D H Solar Tracking systems ?

Is anyone familiar with the D H Solar tracking systems

link here

http://dhsolar.net/dh_solar_003.htm

Attachment not found.

They claim up to 40% more than fixed -- this seems a bit optimistic but I wonder what real world increases would be


they do seem a bit pricey but I have seen a number of them in WI up close and they are built very heavy duty

they use a kind of unique method to track the sun not using light sensors -- instead it runs off of a timer device

any input would be helpful before I look into them further

Comments

  • BB.
    BB. Super Moderators, Administrators Posts: 33,613 admin
    Re: D H Solar Tracking systems ?

    PV Watts has a zero, one, and two axis calculation. Pick the location closest to you and see what the results are between zero and two axis tracking.

    As a start, use the default derating of 0.77 for a grid tied system and 0.52 for an off grid battery/inverter based system (depending on battery and inverter options, you could get upwards of 0.62 derating).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • WillWinston
    WillWinston Solar Expert Posts: 45
    Re: D H Solar Tracking systems ?

    BB

    That calculator seems to indicate about a 30% increase in power over a year's time in SW Wisconsin for a 2 axis and 20% for a single axis tracker versus a fixed panel

    this is indeed significant but the cost of the DH tracker is about $20,000 (after tax credit) -- at today's panel prices that would buy a lot of fixed panel watts

    They advertise a 4 KW system for $28,000 (with panels) ($20,000 with Fed rebate-- is this still on for 2012 ?)

    Street price of 4 KW panels at $2/watt equals $8000

    bump this to 6 KW (50% increase) of panels @ $2/watt equals $12,000

    still cheaper than $20,000 with more output

    These are the results from the PV site (thanks for that link BTW)

    fixed tilt for 4 KW panels ~5000 KWHr/yr

    fixed tilt for 6 KW panels ~ 7400 KWHr/Yr

    2 axis tracker 4 KW panels ~ 6500 KWHr/Yr



    It would seem that this tracker would never make economic sense at todays panel prices

    There would also be some cost for fixed mounts and maybe additional charge controllers --estimate $2000 but still cheaper than $20 or $28 K

    Am I missing something
  • BB.
    BB. Super Moderators, Administrators Posts: 33,613 admin
    Re: D H Solar Tracking systems ?

    Dave Sparks (an off grid installer in the California Sierra Nevada Mountains) really likes trackers because it gives more hours per day to recharge the battery bank... His experience is a slower/longer charge rate can help the battery bank last longer than high current/fewer hours per day.

    But--yes, trackers are expensive relative to more fixed panels.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • WillWinston
    WillWinston Solar Expert Posts: 45
    Re: D H Solar Tracking systems ?

    Well, that makes sense about the batteries but....


    $5 to 10K will buy lots of batteries too
  • WillWinston
    WillWinston Solar Expert Posts: 45
    Re: D H Solar Tracking systems ?

    A follow up

    I went by a 40 panel DH yesterday and stopped to see how it was handling the wind storm -- 25 mph gusts to 35 mph yesterday

    I did hear a couple creeks (I was standing under it) but it seemed unfazed
  • Dave Angelini
    Dave Angelini Solar Expert Posts: 6,894 ✭✭✭✭✭✭
    Re: D H Solar Tracking systems ?
    BB. wrote: »
    Dave Sparks (an off grid installer in the California Sierra Nevada Mountains) really like trackers because it gives more hours per day to recharge the battery bank... His experience is a slower/longer charge rate can help the battery bank last longer than high current/fewer hours per day.

    But--yes, trackers are expensive relative to more fixed panels.

    -Bill

    Hey Bill ! Is Tommy's Joint on 19th avenue still open?

    The hours are really what matters. I can arrive home at 6: 30 PM and get 2KW out of my 3KW arrays and heat or cool the house. ( We were heating yesterday... Damn weather) Heat pumps and water transfer offgrid really make the case for tracking. You do not have to have the array turn to track. With solar so inexpensive why spin them? They are a beautiful thing to watch though. I have kids from the Mariposa schools up looking at them. There are some nice Youtubes on the Wattsun array technology site. They are making a new utility tracker that I have used. It is a 90 degree affair that is cheap and really low to the ground.

    Still, watching a dual axis go 260 degrees is pretty cool ! And having it point to the sun that one hour when a winter storm cloud clears is incredible.
    "we go where power lines don't" Sierra Nevada mountain area
       htps://offgridsolar1.com/
    E-mail offgridsolar@sti.net

  • BB.
    BB. Super Moderators, Administrators Posts: 33,613 admin
    Re: D H Solar Tracking systems ?

    Hi Dave,

    Tommy's Joynt is on Geary and Van Ness (at least the one I am aware of). Google/website says it is still there and looks the same as the one time I ate there around 1978 (across the street from the old Mark Hopkins/Cathedral Hill hotel).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • Dave Angelini
    Dave Angelini Solar Expert Posts: 6,894 ✭✭✭✭✭✭
    Re: D H Solar Tracking systems ?

    That is right, near the old "Elis Brooks today for a Chevrolet" On Van Ness. I think I ate the Buffalo Stew there. Glad that somethings do not change! Thanks!
    "we go where power lines don't" Sierra Nevada mountain area
       htps://offgridsolar1.com/
    E-mail offgridsolar@sti.net

  • WillWinston
    WillWinston Solar Expert Posts: 45
    Re: D H Solar Tracking systems ?

    Uhmm is this what they call thread drift ;)



    anyway at what price would a tracker be 'worth it' for say (twelve 210 watt) 2.5 KW of panel at $2.0 per watt


    let's see if this makes sense


    Assume 30% increase in power for a 2 axis tracker (conservative estimate from the PV WATT website)


    30% X 2.5 KW = 750 watts

    750 watts X $2 = $1500

    so does this make sense for a 'break even' cost at todays panel street prices ? a $1500 tracker


    @ 40 % increase it pencils out to a $2000 tracker cost


    a long, long ways from $20,000 after rebate for a DH, I think
  • niel
    niel Solar Expert Posts: 10,300 ✭✭✭✭
    Re: D H Solar Tracking systems ?

    the drawback with trackers is that because they move they break down. if this wasn't a factor then i'd say it would be pretty even.
  • Volvo Farmer
    Volvo Farmer Solar Expert Posts: 209 ✭✭✭✭✭
    Re: D H Solar Tracking systems ?

    But if a tracker breaks, only the additional power it made is lost. All the power from a stationary array is still available. Now if your wind turbine breaks..... :)
  • Dave Angelini
    Dave Angelini Solar Expert Posts: 6,894 ✭✭✭✭✭✭
    Re: D H Solar Tracking systems ?
    BB

    That
    There would also be some cost for fixed mounts and maybe additional charge controllers --estimate $2000 but still cheaper than $20 or $28 K

    Am I missing something

    If you are talking about grid-tie or utility you are missing nothing. If you are talking about offgrid it is not the increase in harvest as much as the increase in hours of power. Right now about 6 am to 8PM to pump water, condition space, or just to have more hours when you are off the battery. In winter offgrid, in a reasonable location, an array that tracks is will enable you to never have to run a generator to charge batteries.

    A tracker that I use is about 3K$ and a fixed array is about 1.8K$. They don't break, they need a squirt of grease every year, they are
    the key to long battery life.
    "we go where power lines don't" Sierra Nevada mountain area
       htps://offgridsolar1.com/
    E-mail offgridsolar@sti.net

  • WillWinston
    WillWinston Solar Expert Posts: 45
    Re: D H Solar Tracking systems ?
    If you are talking about grid-tie or utility you are missing nothing. If you are talking about offgrid it is not the increase in harvest as much as the increase in hours of power. Right now about 6 am to 8PM to pump water, condition space, or just to have more hours when you are off the battery. In winter offgrid, in a reasonable location, an array that tracks is will enable you to never have to run a generator to charge batteries.

    A tracker that I use is about 3K$ and a fixed array is about 1.8K$. They don't break, they need a squirt of grease every year, they are
    the key to long battery life.


    What tracker is $3 K and how many KW of panel does it have

    $1.8 K for fixed seems high unless you are talking pole mount -- if you have the real estate a purpose built wood or steel mount on the ground would be much less than $1.8 K for 10 to 15 panels
  • Dave Angelini
    Dave Angelini Solar Expert Posts: 6,894 ✭✭✭✭✭✭
    Re: D H Solar Tracking systems ?

    Well what you are saying is to compare apples and oranges. I can't do that. I like to help here sometimes. Good Luck!
    "we go where power lines don't" Sierra Nevada mountain area
       htps://offgridsolar1.com/
    E-mail offgridsolar@sti.net