A solar power system’s size and potential output can be drastically impacted by the selected solar panel wattage.
The wattage of a solar panel refers to the amount of energy it can produce. Today, most solar panels used in residential projects have an output of 350 to 450 watts in ideal conditions.
As technology continues to develop, 250-watt solar panels have become outdated and are rarely installed with new solar systems.
In this blog, we’ll take a closer look at 250-watt panels and how many you’d need to cover your energy needs.
How much energy can 250-watt solar panels produce?
A solar panel's wattage is a measure of the amount of electricity that the panel is rated to produce under ideal conditions, known as standard test conditions (STC). STC is when there is a cell temperature of 77F° (25C°), and 1 kilowatt per square meter of solar energy shining on the panel.
The energy production of a solar panel is measured in the number of kilowatt-hours (kWh). A 250-watt solar panel will produce approximately 1 kWh of solar power per day. This figure will vary depending on your geographic location, shading, the panel's power tolerance, and the angle of your panels.
How many 250-watt solar panels would you need?
Below is a table showing you different system sizes and how many 250-watt solar modules you will need. Note that according to the US Energy Information Administration the average household consumes approximately 877 kWh per month.
| System Size | Monthly Energy Production | Number of 250W Panels |
|---|---|---|
| 4 kW | 480 - 600 kWh | 16 |
| 6 kW | 720 - 900 kWh | 24 |
| 8 kW | 960 - 1,200 kWh | 32 |
| 10 kW | 1,200 - 1,500 kWh | 40 |
| 12 kW | 1,440 - 1,800 kWh | 48 |
The energy a solar panel can produce will determine the number of solar panels you need. This is why if you have limited space on your roof you may have to opt for a higher wattage solar panel like a 400-watt solar panel.
Our solar panel cost and savings calculator is the fastest and easiest way to find out how many solar panels your home needs. We’ll also tell you the average cost of the system and how much you will save on your electricity bills.
Are 250-watt solar panels still used?
If you had purchased solar panels prior to 2018, then 250-watt solar panels would have been the average module size. With advancements in technology in the solar industry, 250-watt solar panels are now far less common and are rarely installed for a new solar array.
With improvements in solar panel output potential, we have seen major growth in the power wattage of high-quality residential solar panels. With high output solar panels, your system is able to have a higher maximum power. Solar panels with a higher wattage will also allow you to use fewer solar panels to fulfill your energy needs. Examples of these panels include Canadian Solar’s 400-425 watt panel and SunPower’s 435-watt panel.
Outdated technology in 250-watt solar panels
Due to the fact that 250-watt solar panels are no longer being manufactured, if you were to install these panels on your roof, then you will be installing outdated technology. In recent years there have been many innovations in solar panel technology that have improved panels' efficiency and performance. For example, 250-watt solar panels are lacking technology such as half-cut solar cells, which improve performance under shade and increase power output.
250-watt solar panel kits
While 250-watt solar panels are no longer a great size or wattage for on-grid solar systems, they are a popular option for off-grid systems. Solar panel kits are becoming increasingly popular for things such as powering RVs and camping appliances or battery charging.
Renogy and SanTan Solar are popular providers of 250-watt solar panel kits. The main components of these solar panel kits include a 60 cell polycrystalline solar panel, solar charge controller, solar inverter, connectors, circuit breaker, and mounting brackets. The panels in these kits are also often foldable or flexible solar panels.
SanTan Solar T Series 250W Solar Panel Kit. Image source: SanTan Solar
Are 250-watt solar panels right for your energy needs?
When deciding on the specific wattage of a solar panel you would like installed, there are two main considerations. The two factors you should consider is the power output you require from the system and the roof space you have available. These two factors will determine what solar energy system is best for you.
Solar energy systems consisting of 250-watt solar panels may be suitable for very low energy usage households (under 6,000 kWh annually). But you may have to look for higher wattage modules if your energy usage is moderate to high. This is mostly due to the available roof space on your home. For example, if a 6kW system (typical residential system size) was built with 250-watt panels you would need a total of 24 panels, as opposed to needing just 16 panels that are 400 watts each.
If you’re looking at installing a solar system on your home in 2023, then we would recommend looking at using high-efficiency solar panels of around 400 watts.
For a fast and easy analysis of your potential solar panel costs and savings, we recommend you visit our solar calculator.
Key takeaways
- 250-watt solar panels are rarely used in new rooftop solar installations in 2023.
- A 250-watt solar panel will produce approximately 1 kWh of solar power per day, depending on your geographic location and shading.
- To cover the energy requirements of the average American household you will need thirty-two 250-watt solar panels in your system.
- If you’re looking at installing a solar panel system, we recommend using solar panels of at least 350 watts.
Chiquita Keil
Blog Author
Cameron is a business analyst and content specialist at SolarReviews.