150 watt Solar Panel: How Many Amps (Specifications, Power Output & Much More…)

Written By Chris Tsitouris

Last Updated: March 3, 2023

This blog post contains everything you need to know about 150 watt solar panels

You’ll learn:

150 watt solar panel real-world output average (watts, amps)
What can you power with it
What size battery for 150 watt solar panel
What size charge controller for 150 watt solar panel
And much more…

Let’s get started…

Table Of Contents show

How Much Power Does a 150 Watt Solar Panel Produce?

Use this calculator to get the real world estimated output from any size solar panel

Example

I would take 5 hours of peak sunlight for this example (below I have mentioned a way to calculate the number of peak sun hours)

On Average, a 150-watt solar panel will produce about 600 watt-hours of DC power output per day. Considering 5 hours of peak sunlight and 20% of solar panels’ inefficiency during peak sun hours.

Why 20% system loss? And what are peak sun hours? Keep reading i’ll explain in a bit now

150-watt Solar Panel How Many Amps?

An ampere or amp is the basic unit of electric current according to the international system of units.

The panels are rated in watts ( Watts = Amps * Volts ).

So to calculate the value of amps we use this formula (amps = watt/volts)

A 12v 150 watt solar panel will produce about 18.3 volts and 8.2 amps under ideal sunlight conditions. (inc. 1kw/m² of sunlight intensity, no wind, and 25^oC temperature)

The above values are based on DC (Direct current) output, but to run most of the household appliances we need AC (Alternating current)

AC vs DC watts

Solar panels produce power in direct current (DC), and batteries also store power in DC but most of our household appliances required AC (alternating current)

So to convert DC into AC, we use an inverter. And like the other electronics, the inverters are not also 100% efficient.

Most of the inverters available right now are about 85-95% efficient

This means there will be a 5-15% power loss when converting DC into AC.

Let’s convert the above calculated DC value into AC based on a 90% efficient inverter.

600 * 0.9 = 540 watt-hours (AC)

On average, 150 watt solar panel will produce about 540Wh of AC output per day with 5 hours of peak sunlight.

I have discussed this in detail about this topic, Read the below-mentioned article for more in-depth information

Related Post: Solar DC Watts To AC Watts Calculator

Now let’s dive deep into some technical stuff about solar panels and their power production in the real world scenario

150 watt solar panel specifications

Before explaining anything let’s start with the specs of 150 watt solar panels.

There are only a few things to consider in the specs of any solar panel, its max output voltage, power, and current (Amps)

Here are the specs of a 12v 150 watt solar panel specs

Specification	Description
Maximum power output	150 watt
Optimum Operating Voltage (Vmp)	18.3v
Optimum Operating Current (Imp)	8.2A
Dimensions	39.5 x 39 x 1.4 in

Note! The values are based on laboratory test conditions - STC

How Solar Panels Are Tested? – STC

First, let’s discuss how the manufacturers give the wattage rating to any solar panel.

The solar panels are designed to produce their rated power output under Standard Test Conditions (STC).

This includes the intensity of the sunlight as 1000 watts per square meter, Temperature 25℃ or 77℉, and no wind

So in the real world, it’s rarely gonna happen when you’ll receive the 100% rated wattage output from your solar panel.

Now let’s discuss some factors which will affect the power output of a solar panel.

Before going further watch this video to understand the basics of electricity (Watts, volts, and amps). This guy explained it well!

What Are Peak Sun Hours?

1 peak sun hour = 1000 watts/ meter² of sunlight intensity

As we already have discussed under which conditions the solar panels are designed to produce their rated wattage output

That is why the number of peak sun hours is considered as the baseline when estimating how much power any solar panel system will produce.

How To Calculate Peak Sun Hours?

Every location receives a different amount of total solar radiation per day. Luckily some geniuses have gathered this information and made it easy for us.

Use this PV solar peak sun hour calculator to find out how many hours of peak sunlight your city receives.

Step 1: Enter Your Address

Enter your complete address or just simply mention your city

Step 2: Select Results

Now this will be the number of total solar radiations your city/house receives per day month by month.

As you can see i live in Florida city, and here we receive about 4.8 – 6.9kWh/merter² of solar radiation (4.8kW in December and about 7kW in April)

I would have to place my solar panels all day to get these numbers of peak sun hours.

Now let’s discuss the average solar panel output during peak sun hours.

Average Solar System Output During Peak Sun Hours

On average you’d receive about 80% of rated wattage output from your solar panel in a peak sun hour. For Example, 120 watts of DC power output from a 150-watt solar panel

The average value is based on my personal experience with my 200-watt solar panel. The average percentage is based on 30 days of output data.

The 20% less efficiency rate will occur due to the changes in weather conditions, shading, some power losses in wiring, & and due to the charge controller

What size charge controller for 150w solar panel?

For a 150 watt solar panel, you need a 15A Charge controller.

To calculate the size of the charge controller, “Divide the solar panel ratted wattage by its voltage and add an extra 25% to the value”

For Example

150 watt / 12v = 12.5 + 25% or 12.5 * 1.25 = 15A

The charge controller is what regulates the output voltage from the solar panels to safely charge the battery.

There are two types of charge controllers

PWM
MPPT

Before explaining the difference between these two of them, first, keep in mind that the formula for power is (watts = volts * amps)

PWM: This type of charge controller will only decrease the voltage and the current (amps, A) will remain the same. which makes them 20-30% less efficient than the MPPT charge controller

MPPT: This type of charge controller will not only decrease the voltage output from solar panels to match the voltage of the battery but also will increase the amps to cover up the losses. Which makes them about 98% efficient.

So i would recommend buying an MPPT charge controller. It’ll cost more but is worth the investment.

What can a 150 watt solar panel run?

Calculate the estimated power output according to your location and season time (explained above).

Now you can store this power in batteries for later use and can run any appliances.

As long as you’re following these two rules.

If the battery has reached its DoD limit, then the total output load should not exceed the output of the solar panels at that time
Output load should not exceed then the battery’s discharge rate limit. (check your battery’s specs, it’ll be mentioned as C-ratings. 1C = 1 hour)

Here’s a list of some appliances which you can run on 150 watt solar panels.

Light bulb 20w (30 hours)
LED TV 50w (6 hours)
Phone charger 6w (100 hours)
Laptop charger 50w (6 hours)
Electric blanket 200w (2 Hours)
Ceiling fan DC 75w (8 hours)
Portable fan 25w (24 hours)
mini fridge 70w (6.5 hours)

What Size Battery For 150 Watt Solar Panel?

For a single 150 watt solar panel, you’d need about 12v 70-100Ah lithium or 12v 140-200Ah lead-acid battery. The exact value will depend on the amount of peak sun hours your location receives.

To calculate the size of a battery pick the highest number of peak sun hours your location receives.

In my case, I’ll be April with 6.95 peak sun hours. Let’s make it 7

Now multiply the rated wattage of your solar panel with the highest peak value of sun hours

7 * 150 = 1050

For a 12v battery system divide the result by 12

1050 / 12 = 87.5Ah

This is the highest output i can receive from a 150 watt solar in Florida city (considering perfect weather conditions)

Now multiply the Ah value by 2 for lead-acid, AGM, or Gel batteries (because of their 50% DoD limit). Only lithium-ion (LiFePO4) battery type can be fully discharged up to 100%

87.5 * 2 = 175Ah

DoD limit? Depth of discharge: How much energy is discharged from the battery before it is charged to 100% again. (read more)

What Size Inverter For 150 watt Solar Panel?

Choose the inverter size according to your battery’s C-rating or the number of total load you’d need to run.

When selecting the size of an inverter, there’s a rule of thumb to add an extra 20% to the total load wattage that you’d run on an inverter.

I would recommend a 500 watt inverter with 150 watt solar panel. Which would be enough to run some of the basic appliances.

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Chris Tsitouris

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.