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How about sharing what you've done/are doing, for backup power...

Titan

Titan

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I'm getting very serious about a 'whole house' backup power system, capable of running most things 'off grid' if it comes to that.

I already have a gas powered 6000W gas generator, but am particularly interested in any battery based solutions replenished by generator, solar, or wind.

We have two refrigerators, a chest freezer, a water pump, TV and computers that should be included in my plan.

Any obstacles encountered with installing wind turbines or solar panels? Approximate costs, tax breaks, etc.

Pics of your setups would be fabulous.
 
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1 car battery has about 50 amp-hours = 600Whours. That means that after converter losses you can run one 60W bulb for about 8hrs on a car battery. A fridge takes a lot more. I'm with JimB. You have to run real lean if you plan to have batteries involved.

For me, nuthin but a 3500W putt-putt to run the sump pumps & fridge in summer and furnace in winter. My house has natural gas and I plan to be here a while so I'm considering one of those self-starting units so I don't have to worry about the basement flooding if I'm away. I'm thinking 10KW should run what I need: furnace, 2 sump pumps, fridge and a few lights. I'm assuming no cable or internet so the TV will be restricted to what we have on disks.

Solar Panels: an engineer friend is going through the planning for his house. With tax breaks and the $ for the power they generate they MIGHT pay for themselves after 5 years (assuming you don't have any maintenance issues).
 
i set my moms house up before i moved out she was concerned from the major power loss she had during the ice storms a few years back. she has a big old house she has a 5500w gen that hooked into the breaker box. when the power goes out the electric stove the fridge and freezer as well as her oil furnace are primary. then she has a plug and a light in the kitchen bathroom bedroom and living room. she has never overloaded the gen. she doesnt get greedy with her plugs when the power goes out. and averages a tank every 12 hours. If you want to run that kinda stuff with solar or wind generators your talking some serious hardware.
 
Im surprised more people dont consider a propane or LP fridge. That would eliminate quite a bit of the demand your setup needs to satisfy.
Ive got a 12250 starting/7000 watt propane genny that operates at least one plug in every room, one light in every room, an exterior light front and back, gas furnace/hot water/heat, gas dryer,gas oven and fridge. The gas cooktop doesnt need power as I can light that with a match.
Ive also got a 1500 gallon propane tank buried in the back yard.
 
Lucas McCain said:
I pretty much run my whole house off of solar panels and batteries. I am grid tied but only get about 10-20% of my power from there, most of it comes from the sun except for the winter time. See this thread, http://www.northeastshooters.com/vb...yone-here-know-about-solar-panels-(roof-mount)
I will try to post a few pictures to this thread later on when I get the camera out.
Click to expand...

Thanks, that would be great.

I remember that thread, but couldn't find it. I'll have to check it out again.
 
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Business said:
i set my moms house up before i moved out she was concerned from the major power loss she had during the ice storms a few years back. she has a big old house she has a 5500w gen that hooked into the breaker box. when the power goes out the electric stove the fridge and freezer as well as her oil furnace are primary. then she has a plug and a light in the kitchen bathroom bedroom and living room. she has never overloaded the gen. she doesnt get greedy with her plugs when the power goes out. and averages a tank every 12 hours. If you want to run that kinda stuff with solar or wind generators your talking some serious hardware.
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Thanks.

There's two scenarios I'm planning for....one is normal short term power losses due to storms, electric company diddling, brown-outs, etc.

The other is a self sufficiency operation if and when the SHTF. I understand that in that scenario, I would have to scale back. I'm doing research to determine if I can get water from my well without a pump (hand pump). That would leave heat (for the winter) and some minimal refrigeration as the primary concerns.

We have propane capability, so I'm also looking into a large storage unit.
 
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Plural of Mongoose said:
Im surprised more people dont consider a propane or LP fridge. That would eliminate quite a bit of the demand your setup needs to satisfy.
Ive got a 12250 starting/7000 watt propane genny that operates at least one plug in every room, one light in every room, an exterior light front and back, gas furnace/hot water/heat, gas dryer,gas oven and fridge. The gas cooktop doesnt need power as I can light that with a match.
Ive also got a 1500 gallon propane tank buried in the back yard.
Click to expand...

That sounds great, and I may end up going that way, but I'm also interested in anyone who's backing up what they have with some solar and/or wind.
 
I am still collecting data for the other post but I can tell you this, my initial estimate of payback in 7 years is pretty much correct. I commissioned the system in late September and my electric bill went from about $120 per month to about $17 per month.

My system consists of six 235 watt solar panels with 840 AH of FLA batteries, I have a 4KW Xantrex inverter and 2 solar charge controllers. For backup I have a Honda EU5000I autostart generator. My panels are rated for 1440 KW and at this point in the season, I am collecting about 6.5 KWh per day on a good sunny day. I have seen my panels peak out at over 1750 watts on rare occasions when it is very cold out.

I applied for and received a tax break of 30% of the cost of the system which went a long way toward reducing the payback time.

During the months of January and February, I collected zero from the sun because there was a foot of snow covering the panels. My panels are flush mounted to my garage roof and normal snow will slide off but when we get a foot of snow a week, its all over.

I have had no real issues with the system since I installed it, it is essentially automatic once you get it programmed properly and that is no easy task, there are quite a few things to adjust. The only thing you have to maintain are the batteries, you must keep an eye on the electrolyte and add water about once a month. I have flooded lead acid batteries but if you install AGM type, you will not have to maintain them.

I also have an autostart generator so if the grid is down and the sun is not shining, when my batteries get low, then the generator will automatically kick in.

P9100206.jpg P9090202.jpg

These pictures were from last year, I have many more batteries now. As soon as this most recent snow melts I will take pictures of the roof install.
 
Good post Titan,I've also had the same thoughts and questions.My well pump would be key in a no power situation.I have a generator but would like to be off fuel in the long term.
 
Tim L said:
Good post Titan,I've also had the same thoughts and questions.My well pump would be key in a no power situation.I have a generator but would like to be off fuel in the long term.
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I've lost track of the thread, but someone on here posted, awhile back, info on a hand pump they had installed on a reasonably deep well. It's located in the cellar, where the supply comes into the house, and is intended for emergencies when power is lost to the pump.

If the original poster, recognizes what I'm talking about, it would be fantastic if he could post a link to the right thread (no luck with even advanced search).
 
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Does everything run off the inverter, or do you have 12V or 24V distributed in the house?

Most chargers (including laptops), LED lighting and other small electronics will run more efficiently off a distributed 12V than inverting it and re-rectifying it after distribution.
 
My inverter output is wired into my old breaker panel (where the grid used to go). I have one "diversion load" that runs directly off my 24 volts battery bank. It is a small 20 gallon water heater that I dump excess energy into. I run my inverter in grid support mode, that means I can set where I want the battery level to be and the remainder runs the house during the day, during the evening, the house runs off the batteries.

The issue is that if my batteries are charged and the sun is out, I produce more power than my house consumes. That is where the diversion load comes in. ather than wasting the surplus power by unloading the panels, My controller will divert all the excess power to heating the water in the small tank.

So I am essentially "heating" warm water instead of cold well water.

Other than that, I dont have any auxillary loads on my batteries, for charging things, laptops , etc. I just use the AC.
 
A couple of things that you might consider:

24V LED lighting - will be a lot more efficient than inverting to 110 and then using compact florecent lamps or AC plug LED lamps.

I'd also look into a 24V to 12V DC/DC Converter - that kind of conversion ratio can be extremely efficiency (95%) which would allow the use of Automotive designed electronics (radio, cell-phone & laptop chargers) which will be much more efficient than their AC wall-power counter parts.
 
ShadeWPI said:
A couple of things that you might consider:

24V LED lighting - will be a lot more efficient than inverting to 110 and then using compact florecent lamps or AC plug LED lamps.

I'd also look into a 24V to 12V DC/DC Converter - that kind of conversion ratio can be extremely efficiency (95%) which would allow the use of Automotive designed electronics (radio, cell-phone & laptop chargers) which will be much more efficient than their AC wall-power counter parts.
Click to expand...

I have a 4KW inverter running the house, that runs typically between 95 and 98 percent efficiency. If I ran a DC bus, the voltage drops alone would lower my efficiency not to mention the buck converter I would need to create the bus from 24 volts to 12.

Believe me, the 20 watts or so I would be drawing from the DC bus would not justify the hassle. I am running big stuff from the inverter, well pump, furnace, microwave, etc. Quite frequently I approach the 4KW limit, unloading 20 - 30 watts would be negligable.

As far as the LED lighting, I have most of my incandescents replaced with LED bulbs, my 60 watt bulb draws about 11 watts and the 40 watt bulb draws about 8 watts. Thats a good enough improvement in efficiency for me![smile]
 
Lucas McCain said:
I have a 4KW inverter running the house, that runs typically between 95 and 98 percent efficiency.
Click to expand...

Mind sharing where you got a 95-98% efficient inverter? Most of the ones I've found in that power level are 90% efficient at 80% load and only 95% efficient at about 30% load.

If I ran a DC bus, the voltage drops alone would lower my efficiency not to mention the buck converter I would need to create the bus from 24 volts to 12. Believe me, the 20 watts or so I would be drawing from the DC bus would not justify the hassle.
Click to expand...

For 2A of current, you're likely right, of course I was figuring you had more than 2 or 3 lights in the house. Figure 10 lights drawing 10W each, and you're at 100W. Add a lap-top charger (90W) Cellphone charger, etc and you're quickly looking at a lot more than 20W of power.

Even a BUCK 24V to 12V @ 20A (240W capable) is going to run 95-98% efficient.

As for the DC losses. Using 15A residential wiring (14 AWG) for a 60' run, and pulling that full 20A through the wire, you're still delivering 85% of the energy to the load. - about the efficiency you get from the AC/DC convertion at the screw-in LED light bulb. So, as long as you're not trying to run 20-30 lights in the house at the end of a 60' line, you'll save power.

I am running big stuff from the inverter, well pump, furnace, microwave, etc. Quite frequently I approach the 4KW limit, unloading 20 - 30 watts would be negligable.
Click to expand...

Well Pump and possibly furnace could also be run directly off the 24V battery to save power. If you are willing to have a large storage tank, you can even get continuous running "slow-flow" pumps that are designed to run extremely efficiently off a 24V solar system - They pump about 1 gallon / minute, but only draw about 1.5W / foot of lift. This would likely be your biggest power savings.

As far as the LED lighting, I have most of my incandescents replaced with LED bulbs, my 60 watt bulb draws about 11 watts and the 40 watt bulb draws about 8 watts. Thats a good enough improvement in efficiency for me![smile]
Click to expand...

BTW - that 11W 60W relacement bulb is likely delivering less than 8W to the actual LED with the other 3W burned up in heat converting 120Vac to low-voltage DC and controling the current in the LEDs. A 24V LED lighting system would likely save about 2W / bulb. An you'd lose about 1/10W delivering that 24V through 60' of 14ga wire.
 
cockpitbob said:
Can you elaborate on that?
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Sure, first, the 3-1 is not a hard fast rule but a very good average. Essentially it comes down to basic math, without going into a long dissertation on alternative energy costs (and I don't want to type THAT much) look at this solar panel
http://sunelec.com/index.php?main_p...id=544&zenid=a3d87371f8b2b50c4c9ed067a334fc73
You will be paying $2.23 per watt and this is only for the panel, for the sake of simplicity we won't add in the cost of charge controllers, inverters, batteries, and associated hardware and installation. So for every watt you conserve you save $2.23 off the system cost. If your really interested in this I would suggest the book The Renewable Energy Handbook by William Kemp, it's an invaluable resource for all the information you would need to set up and operate a grid tie or off grid system. Hope this helped!
 
ShadeWPI said:
Mind sharing where you got a 95-98% efficient inverter? Most of the ones I've found in that power level are 90% efficient at 80% load and only 95% efficient at about 30% load.
Click to expand...

Well my inverter draws about 30 watts from the batteries, true at low loads, the 30 watts becomes dominant and the efficiency drops to about 95%, when the inverter is honking along at 3-4 KW, the 30 watts becomes negligible. The efficiency graph in the owners manual shows that in the load range I am operating in, my efficiency is between 95 and 98%.

xxx.png

OK, looking more carefully at this plot my efficiency is right around 95% maybe as low as 93%

For 2A of current, you're likely right, of course I was figuring you had more than 2 or 3 lights in the house. Figure 10 lights drawing 10W each, and you're at 100W. Add a lap-top charger (90W) Cellphone charger, etc and you're quickly looking at a lot more than 20W of power.
Click to expand...

Maybe at the most I am looking at 20 Watts for all the wall warts in this place.

Even a BUCK 24V to 12V @ 20A (240W capable) is going to run 95-98% efficient.

As for the DC losses. Using 15A residential wiring (14 AWG) for a 60' run, and pulling that full 20A through the wire, you're still delivering 85% of the energy to the load. - about the efficiency you get from the AC/DC convertion at the screw-in LED light bulb. So, as long as you're not trying to run 20-30 lights in the house at the end of a 60' line, you'll save power.
Click to expand...

Yup

Well Pump and possibly furnace could also be run directly off the 24V battery to save power. If you are willing to have a large storage tank, you can even get continuous running "slow-flow" pumps that are designed to run extremely efficiently off a 24V solar system - They pump about 1 gallon / minute, but only draw about 1.5W / foot of lift. This would likely be your biggest power savings.
Click to expand...

OK, $800 for a new pump plus the stuff to install it. For the amount of time the pump is on, its not worth the investment to me. I am not here to wring out every watt I possibly can. I never heard of a domestic furnace that runs off 24V but if it exists it probably costs a fortune.

BTW - that 11W 60W relacement bulb is likely delivering less than 8W to the actual LED with the other 3W burned up in heat converting 120Vac to low-voltage DC and controling the current in the LEDs. A 24V LED lighting system would likely save about 2W / bulb. An you'd lose about 1/10W delivering that 24V through 60' of 14ga wire.
Click to expand...

Yup, but its better than an incandesent or CCFL. Bottom line is that all this stuff will make a slight efficiency improvement but its not in the plan.
 
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