How Much Solar Power to Run a Toaster off-grid

A toaster is a great appliance that helps to prepare breakfast. It’s perfect for making toast, but it can also be used to cook so many other things like bagels, muffins, and even sandwiches. Toasters use less power than most other household appliances. 

The amount of power used depends on how long it takes for your toast to brown completely. Some people like their toast well-done and others prefer it barely toasted with just a hint of browning on the surface (or even raw).

So how much solar power will you need to run a toaster? 

Solar Power for a 900-Watt Toaster

A typical household toaster is rated at around 900 watts. To power this toaster for an hour you will need a 100-watt solar panel with a 200Ah 24v battery. To run the same toaster for 15 minutes you can use a 100Ah 12v battery.  

Read more on this article to find out how we came to these numbers. 

Toaster Energy Requirement 

When you are determining how much energy a device uses, you must consider the amount of time that it will be used. A Watt-hour is a product of multiplying a device’s wattage by its run time in hours. To calculate Watt-Hours you multiply the Wattage of the device or appliance and multiply by the number of hours you use the device. 

Watt-Hours = Watts X Hours 

If you are using a toaster for an hour you’ll need 900 Watt-hours of energy. This is as much power as sump pump will need for an hour.

If you want to use a toaster for 15 minutes, you will need 225 Wh of energy. 

How Many Solar Panels for a Toaster 

The size of the solar panel is dependent on the area, altitude, and how far you are from the equator. For example: If you’re in North America and want to charge a toaster using solar energy, then you would need a larger solar panel than if you were in Australia or South America.

This is why we use a ballpark figure of 4 hours as this would apply to everyone in any season. However, sun hours can last up to 6 to 8 hours in some regions. 

If you are in an area that receives around 4 hours of sunlight a day you will divide the total Watt-hour requirement by this number. 

In order to determine how many solar panels are needed for a toaster, we divide the total watt-hours required by the number of sun hours we get in a day. So In the case, we are using our toaster for an hour then we need 900Wh. 

An example is to use an average of 4 hours which could be high peak hours in the afternoon between 12 and 4. If you get more than 4 hours of sun per day, then use that number. 

900Wh/4= 225 Watts

A 225 Watt solar panel will be enough to provide 900Wh in the course of the day. Solar panels are not that expensive so you can even go double up to a 500-watt solar panel or two 200-watt solar panels and collect more power. 

In the case of 15 minutes 

225Wh/4 = 56.25 Watts 

If you’re looking to power your toaster with solar panels for 15 minutes, you’ll need to size your system based on this load. You can go as high as three times with a 150 Watt Solar Panel but twice will be enough. This means that you’ll need at least 100 Watts of solar panels if you want to power your toaster with solar energy for 14 minutes. 

What Size Battery for a Toaster

The next thing we need to do is determine how many amp-hours we will need to store all of this power generation capability from our solar panels. 

To calculate Amp-hours you divide the Watt-hours by the voltage. 

The voltage in a battery bank is usually between 12v and 24v depending on how you wire the system. 

To find the size of the battery, you divide the watt-hours by the voltage. In the case, you have a 12-volt system, so you divide 900Wh by 12V and for the 24V system, you divide by 24V. 

900/12 = 75 Ah

900/24 = 37.5 Ah

This however does not give you the size of the battery you need but the capacity of the battery reserve that the toaster is pulling through your inverter.  So you need a battery that you can safely pull 75 amps per for the 12v system and 37.5 amps per hour for the 24v system.

While a LiFePO4 battery has a 1C rating which means you can pull the full capacity from the battery manufacturers usually recommend 0.2C meaning you discharge 20% of the capacity. This means to pull 75 amps you’ll need a 400Ah battery and a 200Ah 24v battery for 37.5 amps. 

If you run a toaster for 15 minutes a 100 Ah LiFePO4 12v battery will be able to support it. However, you should not hook up many high-wattage appliances at once. 

It will also support the 12.5 amps from the 150-watt solar panel comfortably to fully recharge in around 8 hours. Since the battery can support 20 amps of charge you can size the solar panels up to 300 watts because of efficiency losses. 

225Wh/12v = 18.75 Ah 

Remember we are discharging the 18 amps in 15 minutes and not an hour. So in an hour, the total amp-hour discharge is 75 amp-hours. This is important as a battery has a C rating that dictates how much power you can pull from the battery. 

Inverter Rating Requirement

You also need to match your toaster with a suitable inverter. With inverters, you also need to oversize a bit because of efficiency issues. Inverters are known to work at 90% efficiency. So for a 900-watt toaster, you will an inverter that is rated at least 1000 watts. 

 If you using a 24v battery bank you will need to match it with a 24v inverter. 


Toasters come in different wattages, with higher wattages meaning that the appliance uses more power. While making toast off-grid may not be a priority the good news is that even with a small solar system you will be able to support your toaster for at least 15 minutes a day. 

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