Ciel & Terre USA recently announced the completion of a new 252 kW floating photovoltaic power system for the Lake County Special Districts on behalf of Kelseyville County Waterworks Dist. #3. Over 700 floating solar panels were used with SolarEdge solar optimizers for the installation. Chris Bartle, Business Development Manager for Ciel & Terre USA, answered some questions about the project for CleanTechnica.
Why was floating solar chosen instead of ground-mounted panels?
The waste water district did not have land available for ground-mounted.
Do floating solar panels impact aquatic life within the body of water they are located in?
We have done 2 environmental studies on this, one in France and another in CA. The conclusions were both neutral to positive.
What kind of cables/wires are used to transfer the electricity generated by the floating system, and is there any special care they require?
Marine grade cabling systems are used. No special care required.
At what depth does the floating solar apparatus sit in the water?
2-3 inches below the surface with no personnel walking on the floats. 5-6 inches when a person is standing on a float.
What is the apparatus made of?
The floats are blow molded High Density Poly Ethylene (HDPE) plastic. Same material and manufacturing process as food grade containers.
How much cooler are solar panels in water kept versus ones mounted on the ground or one a roof?
The temperature difference on the panels depends on the air temperature, but there is a definite cooling effect from the panels being so close to the water thus enabling greater power generation than on ground or on rooftop.
If this installation is a success, where will other floating solar systems be installed, and how big will they be?
Ciel & Terre USA is working across the US on systems ranging in size from 100kW to 20+MW. Our primary target markets are water districts, waste water districts, irrigation districts, municipalities, hydroelectric dams, farms and ag companies, and industrial companies. Any entity that owns a water body. Mainly targeting man-made water bodies.
Do floating solar power systems cost more to install, about the same, or less?
The main drivers in this comparison are the amount of land preparation (tree removal, excavation, leveling, etc.) required and/or the difficulty accessing and working on the land or roof. Typically a turnkey floating system is comparable in total system cost to ground or roof mounted systems.
Are the solar panels exactly the same as the ones used on roofs?
Yes. Panel manufacturers give the same warranty on water as for traditional ground mounted systems.
Which manufacturer for the panels did you choose?
We are able to accommodate 60 and 72 cell panels that are standard width of ~39″. We have no preference for manufacturer. It is up to our customer to choose the panels they want to use. In Kelseyville, they chose Canadian Solar panels.
What is the longevity of a floating solar system?
Our standard warranty for our systems is 5 years, but we offer extended warranties for up to 20 years. The material of the floating system is commonly used in many industries and has a lifetime of over 20 years.
Do floating solar systems require about the same maintenance as roof-mounted ones?
Often time they require less and easier maintenance. No trucks or other heavy equipment is required. Workers with brooms or mops simply walk the rows between panels, dip the broom or mop in the water and wipe down the panels for cleaning. All other maintenance is also easily accomplished walking the rows between panels.
Because the panels are floating in water, are there any special safety considerations to follow to prevent electric shocks?
Electric shocks are not a risk. Of course, life preservers are required for installation and maintenance crews.
First California Public Floating Solar Power System Delivered By Ciel & Terre, by Jake Richardson, PV Magazine, October 1, 2018.