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living happily on solar and DC(Direct Current) power  RSS feed

 
Dean Howard
Posts: 127
Location: NE ARIZONA, Zone 5B, 7K feet, 24" rain
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What I find frustrating about solar power in general, is the (apparent) need, or maybe the political push, to convert all the solar energy oozing out of panels back into AC, so we can run appliances, lights, etc. as if it's business as usual.

BIG QUESTIONS...

Are you finding success, or frustration, living on a DC SYSTEM? (Can you find alternatives for your wood shop, power tools, radios, TV, computer, fans, pumps, water tank heaters, etc.)

Are there enough DC appliances available?

Are there enough alternatives to AC light bulbs?...and by that I mean really good LED, or DC only light bulbs.
IE; Philips sells an 8W and 10W LED light bulb that they swear us using less energy... when I touch it, it's just as hot as a standard 100W bulb... Heat is the result of amperage, plain and simple. Perhaps the AC to DC conversion is really expensive, but the LED half of their light bulb is really efficient. Dishonest, absolutely. No truth in advertising whatsoever.

What are your really good sources for these supplies? LINKS, please.

What batteries, or battery technologies are affordable, easily serviceable, readily available, reliable, and long-lasting in your experience

Are you wiring your homes for AC and DC, or have you gone to DC ONLY?

What are the limitations? What are you doing without?

What do you consider a minimum-sized system would be for a given square footage of living space...and work space (garage? workshop? hand tools, pumps)...



I'm not going to be around for your responses, but I'm hoping this post will build into the kind of resource post we can learn from, and also to provide links in one common place we can refer to. Thanks to all!
 
Dean Howard
Posts: 127
Location: NE ARIZONA, Zone 5B, 7K feet, 24" rain
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Wow, really... no one home? Well, I better give it a year or so... Now, I know Permies has gotten Sooo HUGE, it's hard to find every little post...that's actually really great for the site. Carry on!
 
thomas rubino
pollinator
Posts: 883
Location: latitude 47 N.W. montana zone 6A
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Ok, I've been off grid solar / hydro since 1982. I started out dc only. After 33 years I still have a dc system in use in my home (led lighting !) but... I have a complete ac system as well. 12 volt only products are available but most are outrageously overpriced. 110 vt pure sine wave inverters allow us to easily be in the computer age . Batteries are the current limitation on off grid living. Lead acid / nickel iron / 1.5,2,6 ,12, volt, stack them up to any dc voltage you want .... but all of them will fail in the long term until new battery technology is discovered or released by the government. As far as led lighting, Flat panel and recessed led are by far the best way to light your off grid home. Some will only run on 110 vt but some (led light store ,amazon) work on 12 volt dc and boy do they work well ! My 85 year old cabin has never been lit up on so little power as it is now! Grid intertie solar systems are the newest "thing" in the city. I for one, am glad to see any step away from fossil fuels! Personally I believe a stand alone system is the way to go but by allowing big business to continue making money (and controlling you) the price on solar panels will continue to come down for those of us that have disconnected from the grid.
 
Alder Burns
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Posts: 1393
Location: northern California
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I too had a DC system the first few years I was on solar, mostly due to budget considerations.....I did not even want to blow $50 on a cheap WalMart vehicle inverter! My panels were home-made by a friend who bought broken pieces and then soldered them meticulously together backed up onto a window with silicone caulk, my batteries were scrounged from the recycling centers, and my wiring and outlets were scavenged as well----I used AC outlets and plugs with one prong defined as positive and the other negative. I had a couple of scrounged camp lanterns where I wired directly onto the nodes where the ends of the batteries connected, music box wired similarly, an answering machine for the phone, and, eventually, a laptop with a DC car power supply, and a small vehicle refrigerator similarly powered. All went well, except for a few times when visitors plugged in AC stuff into my DC outlets and fried them.....(thankfully only up to a CD player in value!), and then when the lanterns died out, I ended up mailordering a rather expensive DC fluorescent fixture. Appliances of all sorts are out there....you can find them at truck stops, RV centers, and boating places....since all of these things run on DC; but they will be pricey relative to their AC alternatives, as noted above. Eventually it will become cheaper and easier to go with an inverter and do AC, unless you keep your system very small.
The other advantage of AC is that if your panels have to be at some distance from where the power is used, you will need very fat wire to move it effectively.....much less of an issue if you convert it to AS first. Fat wire is costly.....
 
Jeremy Whitish
Posts: 1
Location: Rockies
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**This turned more into a novel than I anticipated. So top off your coffee and enjoy!**

My husband and I have been back and forth between on and off-grid since 2012. Our first experience was working a ranch in the Okanogan (north-central Washington) where our housing was an 11'x11' plywood box, in which we eventually put up a half loft. There, we were on 12 volt direct current (VDC) exclusively. The ranch owner had purchased a Harbor Freight PV panel years before, but it was no longer working. This was before I was familiar with solar systems so I couldn't "diagnose" the issue at that time. Looking back, I think the charge controller just wasn't wired properly...but no way to tell now. There were two used Trojan L-16 batteries that were cracked from being outside and uncovered for many winters, and to charge them we used a Honda 1000 generator via its 12VDC plug. This system ran two 12VDC incandescent bulbs, a small AC/DC television (which we never used, it was just left there from the previous Hand), and a cigarette port we could charge our cell phone with. Without service in the area, we mostly left the phone in the truck and charged it when we went into town for supplies. Sticking with your question, we were happy for the lifestyle we were living. We would visit family on the coast periodically and got our Netflix and internet fill then. We had no computer, no blenders, no ipods, nothing besides a light bulb and a Sony shortwave we listened to local radio with. There was a 4000 watt (W) generator used for the well pump.

Moving on in life, we rented a small cabin in North Idaho that was sort of a cheater off-grid. The landlord's house had grid power, but the cabin did not. It was close enough we were able to run one extension cord to the cabin and powered a desk lamp and a battery charger. By then, we had moved up the technological ladder and brought our laptop computer and ham radios with us. Even though the battery (a used Carquest battery a friend gave us) ran everything we needed minus the one desk lamp, it was charged via a battery charger from the grid. So technically not off-grid, it is what we had to work with. The radios were wired direct and could last a day or two without charging. We had a cigarette lighter extension from Wally's we charged our phone on, and I got a vehicle charger for the laptop as well. No internet, but we could listen to music on it and will eventually get on digital ham radio. We got our water from the frost-free spigot hooked up to the community water system and used a three gallon Gatorade jug to gravity feed our sink which had a grey water five gallon bucket below. We used the outhouse, and for bathing we did one of three options: showered at work, sponge bath/sink shower, or used the landlord's shower when available. Again, not technically off-grid, but it gave us a good taste of where we wanted to land between primitive life and still having some technology.

We now live in a 19' pull behind trailer parked at an RV park for the winter while in Wyoming for work. We spent a few months camping on BLM range while the weather was good this fall and saved a lot of money on rent. At that time, we charged the trailer's battery by hooking up jumper cables to the truck while it idled in the mornings. We used only the lights in the trailer, and sparing at that. These 12VDC automotive bulbs (type 1156) in the RV fixtures suck power...definitely an example for LED lighting in the future. We tried automotive LED 1156 bulbs in the fixtures, but they were just way too intense for comfortable lighting. I do know dedicated 12VDC led lights for houses with a warmer light are very comfortable. Again, we charged our laptop and phones in the truck while driving into work. Eventually moving into an RV park, we are plugged in now. We do use the 110VAC plugins for pretty much everything minus the radios because the power is available.

We have two more weeks here then we will be headed back west into the Rockies were we are buying a few acres. We are going to start by living in the trailer on the property until we get a garden going and then move onto building a cabin of sorts. We are leaning towards an earthbag style structure, but much of it depends on the resources available on the land we buy. Getting back to the power subject, we just bought a Renogy 100W panel to keep the battery charged. At the point of moving onto land, we will be 100% off-grid, and run only on 12VDC. We are not at all afraid we will be uncomfortable or be lacking anything without 110VAC. We do have a 85W cigarette lighter inverter we may use with our string of LED white Christmas lights, and to charge the laptop. Already, this LED string light appears to be much more efficient over the incandescent bulbs (even with loss from the inverter) and are a comfortable, warm color. Phones will be 12VDC charged from the cigarette lighter plugin. Ham radios are direct wired to the battery. Otherwise, we are not using any other power. No refrigerator, no electric heater (minus the LPG furnace if we really need it), no microwave. The fridge and built in microwave are extra food storage.

We are a mix of both 12VDC and 110VAC, but see the majority of our use on 12VDC in the near future and do not have any longings. Maybe having a blender for smoothies or home-made almond milk might be nice, but we make due without.

--SUMMARY--

Tools - Look into battery powered equipment. We have a few year old Makita drill and impact driver that charges quickly off of the small inverter and lasts most of a small project (two batteries would be handy, though). My husband uses a battery powered impact at his job at a tire shop and says he finds them to be equal in power with pneumatic tools and last quite a while. I have used a battery powered Kawasaki circular saw and jig saw, both of which I found to be lacking in power and longevity.

Appliances - Computers, fans, cell phones, pumps, televisions, et cetra all have 12VDC options. You may have to buy another piece like an automobile charger for your laptop, but there are all sorts of options nowadays. Stoves, refers, freezers, and water heaters also have either LPG or 12VDC options. I lean heavily towards propane or alternative for these. The 12VDC options tend to be expensive or still use a rather large amount of power. If you are in a position to look at sun powered water heaters, food dryers, and cold storage/root cellars, this will cut out a lot of extra appliances. It means you may not be able to have ice cream in July and you have to jerk or can meat instead of freeze it (with exception of winter depending on where you live)...but it is a sacrifice the 'poor man' has to make to stay off the grid. I use 'poor man' for those like me who cannot afford such a large system to accommodate a 12VDC freezer/refer, et cetra, or do not want to spend the propane on them. **A 'truckers' AC/DC fridge/freezer is not very expensive, maybe around $100 or so, but I cannot attest to how much power it uses. Perhaps keeping it in the root cellar much cut down the power use somewhat.** If you are willing to scavenge some appliances from used/wrecked RVs or boats, you can save a lot of money over new 12VDC or LPG appliances. I plan to do this for at least a stove/oven, and would only consider this option for a water heater or fridge/freezer should I decide to include these into the future house...which they currently are not included in the initial build plans.

Lights - We use two strings of LED white Christmas lights as a supplement to the incandescent bulbs in the camper. They are 4.8W at 0.04 amp (A) a piece per the label. These work awesome, and light up about half of the camper comfortable enough to read by. For cooking or cleaning guns or other things that require more direct light we do have to turn on more lights. (Headlamps also work great!) I have experience with Backwoods Solar, and they have a few options for LED lighting that I like a lot. I have been to their storefront and have seen this bulb personally: http://www.backwoodssolar.com/products/lighting/led-lighting/12v-ultimate-6w-bulb-w-screw-base which I found to be a very comfortable warm color, very close to an incandescent bulb. I don't know about any of their other bulbs.

Batteries - Per the Backwoods Solar guys, my off-grid friends in North Idaho, along with my own independent research, the Trojan T-105 just seems to be the way to go for dollars per amphour and longevity. Trojan L-16's seem to cost a little more short term per amphour, but long term come out slightly ahead. Currently, I use an Everstart deep cycle RV battery from Walmart. It was $99 and has works fine for my purposes. It will be interesting to see how it fairs when only being charged from this 100W panel. I will want to expand in the future. Deka also makes an adequate battery I understand.

House Wiring - Our house will be wired for DC only. Given our small layout, I see no issues going with a DC only system. 12VDC LED lights...12VDC stereo (think car stereo as a cheap starter system)...12VDC adapters for computer and phones... We will still have the small inverter to charge the Makita if needed. I plan to someday have a larger inverter in the ham shack should we decide we want a blender or other appliance that is not practical on DC.

Limitations - One thing I didn't cover above was internet. I have not found a 12VDC modem/router offered by any company locally (yes, I did call and ask). Unless you get wireless internet from a cell phone carrier on your computer via USB plugin or otherwise, you will probably need a small inverter to run the modem. I do not know if this is considered too sensitive for a modified sine wave (MSW) inverter or if a pure sine wave (PSW) inverter would be needed. If you want to use a block heater on your truck, forget it on this size of a system. Get a 2000W generator and run it a few hours before you leave on cold mornings to "take the edge off". The Honda 1000W kept tripping when we plugged in our 600W block heater. A newer, less abused 1000W may not have the same issues, but that this is why I mention a 2000W.

Size of System - For a 19' camper, we are going to make due with a 100W system but may end up having "power rations". Hopefully we get built and settled by fall. After doing the math, once in the new house we will require at least 200W worth of panel, 400W to be more than comfortable. This is considering two adults, one computer, a few ham radios, and lighting for a ~200-300 sqft house. We have not considered requirements for a workshop in terms of electricity.

--

This is my first post ever on Permies, but I hope this helps those who are still cautious about moving onto a 12VDC system. The alternative energy market is growing every day and prices are constantly falling as advancements are made. I am excited to see how well some of our theories pan out in practice for us when going full bore.

Jeremy
 
Dean Howard
Posts: 127
Location: NE ARIZONA, Zone 5B, 7K feet, 24" rain
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Thanks for your thoughtful and generous posting.
I was worried about wiring up regular AC outlets for DC... Fried Green Tomatoes, or Transistors... Does anyone know of an outlet box that includes AC, and a separate DC, to prevent this
 
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