A quick question regarding a small grid tie.

[Sunking]

Phillip the problem you are running into here is the type of inverter you are asking for help here cannot be used in any Code Compliant Matter because that are not listed or certified to do what you want. Most of the folks here like myself are professionals and we cannot condone such products because it is unethical for us to do so. It is like going to a head shop and buying bongs and water pipes to smoke crack cocaine. Perfectly legal to buy such novelties. Illegal to use for the intended purpose


The inverter you are looking at is poorly made because it has not been made to high standards or had to go through any listing process. Technically they are very inefficient. So look at this how much did that inverter, panel, and all the hardware and materials cost? Let's say $500. At best it wil generate about .5 Kwh/day. At a school I imagine they get a commercial discount rate for electricity. Let's say the school pays $.08/Kwh which is national average for commercial rates. As a point of reference for Residential average is $0.111/Kwh. So at .5/Kwh/day production saves the school 4 cents or a house user 6 cents per day. That comes out to $1.20/month and $1.80/month savings.

Now here is what I suspect you will not teach the students. It would take 34 years to get 0% ROI, and not offset one single ounce of CO2 emissions. This is what professionals and the informed public knows. You will never hear that from advocates.

[russ]

Apparently they are in Michigan - what instructor sends kids out to do something illegal?

[Philliplee]

I understand. Then maybe you should start with using the accepted and safely designed "grid tie" inverters.

There are quite a few that range in their ability, size and cost. The Manufacturers are to name a few; Xantrex, SunnyBoy, Outback, Enphase, Power One.

You would match them to the size and output specification of the solar panels array which consists of the voltage and amperage the panel or panels output at peak sun exposure.

Since most "grid tie" system are not small, the Inverters mentioned above are sized for about 2000 watts and up. Usually it isn't worth installing a smaller system because the cost per kw goes way up. A medium to large system will get you a lower cost per kw which is usually more affordable.

Thank you. What if our objective was more geared towards supplementing part of grid electricity with solar, on a small scale? Rather, say we wanted to power a lamp with any available solar and the difference between what the lamp needs and what the solar provides is met with grid electricity. Is this even viable?

What course does this involve? How much are you expected to design and build? Hopefully your instructor expects more from you than just buying a few parts on ebay and plugging them together. Have you taken the time to understand how a PV system works?

somehow I get the impression your doctor has not understood the expense of prescribing you this treatment for a 'one time' display. You're going to spend $179 on an illegal inverter and then... what?... throw it away? Not likely, more likely someone will continue using it.

I'd prefer not to answer some of these as they are not relevant to this topic, specifically the course, our doctors information, and school. Though I assure you, the device stays in our hands and does get dismantled afterwards.

Apparently they are in Michigan - what instructor sends kids out to do something illegal?

I find this to be a disappointing post, and from a mod! Certainly if I wanted to share my location with the world, I'd happily do so, please respect members privacy. This topic is aimed towards helping students with safety, viability, and understanding on PV systems, not constantly berating me for lack of knowledge on a subject.

Phillip the problem you are running into here is the type of inverter you are asking for help here cannot be used in any Code Compliant Matter because that are not listed or certified to do what you want. Most of the folks here like myself are professionals and we cannot condone such products because it is unethical for us to do so. It is like going to a head shop and buying bongs and water pipes to smoke crack cocaine. Perfectly legal to buy such novelties. Illegal to use for the intended purpose

The inverter you are looking at is poorly made because it has not been made to high standards or had to go through any listing process. Technically they are very inefficient. So look at this how much did that inverter, panel, and all the hardware and materials cost? Let's say $500. At best it wil generate about .5 Kwh/day. At a school I imagine they get a commercial discount rate for electricity. Let's say the school pays $.08/Kwh which is national average for commercial rates. As a point of reference for Residential average is $0.111/Kwh. So at .5/Kwh/day production saves the school 4 cents or a house user 6 cents per day. That comes out to $1.20/month and $1.80/month savings.

Now here is what I suspect you will not teach the students. It would take 34 years to get 0% ROI, and not offset one single ounce of CO2 emissions. This is what professionals and the informed public knows. You will never hear that from advocates.

Thank you for the information, you put it quite elegantly too! The project we are working on is quite small in scale, we don't expect to build something massive, replace a schools power system, or look for any return of investment. We are just experimenting with solar panels and their potential applications.

Edit: Wrote this on an iPad, my apologizes for grammar and spelling.

[SunEagle]

[QUOTE=Philliplee;72002]Thank you. What if our objective was more geared towards supplementing part of grid electricity with solar, on a small scale? Rather, say we wanted to power a lamp with any available solar and the difference between what the lamp needs and what the solar provides is met with grid electricity. Is this even viable?



The only safe way for you to do this is to power the lamp using solar technology and then when the solar is not there you plug the lamp into a grid powered receptacle. The two systems must be kept separate. Any connection between the two must follow Electric Code and Utility Requirements which are put in place to make sure no one is hurt.

I know that is not the answer you are looking for but there really isn't any small scale systems that will do what you want that are legal in the US.

I commend your thoughts and actions to try to develop a solar system like this but the legality of it doesn't exist.

[FloridaSun]

I'd prefer not to answer some of these as they are not relevant to this topic, specifically the course, our doctors information, and school. Though I assure you, the device stays in our hands and does get dismantled afterwards.

Don't blame you for not wanting to expose your doctor or school and evidently your course has nothing to do with electricity or you would understand and accept much of what has been said to you.

[Sunking]

Don't blame you for not wanting to expose your doctor or school and evidently your course has nothing to do with electricity or you would understand and accept much of what has been said to you.

Me thinks the DOCTOR's name is Doc Feel Good. Lot of them walking Jamaica beaches. Or it could be a university professor and like most university professors have never worked in the real world, thus is why they teach. No one would hire them otherwise in the real world.

[SunEagle]

Me thinks the DOCTOR's name is Doc Feel Good. Lot of them walking Jamaica beaches. Or it could be a university professor and like most university professors have never worked in the real world, thus is why they teach. No one would hire them otherwise in the real world.

Or is could be a class where they want to determine the costs and develop a renewable systems to generate power and help offset the Utility costs. It is a feel good type of attitude.

It is not that far out there for people who are uninformed about the technology and limitations concerning grid connected requirements yet want to do something that in their minds may help them or others in the real world.

I was talking to a group of students that worked on the Solar Houses that are used to compete in the event in DC. In between competitions they were then working on a portable solar powered water purification system for third world countries that did not have a readily available clean water supply.

It was pretty cool design where the solar panels were part of the tent that covered the water purification equipment. It was compact and easily broken down so it could be moved in a small truck or van.

I like the idea of University Students thinking outside the box when it comes to this technology. I just wish they can understand some of the hurdles to get over when it comes to Grid Tie systems.

[Sunking]

It is a feel good type of attitude.

When I was forced to retire for the second time in 2003 I taught Trig at a local college at night for 2 semesters to tie me over and have something to do while I started up my design firm. That is all it took for me. Students are far from reality of the real world. Their heads are full of mush our education has filled them with. Completely unreal applications based on ideology.

[FloridaSun]

Or is could be a class where ......

The OP seems embarrassed to clue us in on just what the class is. Only thing I can figure out is the class is about teaching common sense and that is gained by expensive mistakes by some.... which the instructor is willing to dole out. Real life experience, much better than figures on paper. I'm all for creativity, thinking outside the box dreams, but without a touch of reality it's all a puff of smoke.

That portable solar powered water purification system sounds all neat and nifty but sounds expensive. I'll stick to my gravity fed ceramic filter set-up that gives me 3,000-5,000 gallons per filter at less than one cent a gallon. Works on everything from mud (VERY slow flow rate ) to well water (30+ gal @ day capable). Doesn't need a truck to transport either, all contained in a three gallon bucket. Course it's not a desalinator. Is that what the student's solar set up was for?

[FloridaSun]

I taught Trig at a local college at night for 2 semesters.... That is all it took for me. Students are far from reality of the real world. Their heads are full of mush our education has filled them with.

but but but... Dereck, your teaching is 'quite elegant' and those students need your practicality.


(I can imagine the frustration)

[Sunking]

but but but... Dereck, your teaching is 'quite elegant' and those students need your practicality.

If I ever teach again it will be at the Board of Directors level instructing the staff with a 2 x 4, and telling the NEA, NTA, and AFT to kiss my rosy red hemorrhoids.

[SunEagle]

The OP seems embarrassed to clue us in on just what the class is. Only thing I can figure out is the class is about teaching common sense and that is gained by expensive mistakes by some.... which the instructor is willing to dole out. Real life experience, much better than figures on paper. I'm all for creativity, thinking outside the box dreams, but without a touch of reality it's all a puff of smoke.

That portable solar powered water purification system sounds all neat and nifty but sounds expensive. I'll stick to my gravity fed ceramic filter set-up that gives me 3,000-5,000 gallons per filter at less than one cent a gallon. Works on everything from mud (VERY slow flow rate ) to well water (30+ gal @ day capable). Doesn't need a truck to transport either, all contained in a three gallon bucket. Course it's not a desalinator. Is that what the student's solar set up was for?

Ok. Ya got my interest in your ceramic water filter. Something you designed or something that can be easily purchased?

I do not believe the portable water filter system the students were working on had desalinization capabilities. They were more focused on providing clean water that was contaminated by impurities anywhere from natural to human.

I don't remember everything about the water system but it did have a way to sterilize and disinfect the water so that it could be drank without having to boil it which would mean using a fossil fuel or some kind. The flow rate was not that much for the smaller unit but then there were only a few solar panels to provide power. They were working on a much larger "field" unit that had more panels and a bigger water filter system.

When it came to providing pure drinking water for the population I believe these would be cost effective for some countries to provide to small villages then to build large water treatment plants and pump the good water throughout the countryside where there wasn't any consistent power distribution system to power the pumps.

[Sunking]

I don't remember everything about the water system but it did have a way to sterilize and disinfect the water so that it could be drank without having to boil it which would mean using a fossil fuel or some kind.

That would have to be a chemical treatment like chlorine wouldn't it? Just like any municipal water system. Another way is to NUKE IT like most packaged food today is.

[FloridaSun]

Ok. Ya got my interest in your ceramic water filter. Something you designed or something that can be easily purchased?

Easily purchased online. ... ah, guess I can post a link, no competition with our sponsor.

http://www.homespunenvironmental.com/

Best deal I've ever seen for easy pure water. Only extra item you need is a bucket. I use a single 3 gal. white paint bucket from walfart tho the two bucket system they show would provide better convenience. I never have to buy bottled water and no need to store the usual 20 gal. that I used to stock for hurrycane season as I've a lake in the front yard. If people had these in N.O. when Katrina hit they wouldn't have been so thirsty.
Removes:

• 99% Hydrogen Sulfide (H2S)
• 95% Chlorine and Chloramines
• 99% Taste
• 99% Odor
• 98% Aluminum
• 96% Iron
• 98% Lead
• 90% Pesticides
• 85% Herbicides
• 85% Insecticides
• 90% Rodenticides
• 85% Phenols
• 85% MTBE
• 85% Perchlorate
• 80% Trihalomethanes
• 95% Poly Aromatic Hydrocarbons
• 99.99% of particles larger than 0.2 micron, including Anthrax (Staffordshire University Labs)
• 100% Giardia Lamblia
• 100% Cyclospora
• 100% live Cryptosporidium (WRc Standard)
• 100% Cryptosporidium (NSF Standard 53 – A.C. fine dust – 4 log challenge)
• 100% E. Coli, Vibrio Cholerae (Johns Hopkins University)
• 99.999% Salmonella Typhil, Shigella Dysenteria, Kiebsiella Terrigena (Hyder Labs)
• 99.9% Virus (Ceutical Lab, a FDA Registered Laboratory)
• National Sanitation Foundation (NSF) Standard 42
• National Sanitation Foundation (NSF) Standard 53
• USA AEL Laboratories
• USA Analytical Food Laboratories
• USA Johns Hopkins University
• Ceutical Laboratory, a FDA Registered Laboratory

[Philliplee]

Yikes, this place is rough.

I'll inquire a more creative and polite group.

Thank you for the time and those who've helped, I appreciate it.