kWh måler til DC

Til min remote station har jeg brug for at kende forbruget i kWh gennem en periode, fx. en måned eller et år.

Energien kommer fra solpaneler og en vindgenerator, og strømforsyningen til udstyret er maks. 50 A @13,8 V DC.

Jeg har søgt her og der på nettet men forgæves. Hvor finder jeg en DC kWh måler til en pris, der er til at betale? Gerne til DIN-skinne montering.

Vy 73 de oZ8ZY Jørgen

Svar til #1:

https://www.aliexpress.com/item/1005001967965453 .html?spm=a2g0o.search0302.0.0.6c0564beA JzcbR&algo_pvid=f894e352-0526-4588-96d3- 679714fc6f20&algo_expid=f894e352-0526-45 88-96d3-679714fc6f20-13&btsid=0bb0623d16 152972153258519e3f8c&ws_ab_test=searchwe b0_0,searchweb201602_,searchweb201603_

Svar til #2:

Tak for input.

Så vidt jeg kan se, kan denne kWh måler ikke vise det akkumulerede forbrug i kWh - sådan som en gammeldags Faraday vekselstrømsmåler kan. Det sidste er, hvad jeg har brug for.

Vy 73 de OZ8ZY Jørgen

Svar til #3:

Eller evt denne her
https://www.ebay.com/itm/Display-LCD-Misuratore- Monitor-Batteria-Amperometro-Voltmetro-P er-Auto-RV-Solar/233354554366

Svar til #1:

Kig på:

LCD Solarcontroller
20A/200A Version V1.40:
http://www.icplan.de/seite19.htm
20A Solarcontroller mit LCD Multifunktionsdisplay und ATMEGA8
http://www.icplan.de/solar.pdf

GPL Ah - ægte GDS/DIY med utydelig håndtegning og assembler kildekode:
A Microchip 16F690 PIC as universal PWM controller for power supply applications:
http://panteltje.com/panteltje/pic/pwr_pic/
Citat: "...
For this reason the current measurement for the LCD is connected to ground, have not decided yet to either use a shunt and an opamp, or use a Hall effect based module to sense current.
...
You can set the output voltage via RS232 with command 'U' in this version, it uses the internal on chip reference divider, with the correct resistor values 0-15 will result in about 0-15 volt.
...
The asm file for a PIC 16F690, plus wiring instructions for the PIC are included in the asm source:
...
Here is a simple terminal program (Linux) that by default will work with power_pic, and also can be called from a script:
..."

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(Næsten) resistansløs DC-sensor:

ACS770ECB-200U-PFF-T. Pris ca. 7-8 euro.
SENSOR CURRENT HALL 200A DC:
https://www.digikey.com/en/products/detail/alleg ro-microsystems/ACS770ECB-200U-PFF-T/447 3976
Datablad:
https://www.allegromicro.com/~/media/Files/Datas heets/ACS770-Datasheet.pdf
Citat: "...
120 kHz typical bandwidth
...
Ultralow power loss: 100 uohm internal conductor resistance
Galvanic isolation allows use in economical, high-side
current sensing in high-voltage systems
4.5 to 5.5 V, single supply operation
Output voltage proportional to AC or DC currents
...
Working Voltage for Basic Isolation: 700VAC
..."

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Kan springes over:

Man har også lavet solceller, der virker på skyfri nætter (og om dagen - men uden sollys!). De kaldes anti-solceller:
https://da.wikipedia.org/wiki/Anti-solcelle

Kilder:

January 30, 2020, scitechdaily.com: Anti-Solar Cells: Thermoradiative Photovoltaic Cells Work:
https://scitechdaily.com/anti-solar-cells-thermo radiative-photovoltaic-cells-work-at-nig ht/
Citat: "...What if solar cells worked at night? That’s no joke, according to Jeremy Munday, professor in the Department of Electrical and Computer Engineering at UC Davis. In fact, a specially designed photovoltaic cell could generate up to 50 watts of power per square meter under ideal conditions at night, about a quarter of what a conventional solar panel can generate in daytime, according to a concept paper by Munday and graduate student Tristan Deppe. The article was published in, and featured on the cover of, the January 2020 issue of ACS Photonics...The device would work during the day as well, if you took steps to either block direct sunlight or pointed it away from the sun. Because this new type of solar cell could potentially operate around the clock, it is an intriguing option to balance the power grid over the day-night cycle..."
https://doi.org/10.1021/acsphotonics.9b00679

Feb 3, 2020, popularmechanics.com: How Reverse Solar Panels Could Generate Power at Night. It's called "optically coupling with deep space.":
https://www.popularmechanics.com/science/a307533 26/reverse-solar-panels/
Citat: "...In a thermal radiation cell, we reset the parameters so Earth is the new sun, and its even minimal accumulated heat dwarfs the cold, midnight black of outer space..."

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Ifølge denne artikel kan man køle op til 10°C om dagen og natten i forhold til omgivelsestemperaturen ved skyfri himmel:

May. 23, 2019, sciencemag.org: This engineered wood radiates heat into space, potentially slashing cooling costs:
https://www.sciencemag.org/news/2019/05/engineer ed-wood-radiates-heat-space-potentially- slashing-cooling-costs
Citat: "..."...If used on a building’s exterior, such as in siding and roofs, the material could drop a building’s temperature as much as 10°C and reduce cooling costs as much as 60%...But in the past 2 years, researchers have devised plastic films and paints that absorb heat and re-emit that energy at longer mid-IR wavelengths, which air doesn’t absorb. If emitted toward the sky, these photons pass unimpeded and dump their energy into deep space. But to use these materials in buildings, engineers need to laminate rooftop or siding materials with the plastics or apply the heat-emitting paints...The researchers hit upon a simple chemical procedure. They soaked basswood in a solution of hydrogen peroxide, which chops normally long lignin molecules into small fragments...it turns white, reflecting virtually all incoming light. The new composite also absorbs heat from its surroundings and reradiates it as mid-IR light. That allows the material to cool surfaces to which it is attached by up to 10°C..."

.

Rekord år 2021:

Man kan køle op til 12°C (14°C i et laboratorium) om dagen og natten i forhold til omgivelsestemperaturen ved skyfri himmel:

March 6, 2021, Radiative Cooling and Solar Heating From One System – No Electricity Needed.
Study describes passive cooling system that aims to help impoverished communities, reduce cooling and heating costs, lower CO2 emissions.
https://scitechdaily.com/radiative-cooling-and-s olar-heating-from-one-system-no-electric ity-needed/
Citat: "...
A study published on February 8, 2021, in the journal Cell Reports Physical Science describes a uniquely designed radiative cooling system that:
* Lowered the temperature inside a test system in an outdoor environment under direct sunlight by more than 12 degrees Celsius (22 degrees Fahrenheit).
* Lowered the temperature of the test box in a laboratory, meant to simulate the night, by more than 14 degrees Celsius (25 degrees Fahrenheit).
* Simultaneously captured enough solar power that can be used to heat water to about 60 degrees Celsius (140 degrees Fahrenheit).
While the system tested was only 70 centimeters (27.5 inches) squared, it could eventually be scaled up to cover rooftops, engineers say, with the goal of reducing society’s reliance on fossil fuels for cooling and heating. It also could aid communities with limited access to electricity.
...
The system consists of what are essentially two mirrors, made of 10 extremely thin layers of silver and silicon dioxide, which are placed in a V-shape.
These mirrors absorb incoming sunlight, turning solar power from visible and near-infrared waves into heat. The mirrors also reflect mid-infrared waves from an “emitter” (a vertical box in between the two mirrors), which then bounces the heat they carry into the sky.
“Since the thermal emission from both surfaces of the central thermal emitter is reflected to the sky, the local cooling power density on this emitter is doubled, resulting in a record high temperature reduction,” says Gan.
...
“Importantly, our system does not simply waste the solar input energy. Instead, the solar energy is absorbed by the solar spectral selective mirrors, and it can be used for solar water heating, which is widely used as an energy efficient device in developing countries,” says Gan. “It can retain both the solar heating and radiative cooling effects in a single system with no need of electricity. It’s really sort of a ‘magic’ system of ice and fire.”
...
The work was supported by funding from the U.S. National Science Foundation’s Thermal Transport Processes program.
..."
https://doi.org/10.1016/j.xcrp.2021.100338

Svar til #3:
Det nederste display er da i Wh som er det akkumulerede forbrug ( energien )
Frank

Svar til #6:

Det har jeg noteret, men jeg kan ikke se, at starttidspunktet kan indtastes?

I øvrigt er metret så billigt, at jeg nok køber det...

Vy 73 de OZ8ZY Jørgen

Svar til #7:
Hej Jørgen,

det kan du jo heller ikke på en Ferrarismåler som du jo efterlyste funktionen på.
Har du brug for en bestemt måleperiode kan du sætte et tænd/sluk ur til at koble den ind og ud i den ønskede periode.
Hilsen
Frank

Svar til #4:

Hej Jørgen

Tak for henvisningen. Det ser ud til, at jeg kan bruge dette meter, så nu har jeg bestilt 2 stk.

Vy 73 de OZ8ZY Jørgen

PS: Det er snart mange år siden, jeg interviewede dig til Aktuel Elektronik....