Solar Power Plant Designed for Coastal Industrial Zone (page 2)
Waste treatment site being cleaned-up turns into educational base for reusable energy
Efficient power generation without interfering with the saste treatment site’s cleanup process
Other Ukishima Solar Power Plant features are it not interfering with the cleanup of the general waste treatment site and the measures taken against strong winds and salt damage caused by the seaside location.
Toshiba built the plant while Sharp and Toshiba Mitsubishi-Electric Industrial Systems (TMEIC) manufactured the solar panels and PV inverters, respectively. There are 37,926 single crystal silicon solar panels installed with 198W maximum output and 28 PV inverters with 250kW rated output.
The land cleanup will be completed by continuing a 20-year cycle of putting filling on the waste, letting rain penetrate the filling, sucking up the penetrated water with pumps and discharging it into Tokyo Bay after purifying the water. Therefore, measures against land subsidence are important when setting up the solar panels.
As a measure against land subsidence, the number of panels set on the mounting system was reduced to six per unit so that if subsidence occurs the number of solar panels to be affected can be limited.
To accelerate land purification, efforts were made to enable rain to penetrate more when setting up the foundation and solar panels. The foundation on which the mounting system is set up has a hollow in the center of the flat concrete mass (Fig. 2). Such a style was adopted with the aim of making rain falling on the solar panels penetrate into the ground as much as possible. The solar panels were also set up after securing a horizontal space so rain can reach the ground easily.
With a space secured for maintenance vehicles needed for purification work, it looks like an airport runway extending into the mass of solar panels.
The measures against strong wind and salt damage and other efforts typical for coastal areas can be found in the foundation and mounting system design, the solar panel angles and the PV inverter installation. For example, the thickness of the concrete foundation is designed to be about 45cm thick by the coast where the foundation supports facilities on the windy side while the thickness is about half that on the inner side in consideration of impacts from strong wind.
Given the resistance against pressure from strong winds that could not be achieved sufficiently at 30°, which is said to be optimum for power generation, the tilt angle of the solar panels is set at 10°.
As for salt damage, the PV inverter housing is shifted to a tougher container type (Fig. 3). One container houses four PV inverters, and a total of seven containers are set up across the site.
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