Photovoltaics & Firewood: An Ideal Combination?

System2

Re: Photovoltaics & Firewood: An Ideal Combination?

HI Paul,
Congrats on being carbon neutral
I might also be concerned about the number of deer in your area?
We had way too many grizzlies out here on the West Coast (and salmon) and Fir trees and clean rivers and killer whales, and even Buffalo before that! We got DOF to manage these items for us!!!!
My point is..... when we allow the fox to manage the chicken coupe we really can't expect a happy outcome for the managees!! Its normal for us managers to promote our own agenda first.
In an attempt to manage er, I mean, interupt the natural order of things we skew off populations which affects millions of things which compounds exponentially on other millions of things which creates all kinds of havoc. Managing domestic wildfowl (ckickens) has created a bird flu epidemic....BEEF (CJB and mad cow disease)and they pollute the WATER (don't get me started)......(Salmon farms??)........enuff already!
Have we lost our ability to control just ourselves?
So my point is .. when there is not enough supply then the demand will fade. So? Let them eat the sapplings and undergrowth (they live here too!) and when there is no food they will surely shrink away in numbers that can be supported by the undergrowth community?
I believe each deer has a footprint that is infinitisimally much smaller than ours....gosh, they even contribute to the biosphere out their backsides. I produce nothing good out of my backside and very little out the front!!!
So what GOOD comes from a deers footprint? ....maybe room for other essential life affirming organisms to grow. (BTW: methane is a carbon gas that is also out of control due to the domestic cow populations that have increased to feed us HUMANS)
Lets us cut back on the # of biggest offenders first! the ones we CAN control? Any guesses?
Or am I just misguided?

paulstamser

Re: Photovoltaics & Firewood: An Ideal Combination?

envelopes2007 wrote: »

HI Paul,
Congrats on being carbon neutral
I might also be concerned about the number of deer in your area?
We had way too many grizzlies out here on the West Coast (and salmon) and Fir trees and clean rivers and killer whales, and even Buffalo before that! We got DOF to manage these items for us!!!!
My point is..... when we allow the fox to manage the chicken coupe we really can't expect a happy outcome for the managees!! Its normal for us managers to promote our own agenda first.
In an attempt to manage er, I mean, interupt the natural order of things we skew off populations which affects millions of things which compounds exponentially on other millions of things which creates all kinds of havoc. Managing domestic wildfowl (ckickens) has created a bird flu epidemic....BEEF (CJB and mad cow disease)and they pollute the WATER (don't get me started)......(Salmon farms??)........enuff already!
Have we lost our ability to control just ourselves?
So my point is .. when there is not enough supply then the demand will fade. So? Let them eat the sapplings and undergrowth (they live here too!) and when there is no food they will surely shrink away in numbers that can be supported by the undergrowth community?
I believe each deer has a footprint that is infinitisimally much smaller than ours....gosh, they even contribute to the biosphere out their backsides. I produce nothing good out of my backside and very little out the front!!!
So what GOOD comes from a deers footprint? ....maybe room for other essential life affirming organisms to grow. (BTW: methane is a carbon gas that is also out of control due to the domestic cow populations that have increased to feed us HUMANS)
Lets us cut back on the # of biggest offenders first! the ones we CAN control? Any guesses?
Or am I just misguided?

Not misguided and I mostly agree, except that the deer footprint on the forest is HUGE and DEVASTATING and much greater than than mine and my chainsaw -- believe it or not.

But there's a little more info about the deer impact on the forest because that too is a PEOPLE problem.

Lots of people here feed the local deer herd a high-energy corn diet as a hobby so they can watch Bambi from their picture window. These super-fed deer drop healthy twin and triplet fawns which in turn are super-fed, super-healthy, and super-fertile. So instead of many of them starving in the winter like nature would have it, they march right on thru and keep reproducing like crazy. Add to that the deer are on VACATION except for the 9 day gun season and what chance is there for vegetation to grow in the forest?

In the natural order deer are a PREY animal to be hunted by subsistance peoples and animal predators 365 days out of the year! Instead with DNR protective laws and very few predators (really none) deer stand there watching you like a pet, and many of them are quasi-pets hanging around these feeders.

So yes, it is a PEOPLE problem too, absolutely, but I despair as the future of my beautiful forest is being wiped out and I am helpless to stop it or risk a $2000 fine!

There is a very great IMBALANCE here deer vs. eco-system.

If I had my way, I'd bring back the wolves and make deer an unprotected mammal and make them truly a wild animal again. The forest here is screaming for it, but trees don't have a lobby like Bambi does and DNR is very old-fashioned with 1950s thinking.

PS: It's nice to brag about being (almost) carbon-neutral, but even my little 50cc chainsaw and mini-tractor depend upon the fossil fuel petroleum infra-structure. So paradoxically to be (almost) carbon-neutral you still need the oil infra-structure to exist.

System2

Re: Photovoltaics & Firewood: An Ideal Combination?

Hi Paul,
I see....I am getting the picture,now!
We have a very similar problem with people feeding the birds.
I am not sure how healthy the humans are making all the birds but the RATS sure are FAT and gratefull!
We have thousands of millions of RATS!!
So, looks like we are fooling with mother nature in everything that we do and to what end?.
I don't know if we can rebuild a system? that is broken? or one that developed over several millions of years.
The only future (IMhO) is MAN in sustainable numbers.
Why? Must we increase our populations? why do we even allow it?
Why is (economic) growth considered so-o GOOD?
Cancer is an uncontrolled growth.
Humans are a cancer on this earth!!
Earth needs LESS cancer, not more?
What do you think?

System2

Re: Photovoltaics & Firewood: An Ideal Combination?

[QUOTE=paulstamser;10869

...50cc chainsaw and mini-tractor depend upon the fossil fuel petroleum infra-structure. So paradoxically to be (almost) carbon-neutral you still need the oil infra-structure to exist.[/QUOTE]

I disagree with this.... you can keep your cave woman and yourself warm with 100% non carbon burning fuel devices like axes and electric chain saws!!! And even you can choose to use an electric tractor? So why not?

The sun provide all the energy we need to heat our world from -1,000 degrees (f) to a balmy average temp of 56'(f). All we have to do is make 14'(F) with our human activity!

Can we not do that without fossil fuels?

Let me know.

now that... is carbon neutral!

crewzer

Re: Photovoltaics & Firewood: An Ideal Combination?

I think this has been a lively discussion, gents, but let's bear this forum's range and rules in mind.

Topical range:

Energy Use & Conservation Energy conservation tips & news, for solar & non-solar powered homes.

Rules:

This forum is owned and operated by Northern Arizona Wind & Sun, Inc.

This forum is free and unrestricted usage for all (even our competitors). We do not generally censor or delete any posts, but there are a few ground rules:

1. No commercial ads, solicitations, or links. No Spam or political - special interest causes. Members may post their private property for sale (but NO eBay links! ). Links to manufacturers and our website is OK (yeah, ok, so maybe links to our site are commercial, but after all we DO pay for this board).

2. No pictures of naked iguanas.

3. No posts praising Al Gore for saving the world.

If there are any questions about those policies, contact us or one of the moderators.

Best wishes to all for the holidays and the New Year!
Jim / crewzer

System2

Re: Photovoltaics & Firewood: An Ideal Combination?

Well, some people might be in favor of no discussion boards.
But how can we gain more knowledge? or educate ourselves? if not by reading others peoples posts (and opinions)!
How can NAWS say its not good to enjoy a lively discussion? Is it not good to stimulate our imaginations!
What does NAWS say about that!

crewzer

Re: Photovoltaics & Firewood: An Ideal Combination?

Moderation is a delicate balancing act. If a caution is made, someone will likely complain about the caution. If no caution is made, someone else may complain about the lack thereof.

It’s my view that the NAWS forum is a superior source of knowledge, education, reading, and opinions about solar energy (PV, wind, hydro, etc.) technology and applications. The forum also provides an area for discussions of energy conservation and tips.

However, NAWS owns the forum and makes the rules. Each of us agreed to abide by the forum rules when we registered. So, discuss away on matters relevant to the forum’s purpose and scope, but, as the general rules state: “No Spam or political - special interest causes.” And “No posts praising Al Gore for saving the world.”

No one said that it’s not good to enjoy a lively discussion or to stimulate our imaginations. And, to the best of my knowledge, no one’s comments in this discussion were edited or deleted. But, it seems to me that this particular discussion had briefly tilted away from energy conservation and towards political/special interest issues.

There are plenty of forums for political and/or special interest discussions, and e-mail is another discussion enabling tool. As far as this forum is concerned, I ask that we keep the topics and discussions limited to its scope and intent. A major reason of why I invest so much time and energy into this forum is becuase of the technical focus and the almost total lack of political rants, special interest promotions, bad science, and flaming. I'd like to do my part to keep it that way.

Feel free to petition Wind-Sun for a separate forum area that addresses other fields of interest. Or, consider starting a forum or blog of one’s own.

Best wishes for the holidays and the New Year,
Jim / crewzer

icarus

Re: Photovoltaics & Firewood: An Ideal Combination?

Jim,

Kudo's for doing the delicate job of keeping all of us in line. I know it is a thankless job and occasionally someone needs to say thanks,

Thanks,

Tony

nigtomdaw

Re: Photovoltaics & Firewood: An Ideal Combination?

Ditto to Niel as well as Jim.

crewzer

Re: Photovoltaics & Firewood: An Ideal Combination?

Thanks, gents. Actually, the vast majority of forum members make the moderation job pretty easy, I believe. I spend much more time on deleting messages for seem to be offers for "African mortgages for sex-change operatons via cell phones in China" that on anything else. :grr

Best wishes for the holidays and the New Year!
Jim / crewzer

niel

Re: Photovoltaics & Firewood: An Ideal Combination?

i will concur with jim that everybody here does make this easier for even during infractions you understand. we all enjoy the subject matter and appreciate what naws has done for us with the opportunity to have this forum. needless to say naws has benefitted from this as well so it's a win win.
happy holidays

paulstamser

Re: Photovoltaics & Firewood: An Ideal Combination?

envelopes2007 wrote: »

I disagree with this.... you can keep your cave woman and yourself warm with 100% non carbon burning fuel devices like axes and electric chain saws!!! And even you can choose to use an electric tractor? So why not?

The sun provide all the energy we need to heat our world from -1,000 degrees (f) to a balmy average temp of 56'(f). All we have to do is make 14'(F) with our human activity!

Can we not do that without fossil fuels?

Let me know.

now that... is carbon neutral!

With all due respect, I think you are straying into the world of idealism and NOT the practical necessities and realities of existing on a remote stand-alone PV homestead and using firewood for heating purposes during a long sub-zero northern winter like we are having this year.

Cutting a year's supply of fuelwood with an axe?

Have you ever tried that?

An electric-powered chainsaw?

Where would I get an extension cord that long? What would I plug it into? My battery-bank? BUT then I'd have to fire up my gasoline (fossil fuel) generator to charge the batteries in order to run the electric chainsaw with all the resultant losses. The direct gasoline fired chainsaw is much more efficient.

As an off-grid homesteader since 1980 and a off-grid PV homesteader since 1988, I must state that next to the solar electric panels in my system (and lead-acid batts), my gasoline chainsaws (I own 4) are the most important and essential tools that help me make this rather ideal lifestyle possible.

If I could escape from the vicious but necessary fossil fuel dependance cycle I certainly would, but the most I can do is cut my own fossil fuel use down to a "few" gallons a year and call it a day. But I'm still needing that petroleum infra-structure "fix" to make my high-tech/low-tech ideal lifestyle possible.

PS: Not to break forum rules and I hope that I'm not. I have years of living the actual PV-firewood lifestyle and see it as having a great number of interacting "systems" that call for compromises and up-close best-choice-under-the-circumstances environmental decisions that I have to make every day.

Thanks for the forum!

icarus

Re: Photovoltaics & Firewood: An Ideal Combination?

I suppose if you really wanted to cut the cord so to speak, you could brew your own ethenol, use veggie oil for the 2 cycle mix as well as veggie oil for the bar. Sounds like a huge waste of btu's however! The world will never be without a use for fossil based oil, but let's use it wisely, both from a conservation point of view, as well as a carbon foot print.

In another of those unattributed "fact" that I once learned: I was once told that there are two man made machines that are more effecient than humans doing it themselves. You can cut more wood with fewer calories burned with a chainsaw than a handsaw, and you can travel farther on a bicycle with few calories burned than you can walk.

Icarus.

paulstamser

Re: Photovoltaics & Firewood: An Ideal Combination?

I was in the hardware store and noticed a 40 lb bag of stove wood pellets for $3.99 packaged in a plastic bag.

Because any dry wood per lb has the same BTU content I do believe, then it would appear that each 40 lbs of firewood I collect is worth $3.99 retail. That means I have many THOUSANDS of dollars worth of firewood already cut, splt, and stacked with an endless supply of solar-powered growing trees for the future.

I didn't think of that, but trees are solar-powered aren't they? Sort of automatically growing green PV panels!

This is like having an automatically self-renewing private gold mine or oil well on ones own property with the added beauty that if managed right, you can actually improve the forest environment and wildlife habitat by harvesting firewood; unlike the environmental harm of having a real gold mine or oil well.

Not bad!

BB.

Re: Photovoltaics & Firewood: An Ideal Combination?

Here is a good general purpose calculator for the cost of heat from various sources (hardwood, softwood, pellets, and fossil fuels/electricity).

And here is a list of BTU per lb/cord for various species of wood (apparently properly dried woods all have roughly the same BTU/lb... It is just soft woods are less dense than hard woods).

-Bill

paulstamser

Re: Photovoltaics & Firewood: An Ideal Combination?

BB. wrote: »

Here is a good general purpose calculator for the cost of heat from various sources (hardwood, softwood, pellets, and fossil fuels/electricity).

And here is a list of BTU per lb/cord for various species of wood (apparently properly dried woods all have roughly the same BTU/lb... It is just soft woods are less dense than hard woods).

-Bill

BB,

That fuel cost calculator is GREAT! Even softwoods delivered to your home beats wood pellets and everything else. The cost of wood you gather yourself must be even LOWER.

Plus trees are solar-powered!

Win-win!

BB.

Re: Photovoltaics & Firewood: An Ideal Combination?

Glad you liked it Paul!

However, I cannot claim finding of the calculator link... It was somebody else here (like Jim or Wayne?) who posted it quite awhile ago.

-Bill

westbranch

Re: Photovoltaics & Firewood: An Ideal Combination?

just a quick comment about photosynthesis and sunshine...
A university professor that gave a lecture to our Siviculture Institute class a few years back brought us up to speed on the latest research on how plants photosynthesise.
Much had been unveiled in the 20 years since I had been in University....the process was still the same but which Carbon and Oxygen molecules went where had changed...
However one mystery (black box) remains, In that process plants can take very low levels of incoming sunlight and split a water molecule into its constituents, Hydrogen and Oxygen, the person that breaks open that black box will be famous and a very rich man.
Think of how efficient trees must be to take incoming light on a cool, foggy day and still be able to split water.
Man has to use almost unimaginable amounts of Hydro to do it... and if this process/research could be applied to PV panels, the output would be unimaginable. This is not pie in the sky stuff, just a mystery waiting to be solved!

Eric

icarus

Re: Photovoltaics & Firewood: An Ideal Combination?

Paul,

Not to pick nits, but,,since we are having a theoretical discussion:

Pellets have a greater density of btu per pound largely because they are very dense, and they are very dry. Second, pellet stoves typically burn significantly more efficiently than do even good woodstoves because of the controlled combustion. Third, there is some considerable energy spend creating pellets. Also if you buy in quantity your price goes down. Go to any local Big box store, and see the shrink wrapped pieces of fire wood for sale stacked on a pallet, perhaps 6 pcs for $4.95. Would be ~$1000/cord. Just like if you bought all your oil in a 2 oz can.

I do go back to my original conclusion, that heating with wood is a good idea for those of us who tend to live in the woods so to speak. To think however that wood heat will resolve either the oil shortage or global climate change is wrong.

Eric,

Your right, it is amazing that even in the worst climates of the world, photsynthysis (sp?) not only works, but it is an amazing phenomena. In sub arctic climates it is amazing to see spring come, and watch the plants that should be frozen solid emerge and thrive as the photo period gets longer.

My favorite time of year is that cusp between our sub arctic winter and spring! It is also amazing to watch the world in the weeks leading up to the equinox and the weeks thereafter. The world changes very dramaticly.

Icarus

System2

Re: Photovoltaics & Firewood: An Ideal Combination?

ICARUS
It also takes less calories to drive an SUV... than ride a bike? or operate a chainsaw? or do dishes? So I am not sure if that argument makes sense!!

As I see it..... the issue is to make a smaller carbon footprint on the earth? Renewable energy for sure is the key to this. We do have electric vehicles but just no where to drive them yet? So, why not electric farm vehicles?


Here is my meteorological perspective....When water molecules get excited they are more likely to reach their gaseous phase. If and when, that happens water vapor tends to turn itself back into liquid when certain conditions are met. In otherwords we generally get it back in spades! But it can be in buckets!!!!

The more water vapor we get into our air (above our oceans) the more rain and snow we get.....and the greater the FREQUENCY and INTENSITY of the weather events. The intensity of some weather events can be crucial to the survival of some species on this planet.

Question is how many Katrinas (then) do we really need?

Stopping the sun from warming the oceans surface is one thing! BTW: Did you know that a few years back, all commercial plane traffic was suspended in NA for about 2-3 days. The resulting absence or lack of any vapor trails over the NA skies allowed the earth surface temp to increase by an average of 1' Celsius ! OMG.... Lord, help us if we ever stop flying those jets!!

But my point is this, its not the temperature of the earth that counts its the energy being stored by the sea. One heckuva large (mass) times a little tiny increase in temp (energy) equals one huge lot of potentially devastating destructive power ie: (force). One large PV panel !!

Remember water molecules are first to react to an increase in energy (heat) and water molecules react big time!! Ice storms in Quebec?

kevin

BB.

Re: Photovoltaics & Firewood: An Ideal Combination?

Global warming tends to heat the poles while the equator remains about the same (according to GW modeling and observed effects). Temperature differences are what tend to drive hurricanes, tornadoes, etc. (these storms are heat engines). So with global warming, the expectation is that storms will tend to weaken in energy as the world "warms".

At this point in time, there is no scientific evidence that Katrina was driven (or not driven) by global warming. And Katrina was a Category 1 hurricane by the time it hit land. This was just the worst case of any strong storm hitting a particularly vulnerable and populated region.

From Real Climate (which tends to support AGW):

Finally, then, we come back to Katrina. This storm was a weak (category 1) hurricane when crossing Florida, and only gained force later over the warm waters of the Gulf of Mexico. So the question to ask here is: why is the Gulf of Mexico so hot at present - how much of this could be attributed to global warming, and how much to natural variability? More detailed analysis of the SST changes in the relevant regions, and comparisons with model predictions, will probably shed more light on this question in the future. At present, however, the available scientific evidence suggests that it would be premature to assert that the recent anomalous behavior can be attributed entirely to a natural cycle.

When it was actually damaging levies in New Orleans:

Katrina might have further downgraded to a strong Category 1 system with 95 mph winds when it punched water through New Orleans' levees, severely flooding most of the city and killing hundreds. The levees were designed to withstand a Category 3 storm. If verified, the wind information compiled by the National Oceanic and Atmospheric Administration's Hurricane Research Division could have chilling ramifications.

Also, as Jim (Crewzer) reminded me in another discussion--Much worse modern storms include Mitch and Wilma -- both Cat 5. Mitch killed a lot of people in Central America... we don't seem to hear much about that. The 1900 Galveston hurricane was a Cat 4 -- which was during the "global cooling" phase of the beginning (and before) of the 20'th century.

And, water vapor is the major constituent of "Green House" gases in the atmosphere. CO2 and others (methane) make up the balance of the gases. Again, from Real Climate:

The overlaps complicate things, but it's clear that water vapour is the single most important absorber (between 36% and 66% of the greenhouse effect), and together with clouds makes up between 66% and 85%. CO2 alone makes up between 9 and 26%, while the O3 and the other minor GHG absorbers consist of up to 7 and 8% of the effect, respectively. The remainders and uncertainties are associated with the overlaps which could be attributed in various ways that I'm not going to bother with here. Making some allowance (+/-5%) for the crudeness of my calculation, the maximum supportable number for the importance of water vapour alone is about 60-70% and for water plus clouds 80-90% of the present day greenhouse effect. (Of course, using the same approach, the maximum supportable number for CO2 is 20-30%, and since that adds up to more than 100%, there is a slight problem with such estimates!).

What ever is the "best temperature the earth is supposed to be"... There are lots of interactive processes going on here. And the outcome of GW (whether man made or not) is not obvious. From the Telegraph (UK Paper):

A key article of faith for the "warmists" is a supposed increase in the incidence of extreme weather events, such as droughts. As [name redact ed per forum rules] claimed to a US Senate committee in March, "droughts are becoming longer and more intense".

But US researchers, led by Gemma Narisma, have now shown that, far from becoming more frequent in recent decades, serious droughts have in fact become rarer than they were a century ago.

In a paper (reported on the website CO2Science.org) they identified the 30 most "severe and persistent" drought episodes of the 20th century.

Seven of these occurred before 1920, seven between 1921 and 1940 and eight between 1941 and 1960, dropping to five between 1961 and 1980.

The last two decades of the century, when the world was supposedly hotting up more than ever, saw just three. The worst drought affecting the developed world was the US Dust Bowl disaster of the mid-1930s.

We are going to have more issues as the rest of the world tries to catch up to the level of energy use that we have grown use to in the western world (ibid):

China, now building a new coal-fired power station every four days, last year added 102 gigawatts of new generating capacity, 25 per cent more than the entire capacity of the UK. As ever more pointed question marks rise up over the global warming thesis, who is to say it is the Chinese who are mad?

In the end--this discussion is probably way beyond what the intent of Wind-Sun's Forum is intended to be...

We are here to discuss the best way to accomplish some specific goals--conservation and renewable energy systems. Why each of us wants to do this is beyond what our kinds hosts can manage here. We all hold personal opinions and believes that could easily make it a nightmare for Jim, Niel, and Wind-Sun to moderate if fully aired here.

Take care,
-Bill

System2

Re: Photovoltaics & Firewood: An Ideal Combination?

How do You add a footnote to your postings!!

BB.

Re: Photovoltaics & Firewood: An Ideal Combination?

Envelopes...

I don't think you can do "footnotes" here... Are you asking about "links" or "Quotes"???

If so, when you go to post (or "Quote Post"), you will see a line that begins with B I U... Go to the right, there is a "globe" with a chain (highlight the text and click globe--a pop up will appear where you put your http:// stuff).

If it is the QUOTES... There is yellowish box that looks like a cartoon thought bubble. Either click the button and two start quote / end quote "key words" will appear--and you can type/paste your text into that... Or enter your text and highlight--then push the Quote button and it will add the tags to the beginning and end of your quote... (you can also manually type in the key words/tags if you know what they are--you will see them in your edit window as you start using them).

If you "hover" your mouse over the buttons, a little tag will appear with a bit more information about each function.

-Bill

icarus

Re: Photovoltaics & Firewood: An Ideal Combination?

envelopes2007 wrote: »

ICARUS
It also takes less calories to drive an SUV... than ride a bike? or operate a chainsaw? or do dishes? So I am not sure if that argument makes sense!!

As I see it..... the issue is to make a smaller carbon footprint on the earth? Renewable energy for sure is the key to this. We do have electric vehicles but just no where to drive them yet? So, why not electric farm vehicles?


Here is my meteorological perspective....When water molecules get excited they are more likely to reach their gaseous phase. If and when, that happens water vapor tends to turn itself back into liquid when certain conditions are met. In otherwords we generally get it back in spades! But it can be in buckets!!!!

The more water vapor we get into our air (above our oceans) the more rain and snow we get.....and the greater the FREQUENCY and INTENSITY of the weather events. The intensity of some weather events can be crucial to the survival of some species on this planet.

Question is how many Katrinas (then) do we really need?

Stopping the sun from warming the oceans surface is one thing! BTW: Did you know that a few years back, all commercial plane traffic was suspended in NA for about 2-3 days. The resulting absence or lack of any vapor trails over the NA skies allowed the earth surface temp to increase by an average of 1' Celsius ! OMG.... Lord, help us if we ever stop flying those jets!!

But my point is this, its not the temperature of the earth that counts its the energy being stored by the sea. One heckuva large (mass) times a little tiny increase in temp (energy) equals one huge lot of potentially devastating destructive power ie: (force). One large PV panel !!

Remember water molecules are first to react to an increase in energy (heat) and water molecules react big time!! Ice storms in Quebec?

kevin

Kevin,

With all due respect, I think you missed my point about calories vs work. (NB for thems that may not know, a calorie is just a unit of heat, like a btu only smaller)

My point was that it takes less energy to ride a bicycle or cut wood with a chain saw than walking or cutting by hand. The only activities that I know of that are more efficient than man doing it himself.

Icarus

niel

Re: Photovoltaics & Firewood: An Ideal Combination?

envelopes2007,
i think what you are refering too is the signature line. that's the same line you see what everybody has for their solar setups at the bottom of every post they make.
to get there go to your profile by clicking on your user name and you'll see "user options" on the right hand side. go into that and it should ask for your password again. once in there you'll see in the 1st column, below your birthday, an area that you can place what you have or something in general you'd like seen from every post that is marked as the "signature". the line in question is where i placed "NIEL-N3GHX(not employed by naws)". i hope this is what you were looking for and helps and please follow the rules when doing the signature too.

System2

Re: Photovoltaics & Firewood: An Ideal Combination?

The definition of a machine is something that will do work or overcome friction?. The calories burned by a human body to operate a machine is what you seem to be referring to in this post?
Ice skates, golf clubs, rolling pins, washing machines? I don't get it. All require few calories to operate but have huge advantages over humans doing it themselves
Are you saying the BTU's from burned wood exceed the calories burned by the chainsaw operator?
I'm not sure I do understand
Can anyone else explain what I am missing?
Yes, signature was it!.
Thanks

BB.

Re: Photovoltaics & Firewood: An Ideal Combination?

Kevin,

Not sure what your question is... If you want the amount of power from a human, you can calculate it here:

A 2,000 Kcalorie daily diet is 7,936 BTU, 0.0644 gallons of gasoline, or 96.9 watts / 0.13 HP of continuous "power" (averaged over 24 hours).

A 150 lb man running an 8 minute mile outputs about 280 watts, 33 miles to burn off a pound of fat, and the body is about 25% efficient at energy conversion....

From here, a cord of wood has about 10 to 20,000,000 BTU (of recoverable heat) per cord of wood. A cord of wood is 128 cuft--so 1 cuft of wood is 78,125-156,250 BTU.

And, if you want compare the costs of various fuels--this oldy but goody link to the Fuel Cost Comparison Calculator works well.

Or 1 cuft of wood represents about 10-20x the amount of "heat" of a highly feed westerner...

What also matters, but gets little discussion because of all variables, is what is available... Food for people? Firewood? Tools? Oil? What is it we are trying to minimize? CO2, pollution, returning farm land to "natural" wilderness, make things easier so I don't have to work so hard (push a few buttons or swing an ax and pull a plow), or what?

-Bill

System2

Re: Photovoltaics & Firewood: An Ideal Combination?

Hi Bill,

Here is my question

icarus wrote: »

Kevin,

With all due respect, I think you missed my point about calories vs work. (NB for thems that may not know, a calorie is just a unit of heat, like a btu only smaller)

My point was that it takes less energy to ride a bicycle or cut wood with a chain saw than walking or cutting by hand. The only activities that I know of that are more efficient than man doing it himself.

Icarus

I am trying to understand this point?
I am confused.

Otherwise, I am burning calories on my signature

Kevin

mike95490

Re: Photovoltaics & Firewood: An Ideal Combination?

I think what he's trying to say is that a Chainsaw, burning a couple of drops of fuel for each cut, is more efficient than a human pumping a saw back and forth.

Likewise with a bicycle, the calories spent to pump the pedals with your legs, is less than what a motor would burn to do the same work. (but legs aren't as fast as a motor)

icarus

Re: Photovoltaics & Firewood: An Ideal Combination?

Thank you Mike!

I may not be smart, but I make up for it by being slow.

I realize that when I wrote this is the late night hours, I wasn't being very clear. You got it right!

The act of cutting with a chainsaw uses few btus, than a person doing it by hand! Same for riding a bicyle as opposed to walking.

Once again, I'm sorry that I wrote it so poorly that Kevin couldn't get it, and B: that I cannot attribute it to any source

Icarus


PS
Just to recap my thought: I was once told the following factoid. "There are only two machines invented and used by humans that are more efficient than the many doing it by hand"

All work, requires energy and that energy is measured in heat, BTU's or Calories. A chainsaw will cut a given piece of wood than you can cut it with a good sharp hand saw. Like wise you can travel further on a bike given an equal amount of btu's/calories than you can walk.

If anyone can attribute this I would feel better.

Tony