Of course, solar water heaters save money, but they are weather dependent. The uninterrupted supply of hot water depends on the scorching sun.
Installing water heaters can provide continuous hot water, but they have relatively high demands on the electricity network and are very powerful. Small power water heaters make no sense.
Electric volume water heaters are relatively large, so those who require an uninterrupted supply of hot water should choose a larger capacity.
There are two concepts of saving, one is saving electricity and the other is saving money. Larger capacity volumetric electric water heaters can be used for day and night heating and can be used. all day, saving money but no electricity.
There is no energy saving in electric water heaterscudgels. The efficiency of electric heating is the same, both volumetric and instantaneous.
In terms of water volume, a person needs 20-40L of water to take a bath, especially in cold weather, so 60L is not enough for your family. At least 100 L or more is enough. Of course, you can use an electric water heater to wash intermittently. When the water is cold, it will be heated for a while and the people behind you can wash it once the water is hot.
From an energy saving point of view, solar energy is of course cost-effective, and at least the first 60 liters of hot water can be purchased for free. Nowadays, solar energy also has additional electric heating. Once the first 60 L is used up, an electric auxiliary heater can be used.
Another problem is that you didn't say where you are from. If you are in the south, where summer is long and sis barely enough, then it is more profitable to use solar energy.
Also, solar water heaters are actually water storage types, and it also depends on how much L they have.
Another problem is that electric heating inevitably presents problems of scale, which cannot be completely solved. The longer the duration, the greater the electricity consumption.
I therefore suggest that you purchase a more auxiliary solar heating system, 100L or more.