Building Floating Solar Systems - Several Points You Need to Know

Due to issues such as obstructions, obstacles, age of roofs, and limited space, not all roofs are suitable for installing solar panels. Typically, such issues can lead homeowners to seek other suitable locations for installing solar photovoltaic systems. Unlike traditional solar arrays, floating solar systems are installed on the water surface without occupying any other ground space. In this article, we will talk to you about some points we need to know when building floating solar systems.

Floating solar systems

1. What is floating photovoltaic power generation?

This eco-friendly method of electricity generation integrates ocean and renewable energy technologies. Solar modules are designed to float on the water surface, such as dams or reservoirs, and transmit electricity to transmission towers through underwater cables. These panels are designed to be dustproof, lead-free, highly resistant to moisture, and waterproof.

The floating photovoltaic system has many similarities with other ground-based photovoltaics, the main difference being that they are installed on the water surface, thereby avoiding the need for land. Usually, even in countries with vast land and abundant resources, areas close to major energy consuming cities and industrial areas may not have available land, or costs may be too high. In this case, floating photovoltaic systems are an attractive solution as they are not limited by land availability. Especially in areas where land restrictions prevent energy generation, floating solar installations provide an effective way to generate electricity.

1. The advantages of floating solar systems

A. Land protection
 
Ground mounted solar panels typically require the use of valuable land resources. In contrast, floating photovoltaics provide a solution that does not occupy land space, such as being installed in unused water areas such as lakes, reservoirs, or ponds. This can allow the land originally planned for building a ground power station to be used for other purposes. In addition, installing solar panels on water bodies avoids the cutting down trees, thus protecting the environment.

B. Utilizing idle water surfaces

Floating photovoltaic solutions can be applied to various water bodies, effectively increasing the utilization of these spaces while reducing adverse impacts on pond or lake ecosystems.
 
Choosing to build on artificial water bodies also brings the advantage of easy integration with existing power plants, promoting simplicity and synergies.


C. Beneficial to the environment
 
The cooling effect of water improves the performance of photovoltaic modules while reducing water evaporation, which is a key factor in drought-prone areas. In addition, the presence of solar panels on the water surface reduces the occurrence of algae proliferation in freshwater bodies, otherwise this may lead to health problems when found in drinking water sources, or result in the death of aquatic plants and animals. Using floating solar panels to obtain clean energy can help reduce dependence on fossil fuel power generation, thereby reducing greenhouse gas emissions.

D. Improving the efficiency of solar panels
 
Although solar panels perform well even at higher temperatures, their efficiency decreases over time. The constantly rising temperature in turn affects the efficiency of the battery panel. However, water can cool the photovoltaic panels on the water surface, thereby it will improve their efficiency.

3. Design considerations for floating solar power plants

A. Anchor systems

In floating photovoltaic power plants, anchoring systems are essential for stabilizing fluctuating water levels, fixing the entire array in a specific position, ensuring that the floating solar array remains within a reasonable distance from the desired position, and reducing the displacement of the solar array caused by environmental forces such as wind, waves, and water flow.

B. Anchor design

The accuracy of environmental data estimation is crucial when determining the design scheme of the anchoring system. For example, if the design considers a maximum wind speed of 30 meters per second and the actual maximum wind speed reaches 40 meters per second, there is a risk of degradation of many components (including floats, connectors, ropes, and anchors) over time.

C. Floating Bridge/Floating Structure
 
The floating components for fixed solar panels include high-density polyethylene (HDPE) floats, which require a series of rigorous tests, including hunt sealing test, aging test, UV test, and TUV wind tunnel test. Aluminum alloy brackets should also simplify the process of installing solar modules onto the main float, thereby saving labor time and costs. In addition, the service life of these floating bodies is 25 years, which is a good investment for those seeking long-term solutions.

D. Main floating body design elements
 
The material selected for the main float must meet several standards. Firstly, it should be completely recyclable and non-toxic, and have good resistance to UV, alkali, and seawater to ensure durability. Adapting to fluctuations in reservoir water levels is crucial for easy adjustment when needed. The overall structure should be able to withstand extreme temperature fluctuations ranging from -60 ° C to 80 ° C. Finally, it is crucial for materials to have a long lifespan, ideally having 25 years of underwater durability.

E. Installation of inverters
 
Similar to standard solar power plants, the combiner box can transmit the direct current generated by the solar photovoltaic module to the inverter, which converts it into alternating current. You can choose to use a central inverter or multiple series inverters as needed. According to the size of the array and its proximity to the shore, the inverter can be located on an independent floating platform or on land. For smaller capacity floating solar systems, inverters are typically located on land near the solar array.

F. Cable wiring
 
The task of cable management and wiring in floating photovoltaic power plants requires careful planning. Unlike other ground-based photovoltaic projects, floating solar systems may encounter cables of different lengths due to changes in wind loads and water levels that cause the floating platform to move. It is absolutely necessary to provide additional cable lengths (in a relaxed form) to cope with the movement of floating platforms. If you neglect this aspect, it may lead to insufficient cable length, posing a risk of cable breakage under tension. In addition to length, the determination of cable size also depends on the voltage, current, and loss parameters of the cable.

The composition and structure of floating solar systems

What challenges do floating solar energy systems face?

A. Installation cost

At present, compared to normal ground photovoltaic systems, the installation cost of floating photovoltaic systems is higher. The main reason is that these systems require a large number of buoys, supports, and additional anchoring equipment. However, industry experts predict that with the popularization and implementation of floating photovoltaic systems on a larger scale, costs are expected to become more competitive.

B. Corrosion and related challenges

Due to their location on water, these devices are more susceptible to corrosion and other damage. Water bodies are humid environments, and buoys need materials that can withstand such environments. This not only involves metal components, but also extends to wires, adhesives, and sealants, which must also have resistance to these conditions. When considering installation in highly corrosive saline environments like the ocean, the challenge is greater.

C. Drinking water safety

In areas where drinking water sources like reservoirs are located, the materials used to construct floating solar solutions must be pollution-free. Any negligence in this regard may lead to serious consequences. This situation also emphasizes the need to develop new standards and testing methods to ensure the safety and efficiency of floating photovoltaic systems in such situations.