MillerIslandSolar
New Member
- Joined
- Jun 6, 2022
- Messages
- 11
We have an off grid seasonal fishing cabin on an island on an inland lake near Waterville, Maine (04901). Cabin is used Memorial Day to Labor day. System needs to be able to tolerate no heat conditions through the off season.
Everything is now propane - lights (Humphrey), refrigerator, range/oven, water heater, 2 wall heaters. We do use a 3/4 HP swimming pool pump on a 3250 watt gas generator to pump lake water up to a 150 gal. holding tank on the cabin roof for non-potable use via gravity feed (about 10 PSI). To charge our electric devices we take our boat to the mainland (1/2 mile) and use an outlet in our small 12' x 16' shore boathouse.
From a design standpoint, we're limited by the size and number of panels. For a number of reasons, we are limited to ONLY FOUR panels each no larger than 42" x 72.5". These will be mounted on a shed roof about 30' away from the main cabin. We do want battery backup.
Our priorities are:
LED Lights - propane lights put out too much heat and cabin gets unbearably hot throughout the summer.
Electrify/automate water supply system (either using existing pump or other system)
Charge 20V Dewalt batteries for tools, able to run smaller hand tools (Circ saw, etc.) on AC
Small fans to move air would be wonderful
As would a small microwave.
We eventually plan to dig a potable water well and would like that system to be electric/automated.
Are we being unrealistic in our hopes? As we are limited by the panels, we'd like to maximize their output capacity for the size we can support.
Any comments/suggestions/component lists would be appreciated. We are currently attracted to the "rumored" Point Zero Titan 2.0 system but don't know enough to know if that is a good direction.
Thanks for any hep.
UPDATED IN RESPONSE TO QUERIES:
We are not too worried about electric lights and charging small electronics. Our main concern is existing and future water system, the potential for small kitchen appliances (toaster, microwave), and other comfort items - ceiling or other fans, etc.
RE: WATER SYSTEM
We currently use an electric pump down by the shore of the lake (11.2 A @ 115) powered from a 3250 Sears generator (40 years old) on a 100’ 12/3 cord that we roll out and coil up each visit. As a backup we have a 5 HP gas water pump - identical intake and output unions so swap out is a matter of a minute or two.
These pump water up to a 75 gallon (65 gallon usable) holding tank mounted inside the cabin at the peak of the roof above the sleeping loft. In the 2nd picture you can see the external overflow pipe below the peak of the roof - mostly(!) prevents people from overflowing the tank into the cabin.
The cabin is 70’ back from the lake. The total elevation, from the lake surface up to the inlet of the holding tank is about 45’. When totally full, the distance from the top of the holding tank’s water level down to a normal use level (3.5’ above the floor for faucets, 6’ for shower) is about 18’ but that decreases to 15’ when the tank is 1/4 full. So, we get about 7 to 8 PSI - low but adequate as all our points of use do operate - most importantly the toilet, then the shower. We use a 40 gallon propane water heater as the flow rate of the water won’t operate an on-demand tankless heater.
Water is used by: Kitchen sink, bathroom sink, bathroom tub/shower, toilet. My wife and I use about 30 to 40 gallons a day. With 2 others, about 75 to 100 gallons per day. We pump daily, each AM when the lake is calmest and water is clearest.
We could increase pressure by moving the existing holding tank to exterior top of roof (about + 8' to 10’ or 4 PSI) or to a nearby tree (+ 15’ to 30’ - about + 7 to 12 PSI). Lots of effort and cost for lake water, doesn’t make the system turn key/self controlling, and we want solar power now anyway and to hand drill a well and convert over to to that for a fully automatic potable water system as soon as we get the money.
Last year we were given a 350 gallon round tank that is under the cabin and currently unused - behind the center post in the 2nd picture. The tank bottom is about 8’ below the cabin floor and the top of the water when full would be about 5’ above that.
I have toyed with just using a stand alone, portable type solar system to directly power 12v pumps.
The simplest would be to use just one at the shore up to the existing gravity tank, but head pressure and duration of run time may be an issue. Filling would be controlled by some type of float valve to kick on when tank is half full (as cabin use volume might be greater than pump fill rate for a short duration and draw down the water level even when pump is running.)
Next easiest might be to use the 350 gallon ground tank (similar float valve control) and a second pump to feed the gravity feed holding tank (with float valve control).
Or use the 350 gallon tank with one pump and a second to feed a pressurized cabin system (either a “constant” demand type at 40-50 PSI or to a pressurized bladder tank @ 30 to 40 or 40 to 50 PSI).
HOWEVER, if my planned 4 panel solar system can drive my existing pump (Specs in 1st picture), I could use it and just instal a float control in the existing holding tank with gravity feed.
If the solar system won’t drive the existing pump, it seems my next option is to install a shore-side pump that the solar system will support and use the gravity holding tank. But, maybe, I’d be better off using the 350 tank and two pumps? OR???? OR????
And, as a final goal, we’d like to rent out the cabin but the esoteric nature of the water system really prevents this. Requires manual monitoring of the holding tank level, knowing when to fill, starting the generator, manually turning on the pump (plug cord into generator), watching the overflow, and pulling the pump cord out of the generator at the FIRST sign of water overflow. The propane lights are a big enough challenge for many city folk and newB’s and this is just too much - we’d end up with a swimming pool in the cabin. So, we really need a totally self contained and automatic water supply system. It is OK for this to be only for non-potable as hauling in drinking water for drinks and cooking is standard in the area.
So, my dilemma is that with no practical experience I don’t know which path to go to end up with the best system for the lowest cost. And even when I settle on a path, the multiplicity of conflicting internet information makes selecting the specific components a daunting challenge.
And, lastly, I analyze everything to death and since we’ve use the existing system (gas or electric shore side pump to gravity feeding holding tank) for decades and we can get by with it for years more, it is easier to do nothing.
Everything is now propane - lights (Humphrey), refrigerator, range/oven, water heater, 2 wall heaters. We do use a 3/4 HP swimming pool pump on a 3250 watt gas generator to pump lake water up to a 150 gal. holding tank on the cabin roof for non-potable use via gravity feed (about 10 PSI). To charge our electric devices we take our boat to the mainland (1/2 mile) and use an outlet in our small 12' x 16' shore boathouse.
From a design standpoint, we're limited by the size and number of panels. For a number of reasons, we are limited to ONLY FOUR panels each no larger than 42" x 72.5". These will be mounted on a shed roof about 30' away from the main cabin. We do want battery backup.
Our priorities are:
LED Lights - propane lights put out too much heat and cabin gets unbearably hot throughout the summer.
Electrify/automate water supply system (either using existing pump or other system)
Charge 20V Dewalt batteries for tools, able to run smaller hand tools (Circ saw, etc.) on AC
Small fans to move air would be wonderful
As would a small microwave.
We eventually plan to dig a potable water well and would like that system to be electric/automated.
Are we being unrealistic in our hopes? As we are limited by the panels, we'd like to maximize their output capacity for the size we can support.
Any comments/suggestions/component lists would be appreciated. We are currently attracted to the "rumored" Point Zero Titan 2.0 system but don't know enough to know if that is a good direction.
Thanks for any hep.
UPDATED IN RESPONSE TO QUERIES:
We are not too worried about electric lights and charging small electronics. Our main concern is existing and future water system, the potential for small kitchen appliances (toaster, microwave), and other comfort items - ceiling or other fans, etc.
RE: WATER SYSTEM
We currently use an electric pump down by the shore of the lake (11.2 A @ 115) powered from a 3250 Sears generator (40 years old) on a 100’ 12/3 cord that we roll out and coil up each visit. As a backup we have a 5 HP gas water pump - identical intake and output unions so swap out is a matter of a minute or two.
These pump water up to a 75 gallon (65 gallon usable) holding tank mounted inside the cabin at the peak of the roof above the sleeping loft. In the 2nd picture you can see the external overflow pipe below the peak of the roof - mostly(!) prevents people from overflowing the tank into the cabin.
The cabin is 70’ back from the lake. The total elevation, from the lake surface up to the inlet of the holding tank is about 45’. When totally full, the distance from the top of the holding tank’s water level down to a normal use level (3.5’ above the floor for faucets, 6’ for shower) is about 18’ but that decreases to 15’ when the tank is 1/4 full. So, we get about 7 to 8 PSI - low but adequate as all our points of use do operate - most importantly the toilet, then the shower. We use a 40 gallon propane water heater as the flow rate of the water won’t operate an on-demand tankless heater.
Water is used by: Kitchen sink, bathroom sink, bathroom tub/shower, toilet. My wife and I use about 30 to 40 gallons a day. With 2 others, about 75 to 100 gallons per day. We pump daily, each AM when the lake is calmest and water is clearest.
We could increase pressure by moving the existing holding tank to exterior top of roof (about + 8' to 10’ or 4 PSI) or to a nearby tree (+ 15’ to 30’ - about + 7 to 12 PSI). Lots of effort and cost for lake water, doesn’t make the system turn key/self controlling, and we want solar power now anyway and to hand drill a well and convert over to to that for a fully automatic potable water system as soon as we get the money.
Last year we were given a 350 gallon round tank that is under the cabin and currently unused - behind the center post in the 2nd picture. The tank bottom is about 8’ below the cabin floor and the top of the water when full would be about 5’ above that.
I have toyed with just using a stand alone, portable type solar system to directly power 12v pumps.
The simplest would be to use just one at the shore up to the existing gravity tank, but head pressure and duration of run time may be an issue. Filling would be controlled by some type of float valve to kick on when tank is half full (as cabin use volume might be greater than pump fill rate for a short duration and draw down the water level even when pump is running.)
Next easiest might be to use the 350 gallon ground tank (similar float valve control) and a second pump to feed the gravity feed holding tank (with float valve control).
Or use the 350 gallon tank with one pump and a second to feed a pressurized cabin system (either a “constant” demand type at 40-50 PSI or to a pressurized bladder tank @ 30 to 40 or 40 to 50 PSI).
HOWEVER, if my planned 4 panel solar system can drive my existing pump (Specs in 1st picture), I could use it and just instal a float control in the existing holding tank with gravity feed.
If the solar system won’t drive the existing pump, it seems my next option is to install a shore-side pump that the solar system will support and use the gravity holding tank. But, maybe, I’d be better off using the 350 tank and two pumps? OR???? OR????
And, as a final goal, we’d like to rent out the cabin but the esoteric nature of the water system really prevents this. Requires manual monitoring of the holding tank level, knowing when to fill, starting the generator, manually turning on the pump (plug cord into generator), watching the overflow, and pulling the pump cord out of the generator at the FIRST sign of water overflow. The propane lights are a big enough challenge for many city folk and newB’s and this is just too much - we’d end up with a swimming pool in the cabin. So, we really need a totally self contained and automatic water supply system. It is OK for this to be only for non-potable as hauling in drinking water for drinks and cooking is standard in the area.
So, my dilemma is that with no practical experience I don’t know which path to go to end up with the best system for the lowest cost. And even when I settle on a path, the multiplicity of conflicting internet information makes selecting the specific components a daunting challenge.
And, lastly, I analyze everything to death and since we’ve use the existing system (gas or electric shore side pump to gravity feeding holding tank) for decades and we can get by with it for years more, it is easier to do nothing.
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Thanks for the laugh though.
