May 23, 2010: I just learned that one has to drill holes in the bottom to let out any moisture. If you don't do that, they steam up. Photo of The humble Farmer's 1811 home,showing 8 flat-plate solar collectors. The four on the left and the bottom one on the right have glass backs. April 14, 2020. The backs rotted out of the top three on the right last winter so I'm going to have to put glass backs in all 8 units. I didn't know about the drain hole in the bottom to let out moisture so I'm going to have to do that, too.

I'd like to hear from you with your suggestions and additions for this page. Thanks. Neighbor humble


May 17, 2011 www.evergreenyourhome.com April 1, 2010

To prevent the hot water collector from creating a convection current, the glazing should be 3/4" - 1" from the absorber plate or the manifold?

Either is fine. Usually with the way we bend up the aluminum flashing, the top surface is just about level with the top of the manifold. The 3/4" spacing is a compromise and the exact spacing doesn;t matter that much. 1" is probably too big when the collector is a lot hotter than the cover glass in the winter and 1/2" gives more conduction loss from the air at the same time of year. In the summer, the system would probably be more efficient most of th etime with no cover glass at all, but I don't think anybody wants to go to that much trouble. Rich

July 12, 2009

Today I bought 8 ten foot lengths of pressed porch lumber.

My neighbor, Bruce the Goose, sawed a slot in the top and used his router to put a ľ or 3/8 inch groove 3/8 up from the bottom.

I am working with two 3-foot ends and two 7-foot sides which I will trim to size as the size of the glass dictates.

Both pieces of glass that come out of a door I get off the dump are the same size. One is for the top. One is for the bottom. The bottom glass fits into the groove. The top glass fits down into the slot.

I am trying to give the bottom glass in the groove room enough to rattle around in there surrounded by the rubber caulk, whatever it is called. I'm glad to see Rich sent me a lot of it.

Will building a unit with glass on both sides work? I donít know. But I am going to give it a try. Perhaps the glass will break. But Iím going to give this a try. Iím filming it in case anyone wants to know how not to do it.

This will eliminate buying some kind of tin or board to put on the back. It will eliminate all the screws it takes to hold on the back. Each corner is held together with three 3 inch screws, for which I bored and countersunk the holes.

Because this pressed board might warp when it dries out (it is wet now), I plan to put 2 or 3 cross brackets on the back. It can't bow in because of the glasss, but the brackets might discourage it from bowing out.

I hope it will also eliminate that angle metal along the top, as the ends of the glass will be protected by being sunk down into the wood on the top. Because I already bought the metal, I can add it if I can be convinced that it would add to the durability of the unit.

Is the glass unit heavier than one with a thin fiber back? Of course. But the only place I am going to carry it is to the side of my house. If the glass on two sides flat plate solar collector works, it should require little or no maintenance. Come by and see this. I hope to work on this tomorrow (July 13, 2009) and hope to be able to put all four of these together in a day as the copper only needs to be painted on the other side and slots cut to set it in the box. Iím putting back side of the copper unit to the sun this time.

Thank you for your help and suggestions.

+++

My neighbor Jean has radiant heat in the floor of her shower and in the floor of her porch-sunroom. I looked at it on May 14, 2009, and now want to put radiant heat in the new cellar which is under the back Bed and Breakfast room on the back of our 1811 farmhouse.

From what I read today, once it heats up, it takes a while for it to cool off. I can open the door and can live with that.

This is what I've learned so far. Obviously, I have a long way to go.

+

How far apart do I put the tubing?

In concrete, the tubing should be spaced on 12-inch centers.

I already have a good, smooth concrete floor in the cellar and plan to put the pipes on top of that. But how thick should this new concrete be?

Should I put down 2 inch blue board on top of the present smooth floor to insulate it, or do I need the heat retention ability of the concrete that is already there?

How big should my storage tank be for the hot water?

Should I have the tank in the cellar or could I build a huge (2,000 gallon) concrete one outside below ground level?






Altenergyweb Solar Panel Estimator

GM Crushes Solar Cars

This rack will hold fifty six 40 watt pc solar collectors. I have 15 or so already built and when I get time I'm going to get them up there.

Hopefully, some guru friends will tell me how to wire it and the magic box that converts it from DC to AC.

What do you know about this that would help me?

Have you ever plugged a pv solar system into the grid?



Evergreen Home Performance LLC, Richard Riegel Burbank


Richard Riegel Burbank

President / CEO

Evergreen Home Performance LLC

15 Tillson Ave, Rockland, ME 04841

www.evergreenyourhome.com

Cell: 207.691.6517

Richard is another one of the good guys. I'm contacting him today about finally plugging some of the leaks in my attic.


Revision Energy


John Luft and my other friends at Revision Energy installed six 220 watt panels on the my farm and they produced 60 kwh more than I used this winter.


Maine Solar Energy Association


The History of Solar Energy


Build It Solar


Mother Jones Solar


Sundog Solar Store in Searsport, Maine



Holland and Foley



Europe's Way of Encouraging Solar Power Arrives in the U.S.

March 13, 2009

By KATE GALBRAITH - New York Times -

Solar cells adorn the roofs of many homes and warehouses across Germany, while the bright white blades of wind turbines are a frequent sight against the sky in Spain. If one day these machines become as common on the plains and rooftops of the United States as they are abroad, it may be because the financing technique that gave Europe an early lead in renewable energy is starting to cross the Atlantic. Put simply, the idea is to pay homeowners and businesses top dollar for producing green energy. In Germany, for example, a homeowner with a rooftop solar system may be paid four times more to produce electricity than the rate paid to a coal-fired power plant. This month Gainesville, Fla., became the first city in the United States to introduce higher payments for solar power, which is otherwise too expensive for many families or businesses to install. City leaders, who control their electric utility, unanimously approved the policy after studying Germany's solar-power expansion. Hawaii, where sky-high prices for electricity have stirred interest in alternative forms of power like solar, hopes to have a similar policy in place before the end of the year. The mayor of Los Angeles wants to introduce higher payouts for solar power. California is considering a stronger policy as well, and bills have also been introduced in other states, including Washington and Oregon. "I'm seeing it with my own eyes - it's really having a good effect on our local economy, particularly in these hard times," said Edward J. Regan, the assistant general manager for strategic planning at Gainesville Regional Utilities in Florida. He said he had gotten calls from other cities and states since announcing the policy. The new payment method is referred to as a "feed-in tariff" in Europe. It is, in essence, a mandate by the government telling a utility to pay above-market rates for green electricity. It shifts the burden of subsidizing green energy from taxpayers, as is common in the United States, to electricity ratepayers. And the technique includes assurances that a utility will pay the high rates for a long period, often 15 to 25 years. The surge of interest in the payment system is a recognition that despite generous state and federal incentives, the United States still lags far behind Europe in solar power. Germany, where feed-in tariffs have been in place since 1991, has about five times as many photovoltaic panels installed as the United States, though they still account for only 0.5 percent of electricity in that country. In the United States, said Wilson Rickerson, a Boston energy consultant, "a lot of people simultaneously reached the conclusion - who's moving fastest internationally? And that's definitely been Germany and Spain." In Gainesville, the new policy has already sparked a rush to put up panels. John Stanton, a retired civil servant living there with his wife, put 24 solar panels on his roof in late January, as city leaders sped the policy toward approval. Gainesville's municipal utility will pay Mr. Stanton and other homeowners and businesses who generate solar power more than twice the standard electricity rate, guaranteeing that rate for 20 years. "It was the thing that sort of put us over the top," said Mr. Stanton, who gained an appreciation of European energy policies after living in Italy for more than a decade.

May 29, 2009

Hi,

Thanks for your interest in heating your hot water with solar energy.

It is possible to use CC3-450 to bond the aluminum to the copper pipes.

I can buy a quart of CC3 for $97, $50 of which is for the shipping of hazardous materials. So you might want to tell me something about that.

Also, I was told by the man who sells CC3, that I need a triple beam balance because if you donít get the mix exactly 100 to 10.4, you have molecules in there running around with no place to go and you donít get a good bond.

http://www.cast-coat.com/cc3-450.html


CC3-450 is a medium viscosity, aluminum filled, bonding resin that has gained wide-spread acceptance as the primary bonding resin used in the assembly of heat sink components and the attachment of heat sinks to sources of heat or cold. This resin system is the most widely used bonding agent in the heat sink industry with a history of many varied applications over the last thirty years.

The website for the thermal conductivity of the GE silicone 1 I can not find right now. The GE silicone II has a thermal conductivity of .21 W/m'C.

The website for the thermal conductiity of the Cast Coat CC3 450 is www.cast-coat.com. The thermal conductivity is 31.5 BTU/ft^2/hr/'F/in. 4.54 to 200 W/m'C.

John also suggested I paint the silver that covers the insulation in the box black instead of leaving it silver.

He also suggested that instead of using expensive brass unions to fasten the four solar collectors together, I simply hook them together with the white plastic pipe.

I can already see that putting that flimsy ľ wood or fiber backing on my collectors was a mistake and plan to replace them all with either aluminum or galvanized metal. One has already fallen apart after only one winter.

I have wanted window box heaters. That is, the black box outside of the windows that simply captures and directs sunshine heat which is then put into the house by a small fan. John says he built one 30 or so years ago and that it worked great in the winter. I didnít realize until he told me that these boxes donít have to be the size of the window, but can be 8 feet long and four feet wide with only a small hole in the top that lets warm air into the window. It never occurred to me that these boxes could be larger than the width of the window.

We got a new energy efficient refrigerator in June 2009.

Thanks for hanging in there. Hope there is something in this note that is helpful to you. If anything John said (or that I have assumed) is not 100 percent on the money, please let me know. This is a collective endeavor.

I am posting this to spare you a lot of unnecessary expense and labor. Call me if you have questions or observations. Your comments and suggestions are appreciated.

+++

May 29, 2009

... the best switching method would be a differential temperature control with 2 sensors. One is at or near the bottom of the hot water tank; the other is at the top of the solar panels. This setup only turns on the circulator pump when the solar heated water is hotter than the cold end of the water tank. Your system will bring in a surprising amount of heat even on a cloudy day.

A universal problem for everyone putting up a solar hot water system is what do you do with the extra heat when your water tank is hot enough? [I am still waiting for this day. humble] Some systems add a few feet of baseboard heater mounted outside to send the very hot water to. Super hot temperatures will degrade the antifreeze and plastic parts. Another solution is to add a very large insulated water tank to absorb all that extra heat. In Spring and Fall, the added heat would be welcome in the house.

When I asked a Revision Energy guy how he handled the overheat problem (they use the fluorescent tube type collectors), he said the water and antifreeze just boils and the steam pushes the water away. He said it didn't seem to degrade the antifreeze much, and they change the antifreeze solution every 4 to 5 years anyway. All their systems are in copper with high temperature solder, so no problem. (At the price of antifreeze, this seems expensive.) Their customers are all well financed so it would not be a problem for them.

Another way to handle the system is to use only water and drain the heater panels when it is too hot or cold. This requires a temperature sensor and drain down solenoids at not much added cost. Because of the freeze damage that could happen if the drain fails, I don't think this idea is used very much. Nice to have a 'build it and forget it' type of system.

Your electric usage seems quite high. Where is all the juice going?

Do you have an electric dryer? Does the wife cook a lot on the electric stove and oven?

Now that you have a solar water heating system, at least this load is not costing you.

How about an air conditioner? [an air conditioner is a joke on the coast of Maine where 72 in August is a heat wave]

What devices are running for how many hours a day? [I have a kill-o-watt and taped John showing me how to use it. We (I) have been turning off things we don't use]

Even now I'll bet you elect. bill will go down sharply.

I wish you well,

H.

June 1, 2009 "Solar Panels are rated in this format as well. (Watts per HOUR). If you research solar panels, and one is advertised as being 100 Watts, it means it creates 100 watts of power per hour of sunlight. Weíve decided above that we need 375 Watts of panels in order to meet our minimum power requirements. In this case, I would buy 4 100 WATT panels to make 400watts per hour of sunlight. (Times 4 hours means 1600 Watts into the batteries every day, enough for all your power needs and to make up for Inverter losses)"

I had a struggle to find the information above. I Googled, "How many solar panels do I need?" and looked at 5 or 6 pages before I found what I thought was a clear answer.

Unless you want to come forth with different figures and a powerful argument, I'm going to accept the above: you DO have to multiply the wattage of the pv unit by the number of hours of sunlight to get the kilowatt hours for a day. In terms of my unit, 56 of my 60 watt panels produce 3.36 kilowatts in an hour of sunlight. Times four hours of sunlight = 13.44 kilowatts in one day.

June 1, 2009 "Insolation is a funny word for the number of hours in a day that a solar panel will produce its rated voltage. While all the day's sunshine counts toward this total, not just the brightest hours, not every daytime hour counts equally. When the sun is low in the sky, a solar panel facing it doesn't produce as much energy as it would at noon. Another way of putting it would be to say that if you crammed all the day's sunlight--weak and strong--into equivalent hours of "peak" sunlight, you'd have the "sun hours", or insolation, number. In your area, while the sun may be up for 10 hours during a February day, not all that light is strong enough to be counted at full value, so the insolation value in your area may be closer to 2 sun hours."

July 7, 2009 Hi Robert,

As the hot water flows into the tank it will rise to the top. There can be quite a variation in temperature between the bottom of the tank and the top, but the two don't really mix. Having said that, there will be a temperature gradient up the side of the tank. The way the pump controller works is simply by comparing the temperature at the solar panel outlet (the hottest point in the system) and the bottom of the tank (the coldest part). Imagine if the pump worked all the time. What would happen is the flow rate of cold water through the solar panel would be too high for it to be heated by the time it came out the hot end. There would also be the problem if it was a cloudy day or at night, the water coming from the panel would actually be colder than what's in your storage tank. Thus you'd actually cool your water instead of heating it. (This is what happens also if you don't prevent reverse thermosiphon). [humble question here. How do I prevent reverse thermosiphon? And, by the way, this letter answered many of my questions. Thanks for helping us.] You only want water pumped from the solar panel when the water up there is warmer than what's in the tank. This is what the controller does; when the water in the solar panel is hotter than the water in the bottom of the tank, the pump switches on, and pumps the hot water down to the tank, where it rises to the top. Once all the hot water in the collector has been pumped through, the pump switches off until it's hot again. Once you've got your system operating you'll see the pump switch on and off every few minutes on a sunny day. On cloudy days it will switch on much less frequently. You don't need to worry about what temperatures the pump switches on and off at; in fact the simpler controllers don't even have any adjustments. That's fine because all you need to go on is the temperature difference between the two sensors. Mine is preset to 8 degrees C. (It isn't critical) This means that if the tank temperature is 50 degrees, then the pump won't switch on until the collector has reached 58 degrees. Thus, the water coming down from the collector will always be hotter. That 8 degree setting is actually the default on my controller and seems to work well enough so I haven't changed it. It is important that the thermistor on the solar panel outlet is secured to the copper pipe so that it's measuring the water temperature. Likewise the sensor at the bottom of the tank needs to be placed on the actual cylinder...you can just poke it in under the insulation so it touches the steel cylinder, or if you've got one with a 1/2" thread, you can screw it directly into the cold water flow with a T piece.

[humble question here. My sensors are on and I can see and feel the pump going on and off. But I'd like to know how to adjust the differential. I can see the temperates change on the dial as the hot water comes in. The one on the bottom of the tank goes up as the outside one goes down. And, my wife wants water that is 126 degrees. Do I mess things up by pumping in water that is 110 degrees?]

bye for now,

John


+

Dear Nancy,

Thank you for sending the article. I personally know all the people mentioned in the article and am happy to see the publicity going out. The 42% efficiency PV cell mentioned in the article was done by Christine (I don't remember her married name but her maiden name was Meyers back when she was a student in our group at Wayne State U) and Henry Brandhorst (old friend from the 1975) may have gotten to 46%, I have heard; but David Brinker (another of our Wayne State students) at NASA in Cleveland hasn't yet verified that. I had a diagram they sent me of the cell structure but lost it when my hard drive died. I am asking Douglas and Susan Kinne down in Nicaragua to send me their copy of the powerpoint I gave on the subject at Fenix's "Solar Saturday" the year before last. I'll also look on the ISES website to see if they have the same diagram.

Chris also designed the PV cells that are powering the two solar electric cars driving around on Mars. They were very expensive to make but cheap compared to the cost of shipping them to where they are driving around. This is like old home week, with Allan Barnett resurfacing after the Astropower debacle. I've known him since he was a grad student at the U of Deleware and he is back there again. What goes around does finally come around,

Rich

On Wed, 22 Jul 2009 09:09:21 -0400 "NANCY ODEN"

Thought of interest to you........ - Nancy

Subject: Very High Efficiency Solar Cells

This article can be found on the I-SIS website at

http://www.i-sis.org.uk/veryHighEfficiencySolarCells.php

Very High Efficiency Solar Cells

########################

The highest efficiency solar cells use innovations in optics to concentrate sunlight Brett Cherry

Much progress has been made in utilising new materials to produce low efficiency, low cost solar cells, but currently the backbone of the global solar industry is still silicon.

The same semiconductor material that was used to build the physical infrastructure of the IT revolution also forms the basis of the solar energy revolution. Today, the largest demand for silicon comes from the solar industry, with Europe accounting for over 80 percent of global solar photovoltaic (PV) demand in 2008, followed by the U.S., South Korea and Japan for new solar installations [1].

Solar cells made from silicon and other PV materials have reached efficiencies over 40 percent. These high efficiencies are achieved by concentrating solar light onto solar devices with three or more solar cells. New pathways of research are also opening up to develop methods of storing solar energy through artificial photosynthesis that potentially could be used in tandem with solar technologies, such as very high efficiency solar cells (see [2] Harvesting Energy from Sunlight with Artificial Photosynthesis , SiS 43).

High efficiency solar modules appear to be primarily for industrial application so far. But the goal of many PV researchers is to make these devices cheaper for micro- generation in the commercial markets. There are a number of strategies to accomplish this. One is to develop super efficient solar PV cells in order to produce a higher power output that compensate for the material costs. Another is to make relatively low efficiency solar cells with cheaper materials as in the case of organic, dye sensitised and amorphous silicon solar cells (see [3] Which Energy? ISIS Energy Report). Using solar concentrators or reflectors in conjunction with highly efficient silicon solar cells has been the most popular method for solar researchers.

New methods to concentrate sunlight

Professor Allen Barnett and a team of solar researchers at the University of Delaware along with more than 12 other organisations in the US have developed the highest efficiency solar PV device in the world so far. They plan to develop a solar cell module of 50 percent efficiency, a project funded by the Defense Advanced Research Projects Agency (DARPA) and managed by the chemical company Dupont.

Once fully developed, it could be the highest efficiency solar PV device for commercial application.

The solar PV device being developed by Barnett, the principal investigator of the project, and the Very High Efficiency Solar Cell (VHESC) team uses a lateral optical concentrator that tracks the sun to focus sunlight onto different solar cells. Each solar cell in the device consists of multiple junctions such as gallium indium phosphide and gallium arsenide (GaInP/GaAs), gallium indium arsenide phosphide and gallium indium arsenide

(GaInAsP/GaInAs) [4], and silicon filtered by GaAs at 20-50 suns. In order to test how this design works, researchers concentrated sunlight using a double-convex lens then guided it to a dichroic mirror where it is split into two bands of light for absorption by the sub-module made up of ?low? and ?mid-energy? tandem solar cells as shown in Fig. 1. The same design would be used for a device with more solar cells.

Read the rest of this article here

http://www.i-sis.org.uk/veryHighEfficiencySolarCells.php

Or read other articles about energy generation here

http://www.i-sis.org.uk/scienergy.php

March 30, 2010 Dr. Richard Komp reports on his trip.

Dear Janet and Everybody,

I am now in Gisenyi, Rwanda and decided to write a small report on my trip:

First of all, the Desalgen Hotel (correct spelling) was quite nice with very good service. They have a booth at the Addis Ababa international airport terminal right outside the luggage claim area and the man, who had a record of my reservation, called the van driver on his cell phone so I had to wait only about 10 minutes to be picked up. The room was actually a suite with a separate tiny kitchen separating the bedroom from the living room/office. It was clean and I saw no cockroaches. The breakfast was part of the package as promised, and was quite nice with a woman cooking an omelet for me, as well as other hot food. It was better than the breakfast I have had a fancy hotels in the US. The price was indeed only $66 US, including all taxes and fees but they charged 4% extra because I used my MasterCard. I verified with them that I would be coming back to stay again on the 22nd on my way to Mali.

Second, all the flights were all within minutes of being exactly on time. However, the long flight from Washington through Rome to Addis Ababa was completely packed, because Easter in the Ethiopian Church is next Sunday, the same day this year as the Western Church (which is quite unusual). The plane was filled with Ethiopians going home for the event, as well as a few western white people going to Africa (to fulfill their "White Mans Burden"?). Lots of kids and everybody was extremely friendly, with the kids running around making friends with each other and everybody talking with each other and to the children of total strangers (something that is frowned upon now in the US).

Because of the crowding, the service was not as good as on other Ethiopian Air flights I have taken and with my window seat where it was, I was the last person on the plane to get a meal. It's a good thing that I am an opportunivore, since I had no choices at all. Except for getting a second little bottle of red wine with my fish. Since the fish had a nice spicy tomato sauce, the wine color wasn't a problem to me (I am always breaking rules). Janet, so far, each window seat I have had has been directly over a wing. Is this what is necessary to get the cheap fares?

And can it be changed on the remaining many legs of my complex journey?

Since it was rainy and cloudy on the flights in Europe and Africa, not seeing much out the window was not a problem, but when I go to Mali, I would like to see the terrain, that I have never been over before.

The electricity is off at the moment so the Internet isn't working at the university here in Gisenyi, so I don't know when this e-mail will go out. We are working today to get the 9000 PV cells out of the customs without paying the duties. I spent yesterday afternoon with the customs people at the airport (since I was there anyway to get off the plane) and not only will we pay no bribes, the man was very helpful after he heard about the project of powering an entire village, he offered some suggestions, which if they work will allow us to pay only about $100 instead of the $900 first quoted. That will help speed up powering the Rugerero Survivors Village, since we will have that much more money for the batteries. I'll let you know later how this works out.

It is sunny and beautiful here and I feel right at home.

Enjoy the spring, Rich




Robert Karl Skoglund
785 River Road
St. George, ME 04860
(207) 226-7442

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humble@humblefarmer.com

www.TheHumbleFarmer.com

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