Instructables
Picture of Solar Hurricane Lighting (and more)

I've spent my entire life living on or near the Gulf Coast. And even though we've had a couple of seasons with no major hurricanes, I can't help thinking about them this time of year. Of course, the big storms are very dangerous and most people should evacuate to safer ground. But those who stay and those who return afterward, are often faced with a loss of electrical power. Even some relatively minor storms can cause power outages.

Power outages suck! Sure we have candles, lanterns, and flashlights, but you have to either station these items in each room or carry them around with you. I was trying to think of some way to have lights in every room of the house in the event of a power outage and, naturally, solar came to mind.

I would love to outfit my house with a complete solar system that produces 5 or 10 kW of power, but I'm not quite ready to make that investment. So I needed a quick, easy way to have lights all over the house, plus the ability to run other small devices such as fans and a couple of phone chargers.

I was walking around my house from room to room thinking about this and it hit me; phone jacks! Even though I haven't had a landline phone in years, there are phone lines run throughout the house and a handy little wall jack in each room. Why couldn't I use this wiring to provide low voltage solar lighting in the event of a power outage?

Well, the first reason is I didn't know if I could legally disconnect the wires inside my house from the phone company's junction box outside. So I called my local phone company office and asked. Turns out there's a customer disconnect right there on the side of the house. They said I can disconnect my house from their line and everything on my side is my property. Awesome!

The second reason is the wire size. Typical phone cables are between 22 and 26 gauge, which means the current capacity is very limited. But I did some research and found that there are all shapes and sizes (and wattages) of 12 volt light bulbs out there and the LED bulbs come is sizes as low as 2 or 3 watts.

Based on the information I found at http://www.engineeringtoolbox.com/wire-gauges-d_419.html I should be able to safely run 3.5 amps through a 24 gauge wire. At 12 volts, that comes to 42 watts. However, since I don't know the length of the wire in the walls, I decided to play it safe and keep it to a maximum of 2-3 amps, which still gives me 24-36 watts to work with.

So I decided to configure a low-end solar system using mostly items I had on hand or could buy locally. What follows is a detailed description of this project. I hope you like it!

UPDATE: I added an inline fuse between the charge controller LOAD (+) lead and the phone line just in case somebody plugs in too heavy a load.

UPDATE: Due to lots of helpful suggestions (and a few outright warnings) regarding my choice of a 110 volt plug for the power outlet, I decided to add some optional 12 volt outlets to the project. Please see Steps 1 & 3 for details.

 
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Step 1: Materials

Here's the list of parts I used:

1 - 12x12x6 PVC Junction box (from Lowes)
2 - 15 watt solar panels
2 - 12 volt 14Ah batteries
1 - 12 volt, 3 watt LED light bulb
1 - 100 watt solar charge controller (from Harbor Freight)
1 - Solar Power Connection Kit (from Harbor Freight)
10 - feet - 1/2" PVC
6 - feet - 1/2" Flexible tubing
1 - outdoor round box w/ 1/2" knockouts (for flood light)
1 - outdoor light kit (for one flood light)
4 - 1/2" PVC threaded male adapters
2 - 1/2" PVC 90s
3 - 1/2" PVC couplings
3 - 1/2" PVC 2-hole straps
1 - Weatherproof switch box
1 - Single Pole light switch
1 - Weatherproof switch cover
6 - Receptacle wall outlets

UPDATE: I added an inline fuse between the charge controller LOAD (+) lead and the phone line just in case somebody plugs in too heavy a load.

1 - Inline fuse holder and 3 amp fuse

UPDATE: Due to lots of helpful suggestions (and a few outright warnings) regarding my choice of a 110 volt plug for the power outlet, I decided to add some optional 12 volt outlets to the project.

Step 3: Replace Phone Jacks with Recepticle Outlets

Rather than buy special 12 volt table lamps or rewire existing lamps to plug into a phone jack, I decided to just use my existing ones as they are. So, I wired regular wall outlets into the phone jack boxes and just swapped the AC light bulbs in the lamps with 12 volt bulbs. It turns out you can buy 12 volt LED bulbs with a regular sized (medium) base. Here are a few examples:

http://www.theledlight.com/12volt-led-bulb.html,

http://www.superbrightleds.com/moreinfo/led-spot-f...

http://www.lightexports.com/servlet/the-8423/8W-LE...

I used a 3 watt LED bulb in my testing. It actually gives off an impressive amount of light for such a low wattage bulb. I've ordered some higher wattage bulbs to compare the results.

CAUTION: If you build this Instructable, please remember to always remove the 12 volt bulb before you plug the lamp back into 110 volts.

UPDATE: I added an inline fuse between the charge controller LOAD (+) lead and the phone line just in case somebody plugs in too heavy a load.

UPDATE: Due to lots of helpful suggestions (and a few outright warnings) regarding my choice of a 110 volt plug for the power outlet, I decided to add some optional 12 volt outlets to the project.

Step 4: My Solar Power Source

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I've been experimenting with solar energy for a while now, so I had a couple of 15 watt panels and 12 volt batteries on hand. I decided to use what I had for my initial installation. I may decide to add more panels and/or batteries later to run more stuff.

I bought a 100 watt solar charge controller from Harbor Freight. I'm sure it's not the best controller on the market, but it only cost $25 and seems to work fine for this project. I also bought their cable connection kit, which I used to connect the solar panels to the controller. I also used the 12 volt female barrel cable as a 12 volt outlet for connecting other devices (see below).

I needed a box to hold the batteries, the controller, and all of the wiring connections. So, I bought a 12"x12"x6" PVC junction box from Lowes to do the trick. I wired the solar panels in parallel and the batteries in parallel. So my voltage remains at 12 volts, but my current capacity (charging time) and battery time improve.

While I was adding the indoor lighting, I decided to add an outdoor floodlight and a 12 volt barrel jack to the project as well. The outdoor light was something I've been needing anyway. The 12 volt jack will be great for running other devices during a power outage including phone chargers, fans, and even a plug-in inverter for running 110 volt appliances.

Since the flood light would be situated between the phone box and the control box and also happed to be close to where the solar panels would be located, the flood light box seemed like the perfect place to wire everything together.

So, I ran the thermostat wire from the telephone box, the solar panel wires, and three pair of wires from the control box into the flood light box. I wired the solar panels in parallel and connected them to a single pair of wires feeding down to the control box. Then, I feed the phone box wires and switch leg for the flood light down to the control box using thermostat wire.

In the control box, I wired the batteries in parallel and to the charge controller's BATT connector. Then, I attached the 2-conductor wire from the solar panels to the charge controller's SOLAR connector. And finally, I wired the phone box wires and the switch leg for the flood light to the controller's LOAD connector.

IMPORTANT: Make sure you watch the polarity on these connections as you should always do with DC power.

Also IMPORTANT: I don't know if it's an anomaly or not, but the Harbor Freight charge controller I bought has the polarity backwards on a couple of the connections. Make sure the LEDs light when you connect your batteries and solar panels to ensure proper polarity.

UPDATE: I added an inline fuse between the charge controller LOAD (+) lead and the phone line just in case somebody plugs in too heavy a load.

UPDATE: Due to lots of helpful suggestions (and a few outright warnings) regarding my choice of a 110 volt plug for the power outlet, I decided to add some optional 12 volt outlets to the project. Please see Steps 1 & 3 for details.

Step 5: Testing it out

The outside flood light works great in day or night conditions as you can see from the first two photos. I ordered a higher wattage bulb to use there, but you can see even the little 3 watt bulb puts out a decent amount of light.

The next photo shows my standard table lamp plugged into the 110 volt outlet with a 13 watt CFL bulb. In the last photo, I replaced the bulb with the 12 volt 3 watt LED bulb and plugged the lamp into the 12 volt solar outlet. As you can see, it works great!

CAUTION: If you build this Instructable, please remember to always remove the 12 volt bulb before you plug the lamp back into 110 volts. I almost forgot to do it while taking these photos. That would have been a big mistake!

UPDATE: I added an inline fuse between the charge controller LOAD (+) lead and the phone line just in case somebody plugs in too heavy a load.

UPDATE: Due to lots of helpful suggestions (and a few outright warnings) regarding my choice of a 110 volt plug for the power outlet, I decided to add some optional 12 volt outlets to the project. Please see Steps 1 & 3 for details.

So there's my project. Like most people on the Gulf Coast, I hope we have another mild hurricane season this year. But if we do have a power outage, I'll be more prepared than most!

Plus, since I have this system up and running anyway, I might as well use it now and save a little bit of fossil fuel. So tonight, I'm turning my solar lamps ON and my grid-powered lamps OFF!

emachine566 months ago

Please visually inspect all the phone wires, splices, jacks and junctions you plan to use. There can be anything between 19g to 26g wiring with all kinds of splices in between. Telco premise wiring was never intended to carry more than 1A of current whether ringing @ 90-105VAC or idle with -48 to -52VDC of talk battery (at least in former BellSouth territory).

If the house was wired by someone other than the local Telco then you could have anything. I've seen 28g speaker wire to ROMEX used. This is a neat idea though. Please look carefully at everything and then revise as necessary and fuse everything as low as possible. I'm an old retired Telco guy and believe me, you don't want to bet the house on the quality of the phone wiring to carry anything over 1A, period. Hope this is of some value to all.

mikesoniat (author)  emachine566 months ago

Thank you for that information. I will definitely inspect my wiring more carefully and modify my design as needed.

Ernest126 months ago

I would never use a 120 Volt outlet as a 12 DC volt outlet. Someone is going to plug a 12 volt item into 120 volt ac circuit and cause major problems. Find an appropriate 12 volt DC plug and receptacle, and use it in your house system, and on any auto or boat so you can have options and above all safety. Also, I would use a 12 volt dry automotive battery, instead of those 12 Ahr alarm batteries. By using an automotive battery you have a backup to start a car, boat, or tractor. More options, more safety.

mikesoniat (author)  Ernest126 months ago

Please see my last update where I said:

Due to lots of helpful suggestions (and a few outright warnings)
regarding my choice of a 110 volt plug for the power outlet, I decided
to add some optional 12 volt outlets to the project. Please see Steps 1 & 3 for details.

adamfaal6 months ago

I do not agree with the comment saying that you should install heavier cables just because you might want to add higher load some time in the future. That kind of thinking creates a LOT of waste in the long run. Overloads should be handled by appropriate fusing.

In XP programming it is expressed like this, but applies to other areas as well:

http://www.xprogramming.com/Practices/PracNotNeed.html

KROKKENOSTER6 months ago

I am also playing around with this idea but I want to use the existing 240 lighting wiring and then use led lamps throughout . Here in South Africa we have "Power shedding" sometimes without warning. This will make the effort on wiring a lot simpler. The cost do come down and soon I think this will be standard way of doing!

jtechian6 months ago

As others have said, never use phone wire for power wire. It looks like you actually used bell wire for doorbells etc. , which may carry some power - but still always plan for a future use rather then immediate use. You mentioned possible a 110v inverter, and they can draw several amps (like 10 amp or better when loaded). So plan for the worst loads. Even for your small system you would be better off running 12 gauge or better 10 gauge wire for all the dc lines. I know its over kill now but you may like solar and decide to add more panels etc.

Thanks for the inspiring build and maybe move others to explore the benefits of solar.

mikesoniat (author)  jtechian6 months ago

The inverter will only be plugged in directly to the control box, not running over the phone wires. As I mentioned in the article, I only plan to use very low wattage lights (3 watts or so) in the house. I added a 3 amp fuse just in case I accidentally exceed that.

sb46 months ago

Here is an idea that may be controversial or not -- it would cost more, but maybe a fun challenge too. The idea is step up the voltage from the solar cells to a higher voltage for transmission through the phone wiring, then step it back down at the jack where it is used. This would allow more power transmission, less loss, through your wiring for the same current. DC-to-DC converters might be best to avoid radiating EMI all over the neighborhood, especially depending on the frequency you choose.

Although this works in theory, maybe the safety issues are too extreme. Actually, even the 12 volt system has safety issues in my opinion, since telephone wiring is probably not rated for significant currents and electrical codes for the wiring probably assume low power (not conduit shielded). However, the phone company did supply around 50V DC I think through that wiring (I don't know what power available), so maybe things are AOK at least up to 50V -- just need to keep the power in reason so a short in the walls doesn't burn your house down. Still, I'd be nervous repurposing telephone wiring for power uses in the end.

This is a great help to a project I plan to build. I have a garage 150 feet from any power source other than a portable generator. To just go into the garage and see where I am going especially at night I have to carry a flashlight and then start the generator for power for lighting. This very detailed instructable you have posted is a great solution. Thanks for sharing your ideas.

mikesoniat (author)  InventSomething6 months ago

You're very welcome! And thank YOU for your kind words!

shortw6 months ago

Your phone wire size and the thermostat wire is way to small for a 12 volt DC system and you will lose a lot of volts and amps while you put a load on it. DC does not like to travel far in an way undersized phone wire without losing voltage and amps under load.

What size of fuse are you using now?

The fuse is here to protect the wire, not the light. The size of fuse depends on the size of wire. And the wire size depends on voltage and amps and how many feet the power has to travel.

What about ground ?

And .....you put a ground wire on the solar panel and mounting rails/hardware and pounded a separate ground rod into the ground and connected your devices to the new ground rod?......right?

mikesoniat (author)  shortw6 months ago

I used a 3 amp fuse based on my calculations above (7th paragraph).

Mackramer6 months ago

Great project. Are you worried about the solar panels being ripped off the roof or damaged during the hurricane? Maybe keep them inside until after the storm passes?

mikesoniat (author)  Mackramer6 months ago

Yeah, I actually plan buy or build some brackets to secure them.

Thanks!

calebwang6 months ago

Awesome instructable! Once I own a house I'd love to try something like this.

mikesoniat (author)  calebwang6 months ago

Thank you!

mikesoniat (author) 6 months ago

UPDATE: Due to lots of helpful suggestions (and a few outright
warnings) regarding my choice of a 110 volt plug for the power outlet, I
decided to add some optional 12 volt outlets to the project. Please see Steps 1 & 3 for details.

spiritplumber6 months ago

I love this but I question using the same plug for 12V and 120V... I recommend you use car cigarette lighter plugs if you have them.

mikesoniat (author)  spiritplumber6 months ago

Thanks, I'm also considering PowerPoles.

http://www.powerwerx.com/powerpole-accessories/powerpole-outlet-cover-plate-electrical-box.html

One thing I have done for a project a while ago (Italian 3-prong plugs and sockets) was to connect the two outer prongs together, that being LIVE and NEUTRAL, and call that 12V+, and use the central EARTH prong for 12V-. The two outer prongs were connected together at the plug.

If someone plugged that into 220V, it'd immediately trip a breaker, and the high current would "stay" in the plug, so at worst, the plug would get burned rather than the device.

Just a thought.
carlos66ba6 months ago

I'd hate to be the guest to your home who connects one of your 12 V appliances to a regular 120 V wall socket... You need to definitely change the connectors. This is akin to putting poison in a coca cola bottle :)

Other than that, this is a superb project! Congrats!!

mikesoniat (author)  carlos66ba6 months ago

Thanks, Carlos! I probably won't have too many house guests during a hurricane, but I'm definitely looking at other options for the outlets.

One more suggestion: add fuses right after the batteries. If by any chance a cable shorts this can cause serious trouble (once I saw a car battery + touch the hood of a car, the result was a 1/2" hole in the metal hood).

mikesoniat (author) 6 months ago

UPDATE: I added an inline fuse between the charge controller
LOAD (+) lead and the phone line just in case somebody plugs in too
heavy a load.

wingman3586 months ago

Great project. I commend your ability to avoid going too big too soon. Along the same lines as captainchaoss, I wonder if you could have a separate plug and connector so there would be no chance of putting 115V across the 12V bulb. Perhaps when you bulk up your system you can look into that. It makes me wonder just how little power is required for daily electrical needs, such as lights, range, PC usage, etc. I bet it would be fairly easy to transition almost entirely (say 80%) over to solar power using 12V house-wide circuits. Might be more trouble than its worth converting all the appliances over to 12V though. What goes into stepping 12VDC up to 115VAC?

mikesoniat (author)  wingman3586 months ago

Thank you, WingMan! Yeah, I may be rethinking the 110V outlet in favor of a more standard 12V plug.

captainchaoss6 months ago

Thank you for an excellent Instruct-able ! I'm not at risk of a hurricane, and have a very stable power grid (so far) but have been wanting to do something similar. Your system is a great idea. Tho I have no land lines through my home any longer, it would be easier to run than regular lines.
my question is, rather than using 110 outlets and LEDs with socket bases, could I rig up d/c LEDs that connect in the phone jacks ? Then, no mistakes with plugging in the wrong appliance.

mikesoniat (author)  captainchaoss6 months ago

Thanks, Captain! Yes, that should work fine. In fact, that was my original plan. I later decided to go with the 110 outlets so I wouldn't have to hack my lamps.