What Size Solar Generator Do I Need? Best Detailed Guide [2021]

The amount of power supply required can make someone ask himself a question that What Size Solar Generator Do I Need? When the power goes out in your home you need an alternative source of energy to power the appliances in your home because the food needs to be fresh and the other devices like cellphones, laptops, etc. need to charge, for this purpose solar generator comes in use.

Solar generators are used as an alternative source for power supply and as its name suggests it derives the energy from the sun rays and provides you with the electricity. It is a one-time investment and reduces your electricity bills.

What Size Solar Generator Do I Need?

What Size Solar Generator Do I Need?: Understanding How It Works

Solar generators come in different sizes and brands, before determining the size of the solar generator you should know the basics of how it works.

1. Components Of Solar Generator

The solar generator consists of solar panels, solar batteries, a solar battery charger, and an inverter. Solar panels play here the main role as they collect the solar energy when it falls on its surface and passes it to the solar battery charger which processes this energy and charges the solar batteries. From here onwards the inverter takes the energy from the batteries and converts them into alternating current, which is used as a backup energy source to power the appliances in your home.

2. Types Of Solar Generator

There are two types of solar generators present in the market which includes backup solar generators and portable solar generators. 

2.1. Backup Solar Generators

Backup solar generators work as traditional fuel or gas-powered solar generators and are installed on-site and contain several batteries which supply high voltages to supply power to all appliances of the house.

There are many factors on which the power supply from solar backup generators depends upon, which includes the duration of the sun present on the site and the size of the site. However, a backup solar generator usually takes 48 hours to charge all of its batteries.

2.2. Portable Solar Generator

Portable solar generator as its name suggests is moveable and can be taken to anywhere with the user type of generator. These types of solar generators are used for outdoor stays; such as camping, to supply power to RVs, treehouses, etc.

These generators are friendly to use as they are light in weight and have a handlebar, just like a trolley so one can move them from one place to another place easily. However they produce sufficient amount of voltages to supply power to small spaces as they do not have larger batteries as the category discussed earlier.

Portable solar generators are user-friendly as they do not emit any noise or pollution so one can enjoy their stay on campsites.

Also Read: Top 10 Best Solar Generators For Van Life: Reviews & Buyer’s Guide

3. Determining The Power Required

Before buying a solar generator you should determine the amount of power required in the house, which will eventually determine the power of the solar generator. Usually, the solar generator is required to supply power to the necessary appliances of the house.

The amount of power required can be seen displayed on the backside of most of the appliances which are usually in watts. However, most of the appliances have power written in volts and current units so you need to multiply those to get power in watts.

By adding the watts of all appliances you will get the amount of power required from the solar generator to run those appliances. For example, if the sum of all the appliances is 1000 watts in one hour, then you will require a solar generator that produces 1000 watts i.e. 1kW.

4. Determining The Energy Consumption Required

Energy consumption is the next step in determining the size of solar generator. Energy consumption can be calculated by a simple method. You just have to determine the amount of power required to run appliances in 1 hour I.e. 1 kilowatt (1kwh) then you will multiply it by the number of hours these appliances are in function.

For example, the appliances remain on for 9 hours a day, so you just need to multiply the watts required in 1 hour (1000 watts) with the hours (9 hours) you will get the energy required i.e. 9-kilowatt-hours or 9kwh.

However, the sun plays a major role in energy consumption as it does not remain on the site for the whole 9 hours. If we say the sun remains on the site for 5 hours so you do need 4 hours of backup for the energy. This will help you in determining the size of the solar panels.

5. Determining the Size Of Solar Panels

Solar panels are the main component of the solar generator as they transfer the solar energy to the batteries, so the size of the panels should be chosen according to the power required.

As stated earlier that your house requires 9kwh energy but the sun is only available for 5 hours, so you need to produce much energy during this time to compensate for the other 4 hours so by using a simple formula you will divide the kilowatt-hours by the hours of daylight i.e. 9kwh/5hrs you get 2.25kwh and this will be the size of your solar panels.

6. Determining The Size Of Solar Batteries

An equivalent amount of energy supply is not enough and is never suggested if you want to supply power to your home for whole 24 hours, so here come the solar batteries in action.

Solar batteries store the excess amount of energy produced and can be used to supply energy to home appliances in case of a sudden power cut-off or any other reasons.

Batteries are connected with panels via a solar charger which makes sure that the batteries are being charged without any complication. Lastly, the batteries are connected to an inverter which converts direct current (DC) into alternative current (AC) which is then used by the appliances.

Determining the size of batteries is simple, for example; a house uses 5kwh energy in the day and requires 4kwh energy in the evening then the size of the batteries should be sufficient to store 4kwh.

12 Ah batteries are the most common ones in the market, so the total size of the batteries will be 333 Ah.  However, you should remember batteries discharge energy during conversion at the rate of 80% so 333Ah will not be sufficient. To compensate for this 80% discharge you will require a battery of 521Ah.

The size of the inverter depends upon the size of the solar panels used. In most cases, we use an inverter of 1-kilowatt capacity. However, you can buy ready-made solar generators from the market as it saves your precious time and technicians will do all the work mentioned above.

Also Read: Top 5 Best Generators To Run A House In 2021

What Size Solar Generator Do I Need?: FAQ’S

1. How do I choose a solar generator?

There are many solar generators present in the market and it depends upon your requirement what kind of solar generator suits you the best. For what purpose you are going to use the solar generator? Is it going to be used as a backup generator or as a portable generator?

However you should look for the following things while buying a solar generator i.e. the battery storage should be sufficient enough to store the energy required in the evening, solar PV input, rating of the inverter, and the components used in the solar generator are of good quality and can work in various environments or not.

2. Are solar generators worth it?

Solar generators are the best to be used as backup power supply or to supply power throughout the day as it is a one-time investment and it reduces the electricity bills. It derives energy from the natural source i.e. the sun and converts it into AC which is then used to power the home appliances.

It is far better than the traditional gas and fuel generators as they produce so much noise and pollution. You need to keep a surplus amount of fuel so it can be used in case your generator is running out of fuel. On the other hand, solar generators do not produce any kind of pollution and you can live a peaceful life as the energy is being generated from a renewable and never-ending source.

3. How much does it cost to install a solar generator?

The rising cost of electricity makes the homeowners install solar generators without thinking for a moment, however, the price of the installation depends upon many factors such as capacity, efficiency, and home location.

In the United States, it costs around 12000 dollars after the additional solar tax to install a solar generator in an average-sized home. This amount can vary depending upon the size of the home. By installing solar generators people can save up to 75% of their electricity bills which ranges from 30000 dollars to 90000 dollars in different states of America over a period of 20 years.


It is concluded that solar generators are powerful equipment as they can supply power to your house even with total cut-off from electricity.

It does not harm the environment as it uses renewable and never-ending energy source and the working principles are very easy to be understood. However one should always go for the ready-made solar generators, otherwise, he will be asking himself that What Size Solar Generator Do I Need? 🙂

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