Megawatt Design: 3 Obstacles You Might Face (…and 3 Solutions!)

Megawatt Design expert Ryan Mayfield addresses 3 obstacles that professionals in the field might experience.

STRUCTURAL ANALYSIS

Student 1: The most common obstacle we run in to is the structural requirement during the initial budgeting phase. Typically the potential customer does not want to pay for a structural analysis of a building roof or soil borings and engineering for foundations. This leaves us “guessing” at the racking support in these cases and clarifying what was assumed in a proposal.

Ryan Mayfield: The best solution I’ve heard from companies tackling this issue is this: try and get a structural analysis up front. If the costumer is unwilling, the contract uses very broad terms and language to cover any and all structural engineering fees that may come along. In my opinion, the trouble there is once the customer gets an expectation on a certain array size or configuration, it is difficult to back track.

PANELBOARD PLACEMENTS

Student 2: With the proliferation of roof mounted string inverters, what options have you been seeing for aggregating the outputs? We have generally been using typical panelboards, but have struggled with their placement since they need to be kept upright (if there are no penthouse walls to take advantage of). Are there any manufactures making any that can be mounted flat? Have you seen installers doing anything creative?

Ryan Mayfield: As this portion of the industry matures, we are seeing more options for AC aggregation. As of now, the options are relatively limited but manufacturers of BOS (Balance of System) equipment are stepping up and providing solutions. For example, Bentek has a NEMA 4 AC aggregation panel listed on their website. I don’t have any direct experience so I can’t say how cost effective or easy it is to work with.

Then, there are manufacturers like HiQ that offer a solution that is designed for their system. If you are stuck with NEMA 3R equipment, building roof racks or running down to an open wall seem to be the most common solutions.

CODE

Student 3: For a lot of my projects, an EPC (Engineering, Procurement and Construction) is really the party that is focusing on IFC (International Finance Corporation) requirements. We have had varying experiences, from AHJs (Authority Having Jurisdictions) that proactively discuss requirements with us at project introduction, to AHJs that really have very little experience with solar farms. They are usually pretty concerned. Another component beyond designing for the IFC is getting local first-responders familiar with emergency procedures for the facility, which seems to be an even bigger focus in our interactions.

Ryan Mayfield: This is one of those areas where asking for forgiveness can be a costly endeavor. I always like the approach of proactively having the conversation with the AHJ. A secondary benefit (sometimes a primary benefit) is you can lead that discussion and make sure your point of view is front and center.

Enroll in Megawatt Design and spend ten weeks learning from Ryan Mayfield, the Solar PV Technical Editor at SolarPro Ryan, along with help from other industry leaders. This course helps experienced solar professionals get their projects permitted and installed faster and cheaper, and goes beyond traditional solar training: it is technical, rigorous, and for experienced professionals only.

Want to learn more about Flat Roof Mounting Solutions, Megawatt System Grounding and PV Circuit Sizing? Enroll in Ryan’s free Megawatt System Design Guide course and keep learning!

About Instructor Ryan Mayfield – President, Renewable Energy Associates

Ryan Mayfield has been working in the renewable energy field since 1999 and is the President of Renewable Energy Associates, a consulting firm providing design, support and educational services for electrical contractors, architectural and engineering firms, manufacturers and government agencies. Ryan serves as Photovoltaic Systems Technical Editor for SolarPro Magazine, regularly writing feature articles in SolarPro and Home Power magazines, and wrote PV Design and Installation for Dummies. Ryan was also a contributor and video team member for Mike Holt’s Understanding the NEC Requirements for Solar Photovoltaic Systems. Ryan teaches various PV courses across the nation for electricians, existing solar professionals, code officials, inspectors and individuals looking to join the solar industry. Class topics include National Electrical Code and PV systems, residential and commercial PV systems. Ryan holds a Limited Renewable Energy Technician (LRT) license in Oregon, is an Oregon Solar Energy Industries Association (OSEIA) board member and chairs the state’s LRT apprenticeship committee.

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