Small-mid sized offgrid solar systems for preppers
Aug 24, 2016 18:20:33 GMT 10
blueshoes, WolfDen, and 1 more like this
Post by shinester on Aug 24, 2016 18:20:33 GMT 10
Plan Z asked me about some further details of the solar systems I have, so here's some details. Your specific needs will be dictated by your application, more than happy to help you work that out if you give specifics of wattage usage and how many hours it's ran. Laptop 40W @ 2hrs for instance. It's easy to work out from there.
Main system
240W Solar & 960Ah [11520Wh] Storage.
$150 S/H - 240W of 12 Volt solar = x2 for winter/day = 480Wh, x6 for summer/day = 1440Wh
$340 S/H - 8x240Ah 6V batteries = 11520W. Lead acid is best run only to half that for long life, so 5760Wh
$150 - 10Amp Inverter, modified sinewave
$15 - Solar Regulator
$30 - power cabling etc
$10 - !2V Circuit breaker 200amp
$10 - 12V switch 300amp
$25 - 15Amp extension lead to run to the house
$50 - smart charger
$10 - mulitmeter -
---------
$790
This is mostly for backup power during extended blackouts [prep like nothings going to happen], I have only to turn it on. I can take panels from elsewhere and run them in parallel if I need to generate more/day. As you can see I can run at least 480W continuously and my LED lighting [say 60W all up] is going to run for about 1/3 of a year on the batteries even without charging. With all of that battery back up I can run anything that a household can without issue, though I'm limited to how much charging goes in. Even with 480Wh/day, can run the lights, comms, and run the microwave for 10mins daily [150Wh] for cooking.
Ideally I'd add more panels. If I want to go stealthy, I'll lay the panels flat on a tin roof which reduces generation though that might be a good trade off depending on circumstances.
Secondary system
100W Solar & 89Ah Storage.
$70 S/H - 100W of 12 Volt solar = x2 for winter/day = 200Wh, x6 for summer/day = 600Wh
$50 S/H UPS [uninterrupted power supply] - 14Ah 12V battery = 168Wh/84Wh usable
- sustained output 600W, surge 865W
- works as a mains power charger for batteries.
- works as the inverter
- kill the buzzer for extended periods, it's annoying, can be done with software on some, though I have a switch
$75 S/H - 75Ah 12V battery = 900Wh. Ideally 450Wh storage connected parallel to the UPS
$10 wire to connect both
$10 solar regulator
------
$215
The UPS has my modem and a light on it 24-7. This has come in handy as it's kept me being able to work whilst having no power, handy when many of my clients are overseas and I can't just call them. I have the other parts ready but disconnected in my day to day activity.
What can you do with that, well you can run led lights [60Wh] and maybe an occasional use of the laptop. You'd need a bigger UPS, more storage and panels if you plan to run a normal washing machine mine uses 800W [600Wh if run for 3/4 of an hour] and a surge is probably double that. I have a small travel washing machine it can run without issue. You might use the microwave for 10mins/day [150Wh] though you'll be making some choices. Perhaps you go in between the two systems? It really depends on what you want to do and I hope there's enough info here to allow you to get some ideas on that.
Tertiary System
40W Solar & 12Ah Storage.
$20 S/H - 40W of 12 Volt solar = x2 for winter/day = 80Wh, x6 for summer/day = 160Wh
$50 S/H UPS [uninterrupted power supply] - 12Ah 12V battery = 144Wh/77Wh usable
- sustained output 260W, surge 365W
- works as a mains power charger for batteries.
- works as the inverter
- kill the buzzer for extended periods, it's annoying, can be done with software on some, though I have a switch
$10 solar regulator
----
$90
Not great but better than nothing. You might get a couple of hours out of a laptop. It's main duty is giving time for wifey to save her files to which some are part of her work. The secondary role of prepper power allows a little extra power or an independent system that I might loan out to relatives in a time of need for lights.
I have quite a few 6W panels with USB out, which is good for phones/radios for their daily usage.
Some further notes
- use the most energy hungry applications just before midday to save on battery drain. The less you drain the batteries, the longer they last. This is especially true in summer as you can get a LOT more power usage but your battery storage levels may be less capable.
- An excess of solar panels is useful because you can use that power during the day as above even with low storage levels. Panels also don't really wear out as such. You're better spending your money here than batteries.
- I'm a good shopper and patient, so expect to pay a little more for second hand gear and lot more for new, this is a rough guide only on pricing.
- Solar panels are pretty well priced compared to second hand most of the time.
- Solar regulators to my mind as long as they have MPPT, are fairly similar on the low amp end as the components are similar. The amps needed for your panels is Watts/voltage. So 240W/12V = 20amps.
- second hand lead acid batteries can be great or crap. If they're been in a fire system or battery back up and hardly ever used and replaced every 3 years they could be fantastic. You don't know and there's ways of testing them [load testing] that you can look up. A 'very' rough approximate is to check their charged voltage, it can give you clues their life. The higher their charged voltage generally [but not always!] they are.
- learn how to check battery voltage for usage and monitor it daily. If you go below 50% capacity you will reduce the life of the batteries considerably. Ideally you don't go below 75% but their usefulness-cost ratio isn't as good [they will last longer however]
- second hand UPS - recent [within a year or so] battery changes are a must or work out the price of new batteries when looking at prices. I use my inverters
- I chose 12V for my system so I could interchange anything, that is for redundancy. 12V isn't the most ideal voltage for a household due to the need to keep cable lengths short or use heavier cable to handle currents.
- if you were willing to only go to 75% car batteries in parallel could be used in a pinch, but they're not great at storage.
- second hand solar cells work great if they're not broken, visually inspect. Even after 40 years solar panels have shown themselves to still be at 80% of their original capacity and there's no moving parts so they're pretty safe to buy. If you're further north your output numbers will be higher [Im in Melbourne] due to more sun, though using my figures will leave you with plenty of leeway.
- all of these systems are fairly easy to make.
- panels ought to be tilted towards the north. It depends on where you live as to the optimum angle [and it varies depending on the time of year] though they will work flat on a roof/ground, just not produce as much power. Tilted is better.
Main system
240W Solar & 960Ah [11520Wh] Storage.
$150 S/H - 240W of 12 Volt solar = x2 for winter/day = 480Wh, x6 for summer/day = 1440Wh
$340 S/H - 8x240Ah 6V batteries = 11520W. Lead acid is best run only to half that for long life, so 5760Wh
$150 - 10Amp Inverter, modified sinewave
$15 - Solar Regulator
$30 - power cabling etc
$10 - !2V Circuit breaker 200amp
$10 - 12V switch 300amp
$25 - 15Amp extension lead to run to the house
$50 - smart charger
$10 - mulitmeter -
---------
$790
This is mostly for backup power during extended blackouts [prep like nothings going to happen], I have only to turn it on. I can take panels from elsewhere and run them in parallel if I need to generate more/day. As you can see I can run at least 480W continuously and my LED lighting [say 60W all up] is going to run for about 1/3 of a year on the batteries even without charging. With all of that battery back up I can run anything that a household can without issue, though I'm limited to how much charging goes in. Even with 480Wh/day, can run the lights, comms, and run the microwave for 10mins daily [150Wh] for cooking.
Ideally I'd add more panels. If I want to go stealthy, I'll lay the panels flat on a tin roof which reduces generation though that might be a good trade off depending on circumstances.
Secondary system
100W Solar & 89Ah Storage.
$70 S/H - 100W of 12 Volt solar = x2 for winter/day = 200Wh, x6 for summer/day = 600Wh
$50 S/H UPS [uninterrupted power supply] - 14Ah 12V battery = 168Wh/84Wh usable
- sustained output 600W, surge 865W
- works as a mains power charger for batteries.
- works as the inverter
- kill the buzzer for extended periods, it's annoying, can be done with software on some, though I have a switch
$75 S/H - 75Ah 12V battery = 900Wh. Ideally 450Wh storage connected parallel to the UPS
$10 wire to connect both
$10 solar regulator
------
$215
The UPS has my modem and a light on it 24-7. This has come in handy as it's kept me being able to work whilst having no power, handy when many of my clients are overseas and I can't just call them. I have the other parts ready but disconnected in my day to day activity.
What can you do with that, well you can run led lights [60Wh] and maybe an occasional use of the laptop. You'd need a bigger UPS, more storage and panels if you plan to run a normal washing machine mine uses 800W [600Wh if run for 3/4 of an hour] and a surge is probably double that. I have a small travel washing machine it can run without issue. You might use the microwave for 10mins/day [150Wh] though you'll be making some choices. Perhaps you go in between the two systems? It really depends on what you want to do and I hope there's enough info here to allow you to get some ideas on that.
Tertiary System
40W Solar & 12Ah Storage.
$20 S/H - 40W of 12 Volt solar = x2 for winter/day = 80Wh, x6 for summer/day = 160Wh
$50 S/H UPS [uninterrupted power supply] - 12Ah 12V battery = 144Wh/77Wh usable
- sustained output 260W, surge 365W
- works as a mains power charger for batteries.
- works as the inverter
- kill the buzzer for extended periods, it's annoying, can be done with software on some, though I have a switch
$10 solar regulator
----
$90
Not great but better than nothing. You might get a couple of hours out of a laptop. It's main duty is giving time for wifey to save her files to which some are part of her work. The secondary role of prepper power allows a little extra power or an independent system that I might loan out to relatives in a time of need for lights.
I have quite a few 6W panels with USB out, which is good for phones/radios for their daily usage.
Some further notes
- use the most energy hungry applications just before midday to save on battery drain. The less you drain the batteries, the longer they last. This is especially true in summer as you can get a LOT more power usage but your battery storage levels may be less capable.
- An excess of solar panels is useful because you can use that power during the day as above even with low storage levels. Panels also don't really wear out as such. You're better spending your money here than batteries.
- I'm a good shopper and patient, so expect to pay a little more for second hand gear and lot more for new, this is a rough guide only on pricing.
- Solar panels are pretty well priced compared to second hand most of the time.
- Solar regulators to my mind as long as they have MPPT, are fairly similar on the low amp end as the components are similar. The amps needed for your panels is Watts/voltage. So 240W/12V = 20amps.
- second hand lead acid batteries can be great or crap. If they're been in a fire system or battery back up and hardly ever used and replaced every 3 years they could be fantastic. You don't know and there's ways of testing them [load testing] that you can look up. A 'very' rough approximate is to check their charged voltage, it can give you clues their life. The higher their charged voltage generally [but not always!] they are.
- learn how to check battery voltage for usage and monitor it daily. If you go below 50% capacity you will reduce the life of the batteries considerably. Ideally you don't go below 75% but their usefulness-cost ratio isn't as good [they will last longer however]
- second hand UPS - recent [within a year or so] battery changes are a must or work out the price of new batteries when looking at prices. I use my inverters
- I chose 12V for my system so I could interchange anything, that is for redundancy. 12V isn't the most ideal voltage for a household due to the need to keep cable lengths short or use heavier cable to handle currents.
- if you were willing to only go to 75% car batteries in parallel could be used in a pinch, but they're not great at storage.
- second hand solar cells work great if they're not broken, visually inspect. Even after 40 years solar panels have shown themselves to still be at 80% of their original capacity and there's no moving parts so they're pretty safe to buy. If you're further north your output numbers will be higher [Im in Melbourne] due to more sun, though using my figures will leave you with plenty of leeway.
- all of these systems are fairly easy to make.
- panels ought to be tilted towards the north. It depends on where you live as to the optimum angle [and it varies depending on the time of year] though they will work flat on a roof/ground, just not produce as much power. Tilted is better.
