may have limited resources at their disposal.