Your Questions About Renewable Energy Content

admin answers:

Hey Brian, interesting question, and one that gets to the heart of many renewable energy myths today. Your explanation might have a couple apples vs oranges. The sun produces much more power than 120,000 terawatts, or terawatts per year, but I’m not sure if TW/Y represents either of those. Total electrical energy use on our globe is about 15 terawatts continuously, or 132,000 TW hours each year. Since solar panels are about 12 to 14 % efficient today, it would take an area of 192 square miles to produce that much power. Problem is, you would need it to work 24/7, and most places on our globe are dark at night. Accomodating for night time, and twilight hours in the morning and evening when the panels would be operating below peak power, the number jumps to about 890 square miles, or about 39,000,000 acres. That sounds huge, but consider that Rhode Island takes up over 1500 square miles, and is one of the smallest states in the US, really that scenario is feasible. The fact is we are never going to do that. The cost, the enourmous demand for silicone, wiring, grids, and so on make it totally impractical. There is also the fact that Rhode Island is pretty cloudy.

Now enter the Germans, they have a fantastic plan to mine solar power from the Sahara Desert. It doesn’t involve solar panels, instead they are going to use solar thermal collectors that will heat oil to several hundred degrees, which will be circulated back into huge insulated tanks, then the hot oil will be used to boil water into steam ,which will turn a steam turbine. This idea has several advantages. First, since we can use both the light of the sun, and its resultant heat as opposed to a silicone panel, which uses only the incoming photons, the efficiency jumps to about 60%. Second, since oil does not boil until around 550 degrees, we can use the stored hot oil well into the night until it cools substantially. Now we have access to solar power at night. And the concentrators and oil(which gets continuously recycled each day) cost much less per unit power than any panel in production today. Since the efficiency is much higher, they will only need 30 to 40 square miles to power all of Europe. If you want to check it out, google, “North African Solar Project,” and read some of the resulting websites. If the system works as well as they plan, it will run most of Western Europe, and then we will probably have one in our desert southwest a few years later. This concentrator will not offset any wildlife, beyond a few scorpions and rattlesnakes living in the far out areas of the desert, and since they will be using sea water to boil into steam, the byproduct of the electrical production will be fresh water. That fresh water will be used for irrigation to farm small quantities of sunlight intensive farm stock in what is now a completely dry desert. Adding small amounts of plant life to the northwest corner of the desert where none exists now will not alter the climate, but does offer another opportunity for carbon to be converted to oxygen, reducing the CO2 content of the atmosphere slightly. There will be jobs there, installation, technicians, maintenance and operations, and as long as the sun shines in the desert, we won’t run out of fuel.

We’ve been powering our home for 11 years now on wind and solar power. I’ve learned many things during that time. One item is that there are two things in large supply in solar power, the sun, and missinformation. Lots of people have been posting interesting “facts” here about solar and wind power, having never laid a hand on a panel or wind turbine. Wind turbines do not kill as many birds each year as living room windows do, powering homes with solar panels does not require massive amounts of space, silicone panels do not need massive amounts of toxic chemicals to manufacture them, and people do not get cancer from spinning wind turbines. These are just a few of my favorites, there are many more. If you want to learn more about this technology, check out some sources below. Take care Brian, Rudydoo

admin answers:

Several new studies, including a gigantic one released this year from the US Department of Energy, show the corn to ethanol process to have a significantly larger positive net energy yield than previously shown. These improvements were largely due to greater efficiency modifications and technological advancements at ethanol plants. In some cases, specific ethanol plants have an almost infinitely positive net energy yield due to groundbreaking technologies used to power the plant such as wind turbine technology.

This study published in january 2009 shows the net energy yield of corn to ethanol to be +50% to 80%:

http://www.americanfuels.info/search?q=net+energy+yield&x=0&y=0

Here are the latest numbers from the Dept. Of Energy, published in May 2009. Go to page 16 of the 20 page summary. In the conclusions section the US DOE concludes that the entire corn to ethanol process yields at least 34% more energy that it takes to make the numbers could be as high as 67% due to rising corn yields secondary to farming improvements and ethanol plant technology improvements. The DOE concludes that corn ethanol is “energy efficient and becoming more energy efficient as time goes on”. They study also concludes that only 17% of the energy used to make ethanol actually comes from fossil fuels:

http://www1.eere.energy.gov/biomass/pdfs/energy_balance_of_corn_ethanol.pdf

Lastly, some ethanol plants are producing ethanol and using virtually zero fossil fuels at all. Many are converting to wind power to generate the electricity for their plants. This makes sense for several reasons. First, wind and corn go hand in hand. The areas in the midwest that grow corn tend to be very windy in general. Secondly, the plants see this as a way to save huge amounts of money on energy costs. Thirdly, using wind turbines makes the net energy yield of producing ethanol even more hugely positive. Cornplus ethanol in Winnebago, Minnesota is one such plant that is producing ethanol from almost entirely renewable sources. Here are 2 links to read about it:

http://connectbiz.com/2005/11/keith-kor/

http://fairmontsentinel.com/page/content.detail/id/500116.html?nav=5003

And here is one more study that shows corn ethanol yields 67% more energy than it takes to produce:

http://www.foodandfuelamerica.com/2008/04/biofuel-myths-vs-facts.html

Now, I want to hear arguments from people that dispute these facts. All 3 studies mentioned above have been published in 2009. Can you provide a newer more current study that shows differently? If you want to argue that the yield is negative please back it up with FACTS and DATA and provide LINKS, as I have done. Otherwise your argument has no weight. If you are going to argue against the net energy yield of ethanol back up your argument with facts, not just your false beliefs. Then again, I guess ignorance is bliss.

Chui, please see my link which addresses the issue you mentioned. We have thousands and thousands of miles of unused land in the US to plant corn and other crops.

Http://www.foodandfuelamerica.com/2007/10/maize-ing-fact-one-bushel-of-corn.html