Posted: 12/3/2012 7:27:08 PM EDT
| Anyone here living with off-grid solar power? I mean living daily with HVAC, most of the daily comforts etc. |
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I'm not sure if anyone here is living "off the grid", exactly how they would "on the grid". I think most people consider not including "really high power consuming appliances" such as heat pumps etc in their off grid plans, although I have seen some that do. There tends to be a huge jump in price over what you would need to finance a system without HVAC.
Of course, solar prices have come way down so such as system would be much more affordable now, at least as far as panels go. Batteries would still be a small fortune. The ideal solar system to me should be able to run lighting, fridge, freezer, radios, a security system, recharging battery stations, perhaps laptop computers or TV. |
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To go truly off grid you have to attack the consumption side first and with a vengeance. You can't live a "normal" suburban lifestyle off grid. Unless of course you are independently wealthy. ...Your information is out of date. American sourced PV is around a dollar per peak watt. Double that for installed price. I am not yet independantly wealthy, but produce Solar Electricity in excess of my needs. |
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Solar does not pay for itself unless there are kickbacks from .gov or you are offsetting huge costs to extend utility power to a remote locations. About two years ago I took a very serious look at this to keep from spending $15,000 getting utility power to our cabin. The $10,000 did not come anywhere close to making solar economical. At that time, I saw numbers in the $30K - $50K to just live close to a 'normal' lifestyle, in a home with some special construction (LED lights, extra extra insulation, inductive cook tops, marginally sized AC and some other things that increase construction cost of the cabin.)
In practice, you will spend 20% - 25% of the original system cost, every five to eight years, to replace the batteries. Your insurance will also go WAY up when you put $20,000 of glass on top of your house. That's 12 - 15 year payback, before we look at the battery maintenance and increased insurance. When I added those, it raises the system break even cost to longer than the life expectancy of the panels. YMMV. I'm sure someone can come up with more current prices and/or a reason I am full of shit. |
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To go truly off grid you have to attack the consumption side first and with a vengeance. You can't live a "normal" suburban lifestyle off grid. Unless of course you are independently wealthy. ...Your information is out of date. American sourced PV is around a dollar per peak watt. Double that for installed price. I am not yet independantly wealthy, but produce Solar Electricity in excess of my needs. Off grid means you have local storage to mitigate low sun days. Grid tied is not off grid, they are very different animals. Cheaper panels per watt does nothing to lower the price of batteries. Batteries you have to replace every 6-10 years. The OP mentioned HVAC. I'd like to see the math of running an all electric 3000sqft home with heat pump off of a battery bank. You HAVE to attack the consumption side. Which has benefits even if you have no solar at all, but you still have to address it. I'm a renewable supporter, but it is no panacea. |
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Quoted: Off grid means you have local storage to mitigate low sun days. Grid tied is not off grid, they are very different animals. Cheaper panels per watt does nothing to lower the price of batteries. QFT ETA: Also, building something code-compliant that will last for years is much different than slapping together some of the cheapest components you can find into something workable. It depends on what you're trying to accomplish... |
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Well, I live part time off grid nicely, and my system is 'slapped' together---
And likely works [far] better than many of the so-called professunal installed ones. 
Many professionals aren't real bright...  Too many folks bow down to them. I don't.
I'm living here as I type this and building up a new PC and loading Win7.  Nice and warm, etc, etc...
Careful shopping and ebay, etc, and my system didn't have to cost an arm and a leg. Yet is rather powerful. 
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Parents house is grid-tied, however they constantly produce more power than they consume (Arizona). However, the added cost of a battery system to make up for overcast days would make the cost to go completely off-grid unfeasible. They overproduce despite HVAC, fridge, freezer, etc. House runs exactly as it normally would if it were only running off grid power, and they still have a surplus. Were it running on a battery system, they couldn't keep up on a no-sun day.
It always makes me laugh that the power company pays them pennies on the dollar for the energy they produce, but turn around and offer "green power" (the power that's backfed into the grid from their "green" customers) to other customers, at an increased rate. I'm still trying to figure out how they separate out the green electrons from the dirty ones so that they can sell the green power to the idiots across the street. |
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EXPY, nobody here doubting your skills or what you've put together. But many folk here have to deal w/ a pesky inspector, who has his own set of rules. I've been working for months to figure out a 3KW system w/ 3 days of batteries, that can supply 240v split phase w/ genny backup, and can't figure out a code compliant combo that'll get it done for < $20K if I supply the labor. Enlighten me brother... I'm sure I'm missing something, but damned if me or the inspector know what it is.. -S h |
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I've seen it done, but the person that did it has insane amounts of money to spend. The system is a 150 amp system with battery stacks that rival ours here at the phone company. A small room full of inverters and battery controllers. She still has to have a backup propane generator "just in case". Full LED light conversion for the house, replacement of appliances with more energy efficient ones. She went all out but still wants to live day-to-day like she's on line power. The killer is HVAC.
I'll be there tomorrow and ask if I can take some selected pictures, but she's pretty secretive about her preps, as we all tend to be. |
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I just got my electric bill. $0.058xxx for electric generation for 2064 Kwh over 2 months; all of which translates into 33 KWh a day or 3.3Kw per hour. It cost 109 dollars for the electricity, and $187 more for delivery, tax, gov interference, etc.
A 2.8Kw solar array w/o inverter and batteries would be about $3,000. That would meet about 2/3 of my current needs. In a protracted ( off the grid ) emergency, I could live with it. But I would need batteries and a 240 volt inverter. The heat pumps would be off and a Varmebaronen pellet boiler takes care of winter. |
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EXPY, nobody here doubting your skills or what you've put together. But many folk here have to deal w/ a pesky inspector, who has his own set of rules. I've been working for months to figure out a 3KW system w/ 3 days of batteries, that can supply 240v split phase w/ genny backup, and can't figure out a code compliant combo that'll get it done for < $20K if I supply the labor. Enlighten me brother... I'm sure I'm missing something, but damned if me or the inspector know what it is.. -S h Maybe make it 'PORTABLE'... 
And DON'T connect it to your house until you need it.
And use a $150 transformer fir the split phase instead of a fancy $$$ inverter. 
Seems to me you're OVER-THINKING this --but what do I know...
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To go truly off grid you have to attack the consumption side first and with a vengeance. You can't live a "normal" suburban lifestyle off grid. Unless of course you are independently wealthy. Excellent advice. The issue here, that sorta frustrates me when I read all the time abt folks wanting to maintain -impractically in the longer term, -their comforts and conveniences -without modification... ...is that if things go south, they won't likely be able to, and they and their fambly will be wholey unprepared to deal with the sacrifices forced on them.
If they can't pull the plug for a day and 1/2 over a weekend as a training experiment, well that says it all. |
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Quoted: Quoted: Quoted: To go truly off grid you have to attack the consumption side first and with a vengeance. You can't live a "normal" suburban lifestyle off grid. Unless of course you are independently wealthy. Excellent advice. The issue here, that sorta frustrates me when I read all the time abt folks wanting to maintain -impractically in the longer term, -their comforts and conveniences -without modification... ...is that if things go south, they won't likely be able to, and they and their fambly will be wholey unprepared to deal with the sacrifices forced on them. If they can't pull the plug for a day and 1/2 over a weekend as a training experiment, well that says it all. I agree. We ultimately plan to go the solar/battery bank route, but we are starting small and working our way up. We are moving to mini-split units for HVAC, putting in in-line water heaters, etc all before we even begin to calculate our needs. |
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dont for get in your 3-day reserve to calculate that even on really overcast days you still get solar.
The successful designs I have seen have been from the ground up. Designing the house to take advantage of alternative energy, not only in power generation but in loss/requirement mitigation. Solar powered pellet/wood burner is great Deep circulation radiant cooling is another one. It involves circulating water under the floor and in ceiling panels through a large underground pipe and cister system to pull heat from in the house and dump it in to the groud below the frost line. system can switch to radiant heat in winter. runs at a fraction of the power requirements of HVAC. all the places i have seen are the 1-4 room bug out cabins though. Comfy for short term and could be made to work long term. |
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I had been interested in this myself, but don't solar panels give out after 20-25 years? I thought the material in the cells was unable to absorb as efficiently over time and that the farther away you are from the equator, the less energy there is to be absorbed.
My research was fairly limited, but it seemed like wind power was much more efficient from both a cost and energy generation method. I think a combination of the two types would be necessary to be totally off grid. It should lighten the load on the batteries on cloudy days and overnight assuming you are in an area that can get some decent wind. |
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Quoted: I had been interested in this myself, but don't solar panels give out after 20-25 years? I thought the material in the cells was unable to absorb as efficiently over time and that the farther away you are from the equator, the less energy there is to be absorbed. My research was fairly limited, but it seemed like wind power was much more efficient from both a cost and energy generation method. I think a combination of the two types would be necessary to be totally off grid. It should lighten the load on the batteries on cloudy days and overnight assuming you are in an area that can get some decent wind. That is a probable life span of common panels. About the same as a roof or quality HVAC system. They will be like most any other household appliance, and will require replacement. Wind is great, but is not without it's limitations. The most obvious of which is presence of useful wind to power the turbine. I considered wind until I actually figured up how much real wind we have, and it's infinitesimal. (thanks to TBS for helping with that) Wind turbines also have the same lifespan of solar panels. |
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I have a battery bank, which will run my critical loads for a MONTH with NO sun.
Had 9 days consecutive heavy cloud in July, ran generator for 8 hours , for a test. . Running 3 seperate PV arrays. 2700 Watt PV array feeds the grid through a Schneider 240V AC inverter. 2 seperate PV arrays, total 4100 watts charge the lead-acid battery bank, which runs house through a stacked pair of Outback Inverters. I can charge batteries with grid power, or generator, if necesary. My two biggest loads are an electric clothes dryer, and Engine block heaters. The rest of the household loads, clothes washer, microwave oven, convection oven, deep well pump, computers, lights, electric heater in bathroom, HeatRecoveryVentilator, dogs heated water dish, boot dryer, etc are pretty easy to keep up with JUST SOLAR power. |
The probable lifespan of a quality solar panel is not necessarily 20-25 years. 
That's IIRC the timeframe when they lose -it's said- ~20% of their efficiency -as a round number. Theoretically they should live a lot longer depending on the conditions they are subject to. Now, all this being said, I expect in 25 years that their general life expectancy for the ORIGINAL owner will be less, considering the Zoombies that will either shoot them or steal them.
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Quoted: The probable lifespan of a quality solar panel is not necessarily 20-25 years. That's IIRC the timeframe when they lose -it's said- ~20% of their efficiency -as a round number. Theoretically they should live a lot longer depending on the conditions they are subject to. Now, all this being said, I expect in 25 years that their general life expectancy for the ORIGINAL owner will be less, considering the Zoombies that will either shoot them or steal them. Yea, my numbers may be a little dated.  |
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I just got my electric bill. $0.058xxx for electric generation for 2064 Kwh over 2 months; all of which translates into 33 KWh a day or 3.3Kw per hour. It cost 109 dollars for the electricity, and $187 more for delivery, tax, gov interference, etc. A 2.8Kw solar array w/o inverter and batteries would be about $3,000. That would meet about 2/3 of my current needs. In a protracted ( off the grid ) emergency, I could live with it. But I would need batteries and a 240 volt inverter. The heat pumps would be off and a Varmebaronen pellet boiler takes care of winter. Most places in the U.S. have an average of 4 hours peak sun per day. (more in summer less in winter). A 2.8kW array produces (on average) 2.8kW for 4 hours = 11.2kWh per day That doesn't take into account losses due to conversion from DC to AC, storage to battery, drawing from battery or inefficiencies in the system, power to run the inverters, etc. The BEST grid tied inverters are ~96% efficient, the BEST off grid inverters are in the 85-90% efficiency arena. So to get a useful 33kWh per day, you'd probably need a 11kW array. 11kW * 4 peak sun hours = 44kWh with 75% system efficiency = 33kWh/day http://www.wholesalesolar.com/Information-SolarFolder/SunHoursUSMap.html |
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I have a battery bank, which will run my critical loads for a MONTH with NO sun. Had 9 days consecutive heavy cloud in July, ran generator for 8 hours , for a test. . Running 3 seperate PV arrays. 2700 Watt PV array feeds the grid through a Schneider 240V AC inverter. 2 seperate PV arrays, total 4100 watts charge the lead-acid battery bank, which runs house through a stacked pair of Outback Inverters. I can charge batteries with grid power, or generator, if necesary. My two biggest loads are an electric clothes dryer, and Engine block heaters. The rest of the household loads, clothes washer, microwave oven, convection oven, deep well pump, computers, lights, electric heater in bathroom, HeatRecoveryVentilator, dogs heated water dish, boot dryer, etc are pretty easy to keep up with JUST SOLAR power. How'd that test go in January (with less peak sun per day)? What capacity (Ah) is your battery bank? Your system sounds like something I am looking at. A combination AC coupled / DC coupled system. The AC side uses the more efficient grid tied inverters. During a grid power failure, the DC side provides the AC side with a false grid electric input so the AC side continues to produce, like a transfer switch to a generator. The DC side provides the backup storage as well. I'd divide the loads in the house into two panels and the critical panel could be powered by grid, battery or generator. I could charge the batteries with solar or generator so I wouldn't have the generator running all night. |
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The probable lifespan of a quality solar panel is not necessarily 20-25 years.
That's IIRC the timeframe when they lose -it's said- ~20% of their efficiency -as a round number. Theoretically they should live a lot longer depending on the conditions they are subject to. Now, all this being said, I expect in 25 years that their general life expectancy for the ORIGINAL owner will be less, considering the Zoombies that will either shoot them or steal them.
This sounds right. I believe they are "warrantied" for 20-25 years, but the articles I read have panels produced in the 70s (with older tech mind you) that are still producing useful electricity today. I'd expect you would still get meaningful production from today's panels for decades. |
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To go truly off grid you have to attack the consumption side first and with a vengeance. You can't live a "normal" suburban lifestyle off grid. Unless of course you are independently wealthy. ...Your information is out of date. American sourced PV is around a dollar per peak watt. Double that for installed price. I am not yet independantly wealthy, but produce Solar Electricity in excess of my needs. I think you are overstating it - To live off grid, you need a lot of batteries, enough that the price of the batteries, which must be replaced, dwarf the cost of the solar panels. I have a 6kw system, with batteries. The batteries are not cheap, and if you want to live a typical 'suburban' lifestyle, you need them. If you are producing energy in excess of your needs with a grid tied system, great, but you are hosed without the grid as a psuedo 'battery'. |
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I had been interested in this myself, but don't solar panels give out after 20-25 years? I thought the material in the cells was unable to absorb as efficiently over time and that the farther away you are from the equator, the less energy there is to be absorbed. My research was fairly limited, but it seemed like wind power was much more efficient from both a cost and energy generation method. I think a combination of the two types would be necessary to be totally off grid. It should lighten the load on the batteries on cloudy days and overnight assuming you are in an area that can get some decent wind. Small scale windpower is unsustainable. Go to the wind power forums and look at the guys who have spent a shitload of money on them, and find out how well they hold up. The economics of frequent repairs of a moving mechanical device don't scale well, and you still need batteries. Solar panels do degrade in efficiency, but don't go to zero - Most of the 25 year warranties are guaranteeing that they will still have a %output at 25 years, but it's not a step function where you wake up one day in the dark. Many panels from the 70's are still in service today. |
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I have a battery bank, which will run my critical loads for a MONTH with NO sun. Had 9 days consecutive heavy cloud in July, ran generator for 8 hours , for a test. . Running 3 seperate PV arrays. 2700 Watt PV array feeds the grid through a Schneider 240V AC inverter. 2 seperate PV arrays, total 4100 watts charge the lead-acid battery bank, which runs house through a stacked pair of Outback Inverters. I can charge batteries with grid power, or generator, if necesary. My two biggest loads are an electric clothes dryer, and Engine block heaters. The rest of the household loads, clothes washer, microwave oven, convection oven, deep well pump, computers, lights, electric heater in bathroom, HeatRecoveryVentilator, dogs heated water dish, boot dryer, etc are pretty easy to keep up with JUST SOLAR power. My system is almost identical, 6kw on 2 outbacks. 4kw of solar won't keep up with engine block heaters (150W) running every night with the other household loads, at least here in colorado. |
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Couple of more things you should not overlook.
I'm not sure about where you live, but big chunks of ice occasionally fall from the sky here...panels can and do get broken. Unless you are willing to stomach this risk alone, be sure to find out what your insurance company will charge to cover them. If you live in a windy, dusty part of the world, that wind blown sand will slowly abrade the panels until they take on the look of frosted glass. This reduces the panel efficiency. Birds shit. Dust sticks to the dew covered panels. Wet leaves fall and stick to panels. Ice/Snow builds up. If you do not keep your panels clear, you will not produce as much power. Batteries: Unless you locate them in a climate controlled space (bad plan, they produce hydrogen when charging) their life span will be even shorter than the manufacture claims.
You have to seriously derate batteries in cold weather. Plan on only getting about than half the rated storage capacity at 0 deg F. This will usually happen when the sun has not been out for days. On the brighter side (pun intended) your solar panels are more efficient in the cold weather. Your solar panels are great big antennas for lightning (and EMP) induced surges. Do not skimp on the DC surge protection. The charge controller surge protection my not be adequate. |
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To go truly off grid you have to attack the consumption side first and with a vengeance. You can't live a "normal" suburban lifestyle off grid. Unless of course you are independently wealthy. ...Your information is out of date. American sourced PV is around a dollar per peak watt. Double that for installed price. I am not yet independantly wealthy, but produce Solar Electricity in excess of my needs. That takes care of the production side of the cost but the Inverters are still $1 a watt, you'll have $5-600 in a charge controller and batteries to run a small cabin will run 2 or 3 grand etc. Solar is definitely cheaper than it was but it's still not cheap. |
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I had been interested in this myself, but don't solar panels give out after 20-25 years? I thought the material in the cells was unable to absorb as efficiently over time and that the farther away you are from the equator, the less energy there is to be absorbed. My research was fairly limited, but it seemed like wind power was much more efficient from both a cost and energy generation method. I think a combination of the two types would be necessary to be totally off grid. It should lighten the load on the batteries on cloudy days and overnight assuming you are in an area that can get some decent wind. Small scale windpower is unsustainable. Go to the wind power forums and look at the guys who have spent a shitload of money on them, and find out how well they hold up. The economics of frequent repairs of a moving mechanical device don't scale well, and you still need batteries. Solar panels do degrade in efficiency, but don't go to zero - Most of the 25 year warranties are guaranteeing that they will still have a %output at 25 years, but it's not a step function where you wake up one day in the dark. Many panels from the 70's are still in service today. micro wind power turbines are sustainable. I will concede that the larger ones are not (w/ exception on larger scales). However, I have been running two 60 watt micro's, home made from d/c motors and have run them for 3 years straight with only the occasional blade replacement due to a freak high wind storm. Sure I only get 20-30 watts on average (combined) from each one but they works as a nice addition to complement the solar array. During a good wind storm I push close to 150 watts combined. They can be built or bought for around $120 bucks. I use them on my camping trailer to supplement the 160 watts of solar. I have two twin 60 watts, wired in series to get power at lower wind speeds: 
I have bought from here for years, this guy does good work and is very customer service oriented, very small operation: http://www.usawindgen.com/ I live off a very large lake and get decent 10mph winds on a consisten basis. Its very nice to look up and see that thing making free power. I charge a couple of golf cart batteries that runs my scanner and CB radio. |
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Couple of more things you should not overlook. I'm not sure about where you live, but big chunks of ice occasionally fall from the sky here...panels can and do get broken. Unless you are willing to stomach this risk alone, be sure to find out what your insurance company will charge to cover them. If you live in a windy, dusty part of the world, that wind blown sand will slowly abrade the panels until they take on the look of frosted glass. This reduces the panel efficiency. Birds shit. Dust sticks to the dew covered panels. Wet leaves fall and stick to panels. Ice/Snow builds up. If you do not keep your panels clear, you will not produce as much power. Batteries: Unless you locate them in a climate controlled space (bad plan, they produce hydrogen when charging) their life span will be even shorter than the manufacture claims.
You have to seriously derate batteries in cold weather. Plan on only getting about than half the rated storage capacity at 0 deg F. This will usually happen when the sun has not been out for days. On the brighter side (pun intended) your solar panels are more efficient in the cold weather. Your solar panels are great big antennas for lightning (and EMP) induced surges. Do not skimp on the DC surge protection. The charge controller surge protection my not be adequate. Panels are rated for hail stones, IIRC, the ones I bought are good for a 1" hail stone at 52 meters per second. |