System Design

Traditionally, the solar industry is plagued by too many cooks in the kitchen.  A developer will sell a project and then start assembling the pieces of the puzzle that they need – the racking, the modules, the inverters, the electrical engineer, the structural engineer, the EPC, etc.  What this leads to is one of the most inefficient processes you can imagine, with disjointed and incongruent shapes being forced together which causes extra costs and system losses.

The most important word in the entire process from cradle to grave of a photovoltaic system is that it is a System.  A system is more than the sum of the parts, it is something that must be harmonious where all of the pieces must function together – and the more thought that goes into that process, the better the system will function. 

Typically, a racking company will come up with a layout. An electrical engineer will come up with a wiring design based on the modules that can fit and the inverters chosen by the developer. An EPC is usually tasked with figuring out the best string layout and equipment mounting location for the items defined by the electrical engineer – or they at the very least argue about it with the electrical engineer.  Somewhere in the background, the developer is trying to get all of these people to do each of these items for the lowest possible cost to make as much money on the project as possible, stressing each of them to find shortcuts and pushing against each other, and what suffers in the end, is the photovoltaic system that is being installed.  What matters least to anyone of these people is what the end customer actually wanted.  Every stakeholder in a process needs to be actively engaged to balance the inputs to the equation and get the desired outputs from the system. 

What should happen is that a system designer is engaged.  A system designer is someone who understands not only all of the necessary components of the PV System, but the underlying needs and motivations of the project developer and the end customer.  They are the focal point for the entire process from the start to the finish, for the developer and all of the associated subcontracted services or vendors.  The system designer arranges the racking layout based on the inverter selection and the strings, so that they are as efficient as possible for the EPC to install. A system designer then works with the racking companies to ensure that they are not changing from this layout, and if they are, it is done in consultation with them to ensure it still allows for design efficiency.  A system designer has been to the site at least once, probably multiple times, and knows the best location for all of the equipment and wire paths, and has not just located them on the diagrams, but will explain them to the EPC so that they can see the value in the design and how it helps them lower their costs to the developer. 

Because the system designer knows the motivation of the developer and the end customer, they can make better decisions and recommendations to the developer on the design.  If a developer is going to own the system, then their motivation might not be to save a penny or two on the installation, they might rather increase the upfront costs and see a greater yield over the 25-year PPA period given the various economic incentives.  A system designer should be able to run quick calculations on a few distinctive design parameters and show the developer what the NPV of those changes would be and if the profitability index warrants various changes or if the developer is better off using those funds to invest in another project. If the project is already funded by a third party and the developer has a set EPC price, then the system designers job might be to design for the bare minimum installed price. This might come down to using different paradigms of design, interrow spacing, MLPE, distributed generation vs. central inverters, tilt angle, mono vs. poly modules, etc.  All of this requires the system designer to understand the developer’s motivation and have the luxury to coordinate all of the other players involved in the field. This is not something that the racking company or electrical engineer will do for them independently. 

System design is a wholistic process that takes the project all the way to project completion. A system designer does not just put a recommendation on the table and then walk away – they are part designer, quoter, logistics manager, project manager, system commissioner, and engineer all rolled into one. The system designer will help specify materials then work with the suppliers for the quotes on them. Depending on the services engaged, they might be creating the PO’s and tracking supplies to site, they will be there for system inspections during installation and for questions from the developer and EPC. They will attend permit meetings and site walks with the client in addition to being there for EDC witness testing and system commissioning. They will have created the plans for your system and the redline/as built drawings as well. If you need an idea of indicative EPC pricing, they will be able to tell you and help find them and vet those EPC’s for you. They can help write the bid packages for a project you have developed, or respond to the bid package for a project you are trying to win. They will even coordinate any and all services necessary to facilitate the project, from structural engineering on a 100 kW roof mount to survey services for a 100 MW farm. 

The scope of services will depend on your in-house capabilities or determined needs – you should expect that the fees will range with the desired work you have engaged them for. At the very least, every engagement should include some basics; site visit, racking layout, electrical design, string design, coordination of PE’s and racking company, EPC site walk, consultative services during construction, and as built designs. If you are being offered less than that by a system designer, then you should look to a different provider. 

When you engage a system designer for your project depends on your business model.  Some developers will come after a project has been sold and look to the system designer to optimize the project from that point forward. Some will bring the designer in once they have an LOI to engage in engineering services and finalize the EPC pricing.  Others will bring the system designer in as part of their sales process when they have a client they are very confident will go to close and they want to drill the pricing down and just want to get a preliminary design that will allow for the removal of contingency budgets from a project. For some companies, the system designer is part of their staff, for some, they are an outside service that is engaged per project. Sometimes it is the same designer for every project, sometimes it is a different designer based on their workload, sometimes it is a firm with multiple designers on staff.

The key to success is to use a system designer in the first place. Having a structural and electrical engineer you always use and the same racking company for every project is not the same as someone who knows how to optimize your projects and your business.  The system designer works for you, and their sole job is to make your project as efficient as possible – with the best design for your goals, be that balance between production and cost, lowest cost, or best production. 

At Men of La Mancha, we specialize in being system designers.  Our team is dedicated and once a system designer starts on your project, they will see it through until completion. What makes Men of La Mancha unique in their service offering, is that all projects are designed in a team atmosphere.  Each of our designers has their strengths and specialties, and while one designer might be the main point of contact or do all of the drawing work and leg work on your project – all of the designers are involved in every project.  If one is more familiar with the inverters selected for your project, that designer will work with your designer on that portion of the design – and go out for system inspections and commissioning.  If your system involves a lot of medium voltage work, then the designer who is most skilled at MV will assist with that portion of the design to ensure that it is created with the best possible outcome.  While all of our work is reviewed by our third-party PE, that does not mean they specialize in design optimization – that is our specialty. 

When you come to the Men of La Mancha, you do not hire one system designer, you hire our team.