Since the very early days of solar cells
people have a all responded up on this question there was a Mac to
efficiency that you can get for this solar energy conversion
and previously I was mentioning to you this
shot require the limit which gives the like some
feeling of energy conversion of our own 32 percent
if you have a single junction nurse or a Seth
but we saw that the we saw that if you increase the concentration of sunlight
than you can further increase the thirst
you can go higher than the 32 percent and you can achieve a energy conversion
enough for rent for a2 percent
similarly fuse more junction say for example if you set to don't generate the
junction or a for junction
base de Soto said you can get efficiency the forty-two
with the and our forty-eight percent and our
going you with higher and higher efficiencies so
the fundamental question the that
I need to still answer is what is the fundamental never done this
the efficiency can or you know what is the maximum efficiency I can not get
by using any any thought I said or any other
are you when you are let's let's not just restrict our itself to just a
thought I said but by any can order
which can work 3rd this the kind words death the
a energy coming up from the Sun into
a useful farm of work so I don't do something
more often omitted due on Thursday with Honda on so that survey put an end to a
question
and I don't do my simple I love to a dynamic to help me find out
what is the maximum efficiency for this for solar
conversion %uh process so I can the
on associate this energy conversion winnow it terms of the energy flux the
fluxes of forward to an intro piano so on
let me start by a growing
with red arrow which represents the energy flux coming up from the Sun
and I represent that do you thing this assembly so
what I am interested then is a finding out home without this energy I can not
been worked into
a useful farm of work which I did you know it by death
color green summer efficiency
then which show is represented often by this the Greeks m.o.e to
which looks like a funny if I love n is this
the efficiency a is a is essentially nothing but death
up this war divided by
you know I dared by the energy flux coming up from the Sun
see you might die and I ask yourself you know what is the mic through efficiency
why which show you can convert this energy from the Sun into the for use
with
phone at work get it be 100 percent
and the answer to that is the No the
the reason is that the second love foot or dynamic the so far Afghan
have considered all the energy but but what
with this energy is that the theater to intro be fluff
Iowa I represent that in this
color blue and this the entropy flux
is at minimum given by this farm in a
whereas with her energy flux divided by the temperature in this case the
temperature above the Sun
to know my second love 2010 nimic states that governor and doing this
energy a conversion there must be an 8th generation
for in Group B which is the which is that taking place a in this %uh process
and I must balance out this the entropy fluxes
for my no of my incoming entropy and my generated Entropia and that move gives
me the
in Toby Flood switches going on so what did say that whatever I'm doing this
the this conversion process there must be a intro P generation which is a
taking place so there will be a cookie which is generated a
in this look inward in this must be always a greater or equal to 0
than I don't know I have this the incoming a
energy which has this associate editor in Group B flat for data over this intro
be a generation so I must also have a are going
you know must have a are going off like suffer in Krabi Associated
and that minute that I V some love this
the energy which was coming up from the Sun into a fav
he'd and I rather than that by the symbol
cue and the corresponding
ago beef like that could be associated love it that can be represented by
this you divided by the temperature and in this case the temperature of the NBA
in with the thingy as being a tease out so I can only stay
the the a visa to love the photo when I to make some more mathematically
and I can use that to calculate this a maximum
efficiency that I i get from this energy
other that I can get from this %uh process let me ride on the first love
but there were no direct which basically says that the energy is our convo
where are you have this circuit was in the net energy is the IRA that can love
and the way i can state that dole mathematically is that this energy flux
though it to us
coming up from the Sun must be equal to do
the amount of aboard of work that I am
generating or this %uh flux forward
blossom owned of he their armored anything or to the flux of heat that
Murray thing or two though my first love to but i wanna make switch it on the
with the which day is that the energy conservation
know I was a the second photodynamic switcher
a these with work on the way shinobi the intro beef like this
so what I have my incoming flux up for entropy
is the safety given by this for me know
blows the entropy whichever generated a in the process
%uh this the entropy flock for love
which is generated 0 the ring with the energy conversion must be equal to
the net in Group B flux so it is going on and that is given by
this suffer amid saddam interested in finding out the maximum value of
death efficiency and again the I can take these two equations from the first
and second off put them in a mix an input and plug it into that's a question
so I can no substitute for example book
flux from this equation and I can write it
my the with mind eighth
cue and this is divided by
he s again semi Mike through evidence the is the city looks like it's a given
by
this for via so to maximizing the efficiency I need to
minimize this that dome which is being subtracted
from heat which with the fact it from its I need to
minimize memorial for heat generation
so dont know let me make you though the secular for 2010 that makes
the do get this the equation I
multiply both the the left hand side in the right hand side
by ES in that case meaning that stone cue
by yes overheard the St
by ES or hair
and then yes get to know it from here
and then I take the temperature for the aim being to a temperature
on the photomultiplier the whole equation by
like two years where than that with its the
might apply this the whole thing
my PA said I get my
you by the with message me
would do its equal to the
a by DS bloodworth
s the G billings DA by
yes to know that this would be a 04 I wanna find the minimum value
this because that would maximize my efficiency
for the minimum value above this would be when this
a in Group B which has generated in this energy conversion will be equal to 0 so
the third thing would be minimal
if 8th year equal to 0 and the minimum value love this with
equal to DEA by TS
so that corresponding me give me a maximum value for the efficiency
and the like somalia of efficiency that I can get
is about one mile US you as by
ES voters that the truth they think to DEA
by the with and this is what %uh the
a also known as the Carnot efficiency in every I the efficiency of
work I know ended the if you if you know if you have studied about
engines then though you might be familiar with this for
with this efficiency levitt it's a it's just a that CAIR
and/or d but it's believed that scar I know this
do you ordinarily the silage and that's because this car know whether
freights person so this is a a Carnot efficiency
the and for our case where are the temperature of the MBA degree can I view
it
to be as you wear it to be around three and that
k to read and I can view in the Sun to be a
black body I around think so then the cat
and in that gave the third guy no efficiency is given by approximately 95
up with it
sarkari to the circle I know efficiency limit
weekend Kanawha ninety-five percent of the
energy coming from the Sunday before
to offer useful work which could be electricity
but dies showing the next year that this as they were possible
for this for solar energy conversion process
so see you in the next 30