PV Tech Power Papers

State energy policy | Acceptance of solar in the boardrooms and living rooms of America along with President Obama’s Clean Power Plan potentially put the US on the precipice of huge solar growth, but the patchwork of state solar policies remains a barrier. John Parnell and Tom Kenning look at some of the US’ leading solar states and ask what others could learn.

Covering a 1,295-hectare estate mostly of fallow farmland, the world’s largest solar plant sits in the Antelope Valley straddling two counties of California. The Solar Star project has been supplying its full 579MW of capacity to the grid since May this year and it will be announced as offi cially complete before the end of 2015. PV Tech Power explored the designs behind this mammoth installation near Rosamond, California, to investigate what key factors had to be considered when creating a solar plant that can supply electricity to more than a quarter of a million homes.

So far in 2015 Chinese domestic PV deployment has outstripped last year’s rates and a possible 20GW has been mooted for the year. This would set a benchmark for China’s new five-year plan for solar development due to come into effect next year, writes Frank Haugwitz.

Off grid | Reducing the reliance on costly diesel-based power generation is high on the list of priorities for off-grid operators around the world. PV-hybrid systems alone can only go so far in meeting this need. The addition of storage can significantly alter this picture by increasing fuel savings and offsetting additional investment. Increasingly sound economics are already convincing circumspect off-grid operators such as mine owners who are starting to build the first large installations.

Battery technologies | The development of battery storage is seen as vital in the grid integration of increasing amounts of renewable power, but the various technologies present different advantages and limitations. Stephan Lux of Fraunhofer ISE weighs up the pros and cons of the main battery technologies in a range of applications.

Aggregation | Tesla’s much-hyped battery announcement in April raised important questions over what business models will drive the deployment of stationary battery storage. As Andy Colthorpe reports, one answer is the virtual power plant, in which residential and commercial battery systems are aggregated to provide grid services

Plant defects | To ensure profitability in PV power plant investments it is crucial to minimise operation risks in the early stages of project development and during planning, installation and commissioning. Potential performance losses and the economic risks due to failures in plant design, employed components and construction must be considered, as Willi Vaaßen of TÜV Rheinland explains.

Plant inspection | Infrared cameras mounted on drones offer a means of detecting instances of equipment malfunction in PV power plants. Claudia Buerhop-Lutz explains some of the faults such an approach can help reveal.

Aerial monitoring | With PV projects growing larger and fleets more dispersed, new technologies are emerging to assist plant managers look after their assets. Tom Kenning looks at the growing use of solar drones and robots in plant operations.

Performance | Potential-induced degradation (PID) has emerged as an issue of concern in the last decade because of the increase in the deployment of utility-scale high-voltage PV systems. Rubina Singh, Cordula Schmid and Jacqueline Ashmore of the Fraunhofer Center for Sustainable Energy Systems CSE present an overview of the mechanisms for PID and the impact of degradation, as well as the factors that contribute to its occurrence. They also discuss techniques for the detection, mitigation and predictive testing of PID.