5 Reasons Going To Mars is a

Robert,

my numbers of a ground based pv cell producing about 1/4 to 1/5 of the same cell based in space is my own it is easy to derive, but I admit that it is a guesstimate:

a pv cell based on GEO (that is important LEO would be very different in this regards) basically has sunlight 24 hours per day (yes there are very short exceptions twice a year, but we will ignore those)

a ground based pv cell does not have a luxury

first of all on average there are 12 hours of night per day giving reduction factor of 0,5

I am assuming a one axis sun tracker here a two axis tracker would be a bit better but has other detriments, a fixed installation would be worse but that means that power output will be lower at the times how much lower is hard to estimate and would need a proper analysis but my guestimate is 0,25

in a good location the atmosphere will reduce power only slightly, but there will be a reduction this reduction will be slight at noon, but much larger at sunset and sunrise, when the sun has to pass through a lot more atmosphere another guestimate is 0,25

finally there will be clouds, dust on the pv cells and other obscuring factors ... lets say 0,3

1*(1-0,5)*(1-0,25)*(1-0,25)*(1-0,3) = 0,197 (or about 1/5)

But as I said I am not sure that this power production advantage of a GEO bases pv cell can make up for the much higher installation and maintenance costs, the transmission losses and the cost of the ground rectenna but that is an economic analysis that has many more fudge factors in it than my little piece above

servus

markus

> "Robert Smith robert@... [spacesettlers]" hat am 2. Mai 2018 um 21:39 geschrieben:
>
> Yes :)
>
> Both, please. I am flooded with data but having more direct sources are always great and helpful.
>
> Thanks!
>
> > > On May 2, 2018 at 3:25 PM "markus baur baur@chello.at [spacesettlers]" wrote:
> >
> > do you mean my comparison of ground to space based solar cell yield? or
> > the data on transmission looses?
> >
> > servus
> >
> > markus
> >
> > Am 02.05.2018 um 21:00 schrieb Robert Smith robert@... [spacesettlers]:
> > > Do you have a pointer to a source of data? Thanks!
> > >
> > >
> > >> On May 2, 2018 at 1:47 PM "markus baur baur@... [spacesettlers]"
> > >> wrote:
> > >>
> > >> Am 02.05.2018 um 18:30 schrieb wlm_efn@... [spacesettlers]:
> > >> > Transmission and conversion losses are on the order of 50 percent
> > >> total. So,
> > >> > in real power delivered to the ground it's 2 to 2.5 times..
> > >>
> > >> that bad? i thought they had improved it in the meantime
> > >>
> > >> this makes the economics case for SPS much worse
> > >>
> > >> servus
> > >>
> > >> markus
> > >>
> > >> >
> > >> > > So the potential revenue per area is about 4 or 5 times that of a
> > >> > ground based
> > >> > > cell
> > >> >
> > >> > > Add to that that a space based solar cell will possibly have a lower
> > >> > life time
> > >> > > (ground based cell today often have a 25 year power warranty) due
> > >> to the
> > >> > > harsher environment.
> > >> >
> > >> > > Additionally: the necessity of the rectenna
> > >>
> > >> --
> > >> markus baur SCA: markus von brixlegg
> > >> schluesselgasse 3/5 tel: +43 - (0)1 - 50 40 662
> > >> a-1040 wien email: baur@...
> > >> austria/europe icbm: 4811'39"N; 1622'06"E
> > >>
> > >> a portrait: http://www.abcgallery.com/A/arcimboldo/arcimboldo9.html
> > >>
> > >> "der Markus?? .... das ist der mit dem Buch..."
> > >>
> > >
> > >
> > >
> > > Robert Smith
> > > Space Studies Institute
> > > web: http://www.ssi.org
> > > the space studies institute is a 501(c)(3) non profit organization
> > > founded in 1977 to promote the education and engineering
> > > for the Human Breakout Into Space
> > >
> > >
> >
> > --
> > markus baur SCA: markus von brixlegg
> > schluesselgasse 3/5 tel: +43 - (0)1 - 50 40 662
> > a-1040 wien email: baur@...
> > austria/europe icbm: 4811'39"N; 1622'06"E
> >
> > a portrait: http://www.abcgallery.com/A/arcimboldo/arcimboldo9.html
> >
> > "der Markus?? .... das ist der mit dem Buch..."
> >
> > >
>
> > >
> > >
>
> Robert Smith
> Space Studies Institute
> web:http://www.ssi.org/
> the space studies institute is a 501(c)(3) non profit organization
> founded in 1977 to promote the education and engineering
> for the Human Breakout Into Space
>

>

my numbers of a ground based pv cell producing about 1/4 to 1/5 of the same cell based in space is my own - it is easy to derive, but I admit that it is a guesstimate:
a pv cell based on GEO (that is important - LEO would be very different in this regards) basically has sunlight 24 hours per day (yes - there are very short exceptions twice a year, but we will ignore those)
a ground based pv cell does not have a luxury
first of all on average there are 12 hours of night per day - giving reduction factor of 0,5
I am assuming a one axis sun tracker here - a two axis tracker would be a bit better but has other detriments, a fixed installation would be worse - but that means that power output will be lower at the times - how much lower is hard to estimate and would need a proper analysis - but my guestimate is 0,25
in a good location the atmosphere will reduce power only slightly, but there will be a reduction - this reduction will be slight at noon, but much larger at sunset and sunrise, when the sun has to pass through a lot more atmosphere - another guestimate is 0,25
finally there will be clouds, dust on the pv cells and other obscuring factors ... lets say 0,3
1*(1-0,5)*(1-0,25)*(1-0,25)*(1-0,3) = 0,197 (or about 1/5)
But as I said I am not sure that this power production advantage of a GEO bases pv cell can make up for the much higher installation and maintenance costs, the transmission losses and the cost of the ground rectenna - but that is an economic analysis that has many more fudge factors in it than my little piece above
servus
markus
"Robert Smith robert@... [spacesettlers]" hat am 2. Mai 2018 um 21:39 geschrieben:

Yes :)
Both, please. I am flooded with data but having more direct sources are always great and helpful.
Thanks!
On May 2, 2018 at 3:25 PM "markus baur baur@... [spacesettlers]" wrote:

do you mean my comparison of ground to space based solar cell yield? or
the data on transmission looses?
servus
markus
Am 02.05.2018 um 21:00 schrieb Robert Smith robert@... [spacesettlers]:
> Do you have a pointer to a source of data? Thanks!
>
>> On May 2, 2018 at 1:47 PM "markus baur baur@... [spacesettlers]"
>> wrote:
>>
>> Am 02.05.2018 um 18:30 schrieb wlm_efn@... [spacesettlers]:
>> > Transmission and conversion losses are on the order of 50 percent
>> total. So,
>> > in real power delivered to the ground it's 2 to 2.5 times..
>>
>> that bad? i thought they had improved it in the meantime
>>
>> this makes the economics case for SPS much worse
>>
>> servus
>>
>> markus
>>
>> >
>> > > So the potential revenue per area is about 4 or 5 times that of a
>> > ground based
>> > > cell
>> >
>> > > Add to that that a space based solar cell will possibly have a lower
>> > life time
>> > > (ground based cell today often have a 25 year power warranty) due
>> to the
>> > > harsher environment.
>> >
>> > > Additionally: the necessity of the rectenna
>>
>> --
>> markus baur SCA: markus von brixlegg
>> schluesselgasse 3/5 tel: +43 - (0)1 - 50 40 662
>> a-1040 wien email: baur@chello.at
>> austria/europe icbm: 48°11'39"N; 16°22'06"E
>>
>> a portrait: http://www.abcgallery.com/A/arcimboldo/arcimboldo9.html
>>
>> "der Markus?? .... das ist der mit dem Buch..."
>>
>
> Robert Smith
> Space Studies Institute
> web: http://www.ssi.org
> the space studies institute is a 501(c)(3) non profit organization
> founded in 1977 to promote the education and engineering
> for the Human Breakout Into Space
>
markus baur SCA: markus von brixlegg
schluesselgasse 3/5 tel: +43 - (0)1 - 50 40 662
a-1040 wien email: baur@...
austria/europe icbm: 48°11'39"N; 16°22'06"E
a portrait: http://www.abcgallery.com/A/arcimboldo/arcimboldo9.html
"der Markus?? .... das ist der mit dem Buch..."