What Measurement Is A 250-Watt Photo voltaic Panel?


Over the previous 20 years, developments in photo voltaic expertise have allowed producers to cater to owners’ wants by offering them with panels of assorted sizes. One such photo voltaic panel measurement that’s nonetheless in use is the 250-watt module.

Since 250-watt photo voltaic panels are comparatively inexpensive, small, and straightforward to seek out, they are perfect for residential rooftop installations. As such, figuring out the typical measurement of a 250-watt photo voltaic panel can actually turn out to be useful.

With this info, you’ll be able to decide the variety of 250-watt photo voltaic panels you’ll be able to slot in your required area, finally figuring out how a lot vitality your system will generate.

On this article, we offer you the typical dimensions of a 250W photo voltaic panel. Moreover, we cowl the variety of 250-watt photo voltaic panels you require and the way a lot vitality they’ll produce.


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What Measurement Is A 250-Watt Photo voltaic Panel?

The usual measurement of a 250-watt photo voltaic panel is roughly 17.5 ft2 (1.62 m2); its dimensions are 65 x 39 inches (about 1651 x 991 mm).

The usual measurement of photo voltaic panels for residential functions (they often vary from 250W to 360W).
Supply: Climatebiz

Nonetheless, these numbers can fluctuate barely relying on the producer, mannequin, and expertise used.

We’ve ready a desk that reveals the scale of 5 completely different 250 W photo voltaic panels from completely different manufacturers:

Model Mannequin Dimensions (Inches) Dimensions (mm)
LG 250S1C-G2 64.25 x 38.82 x 1.65 in 1632 x 986 x 42 mm
Renogy RNG – 250P 65.0 x 39.0 x 1.6 in 1640 x 992 x 40 mm
Sunpower SPR-X20-250-BLK  61.4 x  31.4 x 1.8 in 1559 x 798 x 46 mm
Canadian Photo voltaic CS6P-250P 64.5 x 38.7 x 1.57 in 1638 x 983 x 40 mm
Trina Photo voltaic TSM-250PA05 64.95 × 39.05 × 1.37 in 1650 × 992 × 35 mm
Common ——– 64.02 x 37.38 x 1.59 in 1624 x 987 x 39 mm
Common dimensions of 250W photo voltaic panels, primarily based on the scale of 250 W photo voltaic panels from 5 completely different manufacturers.

Although the scale of those 250-Watt photo voltaic panels differ from model to model, they don’t deviate a lot from the usual measurement beforehand talked about.

Associated Studying: Photo voltaic Panel Dimensions Chart

How Many 250 Watt Photo voltaic Panels Do I Want?

The variety of 250- watt photo voltaic panels you’ll want will depend on:

  • The quantity of electrical energy you want to generate (primarily based in your common vitality consumption);
  • Your roof area; and
  • Effectivity losses resulting from your own home’s location, roof angles, obtainable daylight, and many others.
60-cell solar modules mounted on the roof of a house on a sunny day.
9 60-cell photo voltaic modules mounted on the roof of a home on a sunny day.
Supply: smart-energy.com

So, to find out the variety of 250-watt photo voltaic panels you require, you’ll must estimate your vitality demand, account for effectivity losses, and decide the variety of panels (of this measurement) you’ll be able to match within the area obtainable.

Estimating Your Power Consumption

There are a number of methods to estimate your vitality demand, however the best is just checking your month-to-month electrical invoice — it would inform you the quantity of kWh you devour per 30 days.

Nonetheless, vitality consumption modifications all year long, so it’s best to take into account your common annual vitality consumption. To do that, add the kilowatt-hours consumed every month of the earlier yr and divide this quantity by 12.

In response to the U.S. Power Info Administration, the typical annual electrical energy consumption for a U.S. residential utility buyer is round 10,715 kilowatt-hours (kWh), roughly 30 kWh per day.

Figuring out The Quantity Of Photo voltaic Panels You Require

In order for you your photo voltaic system to produce all of the vitality you devour, you could set up an array that may generate the identical quantity of vitality you devour each day.

Instance: Let’s take into account an vitality consumption of 25 kWh and 5 peak solar hours:

First, deduct the effectivity losses (about 20%); this implies a 250W photo voltaic panel will generate:

250 W – 20% (resulting from effectivity losses) = 200 W

Now, divide the each day vitality consumption by the hours of direct daylight:

25.000 Wh / 5 hours = 5000 W

Lastly, divide this quantity by the facility that one 250W photo voltaic panel can generate (after deducting effectivity losses):

5000 W / 200 W = 25 photo voltaic panels

Checking If You Can Match That Many Panels On Your Roof

You don’t really want an elaborate photo voltaic panel sq. footage calculator to find out the variety of panels a roof can assist (until your roof has a number of faces or odd shapes).

There’s a simple approach to calculate the usable space of your roof:

1) Calculate The Sq. Footage:

You first must calculate the sq. footage of your roof utilizing the size and width dimensions.

2) Account For Setback:

Then, it’s essential account for the “setback,” which is the free area between the photo voltaic array’s edge and the roof’s edge. Doing this establishes an unobstructed pathway round your rooftop in case responders (like firefighters) must entry your own home in an emergency.

The minimal photo voltaic panel setback varies from state to state, however often, it’s about 25% of your roof’s area. Due to this fact, it’s essential multiply the sq. footage of your roof by 0.75 to account for the required photo voltaic setback.

Instance: Let’s say the realm of your roof that will get essentially the most daylight throughout the day is round 700 ft2; your roofs usable space could be:

Sq. footage x 0.75 = 700 ft2 x 0.75 = 525 ft2

3) Divide The Usable Roof Space By The Commonplace Measurement Of A 250 Watt Photo voltaic Panel:

Now that you just’ve calculated the usable space of your roof, it’s essential divide it by 17.5 ft2, the typical sq. footage of the usual 250-watt photo voltaic panel measurement.

The ensuing quantity is the utmost variety of 250-watt photo voltaic panels you’ll be able to match on your own home’s roof.

Instance: If the usable space is 525 ft2, then:

Usable space / customary measurement of photo voltaic panel = 525 ft2 / 17.5 ft2 = 30

Due to this fact, you might match thirty 250-watt photo voltaic panels in your roof.

If this is sufficient to generate the vitality you want, nice! If not, you’ll want extra highly effective photo voltaic panels (300 W, 350W, and even 400W).

Often, thirty 250-watt photo voltaic modules can generate greater than sufficient vitality to energy a mean U.S. dwelling.

How A lot Power Can A 250-Watt Photo voltaic Panel Produce?

On common, a 250 W photo voltaic panel can produce roughly 1 kWh of vitality per day (contemplating 4 peak solar hours and 80% effectivity).

Nonetheless, this quantity can fluctuate considerably. Why? As a result of the quantity of vitality produced by photo voltaic panels will depend on a number of components, equivalent to:

Shading can considerably decrease solar energy production.
Shading can significantly lower photo voltaic vitality manufacturing.
Supply: onestepoffthegrid.com.au
Solar radiation map of the United States.
Photo voltaic radiation map of america. Supply: NREL

Nonetheless, we have to make clear a number of issues:

Photo voltaic panels are rated primarily based on how a lot energy they’ll generate. Let’s recap the distinction between energy and vitality earlier than discussing the vitality output of a 250-watt photo voltaic panel.


In brief, vitality is the flexibility to do work. It has numerous varieties: thermal, chemical, nuclear, mechanical, electrical, and many others.

Electrical vitality outcomes from the motion of electrically charged particles, like electrons.

The unit for electrical vitality is Watt-hours (Wh). In different phrases, vitality expresses the facility used/generated over a time period:

Power (Wh) = energy (W) x time (h)


In physics, energy is the quantity of vitality transferred or transformed per unit of time. In different phrases, it’s the price at which work happens.

Energy (W) = vitality (Wh) / time (h)

It may also be calculated because the product of amperage and voltage:

Energy (W) = amperage (A) x voltage (V)

The unit for energy is watts (W).

Now that we’ve coated how vitality and energy correlate, we will higher perceive photo voltaic panel vitality output.

Photo voltaic Panel Power Output

A photo voltaic panel consists of a number of photo voltaic cells wired in sequence. Every cell produces a particular voltage and present (relying on its measurement).

The facility score of a photo voltaic panel expresses the most energy the panel can produce (in ultimate circumstances). It’s often examined beneath “Commonplace Check Circumstances” or STC.

This doesn’t imply the panel will produce 250W of energy always. It implies that it could possibly produce a most of 250W beneath ultimate circumstances therefore why it’s so difficult to calculate the vitality output of a photo voltaic panel.

There are, nonetheless, a couple of methods to estimate photo voltaic vitality manufacturing. The easiest way is to make use of a web based vitality manufacturing calculator, just like the PVWatts calculator developed by researchers at NREL (Nationwide Renewable Power Laboratory).

One other manner is to make use of the next components:

Power produced per day = Common peak solar hours × photo voltaic panel wattage x 80% effectivity

Please word: the 80% used within the components accounts for all of the effectivity losses that outcome from the beforehand talked about components.

Instance: For a 250 W photo voltaic panel, contemplating 4.5 peak solar hours:

Power produced per day = 4.5 hours × 250 W x 0.8 = 900 Wh = 0.9 kWh

In abstract, the vitality produced by a 250-watt photo voltaic panel varies relying on what number of hours of direct daylight hits the panel.

As well as, a number of different components end in effectivity losses. Due to this fact, a 250W photo voltaic panel doesn’t produce 250 watt-hours of vitality per hour; the quantity is at all times a bit much less.

Closing Ideas

The usual measurement of a 250-watt photo voltaic panel is round 17.5 ft2 (1.62 m2), and dimensions are often 65 x 39 inches (roughly 1651 x 991 mm).

Photo voltaic panels with a most energy output of 250 watts are perfect for residential installations. Their comparatively small measurement makes them simple to put in and match on most roofs. They’re additionally inexpensive and straightforward to seek out.

You could take into account a number of components to construct the optimum solar energy system to your wants.

As an illustration, your common vitality consumption, how a lot usable roof space you’ve gotten obtainable for the photo voltaic array, the situation of your own home, the angle of your roof, the photo voltaic irradiance in your a part of the nation, the effectivity of the photo voltaic panels you’re utilizing, and quite a lot of different components.


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