One of the best ways to get the most bang for your buck in a small commercial solar project is reframing the way you think about project value and moving beyond the traditional dollar per watt measures. Although a fixed-mount system might have a lower cost per watt, dual-axis trackers provide a higher production capacity, are more versatile when it comes to siting and land usage, and ultimately cost less when it comes measuring dollar per kilowatt-hour, creating a much better overall value for the project.
Price vs. Value
The standard industry metric used to describe the cost of a solar installation has always been the cost per watt of the rated generating capacity of a system. However, this measure ignores performance factors. Additionally, because the utility charges customers by the kilowatt-hour, that's how customers look at proposals from solar installers--the cost per watt of the system is not important to them.
Value comes from power produced by a solar system at a competitive price. Installers are selling their customers the ability to generate power over a long time period (typically, at least 25 years), so the most helpful metric a salesperson can use when discussing the cost of a system with a potential customer is the "levelized cost" of a kilowatt-hour. And installers can reduce the cost per watt--which is really what most customers care about--by installing superior modules and using dual-axis trackers instead of conventional panels and fixed solar, even if that means the system will have a higher cost per watt.
Siting and Land Usage
In any solar project, an installer will look at several factors that can have an impact on siting: location in relation to the sun, terrain, access to the grid, land costs, operations and maintenance expenses, and acquisition costs. When you use solar trackers as your mounting solution, a few other considerations come into play. It's important to consider the total land available for installation, as the use of trackers allows an installer to utilize a wider range of terrains and make better use of available ground area than would be possible otherwise.
An installer should also consider current land usage and tax status. For a project intended for land currently under cultivation, the landowner may be able to continue taking advantage of the current agricultural tax exemptions for their property. For example, some states give agricultural land special tax status to encourage conservation of farmland. Changing the usage of the land to non-agricultural use can subject the property owner to a retroactive assessment for the value the land would have been taxed at for the previous five years. Careful design and implementation of a tracker-based installation can reduce the total footprint of land used and ensure the continued production of agricultural good and livestock from the same property.
Trackers vs. Roof-Mount Solar
The chart below features two installations using the same components: 24 SunPower 327 modules (7.848kW), and the same inverters.
The blue bars represent the monthly production of a fixed-angle roof-mount installation with an ideal orientation and tilt, and the red bars represent a ground-mounted dual-axis tracker.
The roof-mount system produces approximately 9,819 kWh annually. Accounting for the ITC, the cost of the system was $3.70/W, and the levelized kWh cost was calculated to be at $0.12.
The dual-axis tracker cost per watt was about 18% higher, at $4.37/W, but produced approximately 36% more power than the fixed roof-mount system, and the cost per kWh was reduced to $0.10.
Though the cost per watt is slightly higher for a dual-axis solar tracker, it creates more value over the life of the system as a result of its superior production capacity. Combined with its flexibility when it comes to siting and its small footprint, it's clearly a worthwhile longterm investment for small commercial projects.
Interested in learning more about building high-production projects? Watch a recording of our recent webinar on Maximizing Power Production for Small Commercial Projects.