Carefree Operations and Maintenance - Part 2 - Less is More
In Part 1 of our Carefree Operations and Maintenance series, we discussed Land O&M and various solutions to lower costs and minimize financial risk, while maintaining an “eco-friendly” approach. In Part 2 of our series, we will be discussing the complexity of system designs and how they affect your overall O&M costs over time. There are a wide variety of issues to take into account when evaluating O&M costs during the lifecycle of your project. These issues could include such variables as system design, environmental variables and materials used in the project. In this article we will be focusing on System Design.
Keep it Simple Solar (KISS)
In previous articles, we have mentioned this approach which we have found to be most effective when tackling O&M costs over time. By focusing on hyper-simple design, O&M costs of systems designed by major manufacturers are getting lower and lower as systems become more refined and efficient. Though approaches vary widely, there are a number of innovative designs and options for your project. Sun Action Trackers’ PST-1AX6 Single Axis Solar Tracking solution highlights a number of innovative additions to lower O&M costs initially and for the lifecycle of the project.
Linked vs. Independent Row Designs
Linked Row Solar Arrays or “centralized tracker designs” move multiple rows of solar trackers with a single motor or actuator, whereas Independent Row or “decentralized tracker designs” require 1 motor or actuator per row. Though the decentralized tracker designs offer some flexibility for land usage, the centralized tracker systems are much more efficient with 25% of the moving parts than its counterpart. Less moving parts lowers the potential for system failures, while also requiring less time to maintain the system overall. In many cases, linked row systems will also require “leveling” of each row to allow the systems to work. The Sun Action Trackers’ PST-1AX6 single axis solar tracker however does not require grading or leveling to make our system work properly.
Linked row and independent row systems also differ greatly in the number of motors that are needed to make the entire system. Figure A highlights an 800Mw project using 8 actuators to run the entire system vs. 28 motors on the independent system as each row requires its own powered motor. Each row also requires its own control box and sensor opposed to the linked row system that uses 1 control box and sensor for every 6 rows. This means a significant increase of energy usage to use the tracker system, and more moving parts to replace and fix moving down the road. As another question, Which do you think would require more operations and maintenance attention? 1 actuator and 1 sensor, or 6 motors and 6 sensors?
Even before tracker construction can begin, the pilings must be poured and secured before steel construction can begin. Figure B illustrates linked row systems vs. independent row systems. As you can see, the linked row system only requires 48 pilings per 100 Kw compared to 56 for the independent row system. This makes a difference in future foundation maintenance and installation time.
When it comes to single axis solar tracking: Simple is King. By limiting replaceable parts that could potentially fail during design and engineering, you will ultimately lower your Operations and Maintenance costs across the board. Minimizing points of failure is going to lead to a system that consumes less energy thus maximizing total production of the system. If you want to make your project more efficient, KEEP IT SIMPLE SOLAR.