Ok, educate me on "green" energy

[Frangible]

Wind/solar... any others?

How much space does it take up relative to a coal/nuclear plant of equal power generation capacity?
How much does it cost to build compared to coal/nuclear for equal capacity, and what is the cost per MWH?
How often does it produce power? (ie, sometimes the wind doesn't blow, there's night time / clouds, etc)

Thanks. Wondering what's changed since I last looked at it.

[mainegreen]

1. Tidal!

Tidal energy is one of the green energy sources thats taking great strides lately. Some of the newer units produce amazing amounts of energy.

http://news.bbc.co.uk/2/hi/uk_news/england/devon/2992996.stm

Its truely green, unlike say hydropower which isnt so green.

[LARED]

2. This is a partial anwer.

One square mile dedicated to Biomass production will generate 1 MW. It would roughly take half the land mass in New Jersey to produce the power that state requires. About 3,700 square miles.

The same square mile will produce 10 to 15 MW's from wind power or about 370 square miles;

or

100 to 150 MW's from solar power or about 37 square miles;

or

or 2000 to 4000 MW's using fossil fuels, this includes nukes.


This is of course simplified and uses NJ as a base line for comsumption so it will not hold for all areas. but it give one a general idea of land use and power issues.

At the end of the day "green" energy cannot compete with fossil fuels. We should continue to develope alternate energy sources (including nukes) and utilize them were it makes sense. Over time the technologies will change for green and fossil and new developments are always a possibility.

[Frangible]

3. Thanks

Tidal does look pretty interesting, and it's good that it won't kill the fish either.

It looks like wind is pretty weak still, as is solar, but the nice thing about solar is the "roofing" concept. Unfortunately the cost is still a bit high for that.

Hopefully in time both cost and effeciency will improve for all of it. Until then it seems we're stuck with conventional sources.

Anyway, thanks for the information.

[midnight armadillo]

6. Sure they can compete!

At the end of the day "green" energy cannot compete with fossil fuels. We should continue to develope alternate energy sources (including nukes) and utilize them were it makes sense. Over time the technologies will change for green and fossil and new developments are always a possibility.

If you want wind & solar to compete, we should either give them the same level of massive subsidies that fossil fuels and nuclear energy get (try this: pull out your home insurance and check out the nuclear accident exemption) or eliminate the subsidies on the nonrenewable fuels.

A major part of research into alternative energy must be research into energy efficiency - it's easier to make vast improvements here. Sandia National Labs estimated we could cut our national energy use by 20% using available, off-the-shelf technology. With abundant and cheap energy, there's no real incentive here, just like there's no real incentive to buy 40 mpg cars (other than moral superiority) when gas is $1.50/gallon.

[The Bish]

8. Maybe compete economically....

..but the point of LARED's post was that they cannot compete in regards to land usage.

[midnight armadillo]

11. On the contrary!

You can put up solar panels on darn near any building, depending on solar access. Micro wind generators can be placed on small lots as well, typicall 1/2 acre and up. Homes and small businesses can then supply much of their own power and feed excess back to the grid. Same with microhydroelectric power for those lucky enough to have a fast moving stream on their property.

The result is that the land use can be in parallel with other uses, which can hardly be said for a coal plant. One should also take into account the land use for extracting fossil fuels and uranium ore to be fair, along with the energy expended to prepare them for consumption for energy production...

[NNadir]

12. Nuclear energy is clean energy:

I agree that wind and solar should get massive subsidies. But nuclear bashing is well, scientifically, environmentally, and technologically illiterate.

Nuclear energy does NOT receive any subsidies, and nuclear energy is clean AND safe. No one, absolutely no one has died in the United States from the operation of a nuclear power plant or its products. In NYC alone over 30,000 people die each year from air pollution resultant causes. In a solar powered world, we have no idea how many people will die from Cadmium poisoning, hydrogen fluoride related processing, etc, etc.

The fact is that NO form of energy is 100% safe and clean, not solar, not wind, not nuclear, and certainly not fossil fuels.

However its very clear that nuclear energy is both cheap and clean, as is the wind form of solar energy. Other forms of energy have a long way to go to match either wind or nuclear.

[Township75]

13. Just look to Greenier Europe and you will see they are NOT afraid...

of nuclear.

But I would be hesitant to call it clean...doesn't it produce some nasty radioactive waste? I thought it did, though it was only about a washer machine size waste. However, it is nasty for a hell of a long time.

[The Bish]

14. usually the longer the better

Radioisotopes are only dangerous when they emit radioactive particles (classified as either neutrons, alpha particles, beta particles or gamma rays). The only time that they eemit these particles is when they decay into another element. For example U-238 has a half life of 4.5 billion years. This means that over a 4.5 billion year period half of the atoms of any group of U-238 atoms can be expected to decay. This releases an alpha particle and the U-238 transmutates into Th-234. So while it lasts a long time it rarely emits any radiation. Now TH-234 has a half life of 24.1 days so it could be considered more dangerous than U-238 since it will emit a lot more radation per unit of time per unit of mass.

A lot less waste could be produced as well if there were plans in place to reprocess the spent fuel rods and reuse some of the material in them. A lot of what is contained in the fuel rods is still usefull if it is reprocessed. This would lower the mass of waste needing to be cared for. Nuclear is not perfectly clean but it is loads cleaner than coal or other fossil fuels which produce millions of tons of waste products every year which are spread throughout the atmosphere.

On another note chemical industries also produce large amounts of waste and most of this waste is not radioactive and thus exists in a stable form. It's danger is not due to its radioactivity so it does not need to decay to become dangerous. An atom of arsinic will remain arsinic and able to kill forever.

And yes as you mentioned Europe is not afraid of Nuclear. 70% of the power in France is produced by nuclear power.

[Township75]

4. Thanks to the responders...

interesting article from the BBC and interesting stats from the 2nd post...could you post the link to where that is from, please?

Also, if any of you have a good energy info website, especially one that explains the differences between the types of energy (or methods to harness the energy), and their effeciency and so forth, please post that too.

Thanks

[LARED]

5. could you post the link to where that is from, please?

Sure

Click on at the bottom.

Some of the other articles are quite good as well.

[midnight armadillo]

7. More info

From the Union of Concerned Scientists.

[Township75]

10. THanks all, keep the links coming*

*

[The Bish]

9. costs

Note these costs include all costs, including construction, fuel, regulation, insurance, taxes, decommishioning and waste disposal ect.

Coal $29.10 per MW/hr
Nuclear $30.00 per MW/hr
Solar $200.00 per MW/hr
Wind $40.00 per MW/hr


From: http://www.nucleartourist.com/basics/costs.htm
http://www.solarbuzz.com/StatsCosts.htm