The Next Generation Utility-Scale PV Plant
Posted 9 December 2014 6:22 PM by Mahesh Morjaria
Since 2010 the average cost per kWh of a utility-scale PV project in U.S. has dropped significantly, from about US$0.21/kWh to $0.11/kWh. This reduction is principally attributed to the rapid reduction in PV module cost. For a typical utility-scale PV system that feeds power directly to the grid, the balance of system (BOS) cost now represents between 60-70% of the total cost of the system from a previous value of less than 50%, showing that further cost reductions can be found in BOS improvements.
A next-generation PV plant architecture based on increasing direct current (DC) system voltage from 1,000VDC to 1,500VDC , the highest DC voltage in the industry, holds the promise of a more cost-effective and productive utility-scale plant due to lower installation and maintenance costs. First Solar is collaborating with BOS component suppliers to develop these next-generation 1,500V DC utility-scale plants. As a vertically integrated company with PV module manufacturing among its core competencies, First Solar has the unique ability to calibrate the output characteristics of its modules to support this new 1,500VDC standard.
There are several technical and regulatory challenges associated with approvals and adoption of the proposed next-generation plant in international markets, but particularly in North America. In North America specifically, both the modules and the inverters have limited field history. In the U.S. the lack of established standards that address 1,500VDC applications often makes it challenging to obtain plant construction permits from local authorities.
The good news is there are no expected long-term barriers to adopting this architecture and active steps are underway in the standards and codes community to address the needs of the growing large-scale PV plant market. As in the case of the previous transition of 1,000VDC architecture, the industry is poised to take this next step as some of the technical and regulatory barriers to constructing the next-generation 1,500VDC PV plants are overcome.
The key elements that contribute to this accomplishment include First Solar’s development of high voltage-capable thin-film modules and GE’s development of the world’s largest PV inverter (4MVA).
A more in-depth technical briefing that explores the challenges associated with the development of 1,500VDC plants and the efforts to address those challenges has been published in PV-Tech Power Magazine. Click here to read the online version.