Bad weather, especially strong winds, is the archenemy of PV power plants.
In 2017, Hurricanes Irma and Maria wrecked the solar power plants in Puerto Rico. In 2019, Typhoon Faxai has destroyed the biggest floating solar project in Japan, setting the solar panels on fire.
PV Tracker’s Wind Resilience Problem
There are more and more PV tracker systems deployed in PV projects. And the lack of building codes for PV tracker systems is not helping an infrastructure that is so defenseless against the winds, as pv magazine reported.
As a result, the ultra-lean, ultra-flexible PV trackers that have not undergone proper testing may easily collapse on itself, even when the wind has not reached the claimed design wind speed.
How Has the Wind Resilience Problem Come Into Existence?
According to pv magazine, there is a void in the PV industry in terms of windproofing. And the following chaos ensues:
- EPCs want to finish their projects ASAP.
- OEMs look for an easier way to windproof their PV trackers.
- Buyers do not want the project to fail when they have already come so far.
- Inspectors are reluctant to point out issues on their clients’ products.
It also cannot be stressed enough that there are no civil engineering codes or regulations for PV installations at the moment.
Furthermore, there is no building code or standard designated for single-axis trackers. Therefore the manufacturers resort to using the building codes for carports as a reference, which are not sufficient.
Thorsten Kray, head of the building aerodynamics department at I.F.I. (Institut für Industrieaerodynamik GmbH), has pointed out the aspect ratio problem in terms of adopting the carport building codes for PV trackers. Carports are generally a lot shorter than PV trackers.
No wind tunnel testing for PV trackers
Currently, no regulation requires PV plants to be wind tunnel tested before being built.
However, as David Banks, head of solar services for wind engineering laboratory CPP, has pointed out, skyscrapers (which also cost millions to build and must withstand incredible wind speeds like PV projects) are legally required to undergo such testing.
This is the only way to identify the instabilities which would not be detected otherwise, Banks explained.
The Lack of Codes Is the Root of All Evil for PV Trackers
This absence of regulation has given way to the following problems of many sorts.
- The performance of the PV trackers may not be reliable
Given the lack of codes or standards, many manufacturers deploy bespoke single-axis trackers that have been designed and made specifically for the site which they are going to be deployed on.
They are more focused on making sure their products are compliant with building codes or regulations that are simplified for other products (such as carports) or accepted by their buyers.
The performance of the trackers is not their top priority.
- The developers & EPC may not be interested in the durability of the PV trackers
According to Banks, not all developers and EPC would get independent engineering reviews and wind tunnel report for their PV trackers.
Even when they do, they do not always easily accept the findings that may have a negative impact on their projects.
Some EPCs simply want to set up and move on. It is not in their best interest to dwell on a project.
- Various reporting methods
Different wind engineering laboratories adopt different methodologies to test the products. Testing the same products against different sets of methodologies may produce different results.
Kray has noted that some of his clients refused to have their products tested against certain methods because the results may not support their claimed design wind speeds.
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