Jump to content


Photo
- - - - -

Drove a Hybrid. Impressed?


  • Please log in to reply
165 replies to this topic

#151 imaginesix

imaginesix
  • Member

  • 5,559 posts
  • Joined: March 01

Posted 02 September 2014 - 18:43

Composed by one of the 47% perhaps?

And read by such.

Advertisement

#152 Peter Morley

Peter Morley
  • Member

  • 1,900 posts
  • Joined: October 02

Posted 07 September 2014 - 11:43

Does a wind turbine, solar cell etc. ever produce more energy than the amount of energy that was needed to produce the materials they are made of - that is, within their operating lives?

Apparently someone has just developed a solar panel that 'produces' more energy than is used in making it.

Thus far every solar panel produced has wasted energy and at the moment all that will happen is that the energy is 'moved' from one place to another.

 

Electric cars are as unsustainable as they were 100 years or so ago (when they were the most common form of car) and for many of the same reasons.

 

Given that cars are mobile they are best with mobile energy generators, static objects (e.g. houses) work best with static energy generators (e.g. power stations) trying to reverse or combine these is a blind alley.

And as for their benefits, banning short haul flights (e.g. budget airlines) would be far more beneficial for the environment.

 

Apart from dubious energy benefits there are major problems in finding the raw materials for things like batteries - rare metals tend to be found in a very limited number of areas, most of which are in countries you don't want to be reliant on, and the quantities required for the numbers for cars etc that are being talked about requires the extraction of  such materials in far greater quantities than has been done so far (e.g. for just one manufacturer to produce the number of hybrid/electric cars they are talking about requires 5 times the total amount of Lithium that has ever been extracted).



#153 MatsNorway

MatsNorway
  • Member

  • 2,056 posts
  • Joined: December 09

Posted 07 September 2014 - 22:10

I don't get why there are not bigger taxes due to polution on short air travels either. New trains got very good regenerative braking and all that. And last for 30 years easily if thats what you want.

 

One of the common locomotives in Norway http://en.wikipedia.org/wiki/NSB_El_14 This one does not have regenerative braking. DC powered by the way.

One of the oldest passenger train http://en.wikipedia....ki/NSB_Class_69


Edited by MatsNorway, 07 September 2014 - 22:13.


#154 gruntguru

gruntguru
  • Member

  • 5,264 posts
  • Joined: January 09

Posted 07 September 2014 - 22:54

Apparently someone has just developed a solar panel that 'produces' more energy than is used in making it.

Thus far every solar panel produced has wasted energy and at the moment all that will happen is that the energy is 'moved' from one place to another.

Absolute nonsense. Same goes for the rest of your post but one thing at a time.

 

http://www.resilienc...tovoltaic-cells  (8 years ago)

 

On the other hand you can work it out for yourself. A 250 watt solar panel lasts at least 25 years and generates about 1.25 kW.hr per day. Lets be conservative and say 1kW.hr/day. 1 x 25 years x 365 = 9125 kW.hr

 

According to you there is more than this amount of energy embodied in the manufacture of the panel. At 5c/kW.hr the energy cost alone would be $456.25. Add in the other costs of manufacture, packaging costs, transport, numerous markups, warranties etc to arrive at the crazy retail price of . . . . . . . . . . . . .

 

 

 . . . . . . . $300.  How do they do it?



#155 Lee Nicolle

Lee Nicolle
  • Member

  • 5,825 posts
  • Joined: July 08

Posted 08 September 2014 - 00:35

Absolute nonsense. Same goes for the rest of your post but one thing at a time.

 

http://www.resilienc...tovoltaic-cells  (8 years ago)

 

On the other hand you can work it out for yourself. A 250 watt solar panel lasts at least 25 years and generates about 1.25 kW.hr per day. Lets be conservative and say 1kW.hr/day. 1 x 25 years x 365 = 9125 kW.hr

 

According to you there is more than this amount of energy embodied in the manufacture of the panel. At 5c/kW.hr the energy cost alone would be $456.25. Add in the other costs of manufacture, packaging costs, transport, numerous markups, warranties etc to arrive at the crazy retail price of . . . . . . . . . . . . .

 

 

 . . . . . . . $300.  How do they do it?

Hardly a secret. Solar panels produce more greenhouse to manufacture than they save. Not more energy. 

And last as little as 3 years. Productive life [meaning they go downhill in productivity] is normally around 7 years.

I am seeing solar panels being replaced semi regularly. And others I know who bought are now getting nothing from them in as little a 3 years.

Solar is probably viable in a commercial scale, better quality panels and lots of them in a sunny area.On rotating plinths to chase the sun all day. Not on a roof in the suburbs semi shrouded by shadow half the time. With your average amount of fallout from a urban enviroment. 

A friend fell off his roof recently cleaning his panels!  They now produce a little more again. Luckily he landed on his feet on the lawn so a weeks rest fixed him!



#156 gruntguru

gruntguru
  • Member

  • 5,264 posts
  • Joined: January 09

Posted 08 September 2014 - 02:06

Bullsh**!!

 

http://info.cat.org....me-pv-panels-uk

 

"More recent research by Fthenakis, Kim and  Alsema, (2008) suggests that the total greenhouse gas emission (including CO2 and other gases)  for electricity from PV panel is between 20 and 80g CO2-equivalent per kWh under UK conditions. This is ten times lower than the emissions for electricity from fossil fuels (UK grid average is around 500g/kWh, electricity from coal can be as high as 1000g/kWh)."

 

Solar panels last 7 years? Even the cheapest rubbish panels on the market are guaranteed to be producing greater than 80% of their claimed output - after 25 years. How do you provide such a warranty when the productive life is 7 years? Most failures you hear about are these cheap panels. I know several people with systems 3, 4 and 5 years old - not one has replaced a single panel.

 

The solar panels on my roof have just clocked up 12 months. I haven't cleaned them once. Sure if I did, the output might go up a few percent, but when I checked the output yesterday they were pumping out 5kW (max for my inverter) so why bother.



#157 desmo

desmo
  • Tech Forum Host

  • 12,975 posts
  • Joined: January 00

Posted 08 September 2014 - 02:40

Actual empirical facts are subject to a personal reality distortion effect around some people I've noticed. The majority of the time I don't think they even care, if it feels good coming out or in, it is true. Facts be damned.

#158 GreenMachine

GreenMachine
  • Member

  • 775 posts
  • Joined: March 04

Posted 08 September 2014 - 02:46

Bullsh**!!


Yep!

I have some skin in this game. 10kw array, three years old, generating just fine (according to the cheques that keep coming in the mail). They may not last 25 years, but there is no sign of that yet. Probably going to outlast me!!

Do the maths, and tracking isn't worth the cost/complexity/potential unreliability. It's not like you have to have them bore-sighted on the sun all day, they handle off axis with relatively little performance drop.
 
I guess if you just bought the cheapest installation you could find, or even fell for one of the many shysters who were operating in the solar sales game at its height, you might have got a dud.  Nobody that I know of has though.

#159 Peter Morley

Peter Morley
  • Member

  • 1,900 posts
  • Joined: October 02

Posted 08 September 2014 - 09:24

According to Stanford university, in the Environmental Science & Technology journal, who looked at the overall picture of building and installing solar panels (which includes such things as the energy required to melt the silica rock to 3000 Fahrenheit to produce the silicon) the industry has just reached the energy balance tipping point.

Other studies have come to the same conclusions.

 

Solar panels are certainly fiscally interesting (partly because they are subsidised by other users) - especially in countries where the subsidy is more generous than the UK - but their environmental benefits are far less significant.

As for the price of the panels that is the reason why the companies are being investigated for dumping - but as more money is invested in them the price and efficiency has certainly improved and when they start using different materials the benefits will improve.

 

Incidentally, rather than subsidising individuals who install panels it would make more sense for electricity companies to supply and install the panels themselves on suitable roofs (possibly paying a rental fee to the householders) but that would not be very good for their profit margins, which these days are far more important than providing a utility.

 

As for the rest of my nonsense where are you going to dig up all the rare metals that are required - presumably you are on great terms with Russia & China, what about North Korea, Afghanistan etc all of whom are well known for their generosity and stability.


Edited by Peter Morley, 08 September 2014 - 09:25.


Advertisement

#160 MatsNorway

MatsNorway
  • Member

  • 2,056 posts
  • Joined: December 09

Posted 08 September 2014 - 15:37

The solar panels on my roof have just clocked up 12 months. I haven't cleaned them once. Sure if I did, the output might go up a few percent, but when I checked the output yesterday they were pumping out 5kW (max for my inverter) so why bother.

Clean them and you peak earlier in the morning and stay at peak longer. A repositioning of them might be benefitial too. 5kW sounds alot. How big is the installation?

 

 

As for the rest of my nonsense where are you going to dig up all the rare metals that are required - presumably you are on great terms with Russia & China, what about North Korea, Afghanistan etc all of whom are well known for their generosity and stability.

 

 

http://www.solarblog...are-earths.html

 

How Rare are Rare Earths?

 
Rare earths are actually relatively abundant in the Earth’s crust; about as plentiful as copper.  The reason for the name is that they are well dispersed, and not often found in concentrations that can be economically extracted.
 
However, rare earth minerals have been mined in India, Brazil, South Africa and the USA as well as China.  China only has 30% of the world’s rare earth deposits.  However, in a move that will resonate with some in the solar PV industry, Chinese producers came to control production by supplying at much lower price, causing mines in other parts of the world to shut down.

 

 

In 2010, thin film PV dropped to only 13.5% of the market in the face of price competition from crystalline silicon cells, and CIGS and CdTe PV are only two thin film technologies among many.
 
So, a fine example of how journalism works.  Two forms of the less widely-used types of solar PV get mentioned in a report that assessed strategic materials such as rare earths; rare earths hit the headlines in a trade war; and we end up with articles that suggest we’re going to run out of the raw materials for solar PV. 
 

Panic over?


Edited by MatsNorway, 08 September 2014 - 15:46.


#161 gruntguru

gruntguru
  • Member

  • 5,264 posts
  • Joined: January 09

Posted 09 September 2014 - 08:01

Clean them and you peak earlier in the morning and stay at peak longer. A repositioning of them might be benefitial too. 5kW sounds alot. How big is the installation?

Unless they are visibly dirty, cleaning is only worth a few percent. A 250W panel is typically 1680 x 950 so about 1.5 sq m. 20 of those for 5 kW.



#162 Lee Nicolle

Lee Nicolle
  • Member

  • 5,825 posts
  • Joined: July 08

Posted 10 September 2014 - 09:34

Unless they are visibly dirty, cleaning is only worth a few percent. A 250W panel is typically 1680 x 950 so about 1.5 sq m. 20 of those for 5 kW.

I look at the crap that builds up on my car in a  week or so. So they will all be fairly dirty after a while. 

As for life? I know many who have had them fail. I see the things being either pulled down or replaced around my area. And they were not around more than 10 years ago. 

25 year guarantee? I would like to see the exclusions! Though 2/3 of the solar industry has gone, amalgamated, changed identity in the last 6 years here.



#163 Peter Morley

Peter Morley
  • Member

  • 1,900 posts
  • Joined: October 02

Posted 10 September 2014 - 14:39

I look at the crap that builds up on my car in a  week or so. So they will all be fairly dirty after a while. 
As for life? I know many who have had them fail. I see the things being either pulled down or replaced around my area. And they were not around more than 10 years ago. 
25 year guarantee? I would like to see the exclusions! Though 2/3 of the solar industry has gone, amalgamated, changed identity in the last 6 years here.

Given they're capturing radiation dirt might not affect their performance significantly, they might also have some clever cleaning technology on them.

They certainly fail and if the return on them is based on a long life (as in the UK where the subsidy isn't very generous) insurance is reckoned to be essential to making sure that you see a return from them - several people I know with panels have had failures before they've paid for themselves. Of course the cost of the insurance has to be factored into their economic viability and the number of replacement panels considered when looking at their environmental impact.



#164 Magoo

Magoo
  • Member

  • 2,478 posts
  • Joined: October 10

Posted 10 September 2014 - 15:59

Actual empirical facts are subject to a personal reality distortion effect around some people I've noticed. The majority of the time I don't think they even care, if it feels good coming out or in, it is true. Facts be damned.

 

 

 

I don't know why we should listen to scientists and engineers when there are so many qualified televangelists and radio talk show hosts willing to educate us on these subjects. 



#165 Canuck

Canuck
  • Member

  • 1,650 posts
  • Joined: March 05

Posted 10 September 2014 - 18:48

I agree but never cease to be amazed by absolute and complete faith people are willing to place in others, especially prevalent when one's own wishful thinking and beliefs are being reinforced. Being a scientist or an engineer does not preclude bias, fallibility, greed or any other human condition any more than being an ordained "man-of-the-cloth".

#166 gruntguru

gruntguru
  • Member

  • 5,264 posts
  • Joined: January 09

Posted 10 September 2014 - 23:03

I look at the crap that builds up on my car in a  week or so. So they will all be fairly dirty after a while. 

As for life? I know many who have had them fail. I see the things being either pulled down or replaced around my area. And they were not around more than 10 years ago. 

25 year guarantee? I would like to see the exclusions! Though 2/3 of the solar industry has gone, amalgamated, changed identity in the last 6 years here.

 

I guess I must be lucky. I have had my solar system for 10 months now. I have never cleaned them. We have had a pretty dry year with only occasional rain to rinse them off. Daily output is currently very similar to what it was 10 months ago and that was close to mid-summer. I guess if I got up and cleaned them, the output might improve as much as 10%. Don't think I'll bother.