Just this week, the SunPower California valley solar plant reached completion and will have an output of 250MW, making it the biggest plant in the world with single-axis tracking technology.
In 2011, neither single axis nor dual axis trackers were seen as cost-effective. Single axis trackers are the technology of choice for PV and increasingly for thin film. They currently deliver as much as a 20% increase in yield over fixed tilt, so the direct cost-benefit is clear.
However, trackers also require more land due to the spacing needed between panels to avoid shadowing. If land prices are high or there are specific spacing requirements then the project becomes less feasible wit. The balance of costs for consideration is relatively complex and in America the capital expenditure is extremely important. Whilst PPAs a negotiated on the basis of cost, utilities increasingly see single axis tracking as an asset because the adjustable tilting means that panels can catch the sun earlier on in the day and until the end of the day. This increase in availability is preferred by a lot of utilities because the plant can assist with resource planning and a smoother ramp up and ramp down.
Even though the moving parts in trackers mean that previously they were not seen as attractive in extremely dusty or windy states, innovation in the last two years has increased their robustness; increasing their reliability in alignment and resistance to the elements. Yet until more recently the main developers and EPCs to deploy trackers have been the large vertically integrated companies such as SunPower and First Solar, and the number of independent single axis tracker companies was a lot lower. It may be that until recently, only vertically integrated companies were able to cost- effectively integrate the engineering and maintenance requirements for trackers into their processes. Perhaps the biggest clue to the cost-effectiveness of trackers is in operations and monitoring strategies and costs.
With large companies such as First Solar and SunPower able to integrate the maintenance and monitoring costs into their service provision alongside modules and other components, the transaction costs for the developer may be too high to make trackers worthwhile if they are dealing with a large number of components sourced from different companies. PV Insiders Utility-scale PV plant optimization summit will be bringing the solar leaders such as First Solar, SunEdison, Juwi Solar SunPower and Sempra Gas and Power to discuss the cost-benefits of tracking systems and modular electronics to ensure that companies are implementing the technology that will help them create a lower levelized cost of electricity.
