Why purchase 400-watt solar panels and which models will perform the best in 2022

A growing proportion of household solar systems employ 400-watt solar panels. Photo credit: LG Solar
The size of solar panels is increasing. The largest solar panels were only 300 watts only five years ago. Now, in 2022, 400-watt or even larger household solar panels are starting to become available.

The development of solar cell technology has allowed for an increase in solar panel size. The growth of new solar panels of 400 watts or more, however, is also a result of solar panel manufacturers competing to have the largest solar panel.

But does size really matter when it comes to solar panels? Is a solar panel with a 400 watt (W) capacity a better option for your home than a 300–350 W panel that is more typical? Which 400 W solar panels now available on the market are worthwhile of consideration? These queries will be addressed in this blog.

What is a 400-watt solar panel?

The size of solar panels is determined by their output capability. Under ideal Standard Test Conditions, a 400-watt solar panel is one that can generate 400 watts of DC electricity instantly (STC).

What is the daily power output of a 400-watt solar panel? 

Depending on your location, a 400-watt solar panel will typically generate between 1,200 watt-hours (1.2 kilowatt-hours, or 1.2 kWh), and 3,000 watt-hours (3 kWh), of DC electricity every day.

Using the peak solar hours for your location, you may check the precise number for where you live. For instance, sunny areas of Texas receive an average of 6 peak sun hours (PSH) daily. To find the average daily power production there, just multiply the panel wattage by the number of PSH (400 W x 6 PSH). This gives us 2,400 watt-hours (2.4 kWh) of power production.

Can I use 400-watt solar panels for my home? 

Yes. To construct the size of solar system you require, you can link up several separate 400-watt panels.

For instance, fifteen (15) 400-watt solar panels would be mounted on the roof to create a typical 6 kW residential solar system. 400-watt solar panels are now available for residential and commercial use from a number of major solar panel manufacturers, including LG and SunPower.

400-watt solar panels are still a rare size in residential solar power installations as of 2022, with the majority of customers choosing panels in the 300-350 watt range.

Can I use 400-watt panels for my RV or boat? 

Yes. RVs and boats can employ a single 400-watt solar panel to meet their off-grid power needs because of their constrained space and power needs.

However, 400-watt starter kits are more frequently used in RVs, boats, and other similar configurations. They typically include an MPPT inverter, solar charge controller, AGM battery bank, four (4x) 12 volt 100 watt panels, which add up to 400 watts of solar capacity, extension cables, and mounting hardware.

Through Amazon, you can purchase kits for 400 watt solar panels from businesses like Renogy, Grape Solar, and Windy Nation.

The best 400-watt solar panels

The top 400 watt or somewhat larger solar panel models are listed below.

We only selected solar panels from the leading solar panel producers, all of which rank among the top 10 brands in terms of customer satisfaction.

These are all monocrystalline solar panels, sometimes known as mono solar panels. Monocrystalline cells are the most popular cell type for high-efficiency and high-wattage panels in 2022.

the best solar brands’ 400-watt solar panels

Only solar panels with cell designs appropriate for household use—60-cell (120 half-cell), 72-cell (144 half-cell), or sizes in between—have been included in this list.

It’s important to note that there are even larger solar panels available; Trina Solar, for instance, currently sells a giant 120-cell, 600-watt solar panel. These solar panels, however, only really work well for solar farms because of their enormous physical footprint.

Are 400W solar panels expensive?

Yes, 400 watt panels are more expensive than smaller-sized ones. Additionally, 400-watt panels are more expensive relative to other panel sizes, meaning they cost more per watt, rather than more expensive simply because they provide more electricity.

To create a solar panel that provides more power without also growing in size, solar panel makers must use more sophisticated manufacturing techniques. Furthermore, solar panel manufacturers like to incorporate a bigger margin on 400-watt panels because they are new, higher-end models.

If you choose to create your solar energy system with 400 W solar modules instead of modules in the more common 300-350 W range, be prepared to pay an extra 5–10% per watt.

Reasons to get 400-watt solar panels

Purchase 400-watt solar panels rather than the more prevalent 280 to 350-watt solar panels for two main reasons: when your roof is tiny and to ensure your panel has fewer sources of failure.

Make the best use of a small space 

The main justification for purchasing a 400 W (or larger) solar panel is a shortage of roof space.

The most effective solar cell technologies are used to construct solar panels that are 400 watts or more. A solar panel needs less space to produce a given amount of power the more efficient it is.

As a result, 400-watt solar panels with a module efficiency of 20% or above are what you should search for if you want to get the most solar electricity possible out of a particular location.

Less points of failure 

You are less likely to experience system issues over the course of the solar panels’ lifetime if you choose 400-watt solar panels.

Why? because utilizing 400-watt solar panels reduces the need for additional modules. Instead of twenty (20) 300 watt panels, a 6 kW solar system can be constructed with fifteen (15) 400 watt panels.

Although it is improbable that solar panels may malfunction on their own, linked equipment is more likely to do so. For instance, to comply with code requirements, each individual panel frequently uses module-level power electronics (MLPE) — microinverters and power optimizers.

A smaller number of panels means less MLPE is required, which lowers the likelihood of issues both during and after the warranty term.

Number of 400-watt panels and roof space required

Assuming they are constructing systems between 6 kW and 12 kW in size, the majority of homeowners installing solar energy systems on their roof will need between 15 and 30 400-watt solar panels.

Before accounting for the state-specific access and setback restrictions, which can range between 329 and 658 square feet, that would require between 329 and 658 square feet of roof space.

The typical values for California, Texas, and Florida are as follows:

**Assuming each solar panel is 79.8” x 39.6”

Please keep in mind that these average numbers are based on just three states. Based on a number of variables, including but not limited to your energy demand, utility costs, and the climate where you reside, you should choose the correct size solar system for your home.