another new solar system

System · July 2008

I have been lurking for a while... Just "finished" (never really finished anything) my cabin system. Here are the details :

The system is 360 watts. I have a page setup here for it : Solar power plan

Here is the plan :

Home made adjustable solar mount (going to cover the base in board & baton like my cabin) with two Sun (re-branded evergreen 180 watt 25 volt) panels wired for 50 volts:

Charge controller, ground bus, negative bus and breakers for battery and solar disconnect to charge controller :

Two Everyready GC-2 6v 200 amp batteries (will be building a box for them in a week or so - plus adding two more batteries), Trace voyager 1512 inverter, 200 amp fuse and 150 amp breaker :

I figure my total cost for everything was About $2600

Parts :

From Sun Electronics
2 x 180 watt Sun panels : $540 each
Outback fx-80 charge controller : $575
200 amp fuse : $65
shipping from Miami to Western New York : $180

From Sams club
2 x Eveready GC-2 6v 200 amp batteries : $75 each

Craigs list
Trace Voyager 1512 inverter : $300

Autozone
2 x 100 amp breaker : $27 each
150 amp breaker : $27

misc
2/0 wire, #2, #4, #6 bare ground wire : About $400 for all wiring (my panels are 60' from my cabin - This added greatly to my costs) - I also have a great deal of extra wire
good Digital multi-meter : $90
Several Lugs and connectors of different sizes : about $30
two 8' ground rods and hardware : about $35

one question I have is settings for the fx-80. With the everready golf cart batteries are there any changes I should make?

Also any other suggestions would be appreciated.

for anyone interested here are the details on the cabin build : Cabin

thanks

BB. · July 2008

Re: another new solar system

Looks like you are growing out your system nicely!

A few observations...

You appear to be missing a wire between your ground bus and your negative bus in your drawing--but there appears to be one in the photograph.

Hmmmm... Multiple ground stakes with 60 feet between them (one at solar panels, another at cabin?). That is the $2,600 question.

So--first question--do you have a good chance of lightning strikes in your area?

If so, then, perhaps you should loose the ground connection between the cabin and the solar stand ground rods. Let the solar stand ground the frames on your panels and the cabin ground rod take care of the rest of the system... (I could very well be wrong here--there are many opinions on grounding and mixing opinions in an installation can be worse than doing nothing).

And get some DC lightning arresters for the input at the solar charger with a good connection to earth ground. Also look at insalling arresters out the output of your AC inverter--Wind-Sun has said here before that the output of the inverters seems to be the most common lightning induced failure they have seen.

Another suggestion, try to run all +/- cables together (same length and bundle tied). This prevents them from behaving like a "loop antenna" and picking nearby lighting strike energy and inducing it into your wiring. The larger the loop, the greater the problem.

And run AC Hot/Neutral/Ground connections together for the same reason--plus, if they go around/pass/through metal conductors (other wiring or metal boxes and like), current in AC wiring can induce AC currents if the Hot and Neutral go through, for example, separate openings in a metal box.

Also, keeping the source and return wires running right next to each other can help eliminate radio/tv interference... For example, if you look at the heavy leads from your batteries to your inverter--you have a nice 3' loop antenna--easier to broadcast or receive RFI or lightning induced currents.

If you do not have lightning and no RFI problems--then you probably don't make any changes now until your next major rewiring.

-Bill

System2 · July 2008

Re: another new solar system

I have a square-d panel I was planning on using at the panels and putting a lightning arrestor in that.

The only reason I was binding the two ground wires togther is everything I have read said all ground roads needed to be... Right now none of the wiring buried so I can make changes at this point.

Thanks for the suggestion about the wiring... I will clean that up.

BB. · July 2008

Re: another new solar system

To be honest--I am not completely sure whether connecting the ground rods together or not is the best answer... In my humble opinion it is probably better to not connect ground rods so far apart. You run the risk of bringing more of the lightning energy into your shed with a panel strike.

If the DC of the panels is well isolated from the aluminum frame ground (as it normally is)--then my $0.02 recommendation would be to keep the two ground "systems" isolated. I would definitely not earth ground the DC
"-" lead at both the solar panels and in the shed...

I have re-read your post a couple of times--you may also be making a comment regarding the connection of the DC Ground and the Earth Safety ground in the shed. Connecting these two together and to the shed earth rod is just fine.

But, in the end--I will leave that to others who live in lightning country and have off grid solar systems that have withstood nearby strikes (or not) to make more detailed grounding recommendations.

-Bill

quid_non · July 2008

Re: another new solar system

Man, that's a nice system you have put together there - thanks for sharing the pics!

Couple of questions:
1. Are those breakers in the pics the resetable ones? If so, any issues around those? I have been thinking about using them.

2. Have you considered installing a battery meter (i.e. Trimetric or similar)? I really like knowing the batt status from a conserving point-of-view.

3. Looks like a great price on the panels - did you get 'em recently?

4. I also have a long run from my panels to cabin (~120') - I'm considering upping the voltage as you have to cut down on the wire loss. Looks like you go from ~50V down to 14V at the house. Is that working well?

5. Off topic, but do you have a fridge ot toilet?

Thansk for the great pics!
Best
Wayne

System2 · July 2008

Re: another new solar system

quid_non wrote: »

Man, that's a nice system you have put together there - thanks for sharing the pics!

Couple of questions:
1. Are those breakers in the pics the resetable ones? If so, any issues around those? I have been thinking about using them.

Yes they are. So far so good. I original saw them in a article I found here : http://www.alpharubicon.com/altenergy/xantrex458jyw.htm . I also saw them in a print catalog I got from real goods. I do have a d-square breaker box that I am going to install at the panels to add a lightning arrestor to soon. I also might replace the breaker in the closet that goes from the panels to the charge controller to a smaller one as 100 amps is way more than I should every pull.

quid_non wrote: »

2. Have you considered installing a battery meter (i.e. Trimetric or similar)? I really like knowing the batt status from a conserving point-of-view.

Right now I am using a digital multimeter picked up at radio shack. It was the best one they sold. I am planning on putting mettering in soon but not sure when or what type. I might just pick up individual meters and add shunts so that I can monitor both the amps the inverter is using, the charge controller is providing and any dc loads plus a voltage meter on the battery. Just not sure yet.

quid_non wrote: »

3. Looks like a great price on the panels - did you get 'em recently?

couple of weeks ago. I hope the price stays done (or maybe lower) for next years batch of four additional panels I want to add.

quid_non wrote: »

4. I also have a long run from my panels to cabin (~120') - I'm considering upping the voltage as you have to cut down on the wire loss. Looks like you go from ~50V down to 14V at the house. Is that working well?

seems to... even with the expanded setup next year (to 6 panels total) the most amps I could pull would be 14 so my #4 wire should cover it fine. Once thing I did note when reading the manual is that as the voltage increases in relationship to the battery bank the charge controller losses efficiency. So a 24 volt or larger battery bank would make more sense. If I ever need to replace the inverter I will probably pick a 24v model to replace it.

quid_non wrote: »

5. Off topic, but do you have a fridge ot toilet?

not yet... I do have an outhouse and another building on the property about 600' away has a full bathroom. I am planning on building a composting toilet system in an addition on the east side of the building next year. Also in the plan is a rain water collection system until I can put together an old fashion windmill on a well.

I am going back and forth on refrigeration... either propane or something like this guy has : http://mtbest.net/chest_fridge.html

I figure with the four extra panels I am planning for next year I could do something like that. my battery bank (once expanded next week to 400 amp hours) might be a little small.

quid_non wrote: »

Thansk for the great pics!
Best
Wayne

thanks

quid_non · July 2008

Re: another new solar system

Thanks for the additional info. Check out the trimetric meter:

http://www.windsun.com/ChargeControls/Trimetric_2020.htm

I have one and really like it, you need to buy a shunt with it.

Is the loss from 50V to 14V that significant? I really like the availablity of 12V stuff, but understand the need to be a efficient as possible. It is easy to find 12V bassalts to run conventional fluorescent lights (up to 40W) - at a low cost. Not sure about how a 24 or 48 V system would be in terms of finding stuff easily.

I saw link to the fridge - lots of threads here also. I'm also not sure what to do yet - add more panels for more power or get a propane model.

We have a composting toilet with a fan running off solar - they really work (so far) and beat that trip to the outhouse when it rains or in the middle of the night.

icarus · July 2008

Re: another new solar system

CLEB,

"I do have an outhouse and another building on the property about 600' away has a full bathroom. I am planning on building a composting toilet system in an addition on the east side of the building next year. Also in the plan is a rain water collection system until I can put together an old fashion windmill on a well."

This is a complete aside, but a few thoughts on composting toilets.

I used to work for a remote bush camp that has used outhouses for almost 100 years. About ten years ago, the new owners wanted to "modernize" . After much research we installed a series of composting toilets to replace the outhouses. It was, for the most part a disaster. The simple fact is that for composting toilets to work they need heat. This camp had to run the generator 12 hours a day only to run the 120vac heaters! Slowly they came to their senses and have discarded most of them. At the time I thought it would be a good idea for my remote island as well, as we are on mostly rock. I even built a propane heater for mine. I got it to work quite well, but I had to burn propane 24/7 and I had to agitate the compost daily, or it wouldn't work at all.

Since we draw our water directly from the lake untreated, water quality preservation is of paramount importance. We have since gone back to the dug outhouse. Way less work, no smell if you take care of it, and the pit will last ~10 years. After that, just move it. (We have a very select few locations that have enough soil to dig a good pit!) At -35 it gets a bit cold, but you can always install a propane heater if need be. We just use foam covered toilet seats. You get used to it rather quickly.

Tony

mike95490 · July 2008

Re: another new solar system

quid_non wrote: »

I saw link to the fridge - lots of threads here also. I'm also not sure what to do yet - add more panels for more power or get a propane model.

If I was building it now, I'd get conventional Energy star fridge, and add the PV's. Propane will become pretty expensive in the future. PV's are affordable now, and name brands are good for 20+ years

System2 · July 2008

Re: another new solar system

quid_non wrote: »

Thanks for the additional info. Check out the trimetric meter:

http://www.windsun.com/ChargeControls/Trimetric_2020.htm

I have one and really like it, you need to buy a shunt with it.

Is the loss from 50V to 14V that significant? I really like the availablity of 12V stuff, but understand the need to be a efficient as possible. It is easy to find 12V bassalts to run conventional fluorescent lights (up to 40W) - at a low cost. Not sure about how a 24 or 48 V system would be in terms of finding stuff easily.

I saw link to the fridge - lots of threads here also. I'm also not sure what to do yet - add more panels for more power or get a propane model.

We have a composting toilet with a fan running off solar - they really work (so far) and beat that trip to the outhouse when it rains or in the middle of the night.

Yeah I have read about the trimetric and will probably end up getting it... but not until the fall... I have to finish up the cabin's other projects for now.

as to the efficiency here is an example. for the conversion :

in 50.8 V 4.7 A -> 238.76 watts
out 14.4 V 14.8 A -> 213.12 watts

during absorbing stage

So I am about 90% efficient. not to good... but could be worse... for my usage (mostly weekend) it will do... and when I grow the system I think I will gain some efficiency. I am also thinking of setting my charge rate to 14.8 v which may or may not effect things. I do not have enough data yet to really make a conclusive opinion yet though...

thanks for the info the the composting toilet... is yours DIY or commercial? if commercial which one? How long have you had it?

System2 · July 2008

Re: another new solar system

icarus wrote: »

CLEB,

"I do have an outhouse and another building on the property about 600' away has a full bathroom. I am planning on building a composting toilet system in an addition on the east side of the building next year. Also in the plan is a rain water collection system until I can put together an old fashion windmill on a well."

This is a complete aside, but a few thoughts on composting toilets.

I used to work for a remote bush camp that has used outhouses for almost 100 years. About ten years ago, the new owners wanted to "modernize" . After much research we installed a series of composting toilets to replace the outhouses. It was, for the most part a disaster. The simple fact is that for composting toilets to work they need heat. This camp had to run the generator 12 hours a day only to run the 120vac heaters! Slowly they came to their senses and have discarded most of them. At the time I thought it would be a good idea for my remote island as well, as we are on mostly rock. I even built a propane heater for mine. I got it to work quite well, but I had to burn propane 24/7 and I had to agitate the compost daily, or it wouldn't work at all.

Since we draw our water directly from the lake untreated, water quality preservation is of paramount importance. We have since gone back to the dug outhouse. Way less work, no smell if you take care of it, and the pit will last ~10 years. After that, just move it. (We have a very select few locations that have enough soil to dig a good pit!) At -35 it gets a bit cold, but you can always install a propane heater if need be. We just use foam covered toilet seats. You get used to it rather quickly.

Tony

thanks... I am thinking of doing something that will be much like an indoor outhouse... using three of these : http://www.autonopedia.org.uk/appropriate_technology/Compost_Toilet/Turntable_Composter.html

for our very limited use and liberal amounts of sawdust (free from local mill) I am hoping for the best... but the outhouse is not going anywhere... I like it... keep the door open and watch the ravine... quite relaxing... but my wife on the other hand... not such a fan of the whole outhouse... so I am going to try this and see what we get... Otherwise I will probably end up with a septic system...

icarus · July 2008

Re: another new solar system

She'll get used to it. My wife keeps a bucket in the shower for overnight needs, filled with peat moss, no noise no smell. I'd be really leery of an "indoor outhouse" if it were me!

Tony

Redford · July 2008

Re: another new solar system

In the past five years we have used (in this order) a dug-pit outhouse, a Sunmar composting toilet, and just this week we received a Storburn incinerator unit.

The outhouse always works, until it's full (ours never got full). The NYS code officer informed me that a permanent residence cannot have just an outhouse. So we bought a composter unit from Sunmar.

We thought we would be slick and build a heated room scabbed onto our house, that worked for about a month. We bought the unit that didn't require power and it didn't work so good, there were smells and bugs....kinda nasty especially bad on humid days. So I cut the room off the cabin and made it into a stand alone outhouse building. Now it works awesome. I put two 10 watt solar panels that charge a 12ah battery that runs (2) LED lights on an auto-sensor and a fan to assist the convection current. It freezes solid in the wintertime and in spring can fill up right to the top of the chamber, but in a week or two it all composts down to about 1/3 the volume.

I'll have to get back to you regarding the storburn unit......I haven't even installed it yet.

icarus · July 2008

Re: another new solar system

Always seems kinda crazy to use energy to burn what nature will take care of any way, IMHO. Lobby you local building official to allow the outhouse! A well taken care of they are very environmentally friendly.

Tony

System2 · July 2008

Re: another new solar system

icarus wrote: »

Always seems kinda crazy to use energy to burn what nature will take care of any way, IMHO. Lobby you local building official to allow the outhouse! I well taken care of they are very environmentally friendly.

Tony

This is a state thing in New York. Not much chance of changing things. I know of people who purchased a composting or incinerating toilet just to meet code but still use the outhouse so as to not use the power running the system... costs money but makes the state happy

Redford · July 2008

Re: another new solar system

cleb wrote: »

This is a state thing in New York. Not much chance of changing things. I know of people who purchased a composting or incinerating toilet just to meet code but still use the outhouse so as to not use the power running the system... costs money but makes the state happy

That's just why we had to buy a composter, to appease the code enforcers. The incinerator will be nice on rainy or really cold days though, I really hope it works out. Between the outhouse, the composter and the incinerator we should have all the alternative bases covered.

System2 · July 2008

Re: another new solar system

Cleb,
Thanks for posting this - it's a really good example of a basic system that still includes pretty much all the pieces you need for a correct setup. I've been noodling with a system (or two) for our remote cabin for a while, but it's been informal/half-ass up to now. This is a great primer on making things more formal. I'm particularly intrigued by the use of the automotive breakers as breaker/disconnects - probably not code compliant, but certainly solves the problem nicely.

The toilet discussion is also one that "we" have been having. Redford - I'd be very interested in staying updated on the Storburn. We had basically decided that it was the best option for us as well, although the price is a bit of a hurdle given our very low usage - it's still on the table but we're deferring until we have a more 'real' structure in place.
We got there by the usual route. The 'dig a hole' option is tough given our very rocky/hard soil, and the 'bucket brigade' approach may have worked if it weren't for the fact that my wife went off and emtied the first bucket; killed that idea pretty quick. We don't have the volume for a true composting solution (not to mention the bears), and being off-grid the commercial composters are pretty much a non-starter. Our temporary stopgap is to use the PETT setup which should be OK for a couple years until we have a better take on our ultimate development plans.

mike95490 · July 2008

Re: another new solar system

What is wrong with our current solar system ?

< Sol, Mercury, Venus, Terra, Mars, Jupiter, Saturn, Uranus, Neptune Pluto >

BB. · July 2008

Re: another new solar system

Well, Pluto isn't half the planet it used to be...

-Bill

System2 · July 2008

Re: another new solar system

dwkdnvr wrote: »

Cleb,
Thanks for posting this - it's a really good example of a basic system that still includes pretty much all the pieces you need for a correct setup. I've been noodling with a system (or two) for our remote cabin for a while, but it's been informal/half-ass up to now. This is a great primer on making things more formal. I'm particularly intrigued by the use of the automotive breakers as breaker/disconnects - probably not code compliant, but certainly solves the problem nicely.

The toilet discussion is also one that "we" have been having. Redford - I'd be very interested in staying updated on the Storburn. We had basically decided that it was the best option for us as well, although the price is a bit of a hurdle given our very low usage - it's still on the table but we're deferring until we have a more 'real' structure in place.
We got there by the usual route. The 'dig a hole' option is tough given our very rocky/hard soil, and the 'bucket brigade' approach may have worked if it weren't for the fact that my wife went off and emtied the first bucket; killed that idea pretty quick. We don't have the volume for a true composting solution (not to mention the bears), and being off-grid the commercial composters are pretty much a non-starter. Our temporary stopgap is to use the PETT setup which should be OK for a couple years until we have a better take on our ultimate development plans.

Thanks... my whole cabin building project has been budget minded. Going solar on a budget is not easy... I did have to dig around alot to find out the most cost effective way to do things but other then the higher end charge controller I think it would be hard to build a similar system much cheaper.

I already have some changes to put in.

1) I heard from someone that the 100 amp breaker I am using is way to large for the PV input. I looked at DC breakers that are sized right for 50-80 volts... they are expensive... So I think the cheaper solution would be to put a 20 amp DC fuse in front of the breaker. So in effect the breaker is really only a disconnect. I can do that for less the $35. I could go totally low budget and get a automotive 20 amp fuse but I think this is a better solution. I might add a similar fuse from the charge controller to the batteries (80 amps) but think this is less important.

2) get the temp sensor for my charge controller as there is no way I can make the changes needed on a daily basis for the temp compensation.

3) add meters (probably this fall - after cabin is finished)

4) route positive and negative wires together as I was told the way I have them routed can create noise and attract lightning

5) put in DC and AC lightning arrestors - this will happen this summer

6) adjust charge settings on controller - I am thinking the trojan battery instructions here will do and will make the changes next trip down. I figure they are close enough as my batteries do not have any better information out there.

7) grounding rods - I am thinking I am not going to connect the tv array ground rod(60 feet from the building) to the buildings ground rod. I will instead add another grounding rod at both locations. There is going to be a shed behind my panels in a couple of weeks which is where another pv disconnect is going to go along with the lightning arrestor. I should be able to put the ground rods atleast 12 feet away from the current ones on both buildings further away from each other. might help and do not think I can hurt.

BB. · July 2008

Re: another new solar system

cleb wrote: »

4) route positive and negative wires together as I was told the way I have them routed can create noise and attract lightning

Just to be clear... the non-parallel routing of wire runs does not "attract lightning"--but make a better antenna which can capture energy from nearby lightning strikes and induce high currents and/or voltage into your AC/DC system wiring and cause damage...

Just an aside--when I used to do FCC compliance testing for computer systems, we always wound the wire in "figure 8's". This makes a poor antenna as 1/2 the loop cancels out the other half of the loop--reducing the overall emissions and improving immunity of the systems.

7) grounding rods - I am thinking I am not going to connect the tv array ground rod(60 feet from the building) to the buildings ground rod. I will instead add another grounding rod at both locations. There is going to be a shed behind my panels in a couple of weeks which is where another pv disconnect is going to go along with the lightning arrestor. I should be able to put the ground rods atleast 12 feet away from the current ones on both buildings further away from each other. might help and do not think I can hurt.

When you layout multiple ground rods--usually you wire them back to a central ground rod (think Star), then you attach your equipment ground(s) to that one point... that way, nearby strikes which create an electrical gradient in the ground--does not induce current into your safety/lightning grounds.

-Bill

quid_non · July 2008

Re: another new solar system

as to the efficiency here is an example. for the conversion :

in 50.8 V 4.7 A -> 238.76 watts
out 14.4 V 14.8 A -> 213.12 watts

during absorbing stage

So I am about 90% efficient. not to good... [/QUOTE]

Thanks...
Based on these numbers, looks like overall @ 50V you are getting ~66% of the panel "label" wattage: (2*180W)/ 238.76W. Is this a correct calculation/assumption? Is this about the amount expected from panels?

If you factor in the "step down" to ~14V - the final is ~60%. almost like a power generated from a single panel. Is this why it is good to somewhat oversize?

Any idea on what would happen to FX perfomance if the voltage loss dus to wiring was ~10-15% on long run?

thanks for the info the the composting toilet... is yours DIY or commercial? if commercial which one? How long have you had it?[/QUOTE]

Ours is an Envirolet MC120. Got it off Craigs List and rewired it to work for 12V (was set up to run on 120V). Did not put in a resistive heater (too much energy consumption at 12v)... We like it fine - it gets used about 3-10 days/month (cabin use). No smell, little upkeep. Located in Western Va - so summer/Fall temps are in the upper 70's to 80's. Winter use may be an issue due to the lower temp effect on composting - -we will see.

BB. · July 2008

Re: another new solar system

I have a Grid Tied Xantrex inverter and it has 0.5% (IIRC) or so accurate internal measurement...

3.5 kW STC of rated panels south of San Francisco CA... CEC rated as 2,933 watts (after all the California deratings).

I have seen, a couple of times in the past ~3 years 2,999 watts (cool clear day fall/spring time)...

2,999w CEC/3,500 PTC panel=85.7% from best panel rated to utility line power (should be pretty much equivalent to what you would see with an FX-80 controller...

Realistically, I get between 2,300-2,500 watts and sometimes in cool mornings 2,700 watts.

The percentage of STC panel rated power vs measured power output: I would expect to see (dirty panels--pretty much gave up washing them over a year ago--2nd story roof, good weather, warm and cool depending on conditions, not very windy, fixed mounted roof array at latitude, array faces SE~155 Degrees), my mid-day peaks run around:

2,300/3,500=65.7% (hot weather, bit of haze)
2,500/3,500=71.4% (cooler weather, clear)
2,700/3,500=77.1% (usually morning on cool clear days)

Since my system is grid tied and a relatively efficient Grid Tied inverter--the numbers should be about the best one could expect (no battery charging current limiting as cells become charged).

-Bill

System2 · July 2008

Re: another new solar system

quid_non wrote: »

as to the efficiency here is an example. for the conversion :

in 50.8 V 4.7 A -> 238.76 watts
out 14.4 V 14.8 A -> 213.12 watts

during absorbing stage

So I am about 90% efficient. not to good...

Thanks...
Based on these numbers, looks like overall @ 50V you are getting ~66% of the panel "label" wattage: (2*180W)/ 238.76W. Is this a correct calculation/assumption? Is this about the amount expected from panels?

If you factor in the "step down" to ~14V - the final is ~60%. almost like a power generated from a single panel. Is this why it is good to somewhat oversize?

Any idea on what would happen to FX perfomance if the voltage loss dus to wiring was ~10-15% on long run?

thanks for the info the the composting toilet... is yours DIY or commercial? if commercial which one? How long have you had it?

Ours is an Envirolet MC120. Got it off Craigs List and rewired it to work for 12V (was set up to run on 120V). Did not put in a resistive heater (too much energy consumption at 12v)... We like it fine - it gets used about 3-10 days/month (cabin use). No smell, little upkeep. Located in Western Va - so summer/Fall temps are in the upper 70's to 80's. Winter use may be an issue due to the lower temp effect on composting - -we will see.

those numbers were from my first day of use (next day it rained all day). I have not been down to the cabin since. Hope to make it out this weekend and check things. On that day I had my panels facing due west on a 90 degree day which was very hazy. I used the battery power that day to run a circular saw and drill for a hour or so combined. I expect that on one of the sunny days after that I had more watts coming out of the panels. I will update this post when I go out next.

thanks for the info on the composting toilet. Still up in the air on this... but I do not have to decide until next summer when I build the bathroom.

quid_non · July 2008

Re: another new solar system

BB. wrote: »

I have a Grid Tied Xantrex inverter and it has 0.5% (IIRC) or so accurate internal measurement...

3.5 kW STC of rated panels south of San Francisco CA... CEC rated as 2,933 watts (after all the California deratings).

I have seen, a couple of times in the past ~3 years 2,999 watts (cool clear day fall/spring time)...

2,999w CEC/3,500 PTC panel=85.7% from best panel rated to utility line power (should be pretty much equivalent to what you would see with an FX-80 controller...

Realistically, I get between 2,300-2,500 watts and sometimes in cool mornings 2,700 watts.

The percentage of STC panel rated power vs measured power output: I would expect to see (dirty panels--pretty much gave up washing them over a year ago--2nd story roof, good weather, warm and cool depending on conditions, not very windy, fixed mounted roof array at latitude, array faces SE~155 Degrees), my mid-day peaks run around:

2,300/3,500=65.7% (hot weather, bit of haze)
2,500/3,500=71.4% (cooler weather, clear)
2,700/3,500=77.1% (usually morning on cool clear days)

Since my system is grid tied and a relatively efficient Grid Tied inverter--the numbers should be about the best one could expect (no battery charging current limiting as cells become charged).

-Bill

Thanks Bill!
That's impressive - looks like your grid tied system generates up to ~15,000KWh per day - is this enough to make your meter run backwards often?

BB. · July 2008

Re: another new solar system

Quid_Non,

My system averages around 13 kWhr per day (not 15,000 kWhrs--unless you are European and your "," is my ".") 365 days per year (4,745 kWhrs per year)... On sunny days, around 15-19 kWhrs per day--on cloudy days--the lowest I have ever seen is 0.3 kWhrs on one really dark January day... My daily load is probably around 8kWhrs per day--so I am a net generator year over year.

Usually, during the day, my meter is spinning backwards around at a 2-2.4 kW rate during the middle of of the day (except when cloudy weather). My forward power consumption (less microwave, is around 200-700 watts (at night)... We are pretty cheap (no big electric appliances, entertainment centers, or AC--we have gas appliances for normal heating applications).

So, all in all, I have generated more power than I have consumed these last three years.

My system is over-sized because I wanted to look at a small electric car and/or some spot A/C when we get our few weeks of 100 degree weather (have the room A/C--but have not needed it yet).

Right now, I get at the end of the year, around a $260 credit--that I loose because of net metering rules--so I have some headroom to run additional loads and not feel guilty.

Since I am on a Time of Use plan--I also get more $$$ credits than would be if I was on a flat rate plan (currently $0.115 per kWhr)... Monday-Friday, my summer noon-6pm peak rate is $0.27 per kWhr and my off peak is $0.09 per kWhr. So--if I avoid summer weekday loads--I can "bank" my summer solar generation excess for off-peak/winter use at a 3:1 advantage (i.e., sell 10 kWhrs peak at $0.27/kWh and buy 30 kWhrs off peak at $0.09/kWh).

-Bill

PS: We have very steeply "progressive rates" in California--I am below "lifeline" power usage (<330 kWhrs per month)... If I was over 1,000 kWhrs per month, I would be paying over $0.50 per kWhr for noon-6pm power (with Time of Use)--so conservation was my first goal before I ever installed solar (insulation, double pane windows, CFLs, Energy Star appliances, fans instead of A/C, and just turning things off when not in use).

System2 · July 2008

Re: another new solar system

so something weird happened when I wired my AC panel up today. This is the first time that I tried to power anything on the AC 2 out from my inverter. I found that I was only getting 90 volts out. Anyone every see anything thing like that? Figure it must be something with the inverter. I just re-wired the panel so everything runs of AC 1 which works fine.

some notes on the solar performance :

Max watts 256 / Max VOC 60.8 / Max Bat 15 - so far we have generated 1 kilowatt that went into the batteries and they are currently full.

On the day when we generated the most power we generated 19 ah / .2 kwh
7.6 Vp / 7.7 Ap / .11Kwp
Max Battery 14.6
Lowest Battery 12.6

We have not used to much power yet so I expect once we do for my numbers to go up when we use more of the battery capacity up.

I put an updated page on my cabin site with the latest pictures and status here if anyone is interested : 7-26-2008

Solar Guppy · July 2008

Re: another new solar system

AC 2 isn't an output, its your AC input ( like a generator ) that passes thru to the output when powered, lose AC 2, inverters transfer switch enages and unit supplies AC via batteries/inverter , according to the documents I found on Google

System2 · July 2008

Re: another new solar system

Solar Guppy wrote: »

AC 2 isn't an output, its your AC input ( like a generator ) that passes thru to the output when powered, lose AC 2, inverters transfer switch enages and unit supplies AC via batteries/inverter , according to the documents I found on Google

Thanks for you but my inverter I guess is a bit different :

Picture%201.png

I am not sure why they call it a convenience outlet though...

another new solar system

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