Lister Engine Forum
How to / DIY => Generators => Topic started by: carlb23 on December 12, 2007, 01:56:36 PM
-
Hi all,
I am running a 6/1 with a 4kva head that i would like to extract DC current from ( At night) to hook to one of my grid tied inverters. Can i use a standard bridge rectifier say 35 or 50 amp @ 500volt and hook it up to the 2 120 volt leads comming from my generator and get 240 Volts DC. My inverter will operate in a wide input range 150 to 5oo VDC so it would be in the voltage range.
Do you think any kind of filtering to smooth out the waveform would be necessary and if so how would i do that?
Thanks
Carl
-
Carlb23
You will see ripple out of the single phase rectifier in the neighborhood of 30%+. Solar inverters are set up for “real” DC, where there is no ripple. Rectified DC (wind, micro hydro or Lister) is a different animal. From my research there are some inverters that can be fed rectified DC with ripple not more than 5%. I suggest you call the manufacturer and verify the allowable ripple (if any). You don’t want to fry an expensive inverter and void your warrantee.
Scott
-
Scott,
Thanks for the info. I certainly don't want to fry my inverter
Carl
-
Some amount of capacitors will smooth it out.
I agree that 240V AC generator rectified to 240V DC + a solar grid-tie inverter is a logical way to spin your utility meter backwards.
A 3 phase generator would be even better (less ripple).
-
Doesn't exactly work out that way.
What we refer too as 240 AC is actualy the RMS value of the AC wave or the DC equivelent for doing current and load calculations.
http://en.wikipedia.org/wiki/Root_mean_square
So lets say you full wave rectify the the RMS voltage 240 vac what you actuly get ont he other side is the rectified Peak value and thats closer to 340 VDC if my memory serves....
Things can get realy wierd now if you take a multy meter and read that pulsing 340 vdc because the average meter will read the average voltage and depending on the riple that can be much lower ( if you want to take a guess at how low it can be multiply that 340 by .9 to get the average I think ). Now if its a three phase source and or a capacitor to filter you will have less riple and the average voltage will be higher.
Speaking of higher, I'm having flash backs to 1 year electrical at NOITT learning and puzling over all this shite. Oh college daze
Also good reading and much better math and explainations than me...
http://en.wikipedia.org/wiki/Voltage
If you own a volt meter like this
http://en.wikipedia.org/wiki/Image:Digital_Multimeter_Aka.jpg
Flll those two sockets with silicon to the left of the leads....
Someday if you get into the habbit of using them you will forget and change the range on your meter to do a voltage check and poof! You may also get burned or shocked, much better to buy a proper clip on amp meter....
Doug
-
Hi all,
My inverter will operate in a wide input range 150 to 5oo VDC so it would be in the voltage range.
Do you think any kind of filtering to smooth out the waveform would be necessary and if so how would i do that?
Thanks
Carl
Sounds like an unusual inverter with that input range... What do you normally feed it with that outputs that much DC?
Ron
-
Ronmar,
I am using a Fronius IG3000 inverter and I feed it with two strings of 8 panels @187 Watts each. Each panel is rated @ 32.7 volts 7.25 amps. Each string is has a max output of 1496 watts. The spec sheet shows the input voltage from 150 to 500 DC and an operating range for 10 amps to 18 amps input.
carl
-
Doesn't exactly work out that way.
What we refer too as 240 AC is actually the RMS value of the AC wave or the DC equivalent for doing current and load calculations.
http://en.wikipedia.org/wiki/Root_mean_square
So lets say you full wave rectify the the RMS voltage 240 vac what you actually get Ont he other side is the rectified Peak value and that's closer to 340 VDC if my memory serves....
Things can get really weird now if you take a multi meter and read that pulsing 340 vdc because the average meter will read the average voltage and depending on the riple that can be much lower ( if you want to take a guess at how low it can be multiply that 340 by .9 to get the average I think ). Now if its a three phase source and or a capacitor to filter you will have less ripple and the average voltage will be higher.
Speaking of higher, I'm having flash backs to 1 year electrical at NOITT learning and puzzling over all this shite. Oh college daze
Also good reading and much better math and explanations than me...
http://en.wikipedia.org/wiki/Voltage
If you own a volt meter like this
http://en.wikipedia.org/wiki/Image:Digital_Multimeter_Aka.jpg
All those two sockets with silicon to the left of the leads....
Someday if you get into the habit of using them you will forget and change the range on your meter to do a voltage check and poof! You may also get burned or shocked, much better to buy a proper clip on amp meter....
Doug
Doug,
Doug thanks for all the helpful info but, since I am not that good with electronics I think I will not worry about trying to hook up my AC gen to my inverters at this time and risk damaging an expensive inverter.
Thanks
Carl
-
I have several Shunt wound DC motors available to me in HP ratings > 3hp i think they are 190VDC. Can these be used as a DC generator with good clean output?
Thanks
Carl.
-
Solar grid-tie inverters are quite flexible and take in voltages in the 240 to 600 VDC range. I don't know how steady it has to be but I don't think your inverter dies when a plane flies over your solar panel (casting a shadow and putting a blip in the output).
I guess these inverters are for buildings with a roof full of solar panels.
-
Yes Carl any dc motor will make good DC. I would probably add a filter capacitor just to clean up any noise.
You do have to watch them though they require a little more attension because of the brushes.
-
Yes Carl any dc motor will make good DC. I would probably add a filter capacitor just to clean up any noise.
You do have to watch them though they require a little more attension because of the brushes.
Doug,
I found a Baldor cd7503 3hp Shunt wound motor that might want to try. I didn't get to take a look at the wires yet. Do you know if this motor self excite?
-
Yes it will but if you like you can motorize it first or when ever it fails to self start.
You can also use it as a starter motor that charges once up to speed.
Wires will be F1 and F2 field..... A1 and A2 armature......
Baldors are one of the better DC motors out there.
-
Doug,
I assume i connect F1+A1 and F2+A2 together. I can't use it as a starter since I dont have 180VDC to to start the motor
Carl
-
I did the calculation and to smooth out 50 amps of 240V AC rectified to DC, you need 8 of these.
http://theelectrostore.com/shopsite_sc/store/html/high-voltage-electrolytic-capacitors-400v-3900uf.html
Probably far less if the inverter has a wide input range. Also much less if you have a 3 phase generator.
-
No you have the connection wrong.
A1 goes to possitive A2 Neg
F1 pos F2 Neg
There may be two more wires marked S1 S2 if so they go in series with A1 and A2. A1 pos A2-S1 and S2 neg. And if you need to change rotation flip F1 and F2 and S1 and S2 as required ( or A1-A2 am I confusing you yet? )
That motor will spin all the way down to 12 volt it just won't have much torque. If your plan was bulk charging Batteries your best bet would be to put everything in series to charge.
A 180 volt stack of batteries would be something lol.
From personal experience I would rather get zapped with 600VAC than any level of DC about 120 V. This is just a word of causion to you, 180VDC realy hurts and is much harder to pry yours self free.
-
When i posted my connection i should have read A1 and f1 positive I shouldn't have use the + sign. and A2 and F2 Negative. I hope it doesn't have the S1 and S2 wires :). I am not going to be doing battery charging I will be feeding a 3kw grid solar inverter when the sun is down. I dont think I can use it to start the 6/1 since i wont have enough battery power to get it started.
carl
-
I did the calculation and to smooth out 50 amps of 240V AC rectified to DC, you need 8 of these.
http://theelectrostore.com/shopsite_sc/store/html/high-voltage-electrolytic-capacitors-400v-3900uf.html
Probably far less if the inverter has a wide input range. Also much less if you have a 3 phase generator.
Jeff,
The input range of the inverter is 150VDC to 500 VDC. I the 4kva head would supply less than 15amps @240 VAC I dont know what it would be once rectified to DC.
Carl
-
Take it too a rewind shop and see if you can make a deal to swap it.
You can also get 12, 24, 90 volt DC motors from Leeson. Generaly the PM type are cheaper. I remeber years back I used to buy 90 DC motors for as little as 120 Bucks CDN ( that was with a 80 Canadian Peso )
-
Take it too a rewind shop and see if you can make a deal to swap it.
You can also get 12, 24, 90 volt DC motors from Leeson. Generaly the PM type are cheaper. I remeber years back I used to buy 90 DC motors for as little as 120 Bucks CDN ( that was with a 80 Canadian Peso )
Doug,
A low voltage motor won't do me any good since i need to feed between 150 and 500 VDC for the invertor to work.
By my calculations this 3hp motor @ 1725 Rpm should produce about 2.6kwh did I forgot to mention this motor is FREE
-
Sounds like three of those capacitors would work for you.
-
Sounds like three of those capacitors would work for you.
Jeff,
Are you saying if I use my current 4kva AC head and rectify it to DC that using three of those caps should clean up the waveform enough that the inverter will like it.
Can I take the two 120 VAC outputs from the generator and connect them to each of the AC legs on a Bridge Rectifier for 240 or so VDC.
If so would the caps be on the DC side and how would they be wired in.
Thanks
Carl
-
Well, supposedly, but I don't want to be the one to cause you to burn up an inverter.
The 240V from the generator goes into a 400 or 500V full wave rectifier. Each capacitor goes across the output of the rectifier. Be sure to get the + and - correct.
You should end up with something close to 340V DC. Be careful with this!
I'd ask the inverter manufacturer if some ripple will cause a problem. Hopefully the inverter will protect itself from any waveform that could hurt it.
-
Sounds like three of those capacitors would work for you.
Jeff,
Are you saying if I use my current 4kva AC head and rectify it to DC that using three of those caps should clean up the waveform enough that the inverter will like it.
Can I take the two 120 VAC outputs from the generator and connect them to each of the AC legs on a Bridge Rectifier for 240 or so VDC.
If so would the caps be on the DC side and how would they be wired in.
Thanks
Carl
I don't understand why anybody would be doing this?To do this, you have to run the Lister at 650 rpm. My alternator will run at 40 or 50 amps with the engine running at 350 rpm and burn half the fuel. It doesn't cost me to build anythinr either, the alternator was free.
-
Sounds like three of those capacitors would work for you.
Jeff,
Are you saying if I use my current 4kva AC head and rectify it to DC that using three of those caps should clean up the waveform enough that the inverter will like it.
Can I take the two 120 VAC outputs from the generator and connect them to each of the AC legs on a Bridge Rectifier for 240 or so VDC.
If so would the caps be on the DC side and how would they be wired in.
Thanks
Carl
I don't understand why anybody would be doing this?To do this, you have to run the Lister at 650 rpm. My alternator will run at 40 or 50 amps with the engine running at 350 rpm and burn half the fuel. It doesn't cost me to build anythinr either, the alternator was free.
My plan is to run the lister @650rpm but rectify the current to DC and run it into an existing Grid Tied inverter. This will maintain the lister @ about 3/4 rack constant and put the electricity right back into the grid running my electric meter backwards. I can then use the electricity from the grid with no flicker and not have to worry about how big a load i draw at any time since the grid will be acting as a big battery so to speak
Carl
-
Getting into this one a bit late, but as long as you don't mind all the conversion losses and cost of parts etc etc., then it should work, but you'll be getting a worse deal out of it than you would if you bought the power from the utility.
The incoming power has to be incoming for you to use it, if you are pumping some small amount the other way, then most of the imperfections in your output will be present, as the wiring impedances between your set and the utility will allow your generator to override the utility frequency ands waveform, and probably also give you connection problems, as it won't stay in sync very well.
You really need a much larger set-up running with a decent waveform to be able to do that IMO.
Peter
-
The normal setup as far as I understand - you generate DC power to feed a battery, the battery feeds the inverter which sends power out to the grid. The problem is that if the grid drops so does your inverter which leaves you with no power. Alternatively, if you can generate enough power to satisfy all your own needs, you can feed your own system first and then send only the excess to the grid. In that case, if the grid drops, you still have power.
Jens
Jens
Most grid-tie systems skip the battery. I have yet to see one with batteries in the many sites I have visited in my area. The DC(from solar panels) feeds directly to the inverter. The goal of this type system is to send ALL the excess power generated to the grid. If the site load is less than the inverter output, the excess is sent to the grid. If the inverter output is less than the site load, then the additional need is met by drawing power from the grid. A battery in this system would be a waste and since they are so expensive, and have a finite lifespan, this method was developed to cut costs. It is in no way self sufficient. If there is no commercial power comming down the line, the inverter shuts down and the house goes dark, just as it would if the system wasn't in place. Think of it more as a long term financial investment, than as a alternate energy source.
A battery bank could be added as a backup, but using it daily would greatly shorten it's life as they only have a fixed number of charge/discharge cycles. A battery also has to draw it's charge current from somewhere, and that would be energy that is not being sent down the line to help pay for the system over the long term in reduced electrical costs. Used or not, the battery bank also requires regular maintenance and good attention to detail. The systems without the battery take upwards of 10 years to recover the cost of panels, inverter and tracking array. Fixed systems take longer as they are about 40% less efficient for a given panel size, only reaching their peak at local noon. It is something you do for the environment, by investing that extra $20-30K you have lying around the bank in, not expecting to see a penny of that for well over 10 years providing nothing fails or is damaged by mother nature.
For a grid-tie solar system, I think a backup generator($2-3K for a good diesel) makes more sense for emergency use than a backup battery in initial and re-occuring costs. The only place batteries make sense is in a complete off-grid scenario where you don't want to run a generator at night...
Ron
-
Sounds like three of those capacitors would work for you.
Jeff,
Are you saying if I use my current 4kva AC head and rectify it to DC that using three of those caps should clean up the waveform enough that the inverter will like it.
Can I take the two 120 VAC outputs from the generator and connect them to each of the AC legs on a Bridge Rectifier for 240 or so VDC.
If so would the caps be on the DC side and how would they be wired in.
Thanks
Carl
I don't understand why anybody would be doing this?To do this, you have to run the Lister at 650 rpm. My alternator will run at 40 or 50 amps with the engine running at 350 rpm and burn half the fuel. It doesn't cost me to build anythinr either, the alternator was free.
My plan is to run the lister @650rpm but rectify the current to DC and run it into an existing Grid Tied inverter. This will maintain the lister @ about 3/4 rack constant and put the electricity right back into the grid running my electric meter backwards. I can then use the electricity from the grid with no flicker and not have to worry about how big a load i draw at any time since the grid will be acting as a big battery so to speak
Carl
Somebody correct me if I am wrong, but I don't think the power company will pay you the same price as they sell it for. Although they might have to buy it, the government does not regulate the price they pay. My power company for some reason gets away with not buying it at all. If you use the power, You get full price out of your fuel.
It doesn't make sense to buy it at say 6 cents and then run your engine to sell it for 2 cents and pay thousands of dollars for the equipment to do it with.. A grid tie inverter is nothing like a regular inverter. It takes a long time to par fir it and your engine, and that is only if you have free fuel.
It costs me about 30 dollars a month for power from the power company without my generator plus 20 dollars a month for meter rental, 50 bucks total. If I run my generator to charge batteries at reduced speed in the winter, it costs me about 50 bucks a month in fuel, that is break even. If I run it at full speed in the summer for air conditioning during the hot part of the day to generate 125 volts, It costs me about 90 dollars a month. Granted, not many people have 50 dollar a month electric bills. If I had central air, it would be a different story. My air only uses 2 or 3 amps. When I run it slow and charge batteries, everything gets used by me plus I use half the fuel.
-
As i stated before we generate just over 13MwH of renewable energy each year (not counting the lister). We don't sell much back at the end of the year because we use that much energy over the year. We need to heat/cool our house which is a little over 3200 Square feet not counting a full basement. My plan to run the lister and connect it to one of my three EXISTING inverters will cost me very little money (less than 100 dollars). My plan is to use it in the winter to help heat my house running on waste VO and putting electricity back into the grid where it basically will be stored until i use it. All of the infrastructure is in place and no additional cost will be involved with meters etc. Since my Solar Panels are not producing nearly as much energy in the winter as the summer and I can get heat as a by product from running the lister and turning my meter backwards i find this to be a sound plan. Also if i produce the energy form a Renewable source (solar wind bio etc) it qualifies for Renewable energy credits or RECS. Each MWh is equal to 1 REC. Last year I sold my RECs for an average of 250.00 dollars US that was 3200.00 dollars. This year the selling price will more than double because the fines to the utilities for not meeting their renewable energy production will go from 300 per Mwh to 710 dollars per MWh making every credit they need to buy much more expensive.
carl
-
I don't know much about gride ty inverters but if it were me I'd be looking hard at indution generation because its simpler to do.
As good as elelctronics are I just don't put much faith in long term reliability.
-
Somebody correct me if I am wrong, but I don't think the power company will pay you the same price as they sell it for.
Consider yourself corrected ..... it depends which power company you are dealing with. BC Hydro for example charges or refunds you on the NET energy you use over a year. So, if you stick 1000 kw into the grid in the winter while using the waste heat to heat your house and if you pull 1100 kw out during he summer, you get charged as if you used 100 kw.
I do not know the actual rate that they are paying if you were to only use up 900 kw out of the banked 1000 kw. You are of course still responsible for meter rental, transmission charges and whatever else they can think up.
Jens
But what is the price they charge you as opposed to the price they refund you? You said it depends on the power company, so does anybody else agree or disagree with this?
-
I don't know much about gride ty inverters but if it were me I'd be looking hard at indution generation because its simpler to do.
As good as elelctronics are I just don't put much faith in long term reliability.
I agree that an induction motor would be the easiest way to go, but the utility would never approve an induction motor setup without making you jump through hoops. With the Grid tied inverters already installed and approved it is easier for me to go this was.
Carl
-
Somebody correct me if I am wrong, but I don't think the power company will pay you the same price as they sell it for.
Consider yourself corrected ..... it depends which power company you are dealing with. BC Hydro for example charges or refunds you on the NET energy you use over a year. So, if you stick 1000 kw into the grid in the winter while using the waste heat to heat your house and if you pull 1100 kw out during he summer, you get charged as if you used 100 kw.
I do not know the actual rate that they are paying if you were to only use up 900 kw out of the banked 1000 kw. You are of course still responsible for meter rental, transmission charges and whatever else they can think up.
Jens
But what is the price they charge you as opposed to the price they refund you? You said it depends on the power company, so does anybody else agree or disagree with this?
The key is not to sell them the power the key is to have them hold/store it for you until you need it thats why its called net meetering you only pay the difference between what you use and what you produce. With net metering in New Jersey you only true up once a year if you carry an credit at all. If you dont have a credit you will get a bill monthly if you do have a credit you will get a bill showing a credit.
-
But what is the price they charge you as opposed to the price they refund you? You said it depends on the power company, so does anybody else agree or disagree with this?
The key is not to sell them the power the key is to have them hold/store it for you until you need it thats why its called net meetering you only pay the difference between what you use and what you produce. With net metering in New Jersey you only true up once a year if you carry an credit at all. If you dont have a credit you will get a bill monthly if you do have a credit you will get a bill showing a credit.
OK that makes snse. Is it like that everyplace or do some places actualy buy it?
-
Bob,
They will buy it back if you have a surplus at the end of the year. Our goal is to only have a very small amount of surplus KwH left at the end of the cycle. In our case the yearly cycle starts April 1.
carl
-
I don't know much about gride ty inverters but if it were me I'd be looking hard at indution generation because its simpler to do.
As good as elelctronics are I just don't put much faith in long term reliability.
I agree that an induction motor would be the easiest way to go, but the utility would never approve an induction motor setup without making you jump through hoops. With the Grid tied inverters already installed and approved it is easier for me to go this was.
Carl
What kind of reliability do these grid ty inverters have?
In my line of work I can expect 1 in 20 Cutler hammer regen drives ( not an inverter in the same sence but same technology ) to fail within 6 to 12 months in 24-7 opperation that requires replacement.
I can expect just about all the power electronics to develop a problem once a year. Usualy a lighting trip, overtemp trip or other resetable fault.
It doesn't realy seem to matter who builds the electronics although some are better than others ( prefer Askawa drives over ABB or CH AB ect ect ). This is in an industrial setting, so how often do these grid ty inverters trip or fault and what is the most comon problems
-
Doug,
Two of the inverters are Sharp 3500 Watt units and have been online everyday since Dec 1, 2004 obviously they shut down at night but in three years they have be in operation they have never had a problem. The newest one, a Froinus 3,000 watt inverter has only been online for a few months now but it is working fine. All of these inverters came with a 5 year guarantee and the froinus can be extended to 10 years.
Carl
-
Bob,
They will buy it back if you have a surplus at the end of the year. Our goal is to only have a very small amount of surplus KwH left at the end of the cycle. In our case the yearly cycle starts April 1.
carl
OK. I don't know maybe I am missing something here. I can't see spending 2 or 3 thousand dollars to break even or make a couple of dollars at the end of the year. I'd rather spend a couple grand on a spare engine and not have anything to do with the power company. That is just me though.
-
i agree with Bob!
why sell to a power company?
unless they give you at least what they charge you for it, and that varies from state to state
some places won't but it, some will at a deferred cost basis, and some at full rate
even at full rate i don't want their service!
but i do understand there are others that feel differently, :)
i figure if i am selling to them, then that is just another reason for them to be poking around, and asking questions, requireing permits and inspections
and also having them popping in whenever they feel like it for whatever reason they feel is necessary at any given moment.
in the county in kansas where i have my property, all utilities, inspectors etc are bound by law to report anything amiss that they might see while on your property
even if it is outside their area of concern... so a electric utility meter reader is mandated to report you to a building inspector if he see's a new outbuilding
or the mailman if he see's new plumbing being installed,, well drillers etc
so i will get a po box at the post office and provide and consume my own power thank you very much!
even if it cost's me a bit more per kwatt/hr to do so
so far this season the power company has not been all that reliable in my estimation and likely is not going to improve over time
a couple or three of my own gensets, some solar, wind gen's and a battery bank will be far more reliable in my opinion
and i can hook it all up the way i see fit,, without having to educate some inspector that has no clue about AE, DC generation, batteries and all that.
but again, i realize my reality may not be that of others :)
bob g
-
"without having to educate some inspector that has no clue about AE, DC generation, batteries and all that."
Dangerous assumption Bob. I can find fault with some inspectors but generaly speaking they are up on what they do for a livng
"but again, i realize my reality may not be that of others "
Or you might actualy be right and your dealing with people who are not fully versed in home power generation or worse still sounds like you may have a jackass problem to deal with. You can't tell who your dealing with unless you speak to one.
My mail man delivers mail, he usualy runs, and he's got a hair cut like forest gump....
-
Doug:
i don't mean to slight any of the fine folks that are qualified inspectors, they do good work for the most part
what i am talking about is in small sparcely populated counties, where the electrical inspector only has about a half dozen homes to inspect
in any given year, who is also the plumbing inspector, building inspector, dog catcher, part time fire chief and was appointed to the position by his
father inlaw because he isn't smart enough to get a job on his own...
he might be the nicest guy in the world, and he actually may know something about house wiring, but you know the type
he is going to look at an alterntive energy installation and not have a clue.
so he sinks his heals in and refuses to grant the permit, or sign of on one his uncle sold you at the courthouse.
until you either put in what he understands or spend months trying to educate him and provide all the supporting doc's etc.
i have found in the larger area's, the inspectors are much easier to work with, have seen or at least heard of most of the stuff we are doing
that i can work with...
i am just to damned old and cranky to put up with somebodies good for nothing son inlaw, that now thinks he is barney fife
running around with a bullet in his pocket.
so i purposely picked an area of the country that i am familiar with, that doesn't have the man power to give me much trouble.
and the way i figure it what they don't know sure can't hurt me
the less they know about me, the better off i am.
btw, i can wire, plumb and build to code and have pulled permits and passed inspections on all three, on the first pass
so i ain't to worried about not doing something right or unsafe.
bob g
-
i agree with Bob!
why sell to a power company?
unless they give you at least what they charge you for it, and that varies from state to state
some places won't but it, some will at a deferred cost basis, and some at full rate
Well most states do buy it back from you at the same price they charge for it.
Below is how my utility in Ct works there will be exceptions, but in general this is how they work.
In many (not all) the electric bill has 2 components, the commodity charge and the delivery charge. The commodity is just that the, the price of the electricity, lets say .09/kwh. This is a pure pass through charge. The other component is the delivery charge, and lets say that is .10/kwh making the total cost .19/kwh.
So when you produce your own electricity you avoid paying both the .09/kwh commodity charge and the .10/kwh delivery charge. The value of your production is .19/kwh UP TO YOUR DOMESTIC USAGE.
Once you exceed your domestic usage and begin accumulating kwh credits your production is worth less to you. You will be paid .09/kwh, the same price that the utility pays any other producer on their network; this is known as the avoided cost. This avoided cost is the electricity component that the utility has avoided buying from another supplier. They will not pay you the .10/kwh delivery charge, because you do not own the delivery network, they do. You are not responsible for maintaining this network, they are.
This is a pretty good good system, where else can you find an entity that is compelled by law to buy what you make?
Scott
-
i agree with Bob!
why sell to a power company?
unless they give you at least what they charge you for it, and that varies from state to state
some places won't but it, some will at a deferred cost basis, and some at full rate
Well most states do buy it back from you at the same price they charge for it.
Below is how my utility in Ct works there will be exceptions, but in general this is how they work.
In many (not all) the electric bill has 2 components, the commodity charge and the delivery charge. The commodity is just that the, the price of the electricity, lets say .09/kwh. This is a pure pass through charge. The other component is the delivery charge, and lets say that is .10/kwh making the total cost .19/kwh.
So when you produce your own electricity you avoid paying both the .09/kwh commodity charge and the .10/kwh delivery charge. The value of your production is .19/kwh UP TO YOUR DOMESTIC USAGE.
Once you exceed your domestic usage and begin accumulating kwh credits your production is worth less to you. You will be paid .09/kwh, the same price that the utility pays any other producer on their network; this is known as the avoided cost. This avoided cost is the electricity component that the utility has avoided buying from another supplier. They will not pay you the .10/kwh delivery charge, because you do not own the delivery network, they do. You are not responsible for maintaining this network, they are.
This is a pretty good good system, where else can you find an entity that is compelled by law to buy what you make?
Scott
Just as I figured, you're power is worth more to use it yourself and then shut down the engine when not using it. At the price of fuel you can't compete with the power company unless you have free fuel like straight WVO. Even with free fuel, you still have to pay a lot fort he grid tie equipment, wear and tear on the equipment and the hassles.
I can see where it would be profitable if you had a really big wind power system where it runs all the time and produces a lot more than you can use with minimal maintenance. Maybe even a solar system if it was big enough. Maybe if you had a farm and a methane plant or an old well and a generator that runs on drip gas. I doubt you can make any real usable income from the power company unless you had a really big investment.
I have some people that pay me a buck a gallon to drop off their waste motor oil, but at a gallon or a gallon and a half a day, I might pay for the engine in 8 or 10 years and I have yet to determine the affects of the WMO in the engine.
-
Well most states do buy it back from you at the same price they charge for it.
And I think those that do not, are receiving more and more federal pressure to do so these days.
Ron
-
"what i am talking about is in small sparcely populated counties, where the electrical inspector only has about a half dozen homes to inspect
in any given year, who is also the plumbing inspector, building inspector, dog catcher, part time fire chief and was appointed to the position by his
father inlaw because he isn't smart enough to get a job on his own..."
In that case Bob you have my sympathy along with everyone else in your county.
You don't need a guy like that, no one does. Odds are he passes a much bad as he flags off thats good and someday he'll will be held acountable.
We had a water inspector in a town called Walkerton like that. Not sure if he's still in jail now or not, because a lot of people got sick and a few died because he was a moron and got his job threw his family ( brother I think was mayer or something ).
-
This is a good introduction to grid-tie inverters:
http://nooutage.com/inverter1.htm#Utility%20Protective%20Features
I believe it may be possible to build a UL1741 compliant device that would couple a generator to the utility grid. Ie, no conversion to DC needed. I've never seen one though. The safety devices make sense to me - we can't have linesmen and neighbours getting electrocuted.
-
Let me just clear up a few things. We have been producing RE using Solar Panels and a wind turbine since DEC 2004. We produce much more than we use in the summer and consume the excess in the winter. Since all of the solar and wind equipment is already paid for it cost me nothing to run it.
People don't realize just how much money is to be saved and made using RE. SREC's = Solar Renewable energy credit
When we installed our Solar, the State of New Jersey was offering incentives so they paid for 70% of the installed cost Our solar array has all ready paid for itself.
We generate better than 13,000KwH per year just from our solar
SREC's
Generated My cost If i had to pay for the electricity Sold energy credits for total net savings / income
2005 > 10,000 KWh 0 1,500.00 2,650.00 4,150.00
2006 > 10.000 0 1,500.00 2,500.00 4,000.00
2007 > 13,000 0 2,015.00 3,250.00 5,265.00
2008 > 13,000 0 2,015.00 8,125.00 10,14.00 Estimated
The reason the 2008 figures for Srecs is so high is that the State is now fining the utilities 710.00 per Srec it falls short in producing / buying where it had only been 300.00 before 2008.
Trust me when I tell you we pay 0 dollars to the utility for > 13,000Kwh of electricity we produce and use each year,and we sell each of our Solar Renewable Energy credits (13 per year) for no less than 250.00 dollars each and begining in 2008 the Minimum selling price in New Jersey will be 600.00 each. Selling the SREC's does not mean we do not use the electricity. It means we sell the utility the right to say "they made the clean energy".
Carl
-
I think what you are doing makes perfect sense.
Michigan is considering:
* Hydro less than 500 kW: $0.10 USD/kWh
* Biogas less than 150 kW: $0.145 USD/kWh
* Geothermal less than 5 MW: $0.19 USD/kWh
* Wind: $0.105 USD/kWh
* Wind energy from small wind turbines: $0.25 USD/kWh(1)
* Rooftop solar less than 30 kW: $0.65 USD/kWh
* Solar façade cladding less than 30 kW: $0.71 USD/kWh
Let's see, with the new $1/watt solar panels coming and $1/watt for an inverter, that's maybe 3 year payback. I would do that even it it took some labor and additional parts.
-
Jzeeff,
Inverters are much less than $1.oo per watt now. The Froniuis ig3000 that i recently installed was about 1700 dollars for a 3kw inverter
carl
-
Carl, how many kw hrs per year do you get from a "1 kw" rated panel?
-
Carl, how many kw hrs per year do you get from a "1 kw" rated panel?
I'm not Carl, but with 5KW of panels, in a west orientation, in Los Angeles, I got 8MW output last year.
5/8 = 625KW per 1KW of panels/year
Your mileage may vary.
-
Carl, how many kw hrs per year do you get from a "1 kw" rated panel?
I'm not Carl, but with 5KW of panels, in a west orientation, in Los Angeles, I got 8MW output last year.
5/8 = 625KW per 1KW of panels/year
Your mileage may vary.
Mike,
8MWH/year from 5kw of panels facing west is great. My original 7kw system facing SW only did 9.5MWH/year. I guess you just have many more sunny days then we have here in the North East. We just added another 3kw this fall so i expect to be around 13MWH/year on the solar and about 3MWH on the wind turbine.
-
I think of this as 1.7 hrs sunshine per day (caused by over rating of the panels). So maybe 1/2 of this in Michigan?
Hmm, that's more like 8 year payback here.
-
Carl, how many kw hrs per year do you get from a "1 kw" rated panel?
I'm not Carl, but with 5KW of panels, in a west orientation, in Los Angeles, I got 8MW output last year.
5/8 = 625KW per 1KW of panels/year
Mike,
Then I guess that smoke from your electric BBQ is the meat burning? ;D
I wish Ontario, Canada had some grant incentives to assist homeowners to do the right thing. I can build a wind turbine from parts I scavenge from the dump, and I`m trying my best to do so, but I cannot use scavenged materiels to make solar photovoltaic cells. My DIY skills are just not good enough, or the quality of my dump and local scrapyards just aren`t up to aerospace standards. >:(
-
I think of this as 1.7 hrs sunshine per day (caused by over rating of the panels). So maybe 1/2 of this in Michigan?
Hmm, that's more like 8 year payback here.
8 year payoff with only 40 minutes a day, that is better than I thought. Awesome
-
That's assuming the high buyback rates by the utility and $1/watt panels. Neither is avalable yet.
-
That's assuming the high buyback rates by the utility and $1/watt panels. Neither is avalable yet.
yeah but the conversation is about of they pay for themselves, have you forgotten? they definately do.
-
Carl, how many kw hrs per year do you get from a "1 kw" rated panel?
I'm not Carl, but with 5KW of panels, in a west orientation, in Los Angeles, I got 8MW output last year.
5/8 = 625KW per 1KW of panels/year
Your mileage may vary.
This might be 8/5 and not 5/8, which is 1600 kWhkWp and year, a nice value (in Germany we are calculating with 900-1000 kWh/kWp a).
NASA has a nice online tool to view the irradiation, Temperature and Wind on every place:
http://eosweb.larc.nasa.gov/cgi-bin/sse/grid.cgi
I looked for Michigan (klicked between those lakes): It was around 1400 kWh/m² on a 30° tilted surface orientated to the south. This could be good for around 1000-1200 kWh/kWp, depending on the temperature.
Christian
-
Thanks for the correction. So a 1KW panel would supply around $100/yr worth of electricity at normal rates and $650/yr at the high buyback rates proposed here in MI.
(normally $.10/kwh, $.65/kwh proposed)
-
Jzeeff,
Here is a link the the Michigan site that gives you financial information on incentives.
http://www.dsireusa.org/library/includes/maphomeowner.cfm?State=MI&CurrentPageId=1
carl