China’s Largest PV Plant In Quinghai Offers A study On Co-Existing With Nature

China’s Tara Beach, located 60 kilometres southeast of Qinghai Lake, in the island province of Hainan, is bathed with a blue sea of solar panels. It houses the world’s largest renewable energy base that was built by Huanghe Hydropower Development, a state-owned utility company, with technological contributions from ICT provider Huawei. A 2.2 GW solar plant — the Tara Beach PV project — is located in the area and has earned the status of the world’s first ultra-high voltage (UHV) power transmission line with 100% clean energy.

The Tara Beach PV project has also become the world’s largest single PV plant, as well as the quickest renewable energy power generation project to reach completion (from winning the bid to fully connecting to the grid within a year).

Ten years ago, the picture was quite different. Central inverters were still the mainstream power generation solution throughout China. However, in 2013, Huawei joined forces with Huanghe to launch the country’s first large-scale ground-mounted PV plant using string inverters in Qinghai. “This marked a major breakthrough in string inverter development and kicked off an all-new industry trend,” states Huawei.

In 2014, the two companies launched the ‘Smart PV Solution’, based on string inverters, to comprehensively modernise PV plants. By 2017, string inverters had overtaken central inverters as the mainstream power generation solution. These and more technological breakthroughs in renewable energy followed from the Huawei-Huanghe collaboration, resulting in the development of the Tara Beach solar plant, which encompasses an area of 609 square kilometres, and an experimental 100 MW test base.

In a decade’s time, the beautiful landscape nestled between the Yellow River and Tara Beach has achieved six world records: the world’s largest renewable energy base; the world’s largest PV power operator; the world’s largest single PV plant; the world’s first 100% clean energy UHV transmission line; the world’s largest hydro-solar hybrid power plant; and the world’s largest 100 MW experiment and test base.

Huawei states that its contributions, in terms of digital information technology, 5G network application and smart handheld terminals, have enabled Huanghe to construct the largest renewable energy centralised control centre in China, which supports 34 PV plants and more than 20 million data measurement sites. The centre implements centralised monitoring, big data analysis, remote diagnosis, and real-time maintenance of PV plants.

By the end of 2020, the total installed capacity of renewable energy in Hainan reached 18.65 million kW, including 9 million kW from solar power, 5.5 million kW from hydropower, 4.1 million kW from wind power, and 50,000 kW from solar-thermal power.

The Tara Beach area was part of the Gobi desert for a long time on account of drought, low rainfall, and overgrazing. For instance, to reduce the impact of desert winds and sand on solar panels, grass seeds were sprinkled around the solar park.

“We observed that the shade provided by the solar panels reduced the evaporation of surface water, and that the water used to clean the panels seeped into the ground, so the grass grew faster,” said Huan Xingsheng, Deputy Director of the production technical department in Huanghe Company’s PV Maintenance and Repair Company. Consequently, the grass inside the PV park quickly grew much higher than that outside.

However, this development led to new problems: the grass grew too high and began casting its own shadow on the PV modules, which affected the energy yield. In addition, dry grass is easily lit up by fires in winter. Thus, since 2015, Huanghe has allowed 600 sheep to graze inside the park, which has seen positive results. Permitting animals to graze not only facilitates the shepherds, but also ensures that grass within the campus remains below a certain height so that power generation is not affected.

Looking back, it can be observed that 2011 onwards, the construction of PV power stations and the laying of solar panels has weakened evaporation on Tara Beach’s surface and increased soil moisture. Vegetation has gradually been restored, and the ecological environment has been significantly improved. Power is generated through the panels above as sheep freely graze underneath — “a striking image of modern technology and nature co-existing in harmony on the Qinghai-Tibet Plateau,” states Huawei, concluding that Tara Beach has returned to its original appearance. Apparently, the “PV sheep” became local celebrities after pictures of them roaming among the PV park’s solar panels went viral overnight on social media.

Since 2015, Huanghe has been carrying out research on the impact of its large-scale desert PV plant on the site’s ecological environment. Huawei claims that results show that the PV plants’ construction has helped improve soil moisture and restore vegetation. Average wind speeds decreased by 41.2%, the average air temperature decreased by 0.5°C, the average air humidity increased by 2.1%, and moisture within the soil (with a depth of 20 cm) increased by 32%.

The company has also adjusted the height of the bracket from 50 cm to 1.2 m above the ground, ensuring the smooth passage of the sheep.

Huanghe states that despite the increased construction costs, it has explored and developed a model of “PV + eco + local benefits.” The firm signs pasture agreements with the local shepherds, offers job opportunities to villagers for the construction and O&M of the PV park, and allows them to plant cash crops in the park. While developing the PV economy, the company also sought to promote the development of local transportation, urban construction, and tourism, hoping to accelerate the development, prosperity and stability of the upper reaches of the Yellow River where ethnic minority groups reside.

Supported by the world’s largest renewable energy base, Qinghai Power Grid has reportedly become the greenest regional grid in China with the highest proportion of renewable energy.