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THE MOST CONSULTED TOPICS
The most viewed topics
General
questions
Product
Site conditions
Environmental
impacts
Floating pv
design
Electrical spec.
Anchoring
design
Construction
General Questions
What is the yield compared to ground PV plants?
Thanks to water proximity, a cooling effect enhancing the energy production can be expected. The Solar Energy Research Institute of Singapore (SERIS) observed a PV panel temperature 3 to 10 degrees lower on floating PV plants compared to rooftop systems in Singapore with a yield increase of 5 to 10%. Moreover, the Solar Energy Application Centre (SEAC) recorded a decrease up to 6 degrees in PV panels temperature in the Netherlands with a yield increase estimated at 2 to 3%. Generally speaking we see high cooling effect in warm countries with constand wind.
Per hectare, what is the installable capacity?
A 1 MWp floating PV plant has a footprint of approximately 0.65 ha on the water body, a little less than a football field. On the top of that, you need to consider the anchoring footprint that are locally installed, but not covering any space. The overall density of the plant could be impacted at some point by the type of anchoring used, bank or bottom.
Do banks financially support floating PV projects?
Yes, banks have financed and supported many of the floating PV plants built in the world. This includes some of the world’s top-ranked banks. For example, in Japan, both national and regional banks have financed projects. Namely, in France, the 17 MWp O’MEGA1 project has been financed with around €12 million of non-recourse financing.
Where can I purchase floating solar products?
First, you can fill out our contact form, and you will be in contact with our closest Sales Department, which will help you establish your project’s technical and financial feasibility.
Then, our Sales team will handover our project to our Engineering team to execute the detailed anchoring design. At the project implementation phase, we take care of the on-site delivery of our floating solar system. Then, Ciel & Terre can take care of construction and
supervision of floating PV platform and anchoring or we can organize an on-site training session with your construction team to explain the assembly process.
What is the delivery time?
Delivery time varies depending on your project location and the availability of the production lines. Moreover, the floats are produced in just-in-time flow and a minimum of 8 weeks after the order placement is to be expected before the first delivery on the site.
What is the product standard warranty of our systems?
We offer a 10-year warranty for our FPV systems, to cover replacement and repair of any potential defective component of the product. We can also propose as well warranty extensions according to suit your needs. To ensure the best possible durability of your floating solar platform, Ciel & Terre can manage the maintenance of your project. Please discover our O&M service.
How is O&M done on the floating PV arrays?
First of all, operators can easily walk on the floating PV plant via maintenance walkways between PV panel rows to perform O&M tasks such as cleaning PV panels and replacing parts.
Our team must consider preventive and corrective maintenance tasks in addition to operation. Furthermore, we provide our clients with an O&M manual that includes checklists and controls before plant operation.
Also, our team can also perform maintenance on the floating structure and its anchoring system. Discover our maintenance services, or contact us to learn more about our offers.
Where are your products manufactured?
We manufacture our products in France, the USA, Brazil, Japan, South Korea, Thailand, India, Malaysia, Taiwan etc. For large scale projects, we may consider local manufacturing.
For more details about our manufacturing process, please, please visit our web page Supply and Procurement service page.
Product
What are the components of Ciel & Terre's floating structures?
The floats are made of HDPE (High Density Polyethylene), the connection pins are Polypropylene, and the PV panel fixation is Aluminum. Manufacturers add additives to the raw materials to ensure the product lifetime. Discover our product page.
At Ciel & Terre, what tests do you conduct to determine Ciel & Terre's floating structure resistance?
Our solutions have undergone testing and/or certification by a network of historically reliable expert technical partners.
Today, we use our own R&D lab to test and enhance our solutions with benches customized for floating solar. In our lab, we reproduce water movements and their impact on the overall plant using our fatigue test bench. Additionally, we validate extreme anchoring loads with our tensile chamber (to evaluate loads during storms or typhoons). Lastly, we utilize a heating & cooling chamber to measure the weather resistance of the various components that comprise floating solar plants.
Learn more about our validation R&D lab : read the article on our products tests and validation.
What is the lifetime of Ciel & Terre's floating solar structures?
We designed our floating solar structures to withstand a period of over 25 years.
The floats can be recycled at the end of their lifetime since the HDPE and aluminum are recyclable. The product’s lifespan can be as long as 30 years, depending on site conditions.
Are Ciel & Terre's floating solar systems certified?
As floating solar is a recent concept, there is no certification regarding the floats yet (Hydrelio solution is however approved by Solar impulse). We base our test protocols on relevant standards and have, for example, obtained certifications for drinking water compliance (standard BS 6920:2000). In addition, our design methods are certified as well (by bureau Veritas in 2020 and renewed in 2023).
What is the buoyancy of Ciel & Terre's floating structures?
Whatever the configuration of your power plant, we will always propose you an optimal design to guarantee the good buoyancy. Moreover, the design of our floats facilitates the passage of operators on the floating power plants. Our floats have been designed to enable operators to move easily on the floating PV array and safely carry out O&M. Discover our maintenance service.
DOES CIEL & TERRE HAVE A SOLUTION TO PREVENT BIRD EXCREMENTS FROM DECREASING THE PANEL’S YIELD?
Solutions such as lasers or distress sounds can be used to drive birds away. Nevertheless, installing these types of systems is a case by case basis. Floating solar plant has to be well integrated in its direct environnement, including biodiversity. As this is a site-specific, we do not recommend a standard solution without any site study on the topic in order to preserve biodiversity.
Can the color of the floats be changed?
Float color cannot change. Indeed, the grey color of the floats allows UV resistance and light reflection.
What are the possible tilts for Ciel & Terre's floating solar systems?
With our floating system technology, we can provide a 5 to 12° angle. To find out more about our products, visit our dedicated web page.
Site conditions
How to identify water bodies where floating solar can be installed?
At Ciel & Terre, we wish to preserve the environment and recommend studying floating PV projects on artificial water bodies.
Ideal water body characteristics are:
- Regular shape
- Limited depth and water level variation
- Road access
- Space on the banks for construction and storage
- Proximity with the grid is a plus for the project development
But, almost any water body could be a candidate for floating solar. We are happy to assess your site at no cost to you. Contact us
Can Ciel & Terre's floating solar structures be installed on drinking water ponds?
Our floats are made of HDPE (High Density Polyethylene) which has a neutral impact on water.
They are compliant with the standard BS 6920:2000 (odor & flavor test for non-metallic material for use with drinking water), which proves that it is suitable for contact with water intended for human consumption.
Can Ciel & Terre's floating solar structures be installed on salty waters?
The floats are made from HDPE (High Density Polyethylene) and salty water has no effect on this material. We choose the raw materials of metallic pieces to withstand salinity. We are developing a solution that can withstand salinity.
The PV panels and electrical equipment will also need to resist these conditions.
An appropriate O&M plan, especially regarding the electrical parts, will have to be considered.
Is it possible to install Ciel & Terre's floating solar structures on polluted waters?
A water quality analysis will be required to check that our floating solar systems can be installed safely. The EPC should also check the feasibility of the project regarding the electrical equipment.
Can Ciel & Terre's floating solar structures be installed on oceans or seas?
Our floating solar structures are not suitable for harsh offshore conditions. However, they can be installed on closed seas or lagoons where water current, tides and waves are limited. Discover our case on Changbin.
Are Ciel & Terre's floating solar structures compatible with fishing and fish farming?
An environmental study by a specialized consultant will allow Ciel & Terre’s engineers to design the floating PV plant to preserve fishing and fish farming.
Can the floating PV plant lie on the bottom of the reservoir?
In case of droughts, floats will lie on the bottom of the water body without being damaged.
If the water body bottom is not flat or has some obstacles (pipes, rocks…), the site may not be eligible due to the risk of damage to the floating system. Contact our teams to evaluate the feasibility of your project. Contact us.
Can Ciel & Terre's floating solar structures be installed if there is a risk of overflow?
Risk of overflow is not a problem for our floating solar structures if the project is located in an area protected against drifting obstacles such as trees.
However, Ciel & Terre must be informed of potential overflow in order to consider it when executing the anchoring design.
Are Ciel & Terre's floating solar structures capable of withstanding high winds?
We have designed our floating solar structures so that they withstand winds up to 210 km/h (130 mph).
Then we design the floating PV plants case by case and we define its anchoring with the Client, according to site conditions.
Can Ciel & Terre's floating solar structures be installed in cold environments (frost and snow)?
Our floating solar structures have been installed in regions such as Colorado in the USA, Sweden and South Korea. No damages due to cold climate have been noted. It is warrantied down to –22F/-30°C from our trackrecord and to 400N/m2 snow load maximum.
Environmental impacts
What is the impact of your solutions on water quality?
Our floats are made of HDPE (High Density Polyethylene) which has a neutral impact on water. Indeed, our systems are compliant with the standard BS 6920:2000 (odor & flavor test for non-metallic material for use with drinking water) which proves that it is suitable for contact with water intended for human consumption.
What is the impact of our FPV structures on aquatic life?
Both light and heat are expected to decrease creating a new balance for the reservoir’s fauna and flora. The specific impacts on a site can be investigated with the help of a local environmental impact specialist. Also, environmental consultants usually highlight that under 50% coverage, the floating PV plant impact is limited. There are more and more studies on the impacts of FPV on aquatic life, most of the time based on mathematical models, or small-scale projects. Such studies need to be reviewed carefully as it is difficult to make conclusions on environmental impacts based on short-term studies. Real conclusions on biodiversity can be made after several years of analysis.
Do your floating PV technologies prevent evaporation?
Since we cover or shadow a significant part of the water body with the floating PV plant, as a consequence you can expect a reduction of evaporation. However, it might be difficult to quantify the phenomenon as it is very specific to climate conditions.
Several studies (Scavo, 2020) have shown that FPV can reduce the evaporation on water plants, considering 3 factors:
- It reduced exposure to sunlight (less sunlight reaching the water surface means less absorbed heat, leading to less evaporation)
- The reduction of air-water exchanges (the solar plant acts like a barrier at the surface, reducing the action of wind and water aeration, which is a cause of evaporation)
- It also has an impact on water temperature reduction (shadow from the panels).
Does floating solar prevent algae growth?
Indeed, covering a pond with floating PV means that less sunlight is available for algae to grow which reduces their proliferation consequently.
An environmental consultant can help you assess the impact.
Are there any permanent effects on the site’s environment after the operation decommissioning the plant?
Actually, there are few permanent consequences on the site’s environment since we make our floating solar systems to be as neutral as possible. Moreover, during the decommissioning phase, the floating PV arrays will be dismantled easily on the banks.
Are your technologies recyclable?
HDPE is a recyclable material. For instance, there is a set of profitable channels for the use of recycled HDPE. Moreover, aluminum parts are also recyclable.
We recommend complying with local electric standard.
On the Hydrelio® products, PV panels grounding holes are used to do the grounding between PV panels.
What is the information required for the plant design?
For a first site assessment, the information we require are
- The GPS coordinates of your site
- Site conditions including: pond type, water type, max depth and water level variation
- Electrical equipment main features.
These data will allow our engineering teams to determine the exploitable surface of the pond and the maximum capacity for your floating PV plant. Contact us
Is there any limitation of size or capacity?
There is no limitation of size for a whole floating PV plant. However, because of anchoring reasons, there is a limitation for an individual solar array. Thus, we design big-scale projects with several single arrays.
As an example, the 70 MWp project of Anhui Cecep (China) is composed of 13 floating PV arrays. See project
How to install the electrical cables between the floating PV arrays and the banks?
Based on our experience and collaborations with electrical engineers, we recommend 2 options:
- UV resistant-electrical conduits fastened on isolated floats between the floating arrays and the banks
- But also UV resistant floating conduit with electrical cables inside.
Are all the PV panels compatible with Ciel & Terre's floating solar structures?
The floats are compatible with most PV panels available on the market, up to 700 Wp so far (M6/M12).
For our Hydrelio® system, PV panels are assembled with the main floats.
Can frameless PV panels be installed on Ciel & Terre's floating solar structures?
We primarily design our floating solar structures for framed PV panels but solutions to fix frameless PV panels can be found depending on the configuration. Frameless PV panels are, however, more fragile and thus, less adapted to floating PV plants and the environmental challenges.
What PV panels orientations are possible with Ciel & Terre's floating structures?
Depending on the project location and the product chosen, different solar panel orientations can be advised by our teams:
– Conventional (South oriented or North oriented configuration)
– Dual orientation or duo pitch (East-West oriented configuration)
Can the floating PV arrays move and hit the banks?
Because it is anchored with several anchors on each side, the movement of the floating PV array will be limited. During the anchoring design execution, the Engineering team calculates the movement of the floating PV plant and ensures that it won’t hit the banks.
What happens when the water level drops?
We design the floating PV array and anchoring to adapt to water level variation. Due to the slack of the mooring lines, the floating PV array will move on the surface according to the magnitude of the water level variation. Therefore, it is crucial to provide reliable data, so that the anchoring system is accurate and safe at any water level.
Electrical specifications
How does water proximity impact electricity generation?
Water proximity is an advantage for your floating plant.
Water provides a natural cooling effect when the production is at its maximum. This phenomenon reduces the temperature variation peaks thus provides a cooler environment. This cooling effect enables PV panels to generate more power.
WITH OUR SOLUTION, HOW IS THE PV PANEL CABLING DONE AND IS THERE ANY CONTACT WITH WATER?
The construction team does PV panel cabling on the banks during the assembly of the floats and PV panels. These groups are then connected by string, then several strings are connected together before being pushed onto water.
We recommend reducing risks of contact with water by attaching DC cables to the PV panels before the launching of floats on water, by using stainless steel clips for instance. We also recommend to used watertight and UV-resistant cable conduits.
How to install the electrical cables between the floating PV arrays and the banks?
Based on our experience and collaborations with electrical engineers, we recommend 2 options:
- UV resistant-electrical conduits fastened on isolated floats between the floating arrays and the banks
- And also UV resistant floating conduit with electrical cables inside.
Are the inverters installed on the floating PV arrays?
In most cases, plants are designed with central inverters located on the banks and junction boxes on the floating PV arrays.
Depending on the product chosen, it is also possible to install string inverters on the floating PV arrays. Our project engineering team can advise the EPC regarding this matter.
How does grid connection work for floating PV plants?
The grid connection of a floating PV plant works the same way as a ground-mounted plant.
What are the recommendations for earthing/grounding?
We recommend complying with local electric standards.
With our Hydrelio® solution, PV panels grounding holes are used to do the grounding between PV panels.
Does the material need to have a BOS specification (weight, IP code, size)?
We suggest using at least IP 66 equipment. Regarding the weight, the lightest the equipment are, the better.
Because of permanent movement, cables suppliers recommend using copper cables.
The EPC must observe possible local regulations regarding electrical equipment.
How can I protect the DC cables?
Because of UV exposure and permanent movement of the floating PV arrays, we recommend using UV resistant flexible conduits.
Anchoring design
What is the information required for the anchoring design?
The anchoring design is executed at an advanced stage of the project planning as it could have an impact on the array layout (size and shape). The critical data to perform an anchoring design are:
- Topography of the banks
- Bathymetry
- Water level variation (over the lifetime of the plant)
- Waterflow data if there is any wind speed on site is calculated from national building code and approved by the client.
Does Ciel & Terre supply the anchoring and mooring systems?
At Ciel & Terre, we include the anchoring design with the design of the FPV plant because both are indivisible.
Firstly, we define the location of each anchor and the applicable load on each anchor and each mooring line length. In addtion, we provide the anchoring material specifications too.
Secondly, and as the floating solar expert with a strong experience in anchoring, we provide you the support you need to ensure your floating PV plant is correctly anchored.
Finally, our construction team manage the supply and the installation of the anchoring system.
Click on the following link to discover our services: Discover our services, or contact us to learn more about our offers: Contact us.
What are the possible anchoring systems?
Our engineering team will advise the most relevant anchoring system among the following. Of course, that will depend on your site conditions and your preferences:
- Anchoring at the bottom of the reservoir
- Bank anchoring
- Hybrid anchoring mixing banks and bottom anchoring
According to Ciel & Terre, what type of anchors can we use for the FPV project?
At Ciel & Terre, we propose three main types of anchors: drilled anchors, screw anchors, percussive anchors, pile anchors and dead weights.
Nevertheless, if none of these anchors can be used, our engineering team will study other types of anchors.
What is the resistance of the anchoring system?
We design our anchoring systems to resist environmental loads: wind, waves, current.
Firstly, we calculate the wind loads thank to several technics : with CFD, with wind tunnel tests and with wind speed calculated from national building code. Secondly, we measure wave loads based on the floating solar island, reservoir layouts and wind speed. Finally, we analyze waterflow loads based on the FPV array and reservoir layouts and waterflow data.
Do the mooring lines rust?
Equipment must be chosen depending on site conditions, for sure some materials made of steel could be more sensitive to corrosion compared to synthetic ropes but at Ciel & Terre we are able to choose the correct material depending on the site specific conditions in order to resist to long term solicitation such as corrosion. Usually, we use galvanized steel cables and polyester ropes.
How does water level variation impact the anchoring system?
The water level variation will generate slack or tension in the mooring lines, leading to FPV array movement on the water surface. Consequently, a significant water level variation means more movement and will require longer mooring lines.
Therefore, it is highly critical to perform the anchoring design with accurate and reliable data, so the anchoring system is safe at any water level.
Can the floating PV arrays move and hit the banks?
Because it is anchored with several anchors on each side, the movement of the floating PV array will be limited. During the anchoring design execution, our engineering team calculates the movement of the floating PV plant and ensures that it won’t hit the banks.
Construction
How to assemble the Hydrelio® floating PV array?
The assembly process depends on the system we install. For instance, with our Hydrelio® range, the assembly is simple, like a Lego-type construction. As a complement, we provide:
- Manuals and supporting documents
- A training session on site at the start of the assembly
- Advice to increase the assembly efficiency
- Construction drawings in order to ease construction for the installation team
In addition, we can also manage the construction of the floating solar island and its anchoring. You can contact us to have more details and visit our services page to learn more about our construction services : Discover our services.
How do you launch the floating PV arrays on the water?
First, we would recommand to start pushing the island on the water manually to liberate space on the assembly platform when two or three rows of floats and PV panels have been assembled. Once a block is completed (the size of each block will be defined with Ciel & Terre during the planning phase), a boat can tow the PV floating block to its final location and connect it to the anchoring system already installed.
What is the installation time for a floating PV plant?
To install the floating array, including connection to the anchoring system and electrical cables installation, we consider in average a ratio of 2.5 PV panels per hour and per worker. For instance, a team of 15 persons would install about 16 kWp/working hour.
Is there a training session for the installation?
At Ciel & Terre, our construction team can support you with the installation of the floating solar plant and its anchoring. We also provide a training session on site at the start of the assembly and give advice to increase the assembly efficiency. In general, the typical duration is 2 days and can be adapted depending on your needs.
To learn more about our Services: Discover our services.
Is there a minimum size for the construction area?
Actually, there is no requirement in terms of installation platform’s size. However, the bigger the area is, the better. To reach a minimum efficiency, we recommend a 10m large area with a length equal to one string of PV panels.
How many people do we need to install a floating solar plant?
We recommend a team of 15 persons. Of course, to improve the mounting rate for large-scale projects, multiple teams can work on separate areas.
Which tools do we need to install a FPV structure?
Actually, the use of tool will depend on the type of floating solar structure you will select for your project.
Considering our Hydrelio® system, you won’t need heavy or specific tools to assemble the platform nor the PV panels on the floats. Moreover, during the planning phase our project manager will provide a list of tools that you will need to install our solution. In addition, a boat and all the adapted protective equipment (PPE) such as life jackets, helmets, security boots, etc. are mandatory.
What are the methods to secure floating PV plants?
To secure the FPV plant, we can install:
- Video surveillance / CCTV next to the electrical installation on the banks
- Fencing the land
- Installing a floating barrier around the floating PV plant
HOW IS FLOATING PV ARRAY MOVEMENT AVOIDED DURING CONSTRUCTION?
First of all, we begin with the installation of the anchoring system prior to float assembly and connected to FPV blocs during the installation. Then, we install additional temporary anchors and mooring lines to maintain the arrays. For this reason, the temporary anchoring system must be as resistant as the final anchoring.
How to mount our floating solar systems in case the banks are too steep?
If the banks are too steep, we can install a wooden platform with scaffolding to reduce the banks’ slope for safety reasons.
OUR ARTICLES, TO GO FURTHER…
The ponds compatible with floating solar: what are the conditions?
Water level variations & drought: how does floating solar meet the challenge?
