Hi everyone welcome back to a solar energy course. 1
It is the last lecture. 2
We've already discussed the crystalline silicon definition and we take a special type of crystalline 3
silicon which is the monocrystalline solar cell. 4
Today we are going to take the next type of crystalline silicon solar cell which is polycrystalline 5
silicon solar cell their first solar panels based on polycrystalline silicon which also is 6
known as the polysilicone and multi crystalline silicon were introduced into the market in 7
1981. 8
Unlike monocrystalline based solar panels, the polycrystalline don't require 9
the 10
the czochralski process the row silicone is melted and poured into a square mold. 11
Which is cool and cut into perfectly clear waffer but what is the main advantage of this type of crystalline 12
silicon solar cells first. 13
The process used to make that poly crystalline simpler and the cost is less means the amount 14
of waste the silicon is less compared to monocrystalline second polycrystalline solar 15
panels tend to have slightly lower heat tolerance than monocrystalline 16
solar panels, this technically means they perform slightly worse than the monocrystalline solar panels 17
in high temperature means heat can affect the performance of solar panels and shortens the life span. 18
However this effect is minor of and the most the home owner don't need to take it into account 19
but what is the main disadvantage of this type. 20
the efficiency of polycrystalline based solar panels is typically between 13 and 16 percent 21
because of lower silicon impurties. 22
the polycrystalline solar panels are not quite as efficient as monocrystalline solar panel. 23
Second thing is the lower space efficiency you generally need to cover a large surface to output the 24
same electrical power as you would with a solar band made of the monocrystalline silicon. 25
But this doesn't mean every monocrystalline solar panel performs better than those 26
based on poly crystalline 27
last thing is that the monocrystalline 28
And thin film tend to be more pleasing since they have a more uniform block compared to the blue color 29
of the polycrystalline silicon. 30
So we can summarize that the polycrystalline has some efficiencies on the monocrystalline which 31
is. 32
There is no waste of silicon. 33
because they're already shaped in uniform rectangle the second thing the polycrystalline has a slightly lower 34
heat tolerance but the efficiency of that poly crystalline is lower than the monocrystalline 35
which makes that footprint of polycrystalline solar cells greater than 36
footprint of the monocrystalline silicon solar cells. 37
polycrystalline solar cell doesn't have a uniform form monocrystalline and thin film tend 38
to be more pleasing to eyes unlie the polycrystalline solar. 39
cell 40
now we already finished their first type of PV module which is crystalline silicon solar cell in 41
the next lecture. 42
We are going to move on. 43
the next is type which is thin film solar cell. 44
As we already said it can be module but not panel. 45
So we are going to move on the PV module. see you in the next block