When it comes to choosing a solar generator, power is naturally one of the main criteria to consider. Indeed, a device that is too weak implies an insufficient level of energy, while using a generator that is too powerful for the real needs would imply a waste of energy and money.
So how to find the right balance? What are the elements to take into account to determine the ideal power for a solar generator?
What are the criteria to determine the ideal power of a solar generator?
In order to determine the ideal power for your solar generator, three main criteria must be taken into account: the number of appliances to be powered, the respective power of these appliances and their duration of use under the generator.
The number of appliances to be powered
The ideal power for your future solar generator naturally depends on the number of electronic/electrical devices that you plan to feed with. Obviously, the higher this number is, the higher the power of the solar generator must be in order to optimally cover the electrical energy needs of these devices.
However, the number of devices alone is not enough for a proper evaluation. Why not? Simply because not all electrical/electronic devices have the same operating power. Hence the importance of the second criterion.
The power of the devices to be operated
The operating power is not the same for all devices. A television, a light bulb or a toaster. So, in order to determine the ideal power for your solar generator, collect the precise details concerning this aspect of each device.
This information is usually specified on the manual of each device or, failing that, on the website of each manufacturer.
The expected duration of use
The duration of use of each device is also a determining parameter for a good evaluation of the ideal power. The generator you choose must be able to provide the necessary power to meet the needs of each device for as long as desired. If your goal is to use it during the night, it should be sized to last at least 14 hours.
Taking this parameter into account will allow you to avoid that your generator fails in case of simultaneous connection of several devices.
How to estimate the ideal power for your solar generator?
It is difficult to estimate exactly how much power you will need to power your various appliances with a solar generator. However, it is possible to make a rough estimate based on your needs.
Let's take a small practical example. Let's assume that you use a 50 W television, 3 bulbs of 30 W each and a 20 W mini hi-fi system. Let's also consider that the lamps are used for about 2 hours per day, while the TV and the mini-stereo are used for 1 hour per day.
Calculation of the daily power requirement
The calculation of the necessary power for one day is thus done as follows:
- For the TV: 50W for 1 hour per day, or 1 × 50W × 1 h = 50 Wh ;
- For the bulbs: 3 of 30W for 2h per day, that is 3 × 30W × 2 h = 180 Wh ;
- For the hi-fi system: 20W for 1 hour per day, i.e. 1 × 20W × 1 hour = 20 Wh ;
In total, the daily energy consumption is therefore estimated at : 180 Wh + 50 Wh + 20 Wh, that is 250 Wh.
Calculating the ideal power for your solar generator
From the average daily consumption, you can now calculate the ideal power for your solar generator. In this case, you need to produce at least 250 Wh in order to meet your daily consumption.
The rest of the calculation is done by taking into account the average duration of sunshine. In France, the average duration of sunshine is estimated at about 5 hours per day.
On this basis, it is then sufficient to divide the daily power required by the average number of hours of sunshine. For the previous practical case, it is thus enough to make 250 Wh/5h. We obtain 50 W.
Ce qui signifie que pour alimenter l’installation présentée ci-dessus dans les conditions évoquées, un générateur solaire doté d’une puissance minimale de 50 W est suffisant.
In this example, an ecoflow delta 2 is more than sufficient. But be sure to take into account all the power consumption needs that you want to run on your solar generator.
What is the minimum power needed to supply my house ?
In order to determine the power required to cover the energy needs of your house, you just have to use the method detailed above, taking into account the particularities of your home.
To do this, you must therefore take stock of all the equipment you use and assess your energy consumption. However, it should be noted that here you can use the electricity consumption standards for a more or less accurate estimate.
For information, French households use an average of 1,100 kWh per year. As for cooking, the needs are estimated at about 200 kW per year per person. It is then sufficient to convert this data on a daily basis in order to easily identify the power of the generator needed to supply your house.
How much power do I need to heat my home?
For heating, the average household needs are estimated at about 110 kWh/m2/year. For domestic hot water, the energy consumption required is estimated at 800 kWh per person per year. You can also note the energy output of your radiator in order to clearly determine the power required for your generator to operate it.
In fact, if you have a 1000 W solar radiator for example, running it for one hour will require 1000 Wh. Given that you have an average of 5 hours of sunshine per day, you will need a solar generator of 200 W. This will theoretically be able to run the heater for one hour per day.