Graphene Supercapacitor

If you want to solve the energy problems and global warming then liquid thorium salt
reactors followed by fusion reactors are the way to go (with wind, solar, tide, geothermal
ect in their proper measure).

Originally posted by sonhouse
That is what I mean, the sun is too low in the sky to do much power collecting in the morning and twilight hours so you get from say 9 am to 4 pm ish to gather the most power. So that combined with the fact you can't get ANY power after sundown unless you can convert the ten percent of solar energy in the form of neutrino's which isn't happening any time in done, it is just very expensive at this stage of the game both for PV cells and for storage.

doesn't the quote I got from the net:

“...The radiation reaching the Earth's surface is therefore on average 198 W/m2, i.e. 58% of the radiation intercepted by the Earth...."

take into account the fact that half of the time it is night and the angle of the sun is often low in the sky?
So that a solar panel laid horizontally i.e. flat would be, on average, exposed to an average of 198 W/m2 over the 24 hour period? That is my interpretation of what the site said.

note that I have about 4 times the roof area than ~12 square metres so I can have ~4 times that solar panel area if needed.
Plus I have the south side of the house and the roof of the shed so could increase that easily by a further ~50% if needed so thats ~6 times the 12 square metre solar panel area if needed.

Originally posted by humy
doesn't the quote I got from the net:

“...The radiation reaching the Earth's surface is therefore on average 198 W/m2, i.e. 58% of the radiation intercepted by the Earth...."

take into account the fact that half of the time it is night and the angle of the sun is often low in the sky?
So that a solar panel laid horizontally i.e. flat would be, on averag ...[text shortened]... by a further ~50% if needed so thats ~6 times the 12 square metre solar panel area if needed.

Your missing that most of the inhabited parts of the earth are disproportionately away from
the equatorial regions.

Thus placing solar panels on peoples roofs would get significantly less that the average energy
falling on the Earth's surface.

Putting solar panels on the side of the roof facing away from the sun is a total and utter waste
of money and of the resources and energy needed to manufacture them.

In terms of efficiency and practicality you are better off using large solar thermal arrays in hot
dry regions and using long distance DC (or superconducting) power lines to carry the energy
to where it is needed.


Or as I said, use nuclear.

Originally posted by googlefudge
Your missing that most of the inhabited parts of the earth are disproportionately away from
the equatorial regions.

Thus placing solar panels on peoples roofs would get significantly less that the average energy
falling on the Earth's surface.

Putting solar panels on the side of the roof facing away from the sun is a total and utter waste
of ...[text shortened]... cting) power lines to carry the energy
to where it is needed.


Or as I said, use nuclear.

Your missing that most of the inhabited parts of the earth are disproportionately away from
the equatorial regions.

this would only make a difference if a few percent.

Putting solar panels on the side of the roof facing away from the sun is a total and utter waste
of money and of the resources and energy needed to manufacture them.

not if we have run out of suitable horizontal spaces / roof spaces first.
On the south side walls in the northern hemisphere significant amounts of solar energy fall on them.

In terms of efficiency and practicality you are better off using large solar thermal arrays in hot
dry regions and using long distance DC (or superconducting) power lines to carry the energy
to where it is needed.

possibly; if only the politicians were not so stupid to fail to arrange something intelligent as this.

Or as I said, use nuclear.

I am all for nuclear power. My best guess is that it would be generally quicker to replace fossil fuel power with solar, wind etc than it would be to replace it with nuclear power. The energy storage issue with wind solar etc is no longer a significant issue for economically viable off-the-grid storage has already been researched and discovered -all it needs is a bit of political will to apply it.

Originally posted by humy

Your missing that most of the inhabited parts of the earth are disproportionately away from
the equatorial regions.

this would only make a difference if a few percent.

[quote] Putting solar panels on the side of the roof facing away from the sun is a total and utter waste
of money and of the resources and energy needed to manufacture ...[text shortened]... has already been researched and discovered -all it needs is a bit of political will to apply it.

this would only make a difference if a few percent.

Whoa there, this is really not a trivial issue, solar energy levels change significantly with latitude.
This is not a case of a 'few percent' difference. (and this is even before you factor in the increased
cloud cover you find at higher latitudes.

I am all for nuclear power. My best guess is that it would be generally quicker to replace fossil fuel power
with solar, wind etc than it would be to replace it with nuclear power. The energy storage issue with wind solar
etc is no longer a significant issue for economically viable off-the-grid storage has already been researched and
discovered -all it needs is a bit of political will to apply it.

Well your best guess needs some work then.

Have a look at the number of wind turbines and solar panels needed to replace the core grid power produced
by nuclear and fossil fuel power stations compared to the current number of solar panels and wind turbines that
have been produced to date. The increase needed is vast, which has it's own environmental issues.

And the energy storage issue is not a done and dusted one, and energy storage is expensive, the more you
need the more cost is associated with the unreliable renewable sources.
Which means you rapidly reach a point where more renewables costs more than more nuclear.

Making up the core network with Liquid thorium salt reactors [as a stop gap till fusion] with renewables making
up say 20~40% of the total would be faster, cheaper, and more reliable than trying to go for full fossil fuel
replacement with renewables.

Originally posted by humy
doesn't the quote I got from the net:

“...The radiation reaching the Earth's surface is therefore on average 198 W/m2, i.e. 58% of the radiation intercepted by the Earth...."

take into account the fact that half of the time it is night and the angle of the sun is often low in the sky?
So that a solar panel laid horizontally i.e. flat would be, on averag ...[text shortened]... by a further ~50% if needed so thats ~6 times the 12 square metre solar panel area if needed.

But that roughly 200 watts per square meter is what hits the roof. Now you have to factor in the efficiency of the PV cells, you would be lucky to get 20% cells, so now you have 40 watts per square meter out the door.

So your 50 square meters is going to give you 2000 watts max. 7 meters by 7 meters or 14 meters by 3.5 meters, about 1000 square feet, that is called 10 squares by American roofers, 100 square feet = 1 square for them (my dad was a roofer so I got a lot of that🙂 which is = to your 50 square meters. Ten squares is the size roof of a smallish house here.

A lot of houses here have 20 squares, or 100 square meters, still, even if the total area was filled with 20% PV cells, you have 20,000 watts hitting the roof but only 4000 watts out the door, and divide that by three you get maybe 1500 watts 24/7 after you install sufficient electrical storage capacity, whatever technology you use for that, could be anything from pumping air into a tank, forcing water uphill, electric batteries, supercapacitors, flywheels in vacuum, whatever, you will need something like that to get your 1500 watts continuous energy.

There is another way for that though. Here in the US a lot of power companies allow power grids to the house to be two way, that is to say, you can send power back out the wires and sell your surplus energy to the energy companies and in return, your power is partially or totally paid for.

It is tricky to do that though because there are safety concerns, if you are sending power back up the line and an electrical worker is on the pole outside and he has to do work on your transformer, and he does not know you are powering back into the line, he could get shocked if he just disconnects the transformer from the power mains and thinking he has no energy to deal with, starts touching wires coming from your house and gets zapped.

So there has to be special switching gear and all the electrical workers have to be trained on how to deal with energy coming back up the pipe that normally has energy only flowing one way, from the transformer to your house. Transformers can act in reverse which makes it an easy thing to send power back up the pole but the next block down can still be powered up and your power sending up the line can effect workers a mile away so everyone has to be onboard with such technology but it sure can solve the energy storage problem for the local user.

It might even be a nice money maker for a mom and pop power company with a few hundred square meters under PV's, say you have 500 square meters and the average is indeed 200 watts per square meter, now you are talking 100,000 watts reaching the ground and 20,000 watts out the door. Still that is only 7000 watts on a 24/7 basis, and at say, 10 cents per Kwhr, so you end up making about 6000 dollars per year income. However at this stage of the game, that 500 square meters would cost a lot more than an average person could borrow for so it would not be at this point in time a good business model. Even the best systems price wise are something like a dollar a watt so 20,000 bucks for 6000 dollars a year, would take 4 years to just pay back the investment.

Originally posted by sonhouse
But that roughly 200 watts per square meter is what hits the roof. Now you have to factor in the efficiency of the PV cells, you would be lucky to get 20% cells, so now you have 40 watts per square meter out the door.

So your 50 square meters is going to give you 2000 watts max. 7 meters by 7 meters or 14 meters by 3.5 meters, about 1000 square feet, th tt so 20,000 bucks for 6000 dollars a year, would take 4 years to just pay back the investment.

And then factor in latitude, location factors, weather factors, and potential availability of other energy
sources like wind or geothermal which could well in some areas be much more cost effective.

Take Iceland for example.

It's far more cost effective and practical for people in Iceland to use geothermal than photovoltaic.

Here in the UK we have far more readily available wind energy than solar, due to our high latitude and
weather.


EDIT: and I forgot, you also need to factor in the angle of the solar panels to th sun which effects their
power output per unit area.
Ideally they need to be pointing directly at the sun, any other angle and you get less than the numbers
you are using.

So if you are placing them on a pitched roof then you they don't track the sun and thus get significantly
less throughout the day than you are figuring.
Also you have to consider that most pitched roofs only have half the roof pointing one way and the other
half pointing the opposite direction. Which means that at best only half the roof is pointing even vaguely
at the sun (assuming that you are not directly on the equator with the sun directly overhead)

Originally posted by sonhouse
That is what I mean, the sun is too low in the sky to do much power collecting in the morning and twilight hours so you get from say 9 am to 4 pm ish to gather the most power. So that combined with the fact you can't get ANY power after sundown unless you can convert the ten percent of solar energy in the form of neutrino's which isn't happening any time in ...[text shortened]... done, it is just very expensive at this stage of the game both for PV cells and for storage.

It took me some time to find this but:

http://www.contemporaryenergy.co.uk/solarmap.htm

-This is the yearly total for horizontal solar irradiation at ground level thus this takes into account cloud blocking radiation and all the angles of the sun above the horizon and the night periods.
-at my location it is just a bit above 1000 kWh/m2 per year. Lets call that 1000.
that works out as 1000/365 ~= 2.74 kWh/m2 per 24 hour period on average.
That means if my solar panels are just 17% energy efficient, each m2 solar panel area should on average produce ~0.4658 kWh/m2 per 24 hour period.

so, on average, the area of solar panel I would need to fully charge a 10 kWhr battery/ultracap for an electric car once each day would be:

10 kWhr / ( 0.4658 kWh/m2 ) = 21m2 which works out as just one over 4 by 5 meter area.

my small roof area is more than double that so I DO have enough roof area for this.

However, the same web link shows that the daily mid-winter average horizontal solar irradiation at ground level at my location is roughly 5 times less than the daily average for the whole year. I worked out that, on average, I would not have enough panel roof area on average for this at THAT time of year. But even here the south-facing wall will come to the rescue. In mid-winter, the sun is set low in the sky and covering my south-facing wall with solar panels, even taking into account I must not cover the windows and door, will about double the solar power I could get from the panels which makes it up to enough -so, again, that's good enough for the average day even for that worst time of year! And that is not even taking into account that solar panels will get more efficient in the next few years.

Originally posted by humy
my small roof area is more than double that so I DO have enough roof area for this.

But not enough money (which is why you haven't done it already).
It also would only charge that one battery, your house would still need other sources of power for everything else and presumably your power requirements go up in winter (when solar is at its lowest).
Having said that I fully support solar power (coming from Zambia, where the sun is abundant).
Here in Cape Town there is quite a lot of wind, and I think that would probably be more viable. I have noticed that the cameras along the highways each have a little solar panel and a wind turbine.

Originally posted by twhitehead
But not enough money (which is why you haven't done it already).
It also would only charge that one battery, your house would still need other sources of power for everything else and presumably your power requirements go up in winter (when solar is at its lowest).
Having said that I fully support solar power (coming from Zambia, where the sun is abunda ...[text shortened]... noticed that the cameras along the highways each have a little solar panel and a wind turbine.

But not enough money (which is why you haven't done it already).

true. I don't even have enough money for a car let alone that expensive setup.

It also would only charge that one battery, your house would still need other sources of power for everything else and presumably your power requirements go up in winter (when solar is at its lowest).

true. Mind you, the winters here are quite windy where I am. Perhaps a wing turbine? ( yet more cost that I cannot afford )

Originally posted by humy
http://www.sciencedaily.com/releases/2012/03/120315152524.htm

-this could replace batteries because it has several advantages over batteries.

Interesting article

Originally posted by ChessPraxis
Interesting article

The caveat for that is the power density is a lot lower than batteries, so its chief use would be to convert a smaller steady supply of energy into one that can be used in bursts like accelerating from a stop or going up a steep hill. That can make electric cars more efficient combined with regenerative braking. BTW, regenerative braking was first used on cars in the year 1911. It was only the advent of the gasoline engine that killed that technology 100 years ago. There was plenty of energy available in those early cars for running around town for groceries and such.

Originally posted by humy
Mind you, the winters here are quite windy where I am. Perhaps a wing turbine? ( yet more cost that I cannot afford )

Both solar and wind are more efficient for larger installations, so ideally you need to get together with your whole neighbourhood and install a large wind turbine. You then feed it directly into the municipal electricity supply and get them to discount it off your bills. Or better yet, you try to persuade the government to encourage green energy in general.

This is wondering off-topic slightly but I was looking for alternatives to ultracaps for off-the-grid stationary energy storage and I found this:

http://www.orionsarm.com/eg-article/48571ab1cce3c

A superconducting storage device made of normal matter can carry as much as 50 MJ/kg. can store electrical energy indefinitely, and are capable of lossless energy transmission. Note that safety considerations generally limit the effective specific energy of such devices to about 25MJ/kg

25MJ/kg ? This compares with petrol which has a specific energy of about 47MJ/kg -so that makes it about half of petrol. Is the potential specific energy for superconducting storage device really that high or is this link talking nonsense? -if it is that high then if we can make a room-temperature superconductor then I think we have got the energy storage problem just about solved.

Originally posted by humy
This is wondering off-topic slightly but I was looking for alternatives to ultracaps for off-the-grid stationary energy storage and I found this:

http://www.orionsarm.com/eg-article/48571ab1cce3c

[quote] A superconducting storage device made of normal matter can carry as much as 50 MJ/kg. can store electrical energy indefinitely, and are capable of lossle ...[text shortened]... emperature superconductor then I think we have got the energy storage problem just about solved.

Well sure but if a frog had wings he wouldn't have bumped his butt as my old man used to say.

I think such technologies as fusion power, hot or cold, will be working long before room temperature superconductors come along if ever.

One problem with superconducting energy storage rings is what happens if the rings lose their superconductivity.

What happens is you get an explosion. Think about petrol, 47 or so Mj/kg. Try dropping one kg of petrol on a fire when its in a can and see what happens.

One of the reasons superconductive rings are not popular now (they have done it decades ago) is the need for a large ring of copper or some other good electrical conductor around the superconductors so if the worse happens, the copper can absorb the energy and maybe just heat up and melt but not explode.

So as it stands now, maybe you get half the power density of gasoline, all well and good, but when you include the refrigeration that can take them down to around 77 K, the boiling point of liquid nitrogen, where there are a lot of new superconductors that work at that temperature, you have to also include just about the same or greater weight of copper around it as a backup in case you lose refrigeration, at our present level of technology. All told, such a system would probably be a lot more expensive than lithium ion, liquid sulphur batteries or whatever the latest technology in storage is and a lot bigger and a lot heavier and would take energy to run to boot (for the refrigeration)

Such a technology would HAVE to wait for room temperature superconductors to make any kind of sense in transportation.

If it came around, it would lead to a great replacement of all those ugly and terribly expensive overhead million volt power lines looping around the world.

They could be replaced with an underground cable that would carry more energy and could be just buried a few feet underground and eliminate all those hundreds of thousands of very expensive steel and ceramic insulated towers. Those towers lose about 10 percent of its energy going a thousand km and underground room temp superconductors would lose almost nothing so it would be like adding ten percent to our power generation capability for free without building another power plant.

But like I said, don't hold your breath for that technology any time soon, maybe not even in the 21st century, maybe that will be relegated to the super science that will presumably show up a hundred years from now when quantum computers and ultra super powerful classical computers can figure out how to make room temp supercunductors and throw in super strong cables to make the space elevator a reality so we don't have to launch ten thousand ton rockets to get men to the moon and such, but instead ride an elevator a couple of weeks right up to orbital heights.