Useless 'Renewable Energy' Sources

 On the net you read many articles, some of which are good and useful while others are sometimes silly, have no basis in science or engineering, are just a common scam to try to make money. In some cases it is the equivalent of going to a witch doctor with a broken arm. I thought it might be fun to point out a few of the useless types and make the list grow over time. I nominate:

1. Piezoelectric sidewalks - PowerLeap is developing a flooring material which they hope may generate 1 watt-hour per square foot for a cost of 100 to 200 USD per square foot. They project a dance floor made of the material may generate 10 watt-hours per square ft.

2. Solar panels on anything without the correct orientation - as solar panels can only use direct sunlight anytime they are not in the direct sun the output lowers substantially.  PV panels with their low efficiency need a good location to have any chance of generating useful power. Car surfaces offer a very low area with the correct orientation at any given time. 

Say a typical car takes about 0.8 kW per per km. In Izmir for July 2009 we are averaging about 7.5 kW/m2/day according to my weather station. All this comes to the point that 2 m2 of PV panels on a car roof top (which will be in less than the optimum orientation some if not most of the time) should power the car for approximately 2.8 km - really valuable!

3. Wind turbines that are advertised with a rating of say 1 kW in 25 mph winds but generate maybe 50 watts in the more typical 10 to 12 mph winds that most places receive.

4. Sources that rely on the 'subsidies and incentives' to become even marginally useful. The wind turbine described in item 3 is a case in point.

5. Wind turbines on cars that rely on the wind generated by the cars speed to capture power. That wind is generated by the primary fuel of the car and the turbine generates additional drag which causes the car to use more fuel.

6. 'Green energy' sources that utilize more hydrocarbons in their generation than they return for a net negative energy value. Reforming CH4 (even CH4 from biogas) to make H2 is energy negative (takes more energy to produce the H2 than the H2 produced contains).

Additions or disagreements?
Added detail to #2 & 6 on July 12 09
Edited by Russ - 7/12/2009 at 01:04 pm GMT

Haha, you're right. It's kind of like the saying...good intentions paved the road to hell.  But not quite.  You might really think you're doing a good thing by getting solar panels. But unless you know how to tilt them....probably not so useful.  The whole solar panel on the Prius is pretty ridiculous in my book.

What do you think about micro wind turbines?  Ones for residential installations. 

 Hi Eli,

For residential wind turbines you need to either do a lot of study or deal with a reputable and knowledgeable vendor.

Most of the ratings are useless as they show power generated at approximatley 25 mph wind speeds which are rare. It makes a dog of a turbine look good as the power in 25 mph winds is fantastically more than that in 10 to 12 mph winds which are far more common. The turbines that claim to start generating in 2 or 3 mph winds are trying to use wind with practically zero power which in turn means practically zero power will be generated. Wind turbines only conver wind power into electrical power - if the power ain't in the wind then you sure can't generate electricity!

I have yet to see a roof top unit which will ever pay for it's own carbon footprint.

You need a location with no obstructions such as trees or buildings too close. Roof tops don't fill the bill. There are a lot of flaky ideas out there but science is science and engineering is engineering - if you come up with a new concept that is different but many of the new companies are just dreaming. Betz's law still holds true - years back a German scientist described the maximum amount of available power in the wind quite nicely and it still holds true.

Please look up the following sources on the net:
1. site selection and factors influencing small wind sysyems energy output - pdf
2. Warwick wind trials final report - pdf
3. Apples and Oranges at www.homepower.com - these guys tell it like it is and they like wind
4. Wind turbine buyers guide at www.homepower.com
5. http://www.wind-works.org/SmallTurbines/CalculatedYieldofSmallWindTurbinesatZeelandTestSite.html

I like commercial wind and residential on a tall tower in certain locations can be good.

Most 'home' type of systems are only a method of releiving you of you money and trying to get hands on state/federal incentive/subsidy funds. They have little to do with power generation.



Edited by Russ - 6/24/2009 at 07:21 am GMT

 This is more 'useless energy sources' rather than renewable.

Power factor correction devices. The following is from http://energystar.custhelp.com/cgi-bin/energystar.cfg/php/enduser/std_adp.php?p_faqid=4941&p_created=1204908170

Russ, I am new to the green home community. As time goes by there will be more stupid claims. I was wondering are there solar experts in this group? Jim

 Hi jim386,

As I or anyone else comes across something else to add with some kind of support/documentation (not just opinion) I would love to see them added.

There are many good ways to improve life our styles and how we treat the environment. There are also many shysters out there trying to get into your pocket book. There are also many others trying to get into the government money offered via your pocket book.

The huckster kind of person/company I really don't care for and think we need to highlight. 

As regards solar experts in the group, I would suggest others add their name to this category as they feel appropriate. I am only learning on solar - far from an expert. 

I've both owned and installed wind systems and I own and have installed solar systems, but I still don't consider myself an expert. There's always some novel way that somebody finds to screw up house wiring or otherwise sabotage their wind/PV system. I've seen panels installed in the shade and towers not as tall as the surrounding trees, but those are just the most blatant examples. For me it all boils down to thinking that you can just buy a green life without going through the dual processes of trial and error learning (finding what works for you and why/why not) and paying-as-you-can-afford-it.
 

From Gizmag - Another company, New Energy Technologies, Inc, is trying to use the motion of an automobile to recapture energy. In this case they seem to plan to use a mat on the road surface to capture 'small amounts of kinetic energy'.

The power for the motion of the car comes from your gas tank or newly from the battery. You pay for this energy. The mats or anything else which captures that energy is using your power supply at your cost to capture power to put into their account.

In the event of an area where you need to slow down or with speed bumps there may be some small application but I believe that New Energies is kicking a dead horse with this one. They give no idea about the amount of energy they think to capture but I bet it is not very great.

http://www.gizmag.com/motionpower-kinetic-energy-capture/11409/?utm_source=Gizmag+Subscribers&utm_campaign=3d7b0effc4-UA-2235360-4&utm_medium=email 

Russ, The main reason why I have asked the question about solar experts. I am not a young man and I have over 40 years experience in the solar PV industry. So if you or anyone else has any questions I will try my best to answer you. Also years ago before the intranet no one had a clue that solar PV was going to take off like it did. I was in it before solar panels or even silicon we used copper/ carbon and salt to capture the sun's energy.

Russ, you gave me some advice on home solar panels about a month ago.  So far, of all the people I've talked to, you're the closest I've come to a solar expert.

As far as these "shysters,"  I share your loathing for the concept, but I find that most of them are just misinformed.  They honestly believe one tiny wind turbine and a solar panel on the roof angled however will produce the ridiculous amounts of power they claim.

Also, some of the alternative energy sources I've read about are only applicable in third world countries and are useless here in the states or in other richer locations.  An example of this is using a clear tarp and water to generate a focal point to heat your water. 
Edited by greengiant123 - 9/13/09 at 8:09am

I am far from a solar expert but maybe a little better at catching BS parties throw against the wall to see if it will stick. I know from a solar site I follow just how much I don't know and am finding it is more every day.

Renewable energy is interesting and important - however many items offered often do not make sense from an engineering or commercial viewpoint.

Some companies have apparently adjusted their prices upward to take advantage (for themselves) of subsidies and incentives offered. I suppose they think that potential customers have never researched their product at an earlier date.

I would love to find one of the VAWT's (vertical axis wind turbine) that work that I could install at my home. To date nothing is remotely practical. I don't have a good location for a HAWT on a tall tower due to nearby houses but on our hill could manage a VAWT.

I have solar water heating panels and have not used any electricity for water heating since March. I may have to turn on the electric backup in November though. One day coming I will have solar PV panels I hope. 

Yeah there's a lot of this kind of thing people get caught up in, like wind turbines in the middle of suburbia where the wind speed is just pathetic, or solar panels at too high latitudes to be worth it.  

What's worse though is the outright scams, "free energy" and so forth.  Just search on YouTube for "overunity" and you'll see some of the painful physics lies.

I actually wrote an article about it (I'm not trying to promote myself, just don't like repeating myself!) here: http://www.howtopowertheworld.com/over-unity.html

I think most people just don't understand the scale of numbers used.  A 5kW wind turbine sounds great, but then you have to factor in that it even during the few times it does spin, it won't spin at that speed! 

Agreed on motive power but in the case of the Prius with the solar moon roof I think the idea is to allow the car to recirculate air in the car when it's parked in the sun.  This keeps the car cool and so when you get in it you use less gas to power the air-con.  When I've got into a baking car it's taken a good 15 minutes of full blast air-con to get the temperature down because of all the heat stored up in the plastics, etc.

Russ, It is a scam. First read what you wrote. One watt per square foot. You can do that with carpet and a leather pair of shoes. So lets look at the math. 1 watt per square foot. When using solar math there are standard test type math. In direct sun one square meter on the earth's surface is 1,000 watts. To make things simple a square meter is 39" by 39". This is 1521 square inches. Now for a square foot. That is 144 square inches. This is about 10% or less the size of a meter. Well in math one watt per square foot is not even 1% efficiency. So this is the problem. Even thin film solar cells are over 6% efficiency.

Accord Guy, Years ago I would have to agree with you about solar panel facing directly at the sun. Have you ever seen a solar calculator? Take some time and think about that. You do not even need the sun to produce enough power to operate a small solar calculator. Please just think about that one. And get back to me.

Accord Guy, I just want to say I am a expert on solar powered electric motors. One HP= 746 watts without the spike or peak load and that 746 watts is based on the motor being 100% efficient. Most electric motors are at best only 80% efficient and this is without a load. Now the start up spike in electric power draw is at least 5 times the normal run power. One HP; the spike is around 5 KW. AC or DC motors it does not matter. Since there are no standards in time and travel set for your distance. How did you come up with the results? Usually speed X time equals distance. The EPA uses this type of test to measure gas milage of a car or truck. Actually the car or truck is not moving so there is no friction or up hill or down hill movement like in the real world. This is a estimate only. I have no idea why we do that execpt maybe we like to see something to go by. I would like to see a car that gets zero miles per gallon. Think about that.

What a great web page. and I liked the movie. As a optical scientist and a husband you can not get something for nothing.

Hi jim386, - The 'in rush' current is to bring an electric motor to operating speed (1200/1800/3600 RPM) under partial load.

All electric cars will be variable speed drives and the same rules don't apply. I don't have one to play with here to verify this (variable speed motor or electric car for that matter) but in industry we used many of the things. 

Power Factor Correction devices. I have one. Never saw the promised difference. After seeing several blogs on the subject, now Home Power magazine, (Issue 133, Oct/Nov pg 35),  addresses the issue. It is and always has been a scam. At least my neighbor can't laugh at me. He bought one too.

Hi bjnkm - love the part about the neighbor!

Here is a URL someone posted on solar panel talk about the DIY instruction manuals - it is fantastic! The same bunches sell the instructions for DIY wind turbines.

This was posted on a thread showing a roof burned off due to an improper solar panel installation. DIY stuff can not get UL certification - that is fine for solar thermal (air or water) but in dealing with electricity things become much more critical! No UL certification means no insurance coverage so the poor guy just bought a new roof.

http://www.diysolar.com/ 

Yup.  When I was a kid, I had an electric steam engine.  A 750-watt heater boiled the water, and the little engine could go!  So in my 10-year-old mind, I ran a belt from the flywheel of the engine around a bicycle dynamo, and brought wires back to the 110v plug.  Looking for perpetual motion, I guess.  Every time you convert energy, you lose energy.

Jim386:  The solar calculator works because of the absolute minimal current draw of the LCD display and the processor.  Just look how long a non-solar calc can run on the button cell inside it.  (Mine is 15+ yrs old and has never been replaced.)  Even with the tiny solar cell on the calculator, in direct sun it generates like 87 times the current needed to power up the processor.  My solar, however, takes a few seconds to come on when I light a 25-watt bulb above it, but it is on instantly with a 60.

You can get a car to get zero miles per gallon.  Let it idle in the driveway to burn a gallon - it has done zero miles.  Getting into the 40+ range is a challenge, and the 60+ range is even moreso.  Try a google on "hypermiling."  I do some of these things when I think the fuel saved is more expensive than the wear on the starter, clutch, steering gear, etc from having to shut down and refire the engine.

Some are very negative on wind power - If you look at Cleantechnica they think it is the best thing around. Probably the truth is somewhere in between.

From http://www.wind-watch.org/news/2009/04/09/wind-power-is-a-complete-disaster/

"There is no evidence that industrial wind power is likely to have a significant impact on carbon emissions. The European experience is instructive. Denmark, the world’s most wind-intensive nation, with more than 6,000 turbines generating 19% of its electricity, has yet to close a single fossil-fuel plant. It requires 50% more coal-generated electricity to cover wind power’s unpredictability, and pollution and carbon dioxide emissions have risen (by 36% in 2006 alone).

Flemming Nissen, the head of development at West Danish generating company ELSAM (one of Denmark’s largest energy utilities) tells us that “wind turbines do not reduce carbon dioxide emissions.” The German experience is no different. Der Spiegel reports that “Germany’s CO2 emissions haven’t been reduced by even a single gram,” and additional coal- and gas-fired plants have been constructed to ensure reliable delivery.

Indeed, recent academic research shows that wind power may actually increase greenhouse gas emissions in some cases, depending on the carbon-intensity of back-up generation required because of its intermittent character. On the negative side of the environmental ledger are adverse impacts of industrial wind turbines on birdlife and other forms of wildlife, farm animals, wetlands and viewsheds. 
***
"The U.S. Energy Information Administration reported in 2008, on a dollar per MWh basis, the U.S. government subsidizes wind at $23.34 — compared to reliable energy sources: natural gas at 25¢; coal at 44¢; hydro at 67¢; and nuclear at $1.59, leading to what some U.S. commentators call “a huge corporate welfare feeding frenzy.” The Wall Street Journal advises that “wind generation is the prime example of what can go wrong when the government decides to pick winners.”

See the entire article by using the link.