Solar Energy

Now that scientists can look at events the happen on a femtosecond time scale, they will be able to fully understand how plants convert sunlight into energy. Will this improve our solar energy technology?

Photosynthesis is considered to be 5% efficient.1 Solar photovoltaic panels to convert sunlight to electricity that you can buy are from 8 to 22% efficient.2 In the lab they have gotten up to 42% efficiency.3 Solar thermal panels used to heat hot water are from 60 to 80% efficient.4

Google is being a crappy helper.

Solar thermal can be used to generate electricity in large power plants, or can be used to capture heat for water and space heating. Here’s a good site on solar thermal electricity, http://www.ecoworld.com/energy-fuels/solar-thermal-power.html. I’m using solar thermal in New England to heat my domestic water for showers and washing, as well as to heat my house. Here’s a description of it, http://www.altestore.com/gallery/Amy-Beaudet-gallery/v/9358727169/amys_water/. It can be used to heat the water for radiant floors, or heat the air in forced hot air systems.

Solar thermal is used all around the world. China is the largest user of solar water heating, with Japan, Germany, Israel all closer behind. It is now required by law in Hawaii for new construction to install slar water heating, since it saves so much power instead of using electricity to heat water.

Here is how I can prove that it is a universal principle to have a system where Government redistribution of wealth so every American has exactly the same amount of wealth….works…..let me explain why……

1) Suppose you have a pond, and then it rains heavily on one part of the pond. The rainwater would be redistributed equally across the surface of the entire pond. The depth of all parts of the pond would raise by exactly the same amount, whether or not rainwater fell on any part of the pond. And it still rains….because the rain pours on the pond not to enrich just where that cloud is situated, but for the greater good of the entire pond.

Scientifically, if ponds of water behaved like American society, there would be no ponds of water. Because all the rain clouds would have no incentive to exist unless each area of the pond did not connect to any other part of the pond.

As a society, we are all like a pond and we share the earth and wealth and food and solar energy…and this proves my point, we’d be happiest if like that pond, we shared each money cloud in common….

Does this anlogy work for most of you?
Now, to an extent we are like the pond. You give an employee wealth and he consumes goods and services, which helps businesses grow.

You give an employer wealth, and he may hire another worker, enriching that worker….

so why not expedite the redistribution process by just having the Govt do it
As for people, we have a system where people receive tattoos for hard work….just like ponds have ripples to show where rain fell……
Now those who are not working hard would have the least tattoos and people would be disgusted with them for not pulling their fair share…while they enjoy the same amenities for being human

Talk about a dumb example! The pond does nothing to create the water it holds. The pond doesn’t have human nature.

The government doesn’t create wealth, in fact the bureaucrats skim the cream off the top, gaining greater benefits & security than the private sector.

I am looking for the residential and commercial solar panels in San Diego, California, Can some one tell me about the best organization or firm who has a best solar energy panel structure to install on affordable price?

Affordable & Custom Solar Solutions by Clary Solar

They offer solar panels and solar power installation services in California and San Diego. From commercial solar panel to residential solar panel installation. they also we provide customized solar solutions with an emphasis on protecting the environment.

sustainable energy sources in the 1970’s?

Carter started and ethanol program which Reagan promptly stopped after Carter’s defeat. Reagan, to make a statement about which direction we would go, removed the solar panels from the White House roof when elected.

More intelligent societies like German who refuse to be lead my the nose by their corporate masters are light years ahead of us in solar technology.

If we don’t wake up, we will be using solar and wind technology purchased from the Chinese.

Most Americans aren’t smart enough to realize that we are sacrificing our future, our economy and our environment for the sake of oil companies.

Ethanol costs more than twice what gasoline does and causes food prices to rise because there being depleted for fuel. What we should do is tap our own vast resources of oil which is several times that of the middle east. Solar panels are a joke at best they are a supplemental energy source.

How many solar panels would you need to equal the energy output of 1kg of U-235?

if 1kg of U-235 can produce 80 trillion joules (8×10^13 J) of energy how many solar panels would you need to equal this amount of energy?

Any info would be very much appreciated!

Unless the student is supposed to be able to calculate how long it takes the U-235 to produce that amount of energy, there is not enough information. If that is within the scope of the course, the question is way out of my league.

But assuming you just left out the time when stating the problem, divide that into 80 trillion to get joules/sec.

Let’s say the time is 40 billion seconds* for the U-235 to generate 80 trillion J. Divide 80 trillion by 40 billion, that’s 2,000 J/sec. You would need 10 panels. (A typical panel produces 200 Joules/sec.)

*That’s a LOT of seconds, even a lot of centuries. By then the solar panels would have worn out and crumbled into dust, so it’s a silly question in that sense. Is the teacher trying to make a point about the futility of solar power?

can u explain in your own words what these mean!

photovoltaic cells
active solar energy
passive solar energy
concentrating solar power systems

Photovoltaics (PV) is the field of technology and research related to the application of solar cells for energy by converting sunlight directly into electricity. Due to the growing demand for clean sources of energy, the manufacture of solar cells and photovoltaic arrays has expanded dramatically in recent years.

Active solar systems use solar collectors and additional electricity to power pumps or fans to distribute the sun’s energy. The heart of a solar collector is a black absorber which converts the sun’s energy into heat. The heat is then transferred to another location for immediate heating or for storage for use later. The heat is transferred by circulating water, antifreeze or sometimes air..

Passive solar heating and cooling represents an important strategy for displacing traditional energy sources in buildings. Anyone who has sat by a sunny, south-facing window on a winter day has felt the effects of passive solar energy.

Linear concentrator systems collect the sun’s energy using long rectangular, curved (U-shaped) mirrors.

What are the percentages of power/energy saved by using solar energy and wind energy compared to what we use on average? Thoughts or ideas?

When reading about the total capacity of solar power available in the SW US or wind power available in the midwest US you see either on could potentially totally satisfy all of our power needs. However such claims need to be put into some economic perspective.

-Yes, the power is there but transmission to far places is another issue.
-As is the efficiency of such sources of energy.
-Such sources of power may not be as constant as is our need. Our electrical system needs greater capacity for energy storage. This is another technology that is concurrently being developed.

They are improving but lets not expect so much that we will be disappointed if technology does not advance as rapidly as we would wish.

Currently renewable energy is only a small percentage of US power supply: http://www.eia.doe.gov/cneaf/alternate/page/renew_energy_consump/table1.html
and a graph: http://tonto.eia.doe.gov/energyexplained/index.cfm?page=electricity_in_the_united_states

Specific instances for home owners or businesses will vary a great deal based upon local conditions, local incentives, amount of available investment, desired or needed return on investment…

The two methods are
- focusing sunlight onto a liquid that is heated and used to turn water into steam to drive the turbines
- photovoltaic cell (layers of silicon to generate electricity)

I am sure that the photovoltaic panels are more efficient in converting solar energy to electricity as there isn’t much loss in the process.

What are the percentages of power/energy saved by using solar energy and wind energy compared to what we use on average?

I may have misread your question, sorry if I did.

There is no energy savings by using an alternative source. Most of the alternative sources are in fact MORE expensive. People choose to pay more for solar, wind, and other alternative sources…a lot more in some cases.

As alternative energies become more efficient and cost effective they replace fossil fuels more and more, but there is still a cost to the production of the PV cells and wind turbines…lots of metal, and lots of composites including plastics, in relation to the power they produce.

Energy savings comes from conservation and increasing efficiency.

Right now, renewable energy accounts for about 7 percent of US energy consumption. Most of the 7 percent is Hydro-electric and wood burning.