runway lights

Help please, with a solar powered runway lighting system. I live at a rural residential airport community and we would like to run our runway lights with solar. We have 24, 10 watt lights installed. (doesn't seem like they'd be bright enough but they are) A check with an amp probe stye amp meter shows 1.8 amps @ 118v to light em up. I doubt they would be used more than an hour per week but in the unlikely event they may be used 2 hours per day or rather night, what component sizes would I need for the system. Located in the desert southwest, Mojave Ca. to be exact so sunshine and wind are both abundant. Thank You you in advance.

Comments

  • nielniel Solar Expert Posts: 10,300 ✭✭✭✭
    runway lights

    in solar powering this you have 2 options here.

    1 go with 12v lights and run straight from the battery. this would normally be recommended by me, but in your case i'll say no because of the long wire runs creating voltage drops to your lights and because of the replacement of all of your lights.

    2 go with an inverter of about 300w and have any decent deep cycle battery and charge it up with a pv or 2. this keeps your original lighting system intact and keeps voltage losses from occuring to the lights due to low voltage. the drawback would be the efficiency loss created in using the inverter. because the inverter also uses power when not running the lights you should switch it off at the inverter by turning the inverter off. 300w inverters are common and fairly cheap cost-wise as are marine batteries. the cost of the pv(s), mount(s), and controller are another matter for you as this would be much more costly to you than the battery and inverter. luckilly you don't need anything top of the line to do this, but you should have at least current output from the pvs to equal 3% or more of the battery amp/hr capacity. if you will use the lights sparingly you may go slightly less than 3% of the battery capacity, but don't go below 2% as at 2% it will take at least 25hrs to charge up the battery from a 50%(dod) deleted point. 25hrs of full sun would be needed to do that and that's quite a few days not counting cloudy days.
    niel
  • System2System2 Posts: 6,290 admin
    runway lights

    I believe most small airports have a system where the pilot can turn on the runway lights remotely by clicking the microphone 5 times in a row. If this is the case then one system will have to power all of the lights, which is very a long wire run. Or if your thinking of using an independant power source at each light source then a solar cell/battery setup would be needed at each light that turns on a DC light when it gets dark and would stay on all night. You may want to investigate the new Luxeon 1 Watt LED's for this application.

    http://www.theledlight.com/luxeonled_drivers.html
  • crewzercrewzer Registered Users, Solar Expert Posts: 1,832 ✭✭✭✭
    runway lights
    we would like to run our runway lights with solar. We have 24, 10 watt lights installed. (doesn't seem like they'd be bright enough but they are) A check with an amp probe stye amp meter shows 1.8 amps @ 118v to light em up. I doubt they would be used more than an hour per week but in the unlikely event they may be used 2 hours per day or rather night, what component sizes would I need for the system. Located in the desert southwest, Mojave Ca.
    You may have an ideal application for solar energy: Harvest energy during the day with no loads, and then run your loads at night. Your location poses special advantages (lots of sun and little shade) as well as special challenges, and I’ll attempt to address these latter concerns as well.

    Assuming 1.8 A @ 118 VAC, a power factor of 1 (lights are a mostly resistive load) and 1 hour per day (somewhere between one hour per week and extreme occasional requirement of 2 hours per day) of ON time, your maximum daily energy requirement will be 1.8 A x 118 VAC x 1 x 1 hour = 212.4 Whrs / day – slightly lower than 24 lights at 10 W apiece would suggest.

    Assuming 80% battery power charging efficiency and 90% inverter efficiency, your solar energy system will need to generate 212.4 Whrs / (80% x 90%) = 295 Whrs / day.

    Average daily solar radiation collected in December by fixed south-facing PV modules tilted up at latitude plus 15 degrees (50 degrees total) in nearby Daggett, CA, is 5.6 hours per day :shock: Some days will be better, some will be worse. See the following link for Daggett (east of Mojave) solar radiation info: http://rredc.nrel.gov/solar/old_data/nsrdb/redbook/sum2/23161.txt

    Assuming an 85% conversion factor from STC ratings to PTC ratings, your PV array will need to be rated for 295 Whrs / (5.6 hours x 85%) = 62 W. I’d recommend the Shell PowerMax Ultra 85-P PV module for your application. Its 85W rating will make up for other system inefficiencies and, since PV module output voltage drops as the module temperature rises, its high Vmp spec (17.2 V) would be useful in your hot location. It doesn’t cost much more than other 65 W or 70 W modules.

    See: http://store.solar-electric.com/shulsoelpa.html
    And: http://www.shell.com/static/shellsolar/downloads/products/pil_offgrid_12v_us.pdf

    Your lights would require 212.4 W / 90% = 236 W from that battery via an inverter. Running the lights for an average of one hour per night, that would be ~20 Ah from a 12 V battery. Allowing for 3 days of autonomy (essentially no sun) and limiting your battery discharge to 50%, you'll need a 12 V deep-cycle battery rated for (20 Ah / day) x (3 days / 50%) = 120 Ah.

    The Walmart (Exide) Everstart model 27DC-6 battery is rated for 115 Ah and is readily available.

    The temperature ranges experienced in Mojave (97 F avg hi in July, 33 F avg lo in Dec.; 112 F record hi in June, -5 F record lo in March) present a special environmental challenge. You’ll need to find a location for the battery to protect it from hot- and cold temperature extremes.

    Battery performance specifications are based on a battery temperature of 77 degrees F, and charging voltages must be adjusted for battery temperature variations. You’ll need a good charge controller with a remote battery temperature sensor (RTS or BTS) -- usually an option. I recommend the Morningstar PS-30M controller with its optional BTS for your application.

    See: http://store.solar-electric.com/ps-30m.html
    And: http://www.morningstarcorp.com/products/ProStar/index.shtml

    Your intended lighting load will allow you to use a modified sine wave (MSW) inverter to convert the battery DC into 120 VAC for the lights. The Xantrex ProWatt 400 would be about the right size, and it’s cooled by an internal fan.

    See: http://www.xantrex.com/web/id/16/p/53/pt/29/product.asp

    These are the basics. This system should meet the load requirement described in the winter, and it will exceed the summer requirement. Don't forget fuses for the PV modules, battery, inverter and lights.

    Some other issues to consider are the wire type and size between the inverter and the lights, as you’ll want to minimize power loss in that cable. Also, if you haven’t already done so, you may need to research FAA- and/or state- and/or local requirements for system design, documentation, training, operation, performance, maintenance, reliability, back-up and certification.

    HTH,
    Jim / crewer
  • BrockBrock Solar Expert Posts: 633 ✭✭✭✭
    runway lights

    What Jim said ;)

    How do they turn on and off? I have also heard of them being set to come on with pulses on certain frequencies. If this is the case you might have another load running 24/7. Likely it is a small one but being on all the time will add up.
    3kw solar PV, 8 L16's, xw 5548, Honda eu2000i, iota DLS-54-13, Leaf EV, 4 ton horizontal geothermal, grid tied - Green Bay, WI
  • System2System2 Posts: 6,290 admin
    runway lights

    Yes, we have a unit that will detect 5 clicks of the mic key on our airport communication frequency (122.9). This will turn on the lights for 10 minutes and then lights will blink 3 times as a warning that in one minute the lights will turn off. I did not consider the idle current draw of this pilot operated controller. It is solid state and likely draws little current but I will have to look into it. I was intending to install a daylight sensor so that inverter, controller and lighting will work during daylight hours. I suppose if that current draw is still too much I could limit the night time hours of operation?
  • BrockBrock Solar Expert Posts: 633 ✭✭✭✭
    runway lights

    I don't know I wouldn't add a sensor or limit the times because who know what weather you might get and you might want them on in the middle of the day for some odd reason. Also if you add a sensor you add another thing to go wrong. I would just overestimate the power needed and leave it setup up the way it is, just run from an inverter.

    The catch with a small load running 24/7 though is most inverters draw power once they are on. So say you have a 10w load, the inverter might consume 10w to be on, so now you have a 20w load 24/7. Of course if you have a 500w load and additional 10w isn't much, but for small loads it is a lot. Could the receiver be powered at 12vdc or 24vdc?

    I think this setup is perfect for a solar application and if you figure it all out I hope it catches on.
    3kw solar PV, 8 L16's, xw 5548, Honda eu2000i, iota DLS-54-13, Leaf EV, 4 ton horizontal geothermal, grid tied - Green Bay, WI
  • AFWnSAFWnS Solar Expert Posts: 13
    Mic Key Switch

    Could you give me the make & model of the Mic Key switching unit, our local aero club has been looking for such a unit. Thanks,
  • System2System2 Posts: 6,290 admin
    runway lights

    AFWnS
    Could you give me the make & model of the Mic Key switching unit, our local aero club has been looking for such a unit.


    Here's one : http://www.mentorradio.com/m15rcu.php

    Cheers,

    Bad Apple
  • System2System2 Posts: 6,290 admin
    Re: Mic Key Switch
    AFWnS wrote:
    Could you give me the make & model of the Mic Key switching unit, our local aero club has been looking for such a unit. Thanks,

    Our pilot controlled lighting unit was purchased from Wag Aero.
    www.wagaero.com
    Fly-By-Night Switch part # B-125-101 ........ $495.00
  • System2System2 Posts: 6,290 admin
    runway lights
    Brock wrote:
    I don't know I wouldn't add a sensor or limit the times because who know what weather you might get and you might want them on in the middle of the day for some odd reason. Also if you add a sensor you add another thing to go wrong. I would just overestimate the power needed and leave it setup up the way it is, just run from an inverter.

    The catch with a small load running 24/7 though is most inverters draw power once they are on. So say you have a 10w load, the inverter might consume 10w to be on, so now you have a 20w load 24/7. Of course if you have a 500w load and additional 10w isn't much, but for small loads it is a lot. Could the receiver be powered at 12vdc or 24vdc?

    I think this setup is perfect for a solar application and if you figure it all out I hope it catches on.


    Hello, the pilot controlled lighting unit draws 75ma to 200ma @13.7 volts depending on external speaker volume. We were not intending on using a speaker. I think the power draw would be fairly insignificant especially if only turned on during night time hours? I am wondering about inverter warm up though? Seems like the one I used to have has a "warm up" time. 2 minutes or something? Does the inverter draw a load at idle? Would it need to be on all the time?
    I had figured on having a light sensor turn on the controller/reciever at dusk and it in turn would power up the inverter already connected to the lights when called for. Maybe the inverter should be on all the time and the lights turned on and off? Yes, that's probably how it will need to work?
  • BrockBrock Solar Expert Posts: 633 ✭✭✭✭
    runway lights

    Since the receiver is basically a 12v unit I would power it directly from the batteries and let the inverter "sleep" until it sees the lights come on. To power the receiver from 120vac via the inverter would likely use about 500mA due to inverter idle consumption to keep the wall wart powered. You should be able to power the receiver directly from the battery bank being charged from the solar panels and then run the inverter to power the runway lights. Most inverters come on rather quickly now, like within a second anyway.
    3kw solar PV, 8 L16's, xw 5548, Honda eu2000i, iota DLS-54-13, Leaf EV, 4 ton horizontal geothermal, grid tied - Green Bay, WI
  • kc8adukc8adu Solar Expert Posts: 48 ✭✭✭
    Re: runway lights

    why not use the controll output from the radio switch to turn on the inverter directly?
    no idle losses other than the radio switch.
    75ma is nothing.
  • System2System2 Posts: 6,290 admin
    Re: runway lights

    UPDATE:
    We have purchased and installed a Kyrocera 80 watt PV, A "SunLight" SL-10 lighting controller, 2ea. 120 AH deep cycle marine batteries from Walmart, an 800w continous Coleman inverter in addition to the pilot controlled "Fly by Night" reciever/ lighting controller. Ultimately powering our 26, 10 watt each, runway lights.
      I must say that this installation has been a disaster initially. Figuring the use and install would be simple, straight forward, and reliable. We kept blowing the internal fuses in the inverter time and time again. We wired and rewired and up wired and down wired and checked for grounds and shorts, added grounds and basically fought several frustrating days off and on. Getting angry, careless and frustrated with it all. Finally I decided to hook up an old crappy tempermental 300 watt inverter that narrowly escaped being thrown in the trash years ago. Now everything worked fine. No more blown fuses. Lights finally working. Yippie! All our problem have basically been in the new inverter. I don't know why. You can hook it up to loads even greater than our lights and it would run them without a problem.
      Now the trouble is that in the interim of wiring rewiring trying this and doing that to no avail, I managed to short a ground wire in the pilot controlled lighting box harness. A new harness was fabricated with all new wires and connector. Tried, tested and proven with no apparent damage to the reciever. Only now, a day or two later, the reciever no longer works. It's volume slowly began to diminish until it can't be heard and no longer seems to work at all. I'll be sending it back for repair and only hope they have mercy on me and will fix it with out a huge expense?
      To answer the previous question, the Sunlight charge controller turns on the pilot conrolled reciever at dusk
    (off at dawn) which in turn operates a 12 volt auto type relay when called for with 3 clicks on the mic of the aircraft radio tuned to the proper frequency which turns on the inverter which then powers the runway lights.
  • crewzercrewzer Registered Users, Solar Expert Posts: 1,832 ✭✭✭✭
    Re: runway lights
    ...the reciever no longer works. It's volume slowly began to diminish until it can't be heard and no longer seems to work at all...

    Flyby,

    It's possible the batteries are drained and not being recharged, and the receiver might be OK.

    The energy requirements for the receiver and the relay were not specified as a requirement in your original post, so I didn't include them in my calculations. It's possible that PV system's energy production is not keeping up with demand, and that would slowly drain the battery, which may be the cause of the receiver's gradually reduced volume.

    The PV module's output rating is ~4.7 A. That's a high enough rate to charge a single 120 Ah battery during the day, but it's barely above float charge for a couple of 120 Ah (240 Ah total) batteries.

    What's the battery bank's voltage early in the morning? Also, how much current is drawn by the receiver and the relay?

    HTH,
    Jim / crewzer
  • System2System2 Posts: 6,290 admin
    Re: runway lights




    What's the battery bank's voltage early in the morning? Also, how much current is drawn by the receiver and the relay?

    HTH,
    Jim / crewzer

    The radio reciever/light controller is turned on at night only and draws 70ma when idle and works on 13.2volts plus or minus 20% as I recall. The unit being idle 99.9% of the time. The paperwork says 70 to 200ma depending on speaker volume. The relay draws less than 50ma when engaged I would guess as that is the max allowable by the reciever specs but I did not measure it.
    We have only had one battery hooked up thus far as the battery housing part of the installation has not been completed. We were in a test phase I suppose you could say. Anyhow the voltage at the battery after most of a full day of charging followed by a night consisting of perhaps an hour or more of lighting use was 12.97 volts. A drained battery does not seem to be the issue with the radio. Besides, the system can not be drained past 50% capacity according to the "SunLight Solar Lighting Controller" nomenclature. It will turn off the "load" at that point with the LVD feature.
  • crewzercrewzer Registered Users, Solar Expert Posts: 1,832 ✭✭✭✭
    Re: runway lights

    Flyby,
    ...  We have only had one battery hooked up thus far...
    Sounds good!
    ...the voltage at the battery ... was 12.97 volts. A drained battery does not seem to be the issue with the radio...
    I agree... good luck with the receiver repair.

    Regards,
    Jim / crewzer
  • System2System2 Posts: 6,290 admin
    Re: runway lights

       OK,  Back again after about a year now. After checking battery condition and doing a cursory inspection just a few minutes ago, I decided to log on to this forum and do an update after a year has passed since the Solar powered runway light installation.
       The radio receiver was repaired at considerable expense and reinstalled. Everything is or rather has been working fantastic for about a year now. I would like to thank anyone and everyone who helped with their comments, suggestion and even questions. After some initial stumbles, all has turned out to be a raging success. It even passed Kern Co. CA Building Dept. muster to boot. (I didn't want to shoulder the liability of some oversight or failure so I went against my usual instincts and obtained a permit from the county)
      Thanks to Northern Arizona Wind and Sun for this forum and their help. I felt they gave me good advise and a good deal on all solar materials needed.
       I would like to be energy self sufficient someday and know where I can turn for help.
       Anyone who desires a photo of the installation can contact me but do it soon cause I'll be changing this address in the near future.   [email protected]
  • nielniel Solar Expert Posts: 10,300 ✭✭✭✭
    Re: runway lights

    good deal flyby and i'm glad we were able to help in this unique circumstance. maybe wind-sun would be interested in putting this into their archive of pics.
  • crewzercrewzer Registered Users, Solar Expert Posts: 1,832 ✭✭✭✭
    Re: runway lights

    8-) Congratulations on your system, and thanks for the report!

    Regards,
    Jim / crewzer
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