Hot Water Heating Cost Calculator

How much does an electric water heater consume?

Volume (liters):Power (W):Initial temperature (°C):Desired temperature (°C):kWh Price (€):Important!Calculate

The electric water heater energy consumption calculator is a handy tool that allows you to estimate the energy (in kWh) and time needed to heat water in your electric water heater. It also helps you calculate the energy cost based on your current price per kilowatt-hour (kWh).

Important: This calculator assumes that the heating element operates at nearly 100% efficiency—meaning the heater is free of scale buildup or other issues. Also, keep in mind that the kWh price on your electricity bill includes more than just the energy cost. For realistic results, it’s advised to double the price per kWh listed by your electricity provider to account for all charges. This is, of course, open to discussion, so feel free to share your thoughts in the comments section below.

Possible Uses of the Calculator

This tool can be helpful in many ways:

1. Understand Your Energy Consumption: See how much energy you use to heat water and discover opportunities to save.

2. Compare Costs: Compare the operating costs of different heaters with different power ratings.

3. Calculate Savings with a Solar Water Heater (SWH): See how much energy and money you could save by switching to a solar water heater that uses the sun instead of electricity.

Connection to Solar Water Heaters

Solar water heaters are one of the most effective ways to reduce electricity consumption. By calculating the energy required to heat your water, you can estimate how much you could save by using a solar system.

For example, if the calculator shows that heating 100 liters of water from 20°C to 60°C requires about 4 kWh, you can calculate the cost and compare it to the free energy provided by the sun.

The Theory Behind the Calculation

The energy required to heat water is calculated using the formula:

E = m × c × ΔT

Where:

• E is the energy in joules (J)

• m is the mass of the water in kilograms (equal to the number of liters)

• c is the specific heat capacity of water (4.186 J/g°C)

• ΔT is the temperature difference in °C

The result is then converted into kilowatt-hours (kWh), where 1 kWh = 3.6 million joules.

Types of Water Heaters

This calculator works for all types of electric water heaters, including:

1. Standard Resistance Heaters: Use electric heating elements to warm the water.

2. Solar Water Heaters with Electric Backup: Useful for estimating additional energy and cost when the solar heater provides only lukewarm water on cloudy days.

Conclusion

The electric water heater energy calculator is a valuable tool for anyone looking to understand their energy use, reduce expenses, and explore more sustainable solutions like solar water heating. Try it out to see how much energy you could save and make more informed decisions for your wallet and the planet.