solar panels. heres a little research ive been doing

[shootthebandit]

So I had a little thought the other day. How much solar energy would you need to power the entire earth and how much space would be taken up? So ive done some maths

My first thing to look at was the power and size of one panel but this deemed difficult to find and domestic panels will not be powerful enough so I found this article [http://www.extremetech.com/extreme/188328-californias-new-solar-power-plant-is-actually-a-death-ray-thats-incinerating-birds-mid-flight]. The article states that there is a huge solar array in California which spans 1600 hectares. A quick conversion and thats 1.6×10[sup]7[/sup]sqm. It also says that it generates 1,000 gigawatt hours every year or 1 Terawatt hour (Twh). According to this website [http://yearbook.enerdata.net/electricity-domestic-consumption-data-by-region.html] we used 20000 twh in 2013 so we would need 20,000 of these arrays.

Now remember this one array is 1.6×10[sup]7[/sup]sqm so if we multiply that by 20,000 then we need a total square meterage of 3.2×10[sup]11[/sup]. I then found out that the sahara desert is 9.4×10[sup]12[/sup]sqm [http://en.m.wikipedia.org/wiki/List_of_deserts_by_area]

Divide the area of the sahara by the area required and we can fit enough solar panels to run the entire earth in 1/30th the size of the sahara dessert.

N.b. This is just a bit of research ive been doing for myself. It wouldnt exactly work that way because you'd need miles and miles of cabling that you would get a lot of loss through. In pratice its a bit more complicated but I thought it was just a nice little food for thought to think about

Edit: To put this into perspective. This is an area about the size of the UK/Ireland combined

 

[Batou667]

To determine whether it'd actually be energy efficient we'd also need to factor in the initial energy outlay in manufacturing, transporting and installing all of those panels, plus any maintenance they'd need over their lifetimes. I haven't checked up on the subject in a while but IIRC solar cells were running at a net efficiency of well under 1 and were only used on spacecraft because they're lighter than solid or liquid fuel. I'm not sure whether the technology has improved and they run at a rate of >1 yet.

But in theory, this kind of large-scale renewable energy farming in unpopulated areas is exactly what we need.

 

[shootthebandit]

To determine whether it'd actually be energy efficient we'd also need to factor in the initial energy outlay in manufacturing, transporting and installing all of those panels, plus any maintenance they'd need over their lifetimes. I haven't checked up on the subject in a while but IIRC solar cells were running at a net efficiency of well under 1 and were only used on spacecraft because they're lighter than solid or liquid fuel. I'm not sure whether the technology has improved and they run at a rate of >1 yet.

But in theory, this kind of large-scale renewable energy farming in unpopulated areas is exactly what we need.

Of course there are thousands of other factors. This is just the simplest level of maths. It would take me years to actually work out taking every factor into account

The solar roads seem like a good idea too

 

[Thaluikhain]

As well as distribution, there's also storage. Currently, there aren't any great ways of storing power, though this is something people are of course looking into.

However, it'd be fine for things that you didn't need to run all the time. If you had a factory or plant that only ran during the day time when the sun was out, for example, and you just accepted not producing anything the rest of the time.

 

[shootthebandit]

As well as distribution, there's also storage. Currently, there aren't any great ways of storing power, though this is something people are of course looking into.

However, it'd be fine for things that you didn't need to run all the time. If you had a factory or plant that only ran during the day time when the sun was out, for example, and you just accepted not producing anything the rest of the time.

You'd also need some huge ass transformers and inverters to make the power the correct phase and voltage etc

 

[Thaluikhain]

As well as distribution, there's also storage. Currently, there aren't any great ways of storing power, though this is something people are of course looking into.

However, it'd be fine for things that you didn't need to run all the time. If you had a factory or plant that only ran during the day time when the sun was out, for example, and you just accepted not producing anything the rest of the time.

You'd also need some huge ass transformers and inverters to make the power the correct phase and voltage etc

Well, yes, but why any more than any other form of generating power?

 

[shootthebandit]

As well as distribution, there's also storage. Currently, there aren't any great ways of storing power, though this is something people are of course looking into.

However, it'd be fine for things that you didn't need to run all the time. If you had a factory or plant that only ran during the day time when the sun was out, for example, and you just accepted not producing anything the rest of the time.

You'd also need some huge ass transformers and inverters to make the power the correct phase and voltage etc

Well, yes, but why any more than any other form of generating power?

Fossil power stations generate AC where as your solar panels generate DC so you need an inverter or in this case several huge ass inverters and probably some sort of battery to hold the charge. You'll probably need huge transformers but like you said thats no different to fossil power

 

[OneCatch]

Solar arrays certainly are more efficient that photovoltaics - they require simpler raw materials and less manufacturing, and I think that's the way to go with renewables. There's no point in using some stupidly overengineered renewable generator if it uses huge amounts of finite materials and requires a lot of energy to manufacture.
Make them as simple as possible, with simple construction techniques, simple materials, and simple maintenance requirements. (Though that's also why I think the solar roadways proposal is utterly absurd [http://jalopnik.com/why-the-solar-roadway-is-a-terrible-idea-1582519375]). Tidal power, solar arrays, hydropower, arguably wind are, depending on scale, efficient and have low material costs compared to their lifetime production.

However it's worth pointing out that arrays on this scale are seen as an ecological disaster by some because they incinerate [http://metro.co.uk/2014/08/19/birds-are-bursting-into-flames-over-the-mojave-desert-and-heres-why-4838795/] anything which strays into the field.
That could potentially have serious impacts upon local bird populations, not to mention a lot of migratory birds whose migration routes often pass over the equatorial areas where one would want to build these things for maximum efficiency.

As Thal said, storage is the main issue if you're envisaging a global network. Unless you're going to build enough of these things along the equator that the ones in sunlight at any one time can provide an adequate amount of power you need some way of storing energy. All will involve massive loss, and many are ecologically unsound on a large scale.
Not to mention various state concerns - for example those that host the solar farms cutting off power as a diplomatic tool for example, or the major powers meddling in said areas to receive preferential treatment. Look at the way that the Nile river has been fought over by the countries it runs through for a taster of the kinds of problems which could develop - shared resources are always a point of contention.


The other issue is that I'm not sure a centralised network is the way to go in developing areas. The trend in many developing countries is small-scale local energy generation - in kind of the same way that mobile (cell) phone uptake is incredibly popular in central Africa, where outside of the major cities they've often bypassed the 'landline era' altogether because landlines simply aren't cost effective.
It might be that this will change as energy consumption and population increases in these areas but it's worth considering. Not everywhere uses Western-style energy networks.

 

[Thaluikhain]

Fossil power stations generate AC where as your solar panels generate DC so you need an inverter or in this case several huge ass inverters and probably some sort of battery to hold the charge.

Ah, yes, I had overlooked that. Though, if you are using sunlight to boil water to drive turbines, that's not an issue.

 

[shootthebandit]

Fossil power stations generate AC where as your solar panels generate DC so you need an inverter or in this case several huge ass inverters and probably some sort of battery to hold the charge.

Ah, yes, I had overlooked that. Though, if you are using sunlight to boil water to drive turbines, that's not an issue.

That would probably be a lot more inefficient. Id need to research it but Id imagine you'get a lot of loss as the heat is radiated in the water

Edit: I just realised the escapist posted an article on this earlier today. They mentioned that it has steam generators. I guess its more efficient because solar cells are pretty weak. Its just light reflected onto a tower that generates insane amounts of heat to boil steam. The design is so simple

Solar arrays certainly are more efficient that photovoltaics - they require simpler raw materials and less manufacturing, and I think that's the way to go with renewables. There's no point in using some stupidly overengineered renewable generator if it uses huge amounts of finite materials and requires a lot of energy to manufacture.
Make them as simple as possible, with simple construction techniques, simple materials, and simple maintenance requirements. (Though that's also why I think the solar roadways proposal is utterly absurd [http://jalopnik.com/why-the-solar-roadway-is-a-terrible-idea-1582519375]). Tidal power, solar arrays, hydropower, arguably wind are, depending on scale, efficient and have low material costs compared to their lifetime production.

You are correct. You need to factor in build and maintenance. There was a phase a while ago about hydrogen fuel but the process of extracting hydrogen has a larger carbon footprint than fossil fuels

However it's worth pointing out that arrays on this scale are seen as an ecological disaster by some because they incinerate [http://metro.co.uk/2014/08/19/birds-are-bursting-into-flames-over-the-mojave-desert-and-heres-why-4838795/] anything which strays into the field.
That could potentially have serious impacts upon local bird populations, not to mention a lot of migratory birds whose migration routes often pass over the equatorial areas where one would want to build these things for maximum efficiency.

If you read the links I posted one of them was about the birds getting fried

As Thal said, storage is the main issue if you're envisaging a global network. Unless you're going to build enough of these things along the equator that the ones in sunlight at any one time can provide an adequate amount of power you need some way of storing energy. All will involve massive loss, and many are ecologically unsound on a large scale.
Not to mention various state concerns - for example those that host the solar farms cutting off power as a diplomatic tool for example, or the major powers meddling in said areas to receive preferential treatment. Look at the way that the Nile river has been fought over by the countries it runs through for a taster of the kinds of problems which could develop - shared resources are always a point of contention.

Thats a good point however my point wasnt to have it in one place. I was saying if it was a single solar farm for the entire world how big would it be. My main point was to see if it was viable and I think an area the size of the UK and ireland is pretty feasible if spread out over the equator

 

[Flutterguy]

The project I am on has over 500 panels. They are considered the least efficient on the market, and have one of the shortest life-spans on the market as well.

Now why would a government contracted job decide on these panels?

 

[gigastar]

The project I am on has over 500 panels. They are considered the least efficient on the market, and have one of the shortest life-spans on the market as well.

Now why would a government contracted job decide on these panels?

I can think of two reasons.

One, an election is coming up and someone wants to buy face with his shiny new solar power station.

Two, whoever commisioned the job (or someone working for him) is a fuckwit who didnt do the research.

There could be embezzlement involved, but i doubt anyone in a respectable developed country could get away with it for long.

 

[shootthebandit]

The Sahara is really sandy IIRC (is it also windy?). That's pretty bad for PV because in order to work well they have to be pretty clean.

These are not PV (which I initially thought). They are mirrors which reflect the light (and heat) to boil steam to drive a turbine. I initially thought they were DC PV panels but I was wrong

 

[OneCatch]

Fair enough, though I'd have thought the impact would be similar - dirty mirrors just don't reflect the same amount of light (and therefore heat), though if the surfaces aren't horizontal I guess the issue would be reduced. I've only worked on books about PV though, don't think I've ever looked at this.

Back on PV though, I believe it can be combined with solar heating of water for use in district heating systems, though I think those are pretty rare in the UK.

TBH I'd be worried about it being too windy - not so much because dust or sand would settle on the mirrors, but more because they'd become pitted and corroded with time, reducing reflectivity. But I'd imagine that replacing mirrors would probably be less expensive than the costs of maintaining most other types of power station.

You are correct. You need to factor in build and maintenance. There was a phase a while ago about hydrogen fuel but the process of extracting hydrogen has a larger carbon footprint than fossil fuels

Exactly - this issue is one of the reasons that storage is such a problem. Low-friction dynamos or capacitors or batteries have relatively massive production costs - in terms of energy use and/or relatively rare raw materials.

However it's worth pointing out that arrays on this scale are seen as an ecological disaster by some because they incinerate [http://metro.co.uk/2014/08/19/birds-are-bursting-into-flames-over-the-mojave-desert-and-heres-why-4838795/] anything which strays into the field.
That could potentially have serious impacts upon local bird populations, not to mention a lot of migratory birds whose migration routes often pass over the equatorial areas where one would want to build these things for maximum efficiency.

If you read the links I posted one of them was about the birds getting fried

Sure, I was just pointing out the migratory angle.

As Thal said, storage is the main issue if you're envisaging a global network. Unless you're going to build enough of these things along the equator that the ones in sunlight at any one time can provide an adequate amount of power you need some way of storing energy. All will involve massive loss, and many are ecologically unsound on a large scale.
Not to mention various state concerns - for example those that host the solar farms cutting off power as a diplomatic tool for example, or the major powers meddling in said areas to receive preferential treatment. Look at the way that the Nile river has been fought over by the countries it runs through for a taster of the kinds of problems which could develop - shared resources are always a point of contention.

Thats a good point however my point wasnt to have it in one place. I was saying if it was a single solar farm for the entire world how big would it be. My main point was to see if it was viable and I think an area the size of the UK and ireland is pretty feasible if spread out over the equator

Fair enough - I'd be extremely reluctant to rely on a single power source generally, and I'm still sticking to my point about centralised grids vs decentralised autonomous generation.
But including this as part of an increasingly renewable solution along with large-scale tidal certainly seems feasible on the face of it. And it could be a significant source of wealth for poorer, sparsely populated nations as well.

 

[loc978]

The project I am on has over 500 panels. They are considered the least efficient on the market, and have one of the shortest life-spans on the market as well.

Now why would a government contracted job decide on these panels?

I can think of two reasons.

One, an election is coming up and someone wants to buy face with his shiny new solar power station.

Two, whoever commisioned the job (or someone working for him) is a fuckwit who didnt do the research.

There could be embezzlement involved, but i doubt anyone in a respectable developed country could get away with it for long.

Three, the politician in charge is giving a contract to the company that makes or installs them... and in return he gets a lobbying position with them when his term is up.

Discussion value:
In addressing the storage problem, there are a few new battery technologies in the works.The only one I know of that's designed for infrastructure-level storage goes by the catchy name of "liquid metal batteries". Not inaccurate, but "molten metal batteries" would be more honest: http://www.ambri.com/technology/ we should see how it pans out fairly soon.

 

[shootthebandit]

large-scale tidal certainly seems feasible on the face of it. And it could be a significant source of wealth for poorer, sparsely populated nations as well.

Spoiler: Tidal is such an underrated power which is incredibly reliable and renewable

 

[Ylla]

The government in my country taxes the sun and the wind. So when you install a solar panel in your house, a CFE representative comes and installs an electricity meter, so you can start paying for living in this great fucked up country called Mexico.
I had to get it off.

 

[Zantos]

The government in my country taxes the sun and the wind. So when you install a solar panel in your house, a CFE representative comes and installs an electricity meter, so you can start paying for living in this great fucked up country called Mexico.
I had to get it off.

That's totally ridiculous. In Britain not only do you own the energy you produce using renewable methods, but if you produce more than you need you can actually sell the excess to the country, although there are some rules as to who can sell and how much you can earn from it these tend not to affect people with a panel and/or a turbine on their house.

Personally I think that we need to make PV cells more distributable and less expensive per panel, so although your panels might not be optimally efficient (sorry Shockley and/or Queisser) you can install them or even paint them on any surface that has access to sunlight. Although it's early stages this field has shown good results so far, and I will be jumping on that bandwagon at the next opportunity.