Question about performance monitoring.

OffgridandlovingitOffgridandlovingit Solar Expert Posts: 38
Hi guys. If this has been answered before, please point me in the right direction to find it. I have been reading a lot of the threads about wind power, what works and what doesn't, and I was wondering what you guys would recommend as a good way to get a real idea of the amount of power that my wind turbine is producing. I am sure there is a tool that I can get that would track that information, or a simple method for determining it, but I don't know what that might be, so I was hoping you guys could give me a little advice on it. I know that gusts will affect the reading on my controller, but it doesn't have any way to track the amount of power produced, only to show me the realtime production. Thanks in advance for any advice you may have on the subject.

Comments

  • BB.BB. Super Moderators, Administrators Posts: 29,988 admin
    Re: Question about performance monitoring.

    A Doc Wattson would be great for smaller turbines (around 20-30 amps maximum, I would not put more continuous current through a D.W. meter without modifications).

    A Battery Monitor is great for battery bank current/state of charge monitoring--But not really for wind turbine specifically. Victron is another battery monitor brand that some people here have used with very good results.

    The Pentametric may be the ideal unit for your needs (not cheap, and a bit of work to configure).

    If you want to build your own--This may be a possibility.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • OffgridandlovingitOffgridandlovingit Solar Expert Posts: 38
    Re: Question about performance monitoring.

    Ok, thanks. That helps. I wasn't even sure where to get started in looking for that type of equipment. If you don't mind me picking your brain a bit more, that Doc Wattson one, it's a DC monitor, so I would want to put it on the hot wire for from the DC output of my rectifier/charge controller on the turbine, correct? Mine is 3 phase AC from the turbine into the rectifier and out as DC charging current for my battery bank. So connecting it to the DC out would allow it to monitor what the turbine was putting into the batteries?
  • BB.BB. Super Moderators, Administrators Posts: 29,988 admin
    Re: Question about performance monitoring.
    ... that Doc Wattson one, it's a DC monitor, so I would want to put it on the hot wire for from the DC output of my rectifier/charge controller on the turbine, correct? Mine is 3 phase AC from the turbine into the rectifier and out as DC charging current for my battery bank. So connecting it to the DC out would allow it to monitor what the turbine was putting into the batteries?

    You are correct. the Doc Wattson needs to be in the connection between the rectifier and the battery bank.

    Note, if you have a switch that can short out the wind turbine (to shut it down), make sure the Doc Wattson is on the battery side of that DPDT switch... Otherwise, you will kill the power the the Doc Wattson and possibly send too much current through it while shunting the turbine.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • OffgridandlovingitOffgridandlovingit Solar Expert Posts: 38
    Re: Question about performance monitoring.

    I hate to sound dumb about this stuff, but I don't know, so I have to ask. I want to see how much it is actually putting into my battery bank, so that I can tell if it was actually a good investment or not. Based on the readout from the rectifier, it certainly seems like it will be, but unless I sit there in front of that display and constantly write down numbers as it shows them, then go back and take the average, all I really have is a semi-educated guess based on the state of charge on my battery bank. Hard to quantify that to explain to people that ask if it is worth my while.
  • OffgridandlovingitOffgridandlovingit Solar Expert Posts: 38
    Re: Question about performance monitoring.

    Good to know. Yes, it has a brake switch on the rectifier, but since the unit will be on the DC side of the rectifier, it should not be affected if I read that correctly.
  • BB.BB. Super Moderators, Administrators Posts: 29,988 admin
    Re: Question about performance monitoring.

    That is why you use an Amp*Hour or Watt*Hour meter... These are totalizers. They "count" up as Amp*Hours (and/or Watt*Hours) go from the Turbine to the battery bank...

    I.e., :

    2 amps * 4 hours = 8 Amp*Hours

    If you only had an "amp" meter--you would be looking at it every few minutes and reading 1 amps, 2 amps, 1 amps, 5 amps, etc... And adding the I*Time slices together to get an esitmate AH reading over those 8 hours.

    An Amp*Hour meter does all the logging/reading vs time for you automatically and simply "totals" the current flow (sort of like a gas pump totals the amount of fuel you add to your tank).

    On the other hand a Battery Monitor Adds and Subtracts from the Amp*Hour readings (battery AH reading goes up as it charges, and goes down as it discharges).

    The last thing to think about... A wind turbine (usually) is always connected to the battery bank and outputting its best available current/power... On the battery bank, you will have a "dump load" that, when the battery is full, turns on an electric heater (load bank) to "dump" the excess energy that has nowhere else to go (safely).

    So, in this case, the output from the turbine - the dump load = total useful power...

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • OffgridandlovingitOffgridandlovingit Solar Expert Posts: 38
    Re: Question about performance monitoring.

    Oh ok. So it is like when I figure out my fuel mileage. Miles driven/gallons used= mpg Take the total for the day or the week or month or whatever time I want to use, then divide it by the unit of time I want to figure my output based on and that gives me the average amount of power produced in that unit of time.
  • BB.BB. Super Moderators, Administrators Posts: 29,988 admin
    Re: Question about performance monitoring.

    Pretty much...

    It is very interesting--You can do much of the math here by just watching the units. All units should cancel out (watts, volts, amps, hours, days, etc.) when the equation is complete.

    Similarly, you can look at what you have, and what you want from the equation, and just put in the missing conversion factors to the the answer:

    Miles per gallon (stuff here such as: miles to kM conversion, liters to gallon conv. ,etc) = Liters per 100 KM (used in many metric countries).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • ChrisOlsonChrisOlson Banned Posts: 1,807 ✭✭
    Re: Question about performance monitoring.
    Ok, thanks. That helps. I wasn't even sure where to get started in looking for that type of equipment. If you don't mind me picking your brain a bit more, that Doc Wattson one, it's a DC monitor, so I would want to put it on the hot wire for from the DC output of my rectifier/charge controller on the turbine, correct?

    The Doc Wattson would be perfect for your small turbine, and would not need to be modified with an external shunt. There are several ways to hook up the Doc Wattson and it measures the power on the negative wire of the DC circuit (after the rectifier). I always recommend using the three-wire hookup (shown in the wiring diagrams for it). You only need to hook the source side negative wire of the meter to the output of the rectifier, the load side negative goes to the battery, the positive output from the rectifier can go direct to the battery, and you need to hook the source side positive wire to battery to power the meter's internal circuitry. The load side positive wire is not used.

    With your small turbine the Doc will be very accurate and will display accumulated kWh, amp-hours and peak amps from your turbine, as well as real-time watts output, amp output and battery voltage.

    The Doc Wattson will continue to accumulate kWh and amp-hours produced by your turbine until you reset it by disconnecting the load side positive wire that supplies power to the meter's circuitry. It will accumulate up to (IIRC) 6,999 kWh before it "rolls over" to zero. For many years I would let them accumulate kWh and amp-hours for a month, then write the data in a log and reset the meter for the next month. I have 7 years of logged output data from my wind turbines, most of it logged with Doc Wattson meters. All of my turbines today have Classic 150 controllers, which do much more sophisticated power logging. But for only about 75 bucks for a Doc Wattson there is few meters that can do what they do.
    --
    Chris
  • OffgridandlovingitOffgridandlovingit Solar Expert Posts: 38
    Re: Question about performance monitoring.

    Thanks guys. That is exactly what I would like to do Chris. Document it by the month, keep a log, and be able to say yes it has paid for itself and produces x amount of power, or no it wasn't a good idea, try this instead. I have noticed that many on here make claims that they can't back up, or tend to talk about what they want to try, but very few can show real world numbers for any length of time on what they are trying. That makes me want to document mine that much more. Not really because I want to do it better or whatever, but because I want to be able to show exactly what my results are, to help people make their own decisions.
  • ChrisOlsonChrisOlson Banned Posts: 1,807 ✭✭
    Re: Question about performance monitoring.

    Yes, I think the Doc Wattson would work perfectly for what you want to do. Plus it's kind of fun to log power produced by your system too, especially when you get a year's worth of data where you can go back and see how improvements you have made over time have increased your energy production, or sometimes how weather patterns have affected it.

    For most people who live off-grid and can figure out a way to get a turbine in the air, they pay off quite fast. Generator power is expensive when you have to use one to charge batteries. Battery charging wind turbine is pretty cheap compared to a generator. For somebody who lives on the grid and has one, it's always about dollars and sense. But those of us who live off-grid year 'round know there's more to it than dollars and sense. We have all done it for our individual reasons - none of them based on economics.

    So I'm glad to hear that your wind turbine is working for you. If it only makes 1 kWh/day, for somebody who lives off-grid that 1 kWh can be worth a dollar, where to somebody on-grid it's only worth 15 cents. So that needs to be factored in when you consider how much energy it makes, especially when it makes that energy during the night or during periods of bad weather when solar panels don't work. For an off-grid family that is like a godsend sometimes because you don't have to start the generator.
    --
    Chris
  • OffgridandlovingitOffgridandlovingit Solar Expert Posts: 38
    Re: Question about performance monitoring.

    My meter finally showed up. Will be hooking it into the system this weekend and starting to track exactly how much power this little windmill is being able to produce. Thinking I may want to look into a different blade set, since it is low and small. Looking at a set that will increase the swept area by about 12 inches or so. Not huge, but may make a little difference in the lower winds, giving me more consistent power out of the setup. We will see. This stuff is addictive, and Chris, I absolutely agree. If it were for an on grid system, it probably wouldn't be worth the effort, but as a small supplement on my off-grid system it has been invaluable already. We had over a week of bad weather a few weeks ago, so very little sun, but it was pretty windy for a lot of it and my batteries actually stayed up close to 80% most of that week thanks to the storms. Admittedly, not day in and day out power production, but paid off beautifully when I needed it most.
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