Gravity Film Heat Exchangers or GFX
29 Dec 07 | Conservation, Environment, Solar Hot WaterUpdate: Sun Volt Solar is now an authorized dealer of ECO-GFX gravity film heat exhangers! For more information, check out our GFX web page.
I am always looking for ways to improve efficiency, especially in energy use. I came across something called a Gravity Film Heat Exchanger or GFX system. These units recover heat from waste water and return it to the hot water tank. Since 80-90 percent of household hot water heat goes down the drain, literally, what a great way to recover some of that energy and reuse it.
Here is how they work: Hot water from a shower or sink runs down the drain and out into the sewer. If there is a vertical run of pipe, the water, because of adhesion, runs down the wall of the pipe (and not the center). If the pipe is metal, heat is transfered from the water to the metal pipe wall until the pipe is the same temperature as the water. All of this happens in any sewer line. If the vertical section of pipe has a heat exchanger attached to the outside of it, the heat from the metal pipe is conducted away to be reused. Most often cold water feed into the hot water tank is run through the heat exchanger. The system efficiency depends on the difference in temperature between the waste water and the incoming cold water. The greater the difference, the higher the efficiency.
This system only works where there is simultaneous hot water use and immediate drainage, say a show or sink. Something like a bath or laundry would not work well because the hot water is drawn off, used, then drained away.
It appears that the system is around 45-50 percent efficient. Therefore, if you use 70 percent of your hot water in showers or sink use, you would recover 30-35 percent of your total hot water energy. Not too bad.
These systems would work very well with solar hot water systems. I am contemplating installing one at my house to see if they work as advertised. The only requirement is that they be installed vertically. In fact, in order to work properly, great care should be taken to make sure the unit is perfectly vertical. For more information, see the NREL website on waste water heat recovery or this .pdf file called Heat Recovery from waste water using Gravity Film Heat Exchangers.
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Tags: Environment, GFX, SDHW, Solar Hot Water
Solar Energy Consortium, Kingston NY
21 Dec 07 | Solar Electric, TechnologyI was reading the local on line news source this morning when this caught my eye:
Just under $1.5 million has been secured by Congress for the Solar Energy Consortium in Kingston.
Congressman Maurice Hinchey, who secured the funding, said it will be used to develop solar technology.
“These funds will be used to bring a new manufacturing partner into the field here of the solar consortium, and as a result, that consortium is going to grow as a whole and help strength the Hudson Valley’s identity as well,” he said.
Hinchey has already secured $3.2 million for C9 Corporation to conduct solar research and development in conjunction with TSEC.
Which leads me to the question who or what is C9 and TSEC? Here are some of the answers. About 2 years ago, C9 corporation opened a semiconductor manufacturing facility in Kingston. They have been working on research and development in several areas.
C9 Corp. plans to produce three advanced technologies. First, it will manufacture silicon carbide-based, wide band gap, superlattice wafers for high power electric switching devices and high temperature, high speed chips. Superlattice is an alloy of different elements used to form a highly-ordered, crystal lattice structure in semiconductor materials. Wide band gap semiconductors such as silicon carbide have about three times the band gap of silicon with corresponding increases in power density, temperature tolerance, speed and voltage.
For example, wide band gap silicon carbide would allow organizations like NASA to create 600 degree C Integrated Circuits to tolerate the harsh environments encountered by spacecraft, which it can only do in the lab today.
If you have a background in electronics or electrical engineering, you can appreciate the importance of what they are doing. Basically, the enemy of all semiconductors is high heat. Heat will kill a transistor or computer chip, and it makes photovoltaics run less efficiently. Developing a heat tolerant semiconductor will greatly improve the efficiency of photovoltaic cells.
…C9 is helping Nanodynamics-88 develop and manufacture large, high-voltage SiC Schottky diodes and other power devices for the power conversion market. The contract is for next-generation hybrid electric military vehicles.
Or their civilian counterparts… More interesting stuff:
For 40 years, researchers and the government have been trying to produce silicon carbide semiconductors, which have a Figure of Merit improvement of 136 over silicon. Figure of Merit is a number that represents a composite of all the positive features of semiconductor material.
What has held back the success of silicon carbide is the defects that occur from the extreme temperatures – 1,600 and 1,800 C—that must be used to produce it. The primary defects are micropipes, which show up as Swiss cheese-like holes in the wafer, and screw dislocations, which are crystal imperfections throughout the material.
“C9 has developed a technology that is free of both micropipes and screw dislocations,” said Donegan. “C9’s version of silicon carbide can extend the functions of silicon devices to include high temperature operation. Our form of silicon carbide will complement silicon by extending Moore’s Law of Exponential Advancement to several generations,” said Dr. Wang. Moore’s Law states that the transistors on a wafer will shrink in size by 50% every 18 to 24 months.
Dr. Babiak referred to the potential for C9 to manufacture advanced silicon carbide materials as a technology leap that would result from overcoming a number of technical problems, including the limitations of narrow band gap.The band gap of semiconductor material determines its temperature and voltage characteristics. One of the original semiconductor materials predating silicon is germanium, which has a very narrow band gap and consequently unfavorable temperature and voltage characteristics. Silicon’s wider band gap vastly improved upon that, bringing temperature ranges up to 125 to 150 degree C operation and thereby making electronics available for everyday use in every aspect of life from automotive to home appliances, entertainment and office products.
Silicon carbide’s even wider band gap vastly extends the operating temperature range, speed and voltage characteristics of today’s semiconductors, allowing the creation of new devices that will be a major leap in semiconductor technology. This will affect everyday life in much the same way silicon did 20 years ago with the introduction of microelectronics.
That development would be highly beneficial to photovoltaic technology as well. One of the downsides to photovoltiacs is their low efficiency and high cost. Increasing the band gap width is huge step forward.
Photovoltaic cells produce electricity when they are struck by photons from the sun. When a photon hits the cell surface, one of three things happen; it either passes through the panel, bounces off of the panel (reflected) or is absorbed by the panel. When a photon is absorbed by the panel it excites the electrons in the semiconductor material, which is the desired effect.
However, if the electron is not excited enough to move through the band gap to the next (conduction) level, it generates heat, which is undesired. If the photon contains more energy than what is needed to move through the band gap, the excess energy also creates heat. Heat lowers the efficiency of the semi conductors in general.
By increasing the band gap, more energy will be converted to electricity. By increasing the efficiency of a photovoltiac cell, less raw materials and labor will be needed per manufactured watt, this will be key to lowering costs.
And this is really exciting, to me anyway.
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Tags: photovoltaics, solar power R and D
Name Change
18 Dec 07 | General BusinessIn talking with a potential distributor, it was brought up that the name “Hudson Valley Solar” was too close to another business’s name. In effort to avoid confusion and hard feelings, I have decided to change the name of my business to Sun Volt Solar, which is more generic and less likely to cause confusion and hard feelings with the other guy.
I felt that rather than become a pain in the rear end, I’d rather just come up with something unique for the area and be done with it. So, Sun Volt Solar it is. Good thing I have not printed any stationary or business cards yet. Soon. Soon.
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Tags: Business Plan, business startup
Obstructionist, Corporate lackies, Bush sycophants
14 Dec 07 | CommentaryLast night, at 6:25 pm, the US Senate choose to uphold the current policy of corporate welfare for Big Oil companies and voted for the stripped down version of the 2007 energy bill. Since this bill has everything the Republicans wanted, Bush will naturally sign it into law.
This is a disappointment and a set back for all those that were looking for a change of direction from our elected leaders. The difference between the House bill and the Senate bill are huge. The worst impact, for the ordinary environmentally concerned citizen, is the loss of the tax incentives for installation of solar power, which will expire at the end of 2008.
Fortunately, many states have picked up the ball and carried it a great deal of the way, New York being one of those. As we watch our national “leadership” give away our future to huge mega rich oil companies, it is comforting to know that at least some people have the moral courage to do the right thing. Will it be enough? I don’t know, only the future can tell.
Perhaps during the next election, we can remember the names of the Senators who voted against the non-stripped out 2007 energy bill. Here is a list:
Alexander (R-TN)
Allard (R-CO)
Barrasso (R-WY)
Bennett (R-UT)
Bond (R-MO)
Brownback (R-KS)
Bunning (R-KY)
Burr (R-NC)
Chambliss (R-GA)
Coburn (R-OK)
Cochran (R-MS)
Corker (R-TN)
Cornyn (R-TX)
Craig (R-ID)
Crapo (R-ID)
DeMint (R-SC)
Dole (R-NC)
Domenici (R-NM)
Ensign (R-NV)
Enzi (R-WY)
Graham (R-SC)
Gregg (R-NH)
Hagel (R-NE)
Hutchison (R-TX)
Inhofe (R-OK)
Isakson (R-GA)
Kyl (R-AZ)
Landrieu (D-LA)
Lott (R-MS)
Martinez (R-FL)
McConnell (R-KY)
Roberts (R-KS)
Sessions (R-AL)
Shelby (R-AL)
Specter (R-PA)
Stevens (R-AK)
Sununu (R-NH)
Vitter (R-LA)
Voinovich (R-OH)
Warner (R-VA)
If you are from any of those states, keep this in mind the next time you are standing in front of a voting machine. In the mean time, perhaps the issue will come up again next year and we will get a second chance.
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Tags: Commentary, politics
Filibuster!
13 Dec 07 | CommentaryIn the second procedural vote, the Senate has voted 59-40 for the 2007 Energy Bill. This is not the 60 vote majority needed to prevent a Senate Filibuster by the mostly Republican minority that opposes this legislation. So what, let them filibuster.
From the Energy Smart Blog:
Senator Reid should not be so quick to cave in front of 40 Senators willing to put their fossil-fuel friends before the nation. 40 Senators willing to put their fossil fuel friends before the future of all humanity.
Senator Reid: KEEP THE SENATE OPEN for the weekend. Make the 40 read the phone book in support of tax subsidies for the oil and gas companies. Make this “CALLOUS MINORITY” explain themselves to the nation.
I agree, let Senator McCain, who is attempting a presidential run stand in front of the country and explain why he does not see the need to encourage development of alternate energy. Let the rest of the minority opposition explain why, when oil is trading at $94.00 per barrel, it is not important to invest in renewable energy. Let them explain why, when oil companies are reaping record profits never before heard of in the history of US business, they need huge tax payer subsides. I for one, would look forward to such an explaination.