Page 373 - A Comprehensive Guide to Solar Energy Systems

380 A COmPrEhEnSIVE GuIdE TO SOLAr EnErGy SySTEmS

FIGURE 19.7 Sketch of ground mounted PV panels, with piled or concrete shoe foundations and solar tracker panel
mount. Source: B. Dower (all rights reserved).

19.2.4 Floating Solar Farms
Solar panels can be mounted on pontoons floating on open bodies of water, making use
of not only open flat space, but also benefiting from the cooling effect of water below the
arrays. Solar pontoons have not been built on the sea, but the calmer waters of reservoirs
can be suitable for extensive arrays. Solar power generation is an interesting secondary use
for reservoirs, particularly on drinking water reservoirs where recreational access is not
encouraged. The use of the water surface on a reservoir may also be preferable to using
agricultural land or disturbing terrestrial ecosystems. The visibility of the panels mounted
on low pontoons at a distance from the shore is limited, and the recreational experience of
walking along the shore is not affected greatly.
Europe’s largest floating solar farm opened in 2016, on the Queen Elizabeth II reservoir
2
in Surrey, uK. It is made up of pontoons that cover 57,500 m and provides a 6.3 mW pri-
vate electricity supply for the water plant at the reservoir. The largest scheme proposed is
2
on the yamakura reservoir (Chiba Prefecture Japan), a proposal for 180,000 m of panels,
while the largest scheme in operation is the 2017 floating plant in huinan (Anhui Province
China), generating 40 mW on waters flooding a former coal mining area [9].
Floating pontoons do not cover the water surface completely and are tethered together
for flexibility with water movement, so that there is some light penetration and wind to
aerate the water below. The environment below the floating raft is therefore shaded in part
and provides a variation in habitat within an open reservoir, which can be beneficial to the
ecosystem within the reservoir.

19.3 Key Visual Elements

The main visible elements of free-standing solar farms are the panels, which are typically
dark blue to black and finished with a nonreflective coating to maximize the absorp-
tion of light. Early models had aluminum frames and grid lines between the cells, and
more recent models have no frame or grid and are plain black, making them simpler in
appearance. Fixtures and free-standing panel supporting frames can be galvanized or