Snapshot: Chile’s floating solar PV potential

Chile holds up to an estimated 16.6GW of floating solar PV potential.

The segment remains in the nascent phase in the country and has much space to grow, experts say.  

Floating solar PV could be leveraged, particularly by the agricultural sector, to not only trim electricity bills and decarbonize but also reduce evaporation, a seminar held under the banner of a Chile-Germany energy cooperation partnership was told. 

The 16.6GW estimate, calculated by the Chilean branch of German applied research institute Fraunhofer, is based on available surface area of 342km2, a figure that excludes natural lakes, and capacity density of 1.2MW/ha.

“This potential is located principally in the central zone, between Coquimbo and Biobío regions,” said Fraunhofer project engineer David Jung. This part of Chile is home to the bulk of manmade reservoirs, while the south has abundant natural bodies of water, generally deemed unsuitable given potential environmental impact. 

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In terms of economics, “we see the most potential in the net-billing segment,” Jung added, citing the abundance of relatively small manmade water bodies suited for this size of project.

Floating PV levelized cost of electricity in the net-billing segment in the central zone is around US$70-80/MWh. In comparison, the average cost of electricity in the country is around US$117/MWh. The technology, however, has higher initial outlay and maintenance costs compared with land-based solar PV plants. Associated generation potential is over 27,000GWh/y, the equivalent of 33% of national power output today. The cooling effect of water on panels boosts their generation efficiency by around 3%. 

In terms of helping conserve stressed water supplies, fully leveraging floating solar PV potential would also stop 163Mm3/y of water being evaporated, or the equivalent of 39% of domestic potable water consumption, researchers found. Chile is in the grips of a more than decade-long drought and forecast to continue experiencing water stress.

Energy minister Diego Pardow said in a video: “We’re seeing that when you combine both things [energy and water savings], the higher cost of this technology is offset by these benefits, in terms of both the agricultural and electricity components.”  

Floating solar PV is a relatively new technology in the country. In 2020 local pioneer Solarity cut the ribbon on a grid-connected 150kWp floating solar PV plant – the first and biggest of its kind – installed for agricultural company Hortifrut (pictured). 

Solarity told BNamericas how it develops this type of project: "The cost of the technology is high compared to plants installed on land or on a roof. Nevertheless, either way, this cost has been coming down. 

"Under the ESCO model – energy service company – and despite the elevated price, Solarity implements the project without incurring investment costs on the part of the client. It is a very beneficial model for companies with decarbonization objectives, since they do not represent costs and Solarity is in charge of monitoring and maintaining the plant."

Solarity is focused on behind-the-meter distributed generation solutions, working with various sectors but chiefly agriculture. The company has five plants in this segment comprising more than 4,000 panels. It also operates in the land-based segment. 

On the experience of installing the Hortifrut plant, Solarity said: "We learned that this type of facility is ideal for companies in the agricultural industry, since it generates clean energy and optimizes the space of the reservoir; reduces evaporation and improves water quality by reducing the amount of algae." 

Chile’s government has, among other distributed generation promotion initiatives, financial support schemes for irrigation projects that include non-conventional generation components. An irrigation bill in congress strengthens incentives, including for innovative solutions such as floating solar PV.  

Deploying small-scale projects is typically more straightforward, in terms of factors such as permitting and engineering, than installing a utility-scale plant on the likes of a hydropower reservoir, which would nevertheless benefit from economies of scale, the webinar was told. Such plants would also benefit from easy access to existing grid infrastructure.

PILOT PROJECT

Fraunhofer, meanwhile, installed with regional government support a 15kWp pilot plant, covering around 100m2, at an irrigation reservoir south of capital Santiago. Researchers found that the evaporation rate of water underneath panels averaged 1.3l/m2 a day compared with 7.6l/m2 a day in open water, while annual electricity savings were 2.5mn pesos (US$3,128).