Abstract:
This research investigated the most suitable arrangement of semi-transparent solar cells for
strawberries planting in greenhouses. The study was divided into two parts. The fi rst part was to
evaluate the electrical performance and the amount of Photosynthetic Photon Flux Density
(PPFD) that strawberry required for photosynthesis. In this case, 4.72 watts per cell of
polycrystalline solar cell was used to arrange in 3 patterns: spacing type 1, spacing type 2, and
chessboard type and a 2 m2 of semi-transparent solar panel was created. The study revealed
that the spacing type 2 and checkerboard type obtained PPFD of 755.47 and 751.17 μmol/m2/s,
respectively, which were suitable for strawberry planting. The solar panel performance was
tested to develop empirical equations for predicting the power production from both patterns.
In the second part, the equations obtained from the fi rst part of the study were used to simulate
energy production in the case of installing on a Lean-to strawberry greenhouse roof with a
width of 6 m, a length of 12 m and a height of 4.95 m. It was found that the spacing type 2 model
of semi-transparent solar panel could produce 7,309.58 kWh of electrical energy, equivalent to
32,893.11 Baht/year of electricity charge from the investment of 197,500 Baht and a payback
period of 6.00 years. On the other hand, the chessboard of semi-transparent solar panel was able
to produce 7,477.09 kWh/year of electrical energy, equivalent to 33,646.91 Baht/year with
the same investment of 197,500 Baht and a payback period of 5.87 years