Renewable energy wrecks environment

[MechAg94]

Well, maybe.  Civil engineers generally use high safety factors than others.  Depends I guess.
Mistakes can still be made, but the likelihood is very low.  The biggest factor in that would be changes made from the standard design. 

[Mabs2]

I wish I could afford to convert our house to solar power, not for any cost savings but simply for freedom from the "grid."  Then so what if the power goes off, the sun is still up there

Right now our biggest vulnerability is that our water supply (well) depends on electric power.

What they are saying is that all possible failure scenarios have been reviewed and mapped out and processes/structures have been designed to prevent failure (failure defined as part of the study).  In engineering terms, that means the probability of failure is very low.  Impossible is not an engineering term and every engineer knows that nothing is perfect.  Imperfections are accounted for in design and construction. 

You are probably safer living next to a nukular plant than driving over a bridge   

I'm sure that if you found a way to pay for it it would pay for itself over time.
I took my HVACR course with a teacher who is VERY* green.
He believes in man made global warming, but that's the only thing we disagree with.
His main motivation for going green is, like me, for saving money.
We spent many a whole day goofing off and doing calculations to prove how much you'd save with geothermal heatpumps and solar water systems...
It's seriously very good stuff.

*Well, not very green.  He just likes saving money. :3

[Paddy]

What's not included in the world-cost of a Prius is the pollution around the nickel mine in Canada,

That occurred over thirty years ago, long beforethe Prius.  If you don't like the car, simply don't buy one. It's a free country (or was, anyway, at one time), and choice is good.   I would think you 'free market' types would understand that. 

[Art Eatman]

The big load items in a house are the A/C and the refrigerator.  The starting currents are what are important in sizing the rectifier for a solar system.  There are several companies who will cheerfully send catalogs.  These include calculation guides so you can figure out how big a system you'd need for the size of your house, plus its equipment.

I guess the variable is the life for the batteries; how long before replacements are needed.  If that's known, it's not hard to then figure out the amortization as compared to the present electric bill. 

When I built my house in 1993, doing it myself, the cost of an adequate system was $16,000 plus replacement batteries.  (I'd do the labor.)  I was 60 years old.  My bill had been running at some $60/month for a comparable loading.  So, 700 per year into 16K plus batteries at my age.  I'd have to really live a long time for it to come out ahead.  Easier to stay with the grid, plus a small gasoline generator for outages.

Art

[DustinD]

For what it is worth, windmills beat solar panels hands down for price per watt. Just make sure you buy a decent one, as some are junk.  The same goes for inverters. Outback is a great brand for home sized inverters.

www.homepower.com has had some good articles on the subject for free in their "files" section. They seem to be gone now, but there are some basics on the front page. I have copies of their free stuff I can post a bit later if anyone is interested. They had pretty good info on everything from making large scale pure hydrogen gas, to designing solar thermal systems from scratch.

www.otherpower.com has good info for do it yourselfers. Including designing and building windmills from scratch.

[Mabs2]

For what it is worth, windmills beat solar panels hands down for price per watt. Just make sure you buy a decent one, as some are junk.  The same goes for inverters. Outback is a great brand for home sized inverters.

www.homepower.com has had some good articles on the subject for free in their "files" section. They seem to be gone now, but there are some basics on the front page. I have copies of their free stuff I can post a bit later if anyone is interested. They had pretty good info on everything from making large scale pure hydrogen gas, to designing solar thermal systems from scratch.

www.otherpower.com has good info for do it yourselfers. Including designing and building windmills from scratch.

From what I've heard, windmills were almost junk up until recently.  That true?  From what I can tell these days they turn slowly and are very quiet.

[DustinD]

Some of them like the "Air" series 303, 403, Air X are junk. As where all of the other very high speed, high tip speed ratio (ratio of the blade tip to the wind speed) units. They would last two to three years on average and where noisy as heck. Newer ones can last decades and are completely silent to the point where leaves rustling in the wind will be way louder than the mill itself.

There where a few good brands, and the old Jacobs where good despite (or maybe because of) being designed and built in the 1930's IIRC. But yes, most where, and many still are junk.

I am mostly involved in the homebuilt sector so I can't do many product reviews. I will dig the "apples and oranges" windmill review from Home Power Magazine off of my old HD tomorrow and post it.

If you do buy one make sure you know what the output is at a given wind speed, preferably they will have a graph showing the output at all operating speeds. The power rating is worthless without wind speed because power goes up by a factor of 8 when you double the wind speed.

Avoid high tip speed mills because of noise and the fact that they spin faster to make the generator lighter, and they usually don't work well in lower winds. Reliability also suffers with high tip speeds.

Also make sure you use enough tower. Wind velocity (and thus mill power) and smoothness gets a lot better the higher you go up. Too short of towers is one big mistake lots of people make, as well as not giving the mill clean air. You want the bottom of the blades at least 30 feet above any obstacle within 500 feet away.

If you are thinking about buying a mill I would be happy to give my opinion of it, if I am familiar with it. I know basic mechanical and aerospace engineering as well as aerodynamics for what it is worth.

Also avoid any mill with only two blades due to a phenomenon known as "yaw chatter." It will destroy any mill without yaw control, which non of the small ones have.

[Iain]

DustinD - did you take a look at my gizmag link on the previous page. I'd be interested to hear knowledgable opinion on the content.

[DustinD]

Most of this post will address their website MagTurbine not the article.

(normal turbines) operates at around 1% efficiency in terms of the power it harvests from the wind, due to the deflective blade design and friction losses.

Wrong, modern utility scale turbines are approaching the betz limit. Which is 100% of the capturable wind energy. Also note that the aerodynamic drag of a spinning rotor is comparable to the drag of a solid disk of the same diameter.

As for frictional losses, it is a non issue. I can spin a twenty foot windmill around with my index finger. I am referring to below cut in speeds, or with the generator running open circuited so their is no load from it. These where axial flux gens without an iron core so there was not any cogging either. I have seen many homebuilts from several inches to nearly thirty feet in diameter, most never stop spinning no matter how calm the air gets. Many can also produce energy from five mile an hour winds thanks to buck/boost converters.

As for bigger utility scale turbine drive trains (not counting generator electrical inefficiency), they can lose more than a few percent in some cases, but many of the losses can't be fixed with magnetic bearings. The loss is biggest at low speeds, and magnetic bearings don't work well at slow speeds.

One innovative possible use could be to harvest wind energy from passing cars on freeways to power the roadside lighting.

Cars don't move enough air along the roadside to power lights even if it could be captured 100% effectively. Also the roadside power generating scam has already been done a few times already, they should try something new.

So far almost every vertical access wind turbine business has been a scam. They are often done by the same people over and over again. Note that almost none of them have ever produced any hardware, have any engineers or production capabilities, or have contracted or even contacted anyone with engineering or production capabilities. Many of the founders of these companies are facing legal action or have in the past. Buyer beware. Also www.otherpower.com as well as many other sites have good info on past and present enviro or alt energy scams. This industry is absolutely full of crackpots and unscrupulous businesses taking advantage of people's ignorance and good intentions.

They did not give any sizes that I saw but I can bet that their claims go way over unity. Almost every VAWT generator claim in the past has been a scam, and claimed performance way over unity to the point where you would want to leave it indoors with a fan blowing on it 24/7 get the most power out of it.

[Len Budney]

...The added energy would be tremendous.

So wouldn't the added cost.  Let's say that every household south of the mason-dixon line decided to add solar power to the roof.  Southern climate gets substantially more usable sun than my frostbitten self in ND.

Hey, are you originally from CT?

--Len.

[Len Budney]

I guess that's why Peach Bottom in Lancaster County, Pennsylvania, has had nearly 400 unscheduled reactor shutdowns in those 30 years... You know, disaster lurks where complacency and hubris live.

All American reactors are at least two decades out of date. For one thing, they're all the "giant heap of fissile material" type that can, if not watched carefully, melt down. Completely different reactor types have been invented, but no new reactors have been deployed in the US in thirty years. A pebble bed reactor is literally incapable of melting down or exploding: a Chernobyl or Three-Mile Island type accident is literally impossible, even if all the workers dropped their tools and abandoned the site, and nobody came back to check on anything.

There are of course still issues, such as waste--but coal-fired plants actually produce more radioactive waste than a nuclear plant. They don't have a disposal problem because they send it out the smokestack with other waste products.

So it would be a bit over the top to suggest that nuclear plants are on par with bakeries, safety wise, but modern plants would be much better than pretty much any fueled electric plant in service today. It wouldn't be risk-free, but it would be a big improvement.

--Len.

[Art Eatman]

Last I read, China has a pebble-bed reactor program underway.  Some 35 units. 

The Chinese offered to build a small PB unit for free, in Alaska, IIRC, as a demo to promote further sales of the technology.  They were turned down because of fears of nuke.

Uranium mining company stocks have, this recent year, more than doubled with the rise in the price of U.  Still a good investment...

Art

[Firethorn]

All American reactors are at least two decades out of date. For one thing, they're all the "giant heap of fissile material" type that can, if not watched carefully, melt down. Completely different reactor types have been invented, but no new reactors have been deployed in the US in thirty years. A pebble bed reactor is literally incapable of melting down or exploding: a Chernobyl or Three-Mile Island type accident is literally impossible, even if all the workers dropped their tools and abandoned the site, and nobody came back to check on anything.

There are still issues with PBR designs.  And experimental PBR in england had to be shut down back in the 1970s or so due to the balls cracking.

Besides, there are additional controls in at least some of our updated reactors that would be the same way - if no human inputs are incoming, the reactor would eventaully shut itself off before containment breach without any outside input.  There are systems very similar to fuses that will drop the control rods or even a separate control solution to SCRAM the reactor without human intervention(Indeed, the way they're designed, even human intervention wouldn't stop their release) to prevent worst case scenarios.

The newest designs have them by default.

[DustinD]

The promised apples and oranges article Apples and Oranges. Detailing different turbines and their quality or lack their of.

Birds Vs Turbines. The short answer is that windmill don't kill birds more than other fixed structures.

Wind Energy for Electric Power A report on windmill tech and economics. This will probably not interest most readers.

[Paddy]

Heck, the original VW diesel Rabbit could get 60mpg...

Except that diesels are filthy.  And they  stink. And they're gutless. If I had my way, diesels would only be allowed in commercial applications (maybe with some exceptions)

[Firethorn]

Heck, the original VW diesel Rabbit could get 60mpg...

Except that diesels are filthy.  And they  stink. And they're gutless. If I had my way, diesels would only be allowed in commercial applications (maybe with some exceptions)

You obviously haven't driven one lately.  The new turbocharged diesels over in Europe definitely have guts, have clean emissions, and with the newer low sulfur fuels, stink less than gasoline.

I once drove a rental vehicle in Germany that I didn't realize was a diesel until I pulled in to fill it up.