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Electronics => Power/Renewable Energy/EV's => Topic started by: DougSpindler on November 25, 2017, 08:54:02 pm

Title: Data logging meter for DC
Post by: DougSpindler on November 25, 2017, 08:54:02 pm
I'm looking for a way to record and plot/graph DC voltage, amperage and wattage over time.   I'd like to monitor the amount of power produces by a solar panel, water wheel (I built) and how much is being consumed in lighting circuits I'm building.

Any suggestions?

Thanks



Title: Re: Data logging meter for DC
Post by: Dragon on November 26, 2017, 10:31:57 pm
The Energy Detective (http://www.theenergydetective.com/) can measure amps and volts on any electrical system and offers a web-based method of looking at graphs.  It also offers a web-based api you can query from whatever you want (I recommend Raspberry Pi Zero W).

Watts is more or less Volts times Amps, though it may differ significantly with lower Power Factors.  TED's main unit reports Watts, Volts, Amps, and Power Factor but I'm not sure how it measures PF.  Its optional "spyder" units don't report PF or Volts, relying on the volts measured by the main unit.
Title: Re: Data logging meter for DC
Post by: DougSpindler on November 27, 2017, 01:38:24 am
The Energy Detective (http://www.theenergydetective.com/) can measure amps and volts on any electrical system and offers a web-based method of looking at graphs.  It also offers a web-based api you can query from whatever you want (I recommend Raspberry Pi Zero W).

Watts is more or less Volts times Amps, though it may differ significantly with lower Power Factors.  TED's main unit reports Watts, Volts, Amps, and Power Factor but I'm not sure how it measures PF.  Its optional "spyder" units don't report PF or Volts, relying on the volts measured by the main unit.

The Energy Detective looks perfect.  Thanks
Title: Re: Data logging meter for DC
Post by: mtdoc on November 27, 2017, 01:43:41 am
The ED uses current transformers to measure AC only current I believe. No DC.
Title: Re: Data logging meter for DC
Post by: DougSpindler on November 27, 2017, 02:41:01 am
The ED uses current transformers to measure AC only current I believe. No DC.

Yes, but I think they said they also measure/monitor solar panel output which would be DC.  (Unless it's after the inverter.) 

http://www.theenergydetective.com/Solar (http://www.theenergydetective.com/Solar)

I see what I will call a mistake on their web page.  They call solar an investment.  Solar is a horrible investment.   A solar system will never increase in value.  It's not an investment at all.  An investment is something which should increase in value over time like real estate, bonds or stocks. 

Solar panels are an asset.  They are something your purchase and own like cars, furniture and appliance.  Assets can be sold for cash and you don't expect them to increase in value.  They are depreciated.

The reason you buy solar is to reduce expenses.  Specifically the amount of money you will pay for electricity in the future.  Electricity is an expense and just part of the cost of living if you want to use electricity.  Buying solar is off-setting future expense of paying for electricity.

 

Title: Re: Data logging meter for DC
Post by: NiHaoMike on November 28, 2017, 05:46:24 am
There's the Mooshimeter, but that's not exactly cheap.
Title: Re: Data logging meter for DC
Post by: DougSpindler on December 03, 2017, 11:46:39 pm
There's the Mooshimeter, but that's not exactly cheap.

I purchased a Mooshimeter.  Looks great. Thanks for the suggestion.