Why can't we get all of our energy from the sun?

Question

Why can't we get all of our energy from the sun?

Answer 1

This is precisely what I want to know. We have a basic 3br house facing north, plenty of roof space but to solar power our smallish home would cost in excess of $25,000. This is in Australia where the sun shines 90% of the time. The few times the Gov. subsidised things like solar hot water systems the prices rose steeply still making it too expensive. It all comes down to the GAD and it stinks. Even wind power could be used more extensively but for people whinging about the noise they make.

Answer 2

We can't get all our energy from the sun because we don't have the technology to cheaply and efficiently store large amounts of solar energy.

A larger amount of energy (say 30%) may be achievable (provided from the sun) but money is the sole focus of everything these days, so fossil fuels will continue to dominate.

Answer 3

its really expensive and the sun isn't always out, how would u get energy at night?

Answer 4

We could if it wasn't so expensive!!!  And, a very good idea unless your in Alaska!

Answer 5

If you mean our energy to move cars and power other electronic devices, then the answer is simple:  Much of the sun's energy is reflected back out by the ozone layer so that we don't fry like eggs, and the remaining energy isn't enough to power everything we need.  Also, solar panels are fairly expensive.  The energy is also inconsistent, because during certain times of the year we have less sunlight, and weather would also affect energy intake.  That type of unpredictability would be dangerous.  Furthermore, those who live in the far, far north sometimes go very long periods of time without any sunlight at all due to the earth's tilt.  What would they do?  Lastly, although rural areas could benefit hugely from solar panels, densely populated cities and metropolitan areas consume more power than the sun gives off in those areas at any given time.

Answer 6

Right now, a pricey thing to do......+ costly to change from one type to another.

Answer 7

Well, EVER SINGLE form of electromagnetic energy is emitted from the sun.....

Sound energy cannot travel from the sun (because there is no medium)(and very good too, the amount of sound the sun makes IS HUUUUGE!!!!)

And most of the hard and soft x-rays are absorbed in the higher atmosphere.

Only other waves such as light pass through.

Answer 8

Because we haven't found an efficient/cheap way to harness it yet.

Answer 9

Idea:

It's a matter of cost-efficiency, no?

Anyone see an LMT Liquid Mirror Telescope?

Take a decent dish, add a layer of mercury, spin it up, it forms an optically perfect parabola.

Only thing is its axis will only point straight out from earth.

Do the same, but this time with some kind of resin instead of mercury.

Hardens while spinning.

You could make a HUUUGE cheap optical dish to point at sun.

Say 50 feet across, probably thousands of degrees at the secondary.

Steam-turbine.. Sterling.. whatever to convert.

Now you need consistent power, not intermittent, so make a HUUUGE flywheel to store that. power.

Underground, deep, because if this baby ever gets loose, youre talking the stored up energy of a bomb.

This should power a house, no prob, low cost, totally gridless independance.

Heres another upside. Say it's popular, now we've got thousands of telescopes at night.

SETI's gift from God. :)

The cosmic joke? Just about the time we're patting ourselves on the back for being so energy-advanced, we get contacted by extraterrestrials who feel sorry for us cause we're such cave-dwellers when it comes to energy.

We're such a pathetic little third-world-world.

I crack myself up.

Answer 10

Maybe the earth's temp would lower because some of the light and heat would be changed into something else.  Also it could be expensive and old fashined people don't want to change.

Answer 11

We do.... Fossil Fuels contain energy that was once in the sun and harnessed by plants.

Solar Power is too unreliable and expensive. 12% Efficiency on average.

Answer 12

Specially India...., getting energy of sun......throughout the year.

Answer 13

energy type of energy we get is intialy produced from sun. it reaches to us through foodchain.

fossil fuels are also originated from sun. but their rate of production is much lower. so that we have to use it in some non traditional ways .

but they are much more expensive n are noy efficient.

Answer 14

If you want to be about as active as your common variety tree or garden flower, then sure, humans could survive from just the energy of the sun.

In our present form, it's not possible to do this, we use far more energy than we could collect from the sun alone, so we eat meat. It makes us agile and allowed us to climb down from the trees way back when we still had fur.

:-)

Though if you meant doing all the things we do right now, use computers, aircon, industry, and so on, then no, you'd need solar farms spread across thousands of kilometers.

Answer 15

Because we want too much.   We either have to use stored energy from the sun over millions of years (coal, oil...) or completely change our lifestyles at a high financial cost if we want to continue consuming at our current rate.   If people could learn the difference between a need and a want they would be well on their way to a more sustainable and peacefull future.

Answer 16

We didn't have the correct technology to use all the energy and also sunrays comes in ununiform ways.

Answer 17

Efficient energy sources are those that are readilly available at any time for use.  We only get sunlight during the day which limits it's availability making it unreasonable as a primary source for energy.  You can find out more about solar energy by doing a search at the environmental website www.GoElectricNow.com.  I hope this helps.

Answer 18

For the most part, we do.

fossil fuels merely utilize sunlight stored millions of years ago.

nuclear and geothermal are the only sources that DON'T trace back to the sun.

Answer 19

is everyone stupid? we do! were do you think fossil fuels get their energy from? duh! the sun causes weather cycles that pressurize plant based materials (which get their energy to grow from the sun)  from carbon cycles into compacted fuels in different forms....eg oil and coal..

Answer 20

Actually we do - every bit of energy on the planet is originally derived from the sun.

Answer 21

Because we still have a problem with storing energy, battery's simply ain´t efficient enough to store, they need to much service, they are still to expensive, and their capacity is to small.

Answer 22

We can.  However, there is still money to be made from fossil fuels.  

The almighty dollar rules us all.

Answer 23

Sure, the sun is a powerful star and has enough energy to support life but its power is reduced by the time is gets here so it can't power certain types of things.

Answer 24

bc you cant burn sun based things for energy.

like grass

couldnt do it =/

Answer 25

coz, the current methods and technology we have to convery solar energy to electrical energy are not so efficient to achieve even 50 % conversion. and moreover the current technology is too costly to be implemeted as the only source of meeting all our energy requirements.

Answer 26

Well IDK if you mean like body energy or industrial energy. I'm gonna go ahead and decide its industrial.

So far solar panels are very expensive, and the switch to ANY different major energy source would take YEARS! And because the sun is only up part of the day lol, im sure that the amount of energy it would take to power entire cities of millions of people would need solars panels that stretch across too large a space.

However with improved technology they may become more efficient...

Answer 27

The technology to convert and store the energy from the sun is still to ineffiecient and exspencive to make it a viable alternative for most applications.    Better solar pannel and batery technology will change that hough.  It could take a while.

Answer 28

The earth receives about 5kwatt/m^2 of energy per hour from sun.  The surface of the earth is about 5100 million square kilometers (or 5.1E14 square meters).  Therefore, the sun provides the earth with 2,500,000 terawatts per hour.    

At 2006 world oil consumptions rates, crude oil provides consumers with over 6 terawatts per hour.   Thus the sun provides the earth with nearly 400000 times the energy currently provided by crude oil.   In order to replace oil with solar power, one twelve hundredth (0.083%) of the planet would need to be covered by solar panels operating at 100% efficiency.  

http://www.a2dvoices.com/realitycheck/En...

Other consideration would include adjustments for:

Solar cell efficiencies (50% seems like a high estimate)

Available solar units per day (weather, seasons, ...)

Real estate (only thirty percent of the earth is covered by land)

Power distribution to cities.