Cebu floating solar farm uses elastic moorings tested through one million wave cycles
There is no earth under the solar panels at the Malubog Reservoir.
This is because they float on structures spread over seven acres of water in the mountains of Cebu and generate power that goes to the Carmen Copper mine close to the area.
It eliminates the necessity for a traditional solar farm. This presents a new engineering challenge.
Sungrow states that their floating PV system had successfully completed more than a million cycle fatigue tests compared to the industry standard of only 100,000.
Each panel, connector, and floating platform must stay intact while wind and waves constantly attempt to displace the whole 4.99-MW plant.
It is supposed to be mobile
The floating solar farm cannot be permanently anchored in place like in the case of the rack anchored in the soil.
As a result, the Malubog system is equipped with elastic moorings, which, according to Sungrow, help to absorb and dissipate the energy of waves rather than hold the floating farm stationary.
Waves continue to push and pull. If movement is possible, it makes the forces applied to the floating farm and its anchors more gradual.
According to Black & Veatch, the completed facility uses 304 submerged concrete anchors, connected with mooring lines to the array.
The farm is moving. But the anchors restrict its movement.
Tackling the wind challenge
Moreover, Cebu locates the system in a country where there is frequent exposure to severe tropical conditions.
According to Sungrow, the design against wind and waves was made on the basis of a maximum wind speed of 246 feet per second, which made the design increase impact resistance by 50%.
This refers to a design criterion, not to a statement of wind speeds of this magnitude hitting the facility.
This point is important.
The engineering issue is to create a floating system capable of surviving extreme loads before such loads occur.
In the case of land facilities, foundation loads are transferred to the soil.
In Malubog, the path of the load goes through floats, connections, mooring lines, and concrete blocks under water.
One million cycle testing checks something else
An extremely high loading event is just half the story from a structural perspective.
Smaller loads could be coming continuously for years.
Sungrow states that their floating PV system had successfully completed more than a million cycle fatigue tests compared to the industry standard of only 100,000.
Fatigue testing involves repetition.
It is not necessary for the component to fail in the first loading cycle for repetitive loads to have an impact; the goal of the test is to see whether the system could withstand cyclical loading without experiencing fatigue failure prematurely.
Therefore, one million cycles is not another wind resistance rating.
The design caters to extreme loads. The fatigue test caters to repetitive loads.
The facility was already functioning prior to the panels being installed
This is not just any empty facility chosen for solar energy development.
According to Atlas Mining, this reservoir is owned and operated by them and serves to give fresh water to the nearby communities in Toledo City as well as their own operational activities.
The solar project makes use of this surface for yet another purpose.
The facility was described by Atlas Consolidated Mining and Development Corporation as 4.996 MWp, which can meet about 10% of the electrical requirements of Carmen Copper, with a capacity increase up to 50 MW in the future.
The total number of photovoltaic modules included in this facility is 8,540.
Black & Veatch developed the project in about 15 months and claims that the facility occupies 3 hectares of the reservoir.
The floats are what made the site viable
The mountainous terrain of Carmen Copper is helpful in understanding why locating panels on water was appealing in the first place.
As Black & Veatch notes, the area is poorly suited to a traditional land-based array, whereas the reservoir presented an available open space near the mine.
This construction process led to the creation of the first megawatt-class floating PV system in the Philippines.
The special engineering is located beneath the panels. The modules generate the energy.
The floats, anchors, and elastic cables provide the less glamorous service of allowing the 4.99-megawatt power station to be movable while in the reservoir without being swept away by it.
Kelly is an experienced writer with 15 years of experience exploring the big stories that shape our world, from tech breakthroughs and space exploration to climate, energy, and the fascinating quirks of science. She has a talent for turning complex ideas into sharp, memorable insights that stay with readers long after they’ve finished reading.
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Kelly is an experienced writer with 15 years of experience exploring the big stories that shape our world, from tech breakthroughs and space exploration to climate, energy, and the fascinating quirks of science. She has a talent for turning complex ideas into sharp, memorable insights that stay with readers long after they’ve finished reading.
Kelly is an experienced writer with 15 years of experience exploring the big stories that shape our world, from tech breakthroughs and space exploration to climate, energy, and the fascinating quirks of science. She has a talent for turning complex ideas into sharp, memorable insights that stay with readers long after they’ve finished reading.