How Much Power Does A 250 Watt Solar Panel Produce?

A 250-watt solar panel will produce 1000 watts or 1kWh of power with 5 hours of peak sunlight and 1.4kWh in a whole day. The output will vary from location to location (because of the no. of peak sun hours) and the title angle of your solar panels

This is the average number that you can expect from your solar panel if it's a sunny day, but on some days you will receive more power output, and on some days less than 1kWh.

So keep reading and I'll explain the factors in detail which will determine the output of your solar panels

250-watt solar panel specifications

12V 250W solar panel specs
  • Maximum power at STC (Pmax): 250
  • Maximum voltage (Vmp): 18V
  • Maximum current (Imp): 13.89A
  • Open circuit voltage (Voc): 24.1
  • Short circuit current (Isc): 10.3
  • Module efficiency (%): 15.5
  • Operating temperature: -40 °C ~ +90 °C
  • Maximum system voltage: 1000V
  • Power tolerance: +3%

How to read solar panel specifications

Ideal title angle for solar panels

in winter add 15 degrees to your latitude and subtract 15 degrees from the latitude in the summer to calculate the ideal title angle for your solar panel

Tilt angle is the angle formed between a horizontal plane and the pitch of a solar panel

Or use this calculator to calculate the ideal title angle for your solar panel.

Video - Effect of tilt angle on the solar panel output

Peak Sunlight Hours

Peak sun hours are not the number of daylight hours, but the number of sunlight hours in which your solar panels will produce the maximum power.

Solar panels are designed to produce the highest amount of power when the radiation of the sun is 1 kW/m2

So in the peak sun hours, the radiation of the sun will be 1 kW/m2 which is ideal for the solar panels

Becuase the solar panels are tested in Standard test conditions (STC) in which the traditions are 1 kW/m2, a cell temperature of 25°C, and no wind.

To utilize the traditions during peak sun hours your solar panels should be at the optimum tilt angle which I have discussed earlier

Speaking from experience, in the real world on average you can expect 70-80% of power output from your solar panel under the perfect weather condition

Click here to check the peak sun hours in your location.

So in Florida city, we receive about 5 hours of peak sunlight. Now let's make the calculations

250*5 = 1250wh
1250*0.8(power loss) = 1000 or 1kWh 

This is how it's gonna work. But if you place your solar panel all day (from morning till evening) then you can expect about 400 watts of extra power

1000+400 = 1400Wh or 1.4kWh

Reminder!

These are the average number of output which you can expect if it's sunny day but on raining or cloudy days cut the total power in half

Do Solar Panels Work On Cloudy Days?

how many amps does a 250-watt solar panel produce?

To calculate the number of amps or current we use this formula (amps = watts/volts)

The number of voltage and current will vary from time to time

A 12v 250W solar panel will produce 18 volts under direct sunlight, and 13 amps

This is why we use a charge controller or regulator which regulates the voltage of the solar panel to charge the battery (12, 24, or 48V)

250W solar panel how many amp-hours? to calculate the total number of amps that you'll be able to store in your 12v battery will be 110-120Ah.

So you'll need a 250Ah lead-acid or 150Ah lithium battery with 250-watt solar panels

how many kWh does a 250-watt solar panel produce

kilo-watt-hours (kWh) is the unit to describe the total number of power you can get from your solar panel

A 250-watt solar panel will produce 1.4 kWh of power per day

Disclaimer! this is the average number you can expect from your solar panels

AC vs DC watt output power

Solar panels convert the sunlight into DC (Direct current) but most of our household appliances required AC (alternating current)

Also, the batteries store power in DC, So to run the AC appliance with solar power you'll need an inverter

And inverters are not 100% efficient when converting DC into AC, most of the inverters are 85-90% efficient

which means there will be a power loss so you won't be able to use all the power produced by your solar panels

For an instant, if you're using a 1000W inverter with a 250W solar panel which is a suitable option, Which is 85% efficient

1400*0.85 = 1190 AC Wh

From a 250W solar panel, you'll receive 1200 AC watts of output to run your AC appliances

Related Post: What Will An Inverter Run & For How Long

Some Other Important Factors

  • Avoid shading, shading can reduce up to 50% output from your solar panels
  • Clean the dust, If your solar cells have dust on them it will cause the blockage of sunlight absorption which in result will reduce the efficiency of your solar panels

What can a 250W solar panel run

A 250W solar panel can run a fridge, TV, LED bulbs, Aquarium Pump, Ceiling Fan, Humidifier, Laptop Computer, Sewing Machine, WiFi Router, & other appliances which require under 200-watt input power.

If your batteries are at their discharge limit then your output watts from the inverter should not exceed the output watts of your solar panel

if you use batteries to store the power produced by your solar panels then you can run any large appliance that you can think of.

For instant, in one day if your solar panels have produced 1.4kWh and you have stored the power in the batteries now you can run any large appliance, like a space heater for about 40 minutes, and microwave for almost 1 hour.

How many 250W panels do I need?

To calculate how many 250W solar panels you need is will totally depend on your wattage use or how many appliances you wanna run on solar power

Calculate the total number of loads you need to run on your solar panel and then divide it by 1200 (AC watts) to calculate how many 250W solar panels you need

Here's a table explaining the number of 250W solar panels and the total output

No. of 250W solar panelDC output per dayAC output per day
11.4 kWh 1.2 kWh
22.8 kWh2.4 kWh
34.2 kWh3.6 kWh
45.6 kWh4.8 kWh
57.0 kWh6.0 kWh
68.4 kWh7.2 kWh
79.8 kWh8.4 kWh
811.2 kWh9.6 kWh
912.6 kWh10.8 kWh
number of 250W solar panels and total AC/DC output

Conclusion

The output power from a 250W solar panel will depend on the weather conditions and the number of peak sun hours your location receives.

I hope this guide was helpful to you, If you have any queries contact us. Thank You!

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Chris Tsitouris is a renewable energy professional with 10+ years of experience as Director of Engineering at Solar Spectrum, previously working as Project Manager at SunPower and Energy Analyst at the National Renewable Energy Laboratory. As a thought leader, Chris has authored numerous articles and research papers.

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