Adding solar to an old on grid homestead

[Biggkidd]

Far as space goes it depends a lot on how your batteries are configured and that depends on floor strength. Batteries for this type system are typically racked or shelved so a wall full of batteries or a wall of batteries. Most types of batteries need to be vented! AGM and I believe gel do not. As far as length of life that depends on you and how you treat them. Ten years is entirely possible with good virgen lead AGM type batteries. Read expensive to buy new. Every battery have had here except the golf cart batteries we started with were bought used. It's best if all the batteries are not only the same type brand and age but from the same lot AKA a matched set. Think of buying used batteries from a bank or hospital like buying a three year old corporate lease vehicle that's been maintained by the dealer under contract...

 

[Biggkidd]

Another thought I just had.

If you have to buy new batteries then you may well spend that second 10K on them alone the way prices are rising. Prices have already doubled since a year or so ago from what I have seen.

Before you jump on the Lithium bandwagon check out the fires that happen when one shorts out and the heat / fumes related in comparison to lead type. NOT something I would want inside my home in a large bank. Small highly portable IE: cordless tool batteries sure but big, heavy, non portable in a hurry no thanks

 

[UrbanHunter]

The trouble with propane is it needs heat to vaporize and maintain pressure. I have one with a gauge on it and have seen it drop when it gets cold (even down here) not COLD but cool.... I had a grill and tried to use it at 19F, could barely keep the flame lit, tank was full but not warm enough to vaporize and give you the pressure you needed to run the grill... I have also watched the pressure increase when the sun light started hitting the tank.

That is why the guys in the cold country try to insulate and heat their tanks, against code....

 

[Rebecca]

See I am the complete other side of the debate to @Biggkidd lol. No dig at you here Biggkidd we all have preferences to our equipment.

I'm on the side of why even waste time money and space on lead acid?
Yes lithium ion batteries can burn scary, although I have seen the effects of a lead acid going off! And the fumes from that!!!

But it depends on the type of lithium batteries you have. Not all are made equal.
Lithium ion phosphate is so so much safe and more stable than lithium cobalt oxide. Not saying it won't burn, any battery will burn. But LiFePO4 compared to old lead acid technology is just so much better. They charge better, have many many more life cycles, can be deeper discharged. I also find them lighter, more compact and easier to move than lead acid.

For the Renogy 100ah LiFePO4 we can discharge 80% as recommended by Renogy. So..80Ah. Although given all variables even if we call it 40 amp hours per battery that's still only 3 batteries needed for 120 amp hours.
We actually just got in 2 new ones. For size comparison I have put the picture below, but also for Alaskajohn and his cold weather. The top their claims minus 20 Celsius to plus 50 Celsius. They now have a much better temperature range they will operate at. Although I have not tested that as mine are kept above 0 celcius.

 

[Alaskajohn]

See I am the complete other side of the debate to @Biggkidd lol. No dig at you here Biggkidd we all have preferences to our equipment.

I'm on the side of why even waste time money and space on lead acid?
Yes lithium ion batteries can burn scary, although I have seen the effects of a lead acid going off! And the fumes from that!!!

But it depends on the type of lithium batteries you have. Not all are made equal.
Lithium ion phosphate is so so much safe and more stable than lithium cobalt oxide. Not saying it won't burn, any battery will burn. But LiFePO4 compared to old lead acid technology is just so much better. They charge better, have many many more life cycles, can be deeper discharged. I also find them lighter, more compact and easier to move than lead acid.

For the Renogy 100ah LiFePO4 we can discharge 80% as recommended by Renogy. So..80Ah. Although given all variables even if we call it 40 amp hours per battery that's still only 3 batteries needed for 120 amp hours.
We actually just got in 2 new ones. For size comparison I have put the picture below, but also for Alaskajohn and his cold weather. The top their claims minus 20 Celsius to plus 50 Celsius. They now have a much better temperature range they will operate at. Although I have not tested that as mine are kept above 0 celcius.

View attachment 68169

The storage space would maintain a 52 degree temp year round, so the outside temps wouldn’t be an issue,

The cost of the batteries due to shipping cost to Alaska might kill this deal.

Most types of batteries need to be vented! AGM and I believe gel do not.

So by vented you mean a duct to the outside and a little fan in the duct to push air to the outside?

 

[Rebecca]

The cost of the batteries due to shipping cost to Alaska might kill this deal.

Amazon Prime for free shipping? While we ordered direct from the Renogy warehouse in Canada, they are available on Amazon Canada, so perhaps Amazon.com as well.

 

[50ShadesOfDirt]

From what I can read of your situation, you have grid power year-round; like everyone else on grid power, you have the associated reliability problems. To my way of thinking, you need the generator next. You have a battery buffer, so the gennie could provide both power during outages and power to recharge batteries.

We use a generac propane 22kw "standby generator", model 7042, and we beat the tar out of it ... it is automatic, tied to our inverter and battery system, and is 100% reliable. We don't use it in "standby" mode, it is a key element of our whole power system. If the weather is not cooperating, the inverter fires it up. Like the grid, it provides all the power for any scenario (heavy power tools, anything in the house, etc.) I installed this and maintain it, myself, as no dealer is coming out to our rural location in the mountains.

If you can get propane in bulk, this has been a clean and easy to use fuel for us ... easy to store, easy on the engines, etc. As you are in an extreme cold environment, perhaps you can build warm mini-shelters (equipment shelter, not human) for both propane and the gennie, separated some distance for safety. Just enough shelter to keep both systems in their operating temp range; the grid keeps them warm most of the time, and the gennie can handle it when grid is down.

 

[Alaskajohn]

Amazon Prime for free shipping? While we ordered direct from the Renogy warehouse in Canada, they are available on Amazon Canada, so perhaps Amazon.com as well.

Nothing lithium will ship to Alaska with Amazon. Lithium must come up on a barge to Alaska. The little lithium power station that I have been experimenting with the last couple month was a special order that took a month to get here on a barge. The great success with that little power station is what is causing me to now consider solar.

 

[Rebecca]

Nothing lithium will ship to Alaska with Amazon. Lithium must come up on a barge to Alaska. The little lithium power station that I have been experimenting with the last couple month was a special order that took a month to get here on a barge. The great success with that little power station is what is causing me to now consider solar.

Just to make things that bit more difficult!

 

[Biggkidd]

You don't necessarily have to have a fan but old style lead acid batteries do need to be vented..

Far as LI batteries go I am not say I dislike them I think they are really good I just wouldn't want them inside my home with my children. In a separate building absolutely!

I too have seen lead acid batteries blow apart usually the top blows off and not much if any fire. LI almost always burns IF they short out from what I've read / seen second hand.

 

[viking]

I'll l happily run our lead/acid batteries into the sunset, by the time the GC-2 batteries reach the end of their useful life, we will probably have used everything in our fridges and freezers, candles and kerosene will light our home and fresh, dehydrated, or freeze dried foods will fill in for whatever came out of the freezers. If things go bad in the time ahead, I would be surprised if any batteries will be available. For all I know, I may even be gone by then, each day is a plus, considering that so far I've outlived my dad by 7 years.

 

[Hardcalibres]

You don't necessarily have to have a fan but old style lead acid batteries do need to be vented..

Far as LI batteries go I am not say I dislike them I think they are really good I just wouldn't want them inside my home with my children. In a separate building absolutely!

I too have seen lead acid batteries blow apart usually the top blows off and not much if any fire. LI almost always burns IF they short out from what I've read / seen second hand.

I have seen a garage burn to the ground by a fire started by a bank of mismatched lead acid batteries.

If anyone were going to buy second hand batteries, the risk that they do not have the same batch source and same service history (ie have been cycled exactly the same number of times and to the same depth of discharge and peak of charge) would be my main concern (more so than battery chemistry).

All batteries are dangerous and a fire risk - but you can't really get quiet, renewable, offgrid power without them.

Wood stoves are statistically quite a significant fire risk too - but we survivalists live with them.

In Alaska, there is quite a long list of elevated, location specific risks - anyone who lives there is accustomed to managing risk.

 

[Neb]

I'll l happily run our lead/acid batteries into the sunset, by the time the GC-2 batteries reach the end of their useful life, we will probably have used everything in our fridges and freezers, candles and kerosene will light our home and fresh, dehydrated, or freeze dried foods will fill in for whatever came out of the freezers. If things go bad in the time ahead, I would be surprised if any batteries will be available. For all I know, I may even be gone by then, each day is a plus, considering that so far I've outlived my dad by 7 years.

This video convinced me lead acid could be rebuilt in a pinch.

Battery acid may be very shelf stabile if stored in the dark at stabile temps. ( @UrbanHunter did I learn this from you?)

Ben

 

[Aerindel]

Off grid hot water is pretty easy.

I use an on demand propane hot water heater, it runs off a couple D batteries that last for years at time.

I don't have enough gravity feed pressure from my holding tanks to reliably run the heater so I use a small 200 watt solar system to run a DC on demand pump. This pump uses so little power I think it could probably run for a month off my two deep cycle batteries without charging since it only runs when the hot water tap is on, which amounts to just a few seconds at a time usually, or at the most, half an hour if I'm running a bath.

No propane truck can make it up my road, so its the propane is fed from 100lb tanks hooked up outside than I bring in and take to be filled in the back of my truck. I have a half a dozen of them, which is about six months supply (also covers cooking fuel) Never had a problem with propane not building enough pressure for the heater and the stove, and that includes when I lived in Fairbanks and it got down to -50º

I HAVE had trouble with running my forge because of cold tanks, but my forge uses 100 times more propane per minute than my gas stove or water heater does.

In the summer I have an old pressure tank on the roof painted black that pre-heats the very cold stored or ditch water to outside temp, and in the winter I have another tank that sits next to the wood stove that does the same thing. Saves a lot of propane just raising the water temp from 50º to 70º

In short term power outages, I can run everything for a limited time off my battery bank simply by unplugging power strips from the wall, and plugging them into an extension cord running to my inverter.

Batteries are lead acid and they are just sitting on the floor behind my sofa. So what. I bet half you don't believe in vaccines....well, I don't believe in venting batteries. Fight me.

 

[Biggkidd]

Off grid hot water is pretty easy.

I use an on demand propane hot water heater, it runs off a couple D batteries that last for years at time.

I don't have enough gravity feed pressure from my holding tanks to reliably run the heater so I use a small 200 watt solar system to run a DC on demand pump. This pump uses so little power I think it could probably run for a month off my two deep cycle batteries without charging since it only runs when the hot water tap is on, which amounts to just a few seconds at a time usually, or at the most, half an hour if I'm running a bath.

No propane truck can make it up my road, so its the propane is fed from 100lb tanks hooked up outside than I bring in and take to be filled in the back of my truck. I have a half a dozen of them, which is about six months supply (also covers cooking fuel) Never had a problem with propane not building enough pressure for the heater and the stove, and that includes when I lived in Fairbanks and it got down to -50º

I HAVE had trouble with running my forge because of cold tanks, but my forge uses 100 times more propane per minute than my gas stove or water heater does.

In the summer I have an old pressure tank on the roof painted black that pre-heats the very cold stored or ditch water to outside temp, and in the winter I have another tank that sits next to the wood stove that does the same thing. Saves a lot of propane just raising the water temp from 50º to 70º

In short term power outages, I can run everything for a limited time off my battery bank simply by unplugging power strips from the wall, and plugging them into an extension cord running to my inverter.

Batteries are lead acid and they are just sitting on the floor behind my sofa. So what. I bet half you don't believe in vaccines....well, I don't believe in venting batteries. Fight me.

Long as they are not in an airtight space they are vented. Obviously you don't have a huge bank either or they wouldn't be behind the couch! lol Sounds like something I would have done! ! !

 

[viking]

For really cold climates, a antifreeze system is good setup, it's a closed system using solar coils outside and a coil inside a water tank inside the home using a small circulating pump, works kind of like my grandmothers hot water system where she had a heat coil in the firebox of her wood cook stove, only that was an open system that allowed fresh water to come into the heating coils and through convection, heat the big tank behind the stove. I've seen a close loop cooling system used to keep a computer room cool, the outside coil had antifreeze in it going into the computer room where the refrigerant went inside to a transfer coil in the air conditioning condenser unit.

 

[Aerindel]

Long as they are not in an airtight space they are vented. Obviously you don't have a huge bank either or they wouldn't be behind the couch! lol Sounds like something I would have done! ! !

Its not very big. It doesn't need to be. I built everything from the ground up with the idea of not needing power so a little goes a long way.

The pump only draws 5 amps at the most....and only when the hot water faucet is on, so if you think about how many minutes a day you are actually running the hot water tap you can see how even just a couple cheap 120 amp hour batteries could last a long time running the pump and charging things like headlamps and tablets, even without good sunlight.

Which is very much my case as my house is pretty buried in trees, in the mountains, in the north so I only get a few hours of direct sun a day, but even a few Amp hours is all I need to run the water system and charge my phone etc which I always do off my solar system as DC to DC charging is faster.

This thread is a good reminder actually to check the fluid level in my batteries and run them down a little to see how the panels are doing. Because I barely run them down at night the charge controller is almost always throttled down to just a maintenance charge and I can't tell how much power I can actually make at a given time of year unless I run my TV off the batteries or something for a night to actually draw them down enough for the charge controller to switch to bulk charge mode.

 

[Aerindel]

All batteries are dangerous and a fire risk - but you can't really get quiet, renewable, offgrid power without them.

The thing about prepping or off grid living in general, is that there is a high theoretical risk with most of it.

At the core, what we are doing is storing potential energy. Food energy, heat energy, electrical energy, etc. Heck, in just my woodpile I probably have some fraction of a kiloton of stored energy fifty feet from my front door. Set fire to all the fat in my freezer at once and you would be left with a smoking crater where my house was.

But it will remain theoretical until released. Our actual risk is a matter of our containment measures.

One good thing about the lead acid battery, its a proven technology that is designed to last for many years in a high vibration, high heat, high cold, high cycle count environment without failure. These things get the crap beat out of them and rarely fail.

 

[Supervisor42]

One good thing about the lead acid battery, its a proven technology that is designed to last for many years in a high vibration, high heat, high cold, high cycle count environment without failure. These things get the crap beat out of them and rarely fail.

Yes, dedicated professionals like us tested them in 'real-world' industrial conditions, under every brutal condition imagined, for decades.
When every 'next great thing' came along (like SLA, AGM, VRLA, and even LI-ion), we tested them to death in a year or two.
Some didn't even make it a year.

That reminds me, the lithium-ion battery in my leaf-blower has crapped out after less than 2 years.
It only runs for about 15 seconds and dies.
What do I do?
A replacement battery costs more than the entire blower setup.
The words my dad said, ring in my ears: "Bend over and grab your ankles".
On topic: The choice of batteries is the most important part of a solar power or power backup system for a house.
Don't buy hype.

 

[Alaskajohn]

Yes, dedicated professionals like us tested them in 'real-world' industrial conditions, under every brutal condition imagined, for decades.
When every 'next great thing' came along (like SLA, AGM, VRLA, and even LI-ion), we tested them to death in a year or two.
Some didn't even make it a year.

That reminds me, the lithium-ion battery in my leaf-blower has crapped out after less than 2 years.
It only runs for about 15 seconds and dies.
What do I do?
A replacement battery costs more than the entire blower setup.
The words my dad said, ring in my ears: "Bend over and grab your ankles".
On topic: The choice of batteries is the most important part of a solar power or power backup system for a house.
Don't buy hype.

I hear you! I am naturally a cautious person so I have been thinking this as well. It will probably come down to cost.

I didn't go to town today and will likely not come off the mountain until mid July, so I have more time to kick this around! Super awesome thread so I have learned a bunch!

 

[INresponse]

From what I can read of your situation, you have grid power year-round; like everyone else on grid power, you have the associated reliability problems. To my way of thinking, you need the generator next. You have a battery buffer, so the gennie could provide both power during outages and power to recharge batteries.

This is what I was thinking as I read through this thread. I have a 6000 watt gasoline generator now but I would like to some day get a diesel generator, one that would run on a variety of oil based fuels so I can filter the old engine oil and use that for fuel or mix it with the diesel fuel. I suspect on most days you would only need the generator occasionally.
I assume your winter temps get pretty cold, I would make an insulated shed to house the generator and pipe the exhaust out the side wall. The shed would need a vent to allow fresh air to run the generator but diesels dislike extreme cold so the heat from the engine would keep the shed warm, of course practice will determine if you need a vent to release some heat during long run times.
Solar would be my second step in your situation, after you established the generator set up and fuel storage situation. Depending on you winter snow load the solar panels can make a great roof for a patio or outdoor work area. You would be sloping the roof to face the south so rain and melting snow could be directed to a water catchment if that could be helpful for your situation. The framework just needs to be strong enough to support the weight of the snow load. Others here know way more about solar so I have little to add about the technical side of solar.
For heating water, and for heating your home, my mind is thinking about a rocket mass heater. They are very efficient, give off warm heat for a long period of time after the wood burns down, and you can run water pipes through the mass to give you warm/hot water. If you can heat your water with a rocket mass heater during the winter months that would reduce the need for the electric water heater.
A quick search found this bit on information on rocket mass heaters.
https://sweatsville.blogspot.com/2013/01/rocket-mass-stoves.html

 

[Rebecca]

The above post just reminded me, I wanted to add my own personal rule for solar panels in the North lol. Don't put them on the roof. Put them where you can reach them, because often it will be a lovely sunny day, but there was 6 inches of snow that fell last night and is now stuck to the panels preventing any kind of charging. So you have to go out there and brush that off. It can easily be so cold the sun will not remove that snow for you. And I have my panels at a more vertical angle than most to try and help with that, and it only works to an extent.

 

[Alaskajohn]

The above post just reminded me, I wanted to add my own personal rule for solar panels in the North lol. Don't put them on the roof. Put them where you can reach them, because often it will be a lovely sunny day, but there was 6 inches of snow that fell last night and is now stuck to the panels preventing any kind of charging. So you have to go out there and brush that off. It can easily be so cold the sun will not remove that snow for you. And I have my panels at a more vertical angle than most to try and help with that, and it only works to an extent.

Darn! There goes my location of choice! Actually, it was the roof of a steep A frame that typically quickly drops snow, or on the side of the house. I was thinking about a long pole with a type of sweeper for the roof. But the side of the house brings up another concern.

How susceptible are solar panels to chips from rocks kicked up by weed whackers and lawn mowers?

 

[Alaskajohn]

This is what I was thinking as I read through this thread. I have a 6000 watt gasoline generator now but I would like to some day get a diesel generator, one that would run on a variety of oil based fuels so I can filter the old engine oil and use that for fuel or mix it with the diesel fuel. I suspect on most days you would only need the generator occasionally.
I assume your winter temps get pretty cold, I would make an insulated shed to house the generator and pipe the exhaust out the side wall. The shed would need a vent to allow fresh air to run the generator but diesels dislike extreme cold so the heat from the engine would keep the shed warm, of course practice will determine if you need a vent to release some heat during long run times.
Solar would be my second step in your situation, after you established the generator set up and fuel storage situation. Depending on you winter snow load the solar panels can make a great roof for a patio or outdoor work area. You would be sloping the roof to face the south so rain and melting snow could be directed to a water catchment if that could be helpful for your situation. The framework just needs to be strong enough to support the weight of the snow load. Others here know way more about solar so I have little to add about the technical side of solar.
For heating water, and for heating your home, my mind is thinking about a rocket mass heater. They are very efficient, give off warm heat for a long period of time after the wood burns down, and you can run water pipes through the mass to give you warm/hot water. If you can heat your water with a rocket mass heater during the winter months that would reduce the need for the electric water heater.
A quick search found this bit on information on rocket mass heaters.
https://sweatsville.blogspot.com/2013/01/rocket-mass-stoves.html

Good post. I will look into the rocket stove thought, but I have a well functioning wood stove as primary and a number 1 heating oil powered toyostove as backup for when I am away.

As far as temps, each winter the lows average between zero to -15 F, but each winter we have at least one arctic blast that will get down to -25 to -35F, and this might come with high winds and last for a few days. The typical -15F, when it is dry and no wind is almost t-shirt weather. When I let the dog out I will be in my skivvy's and tee shirt with slip on boots and a wool cap. The 5 minutes like this is good for the soul!

Whatever I go with that requires fuel, I can typically only get a fuel truck up the mountain mid June until the rain starts mid August. Otherwise it would be in a few 5 gallons buckets at a time! The propane and heat oil companies have the smaller all wheel drive trucks that make a couple runs a month during the summer out to top off idiots like me. I always ask to have the driver call me before they depart the city as I want them to know what they are getting themselves into. I always ask them if they have read the notes in their system inputted by previous drivers on getting up my hill. They always thank me for this when they get here.

 

[Rebecca]

If it's already shedding snow fast it may be all good. I perhaps should of prefixed my post with ...the snow we most often get where I am.
Lol I can just imagine how the following will sound to someone who has never had snow...but we know there are different types of snow. I often get a wet heavy snow that sticks to everything, car windows, trees, side of the shed, solar panels, just everything. On the occasion we have a light dry snow it will just slide right off. Most annoying however is freezing rain followed by snow. Now that will stick no matter the angle.

A long pole with a brush should do it. I have a softish extending brush meant for the truck windscreen repurposed for the panels that works very well.

 

[Alaskajohn]

If it's already shedding snow fast it may be all good. I perhaps should of prefixed my post with ...the snow we most often get where I am.
Lol I can just imagine how the following will sound to someone who has never had snow...but we know there are different types of snow. I often get a wet heavy snow that sticks to everything, car windows, trees, side of the shed, solar panels, just everything. On the occasion we have a light dry snow it will just slide right off. Most annoying however is freezing rain followed by snow. Now that will stick no matter the angle.

A long pole with a brush should do it. I have a softish extending brush meant for the truck windscreen repurposed for the panels that works very well.

The early and late season wet snow will need help coming down, so I will want a sweep if I put on the roof.

 

[Aerindel]

The above post just reminded me, I wanted to add my own personal rule for solar panels in the North lol. Don't put them on the roof. Put them where you can reach them, because often it will be a lovely sunny day, but there was 6 inches of snow that fell last night and is now stuck to the panels preventing any kind of charging. So you have to go out there and brush that off. It can easily be so cold the sun will not remove that snow for you. And I have my panels at a more vertical angle than most to try and help with that, and it only works to an extent.

Agreed!.

I mounted mine on a fence.

Believe it or not, solar is more deadly than nuclear per KW by a good margin because so many people get themselves killed falling off roofs doing solar work.

I still don't get the obsession with rocket stoves. People talk about them endlessly on survivalist forums but few seem to actually have one and as a lifelong wood heat user, they seem like a problem in search of a solution.

 

[Biggkidd]

Agreed!.

I mounted mine on a fence.

Believe it or not, solar is more deadly than nuclear per KW by a good margin because so many people get themselves killed falling off roofs doing solar work.

I still don't get the obsession with rocket stoves. People talk about them endlessly on survivalist forums but few seem to actually have one and as a lifelong wood heat user, they seem like a problem in search of a solution.

We used a rocket stove water heater for about 8 years. At that point the 3/16ths steel had burned through. Only problem we had was I over designed it. It would, could and did blow out the section of sacrificial pipe many times. It would flash boil the water to steam if you weren't real careful feeding it and keeping it partially damped down / restricted... A friend brought one of those IR thermometers over and the hottest spot on the stove that day read 2257*F The steel was bright sunshine yellow going to white.

 

[Aerindel]

We used a rocket stove water heater for about 8 years. At that point the 3/16ths steel had burned through. Only problem we had was I over designed it. It would, could and did blow out the section of sacrificial pipe many times. It would flash boil the water to steam if you weren't real careful feeding it and keeping it partially damped down / restricted... A friend brought one of those IR thermometers over and the hottest spot on the stove that day read 2257*F The steel was bright sunshine yellow going to white.

I'm not sure that sounds like a desirable feature....my stove will get rot hot if I overfill it or leave the air vent open too far, but its not something I ever try to do on purpose....

So what problem did/does your rocket stove solve that just a normal wood stove solves. Thats what I really want to hear about.

 

[Biggkidd]

I'm not sure that sounds like a desirable feature....my stove will get rot hot if I overfill it or leave the air vent open too far, but its not something I ever try to do on purpose....

So what problem did/does your rocket stove solve that just a normal wood stove solves. Thats what I really want to hear about.

First off it was outside and the hot water holding tank was inside. As to what it could do a regular wood stove couldn't. It could heat 50 gallons of water from the ambient air temperature to 150 in an hour on a half a 5 gallon bucket of split wood. It would have made a good steam boiler. Since I didn't really know what I was doing when I made it I inadvertently made it work to well! There are pictures or were pictures on homesteading today and backwoods home. I haven't been to either place in a long time so I can't be sure they are still there. I did have the same username if anyone wants to go search.