Balancing Solar Energy Development and Biodiversity

Drive through the countryside in the central Taiwan counties of Yunlin, Changhua, and Chiayi and you’re bound to notice the many barns and chicken coops with substantial solar arrays installed on their roofs. Development of solar power is a major part of Taiwan’s plan to transform its energy sector, eliminating nuclear power generation and bringing the share of renewable energy up to 20% by 2025.

But considering competing demands for land use – and pressures to protect biodiversity – will enough space be available to meet Taiwan’s ambitious goals for solar energy? 

Currently Taiwan has a total installed solar capacity of 2.8 gigawatts (GW) – 2,800MW – rapidly closing in on Taiwan’s rooftop solar goals of 3GW. At the same time, few in the industry believe that Taiwan will ever meet its larger goal of 20GW without moving from rooftops to ground-mounted facilities. But that raises the sticky challenge of where to place all those solar panels.

Taiwan is little more than the size of New Jersey but has three times the population, and around 70% of the island is covered by steep mountains that are largely off limits to development due to landslide risks. Urban areas, agriculture, and industry all compete for room on the western plain, which at the same time serves as prime habitats for endemic and migratory wildlife.

“The Ministry of Economic Affairs and its Bureau of Energy want to promote solar, so they set the target, but the Council of Agriculture (COA) and the Ministry of Interior want to slow down the implementation to ensure preservation of the agricultural sector,” says Sharon Chen, solar analyst at EnergyTrend, a division of local business analytics firm Trendforce. “If a balance can be maintained, the solar sector can see steady growth. But if they don’t reach a balance point between the competing government entities, the result will be stagnation.”

These tensions between different interests are embodied by the “waste lands” that the government has designated as the chief sites for solar power development.

The COA estimates that the 20GW of installed solar capacity will require around 25,000 hectares of land. To limit the impact on agriculture, the first plots of land selected for solar development in 2016 were areas that had been strongly affected by soil subsidence caused by overuse of ground water or other harmful practices. A total of 1,253 hectares of land were selected in Yunlin, Chiayi, and Changhua Counties. 

Sinogreenergy, one of Taiwan’s leading solar-power developers, is among several firms developing projects in designated “salt lands.” Working with Swiss investment firm Partners Group through its local subsidiary, Formosa Solar, Sinogreenergy. The firm has already developed 200 megawatts (MW) of installed solar power capacity – mostly on those farm buildings in central Taiwan – and has another 400MW in the pipeline.

The area being developed by Sinogreenergy for ground-mounted solar facilities is located in Budai Township in coastal Chiayi County and had once been used by the then state-owned Taiwan Salt Co. to evaporate seawater and gather the remaining salt crystals. Unsurprisingly, the area is heavily contaminated with salt, rendering it all but useless for agriculture and other human needs.

However, the same mix of wetlands and salt pans bounded by farmlands and some residences offers a prime habitat for a variety of wildlife, particularly migratory birds including the endangered black-faced spoonbill. Tiny invertebrates that are highly resistant to salt thrive in these saline waters, providing an ample source of food for the birds. For the black-faced spoonbill, this sojourn in Taiwan is crucial for mating behavior. Installing extensive solar farms could prove devastating to the future of this and other threatened species.

Corrosion and contamination

To better understand the impact on the environment, Sinogreenergy approached Professor Lin Hui-chen of Tunghai University’s life sciences department to do a scientific survey of the area under development.

Despite initial skepticism about the value of the project, Lin accepted a commission from Sinogreenergy to head a team monitoring the direct and indirect ecological impact of its solar energy venture. There is little precedence for research into renewable energy development in such conditions.

The purpose of the study is “so we can design a site that limits the impact on the environment,” says K.H. Chen, president of Sinogreenergy. “If we do this successfully, we will be the first case to develop solar in the salt lands and understand how it impacts wildlife.”

The 243-hectare site was divided into nine sections. Originally most of the area was slated for development, but at the insistence of the ecologists involved, the size was later reduced to two sections of a combined 102 hectares. The two plots were the driest and most severely impacted by salt. The 82-hectare Section 8 is being developed by Vena Energy Solar of Singapore, which is not involved with the study, while the 20-hectare Section 9 is being handled by Sinogreenergy. 

Along with Tunghai University, Chang Gong University’s College of Engineering is participating in the study, which began with a thorough survey of the pre-construction environment – including water levels, flora and fauna species, and water and soil composition – to establish a baseline.

Teams of researchers spent weeks in the field taking water and soil samples, putting water through sieves to capture tiny invertebrates, and even rescued an injured black-faced spoonbill along the way. They made several surprising discoveries, among them that certain invertebrates are able to thrive in water with salt content double that of seawater – which kills off their predators, allowing them to flourish.

Others disappear during the dry season, then reappear in high numbers during the rainy season. The researchers are still trying to figure out how that happens. This bounty of invertebrates feeds a plethora of birds. “I’ve never seen so many birds before in one area,” Lin says. 

Construction of the solar farm is currently ongoing and should be completed by summer’s end. But the impact on migratory birds won’t be clear until the birds return to Taiwan in October. 

Sinogreenergy has already spent some NT$8 million (US$254,000) funding the research, and the monitoring is set to continue for the next 20 years until the site is decommissioned.