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Lots of people are getting excited about all the various technologies for using biofuels of one sort or another as a replacement for fossil fuels, and they may present a short-term option. But looking at the various kinds of energy production that are possible gives some insight into the best directions to promote in terms of developing long-term efficient energy production.
A study cited on EV World makes a comparison between different crop- and direct-production methods of generating energy in terms of miles per acre per year, with some eye-opening information.
At the bottom end of the scale is soybean biodiesel, which can provide only 2,400 miles per acre per year. Corn ethanol is more than six times as efficient, yielding 18,000 miles per acre per year. But because of the relatively slow rate of production from plant-based fuels, these options far fall below the productivity of directly produced energy.
The same acre can produce 10 times as much energy from wind as it can from corn ethanol, 180,000 miles per acre per year. But both corn ethanol and wind power pale in comparison with solar photovoltaic, which can produce more than 2 million miles worth of transport per acre per year.
This is not to completely dismiss biofuels out-of-hand. The cost of an acre's worth of solar PV arrays is far more than 100 times more expensive than planting an acre of corn. Many biofuels can be produced on marginal lands that are ill-suited for solar. And cellulosic ethanol can even be produced from waste, effectively making it a zero land-use fuel. And presumably the comparisons are based on sites that are optimal for each mode of generation. A site that is highly suitable for harvesting wind energy may not be a good site for growing corn, and vice versa.
The infrastructure and the existing "car parc" (the entire fleet of all vehicles in the country) is also going to take decades to turn over to the point where a significant proportion of the vehicles on the road are electric vehicles. Both a mix of energy sources and regionally appropriate choices need to be part of a comprehensive energy plan. But this offers a useful comparison that suggests where the best allocation of resources should be focused in terms of long-range planning for our energy future.
Link: EV World (chart halfway down the page)
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Comments (26)
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written by Craig, March 19, 2008
Is it just me or does this just highlight the disparity between the price of energy as automotive fuel and the price of energy as distributed electrical power?
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written by Carl, March 19, 2008
I love the comparison. However, I believe the other side of the story is to compare the price per mile for each energy source. As we've now begun to see in solar, it's not the energy output per panel or square foot, it's the energy output per dollar.
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written by Lucia Freitas, March 19, 2008
That's it. Here in Brazil we can see forests going down so people can plant more sugar cane in order to make alcohool for cars... It's ridiculous. It's criminal. And everebody is happy with it, not considering the future cost. It changes climate!
Sugar cane is responsible, historically, for desertification in northeast of this country. But of course, no one reminds it.
Nice to see this facts. It helps a lot. Let's convert this measurements and tell people here.
thanks for the information.
Sugar cane is responsible, historically, for desertification in northeast of this country. But of course, no one reminds it.
Nice to see this facts. It helps a lot. Let's convert this measurements and tell people here.
thanks for the information.
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written by Roy, March 19, 2008
But we can't plant a fist-full of almost-free seeds to make a solar farm. Wish I could.
Still... that really gives you an interesting sense of scale and perspective. Good find.
Still... that really gives you an interesting sense of scale and perspective. Good find.
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written by Bob Wallace, March 19, 2008
It's not as simple as Jack tossing out his beans.
Even with a perennial such as switchgrass the crop still needs to be harvested, hauled to the plant, processed into fuel and the fuel transported to the consumer.
Each of these steps require a significant up front capital expenditure.
Each of these steps create a significant and reoccurring cost.
Solar is capital expensive. But after the panels/thermal collectors are installed and grid connected there are relatively few reoccurring expenses.
And solar runs essentially CO2 free.
This is a very interesting comparison, but mostly for comparing one biofuel source to another. There's not enough data included to make a sound biofuel/solar decision.
Even with a perennial such as switchgrass the crop still needs to be harvested, hauled to the plant, processed into fuel and the fuel transported to the consumer.
Each of these steps require a significant up front capital expenditure.
Each of these steps create a significant and reoccurring cost.
Solar is capital expensive. But after the panels/thermal collectors are installed and grid connected there are relatively few reoccurring expenses.
And solar runs essentially CO2 free.
This is a very interesting comparison, but mostly for comparing one biofuel source to another. There's not enough data included to make a sound biofuel/solar decision.
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written by Al Fin, March 19, 2008
This analysis leaves too much out to be taken seriously. Where are the solar farms located? What is the cost of transporting power from the solar farms to point of use? How do you deal with the diurnal variation in available solar energy? And like Carl says, what is the cost per mile, given the huge up-front costs of photovoltaics?
This graph does tell us that in 30 or 40 years we are going to be using more electricity than liquid fuels--whether from nuclear, geothermal, or solar, one cannot say.
This graph does tell us that in 30 or 40 years we are going to be using more electricity than liquid fuels--whether from nuclear, geothermal, or solar, one cannot say.
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written by Dan Anderson, March 19, 2008
In a large portion of the crop producing US, we don't get enough sunlight year round for solar to be practical. However, we do not lack in wind. I personally hate corn use for bio-diesel/ethanol. The plant uses way to much water for what you get out of it. Drought in Nebraska is making corn farmers irrigate extensively. Converting some acreages into wind farms could be a very good solution for farmers coping with a drought that has no end in sight.
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written by Bob Wallace, March 19, 2008
Obviously the solar farms are going to largely located in the sun belt. We're going to need to make significant investments in power transmission. (Think HVDC smart grid.)
The solar day will be smoothed out by utilizing thermal solar which can store energy for the 'dark hours', storage systems such as pumped up hydro, compressed air, and batteries (including BEVs).
Additionally the grid won't be fed by only solar. There's also wind, wave, hydro, tidal, geothermal, biomass, fossil fuel, and nuclear. (Until we can phase out fossil and nuclear.)
As for cost per mile with solar....
I did some quick and dirty calcs using the Tesla BEV. I used my weekly driving average (150) and figured that I would need about 1.2kW per panels using a 4 hour solar day (conservative for the sun belt).
Using $5 per watt (high, but should easily cover installation, etc.) I would need to spend about $6,000 for 20 years of 'fuel'.
That's roughly $0.04 cents per mile.
The solar day will be smoothed out by utilizing thermal solar which can store energy for the 'dark hours', storage systems such as pumped up hydro, compressed air, and batteries (including BEVs).
Additionally the grid won't be fed by only solar. There's also wind, wave, hydro, tidal, geothermal, biomass, fossil fuel, and nuclear. (Until we can phase out fossil and nuclear.)
As for cost per mile with solar....
I did some quick and dirty calcs using the Tesla BEV. I used my weekly driving average (150) and figured that I would need about 1.2kW per panels using a 4 hour solar day (conservative for the sun belt).
Using $5 per watt (high, but should easily cover installation, etc.) I would need to spend about $6,000 for 20 years of 'fuel'.
That's roughly $0.04 cents per mile.
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written by ryan lamberg, March 19, 2008
The corn numbers and biodiesel numbers are totally reversed. I am suspect that a website the promotes Electric is out bashing biofuels. The saga continues and makes no sense. You can't fuel a dump truck with solar panels-- no comparison.
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written by Steve Stout, March 20, 2008
This is a good study, but there's still some info missing. Soybeans are grown to feed cattle, the oil is a byproduct. We can't eat solar farms and still get energy out of them.
I'm growing jatropha in tropical countries, employing thousands of rural poor. If we just brought in solar panels there would be no work. My trees also absorb a lot of CO2 and recondition the soil. Some people did bring solar panels to Ghana (one of the places we plant), but with no maintenance program they all failed over time and now produce nothing.
I'm growing jatropha in tropical countries, employing thousands of rural poor. If we just brought in solar panels there would be no work. My trees also absorb a lot of CO2 and recondition the soil. Some people did bring solar panels to Ghana (one of the places we plant), but with no maintenance program they all failed over time and now produce nothing.
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written by Leonard, March 22, 2008
This is the kind of data that looks great at first glance. However, because there is no information on the assumptions made for the calculations to get to the Miles per Acre figures cited, it does not provide much value to the reader. For example, with regard to the Solar calculation, which of the many competing technologies is being used? At what conversion efficiency? At what Capital costs? Data like this is nearly useless without stating the assumptions made. We already know that corn as a fuel source is lousy and that wind and solar are better. In order to make meaningful and realistic quantitative comparisons, assumptions for all the underlying variables need to be specified.
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written by Nick, March 22, 2008
http://lotuslive.org/transport...sgraph.png
This graph compares the cost of driving on ethanol and electricity.
Given 15 cent/kWh PV (take out a loan for it in CA and that's what you get), it's 3.8 cents compared to 11 cents for ethanol. Given 35 cent/kWh PV in MA (ditto), it's 9 cents, still cheaper.
For the given PHEV, the volt, PV in CA is cheaper than ethanol, PV in MA is more expensive. But given good PHEVs (Aptera) and all-electrics, solar (at least on the roof of your garage) is cheaper than ethanol.
This graph compares the cost of driving on ethanol and electricity.
Given 15 cent/kWh PV (take out a loan for it in CA and that's what you get), it's 3.8 cents compared to 11 cents for ethanol. Given 35 cent/kWh PV in MA (ditto), it's 9 cents, still cheaper.
For the given PHEV, the volt, PV in CA is cheaper than ethanol, PV in MA is more expensive. But given good PHEVs (Aptera) and all-electrics, solar (at least on the roof of your garage) is cheaper than ethanol.
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written by Nick, March 22, 2008
Assuming SunPower panels (22% efficient), $9/W installed minus the appropriate CA and MA incentives, given the appropriate insolations in those states, financed at 6% APR.
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written by Dan, March 22, 2008
Sorry, this just does not add up.
To calculate how much energy something is worth compared to another you have to know exactly how much energy was required to MAKE THAT THING.
Energy, specifically electrical energy from power plants, is required to produce the polysilicon used to make solar panels. LOTS OF ENERGY--MEGAWATTS OF ENERGY.
To say, "solar does not use energy or does not produce CO2" is highly erroneous. The only way to look at these things is to account for life to death (and recycling energy if applicable) use of energy. LIFE CYCLE ANALYSIS. WITH COMPLETE ACCOUNTING OF EXACTLY IS IN THE MODEL.
I am certain that the EV World blurb takes a report from a consultant with interest in promoting solar (but the original report requires a payment to actually read--how convenient) that takes into account all the energy that biodiesel and ethanol consume in their production, but conveniently IGNORES the huge amount of energy that is required on the front end of solar power production.
I am not against solar, I just want an objective view rather than "1000x more energy". Solar is progressing, and the amount of energy used to produce polysilicon outside of China is reaching an improved balance. In China, TCS (trichlorosilane) waste is being dumped on the ground. TCS is a significant pollutant! TCS is recycled in the production of polysilicon in environmentally civilized countries. Something else to consider as we grab up the solar panels at Walmart and Costco.
Next stop--perpetual motion patents.
To calculate how much energy something is worth compared to another you have to know exactly how much energy was required to MAKE THAT THING.
Energy, specifically electrical energy from power plants, is required to produce the polysilicon used to make solar panels. LOTS OF ENERGY--MEGAWATTS OF ENERGY.
To say, "solar does not use energy or does not produce CO2" is highly erroneous. The only way to look at these things is to account for life to death (and recycling energy if applicable) use of energy. LIFE CYCLE ANALYSIS. WITH COMPLETE ACCOUNTING OF EXACTLY IS IN THE MODEL.
I am certain that the EV World blurb takes a report from a consultant with interest in promoting solar (but the original report requires a payment to actually read--how convenient) that takes into account all the energy that biodiesel and ethanol consume in their production, but conveniently IGNORES the huge amount of energy that is required on the front end of solar power production.
I am not against solar, I just want an objective view rather than "1000x more energy". Solar is progressing, and the amount of energy used to produce polysilicon outside of China is reaching an improved balance. In China, TCS (trichlorosilane) waste is being dumped on the ground. TCS is a significant pollutant! TCS is recycled in the production of polysilicon in environmentally civilized countries. Something else to consider as we grab up the solar panels at Walmart and Costco.
Next stop--perpetual motion patents.
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written by Arthur, March 22, 2008
Is EV World a peer reviewed journal? This data looks skewed to me and fails to consider many factors. Was the cost of growing corn vs. the cost of growing biofuel crops considered? Was the cost of fertilizer considered?
Corn takes a lot out of the soil which may be one of the reasons the mid west is having problems with their soil. Corn needs highly fertile soil and still must be fertilized. Even so; growing corn depletes the soil. Crops such as soybeans, rapeseed, and switchgrass grow in marginal soil and actually improve the soil.
Most of the biofuel crops mentioned are also food crops and therefore raise the price of food. Palm Oil producers are cutting down rain forests to make plantations. I have a problem with making others go hungry and destroying the environment so I can drive a vehicle.
Corn takes a lot out of the soil which may be one of the reasons the mid west is having problems with their soil. Corn needs highly fertile soil and still must be fertilized. Even so; growing corn depletes the soil. Crops such as soybeans, rapeseed, and switchgrass grow in marginal soil and actually improve the soil.
Most of the biofuel crops mentioned are also food crops and therefore raise the price of food. Palm Oil producers are cutting down rain forests to make plantations. I have a problem with making others go hungry and destroying the environment so I can drive a vehicle.
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written by Veronika, March 30, 2008
In Thailand used cooking oil was supposed to be the source for biofuel but the collection is so complicated that the producers of biofuel turned to use the fresh palm oil, driving up price of cooking oil...
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written by frisbee, March 31, 2008
Trees can accumulate many tons of CO2. Bio-diesel crops leave farming lands hardly grown or ungrown at all for much of the time. So, in order to fight global warming, plant trees (woods) and use desert space for harvesting solar-energy.
Besides: onshore wind-energy can be very well combined with solar at many places and combined with growing (food-)crops at other places. So wind-energy doesn't need to be so little efficient per acre as suggested at all, as long as one is prepared to combine different options!
Besides: onshore wind-energy can be very well combined with solar at many places and combined with growing (food-)crops at other places. So wind-energy doesn't need to be so little efficient per acre as suggested at all, as long as one is prepared to combine different options!
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written by Witchita, April 06, 2008
Did anyone ever played Command & Conconquer before. You know Tiberium? Well Palm Oil is. Useful top to bottom, eco-friendly & practical.
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written by frank, November 27, 2008
Dear Sir/Ms
Hope you are doing well !
We are a leading manufacturer in China of LED & SOLAR lighting.
We supply high quality LED & SOLAR light at most competitive prices.Here are our products list as below:
--LED high power street Solar light
--LED spot light
--LED tunnel light
--LED tube light
--SOALR LED light series
We look forward to hearing from you soon!
Tks in advance and Kind Regards.
Frank lin
--------------------------------------------------------------------------------
EXPERT OF LED & SOLAR LIGHTING
Name ： Zhongshan Hongbao Electrical Co.Ltd
Address ：Wen Cheng Industrial Park,JiXi,XiaoLan Town,ZhongShan City
Tel ： 86-760-22106597 22234666 22831803
Mobile: 86-013726046132
Fax： 86-760-2117461
Website ：www. globalmarket.com/hongbao www.zshongbao.com
E-mail : \n This e-mail address is being protected from spambots. You need JavaScript enabled to view it '> This e-mail address is being protected from spambots. You need JavaScript enabled to view it
Hope you are doing well !
We are a leading manufacturer in China of LED & SOLAR lighting.
We supply high quality LED & SOLAR light at most competitive prices.Here are our products list as below:
--LED high power street Solar light
--LED spot light
--LED tunnel light
--LED tube light
--SOALR LED light series
We look forward to hearing from you soon!
Tks in advance and Kind Regards.
Frank lin
--------------------------------------------------------------------------------
EXPERT OF LED & SOLAR LIGHTING
Name ： Zhongshan Hongbao Electrical Co.Ltd
Address ：Wen Cheng Industrial Park,JiXi,XiaoLan Town,ZhongShan City
Tel ： 86-760-22106597 22234666 22831803
Mobile: 86-013726046132
Fax： 86-760-2117461
Website ：www. globalmarket.com/hongbao www.zshongbao.com
E-mail : \n This e-mail address is being protected from spambots. You need JavaScript enabled to view it '> This e-mail address is being protected from spambots. You need JavaScript enabled to view it
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written by Gallagher, Brian t, April 11, 2009
Looking for information
How much energy would one acre of solar panels generate?
How much energy would 30 acres generate?
How much capital would it take to develope 30 acres?
To distribute energy what would be needed?
To store energy what would be needed?
Any help would be apreciated! ;o)
How much energy would one acre of solar panels generate?
How much energy would 30 acres generate?
How much capital would it take to develope 30 acres?
To distribute energy what would be needed?
To store energy what would be needed?
Any help would be apreciated! ;o)
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written by Gallagher, Brian t, April 11, 2009
Contact info
This e-mail address is being protected from spambots. You need JavaScript enabled to view it
This e-mail address is being protected from spambots. You need JavaScript enabled to view it
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written by Jim, April 22, 2009
I would just like to know, rather than miles per solar panel acre, how much power does one acre of solar panels produce? Power that could be used for any purpose-lighting, auto, manufacuring, water purification...
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written by Theodore, July 05, 2009
What amazes me is how many people complain about the amount of land that's used by solar power and the amount of water it consumes for cooling. Compared to any agricultural biofuel, both are insignificant, yet every time a solar project is proposed, there are people willing to bring these issues up as reasons to oppose the project.
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written by HalfABrain, July 16, 2009
Output isn't hard to guesstimate.
You can buy the SolarWorld SW175 for $795 today from Backwoods Solar. It maxes out at 175 watts, and is 14 square feet in size. You would need 3101.5 of these to cover an acre.
An acre of these would max out at 542 Kilowatts, and cost $2,465,684. On a good day with 5 good hours of sun, you could put out 2,713 KwH. Averaged over a year is 991,217 KwH. Round it out to a million and it's pretty good guess I think.
That means these guys are estimating 2.5 miles per KWH, which is pretty conservative. It's not uncommon for people with converted Geo Metro cars to get 4 miles per KWH. in actual practice, from the electric meter to the odometer.
You can buy the SolarWorld SW175 for $795 today from Backwoods Solar. It maxes out at 175 watts, and is 14 square feet in size. You would need 3101.5 of these to cover an acre.
An acre of these would max out at 542 Kilowatts, and cost $2,465,684. On a good day with 5 good hours of sun, you could put out 2,713 KwH. Averaged over a year is 991,217 KwH. Round it out to a million and it's pretty good guess I think.
That means these guys are estimating 2.5 miles per KWH, which is pretty conservative. It's not uncommon for people with converted Geo Metro cars to get 4 miles per KWH. in actual practice, from the electric meter to the odometer.
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written by Tom, August 08, 2009
Hi, One thing I rarely see mentioned is the waste of space on the top of every building in the world. Why waste perfectly good farmland when we all live under and work under peaked roof or flat roof buildings. Based on HalfABrain's 175 watts per hour per 14 sq foot panel a house with 140 sq feet of roof surface could generate 38325 miles of power for the conservative estimate of 2.5 miles per Kwh. For a geo metro up the total miles per year to 61320 miles or more than enough for 3 vehicles. In addition only the production of the panels harms the environment if you really believe the human race is causing global warming.
-CommonSense
-CommonSense
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