# How do I convert generated cooling capacity in kW to kWh?

I have to program a relatively simple program so I can display values on dashboard representing the part kWh a system is responsible for generating. This will be represented as a percentage.

I have a known value -> total generated cooling in kilowatt-hour.

I have 2 cooling machines where I had to calculate the required power to cool a medium (water) resulting in a kilowatt value.

Using this formula (energy required to heat or cool a medium water in kW).

How do I convert the resulting kW value to a kWh value so I can calculate the fraction of cooling my machine A or B was responsible for?

I wasn't able to figure it out using google, so any help would be greatly appreciated!

• what's difficult about multiplying by time?
– user16324
Commented Aug 26, 2022 at 15:12
• How do I convert mph to miles? I have a known value -> distance to travel in miles. I have 2 cars where I had to calculate the required speed to travel a road resulting in a mph value. How do I convert the resulting mph value to a miles value? Commented Aug 26, 2022 at 16:36

How do I convert generated cooling capacity in kW to kWh?

• 1 kW generated or consumed for one hour is an energy of 1 kWh

• 2 kW over 30 minutes is an energy of 1 kWh

• 0.5 kW over 30 minutes followed by 30 minutes at 1.5 kW is an energy of 1 kWh

• In joules it's 3.6 MJ.

Your formula $$\P = m*c*\Delta t * 1/3600 \$$ is complete nonsens, if you interpret the symbols in your way.

I haven't found a good Web site for that so far (only https://sciencing.com/calculate-time-heat-water-8028611.html) but this site seems to be unscientific...

In fact, to cool (or warm) liters of water, the following equation can be used: $$E = c \cdot m \cdot \Delta T$$ If you handle with pure water (not ice, nor H2O gas) the specific heat capacity $$\c\$$ is about $$\4.19\,\frac{\textrm{kJ}}{\textrm{kg K}}\$$. The $$\m\$$ is the mass of the water, and $$\\Delta T\$$ is the temperature difference in Kelvin (i.e. the temperature difference from starting point to the end point in degree Celsius). Because the density of water is about 1 g/cm3, mass and volume correspond. The volume of 1 liter of water corresponds to the mass of 1 kg.

So you will get the Energy $$\E\$$ in Kilojoule (kJ) which is equal with: $$1\,\textrm{kWh} = 3600\,\textrm{kJ}$$ To calculate the kWh, you can simply divide the result (given in kJ) with 3600 and $$\E\$$ becomes the amount in kWh.

To calculate the power $$\P\$$ for a period of Time $$\t\$$, use $$E = P\cdot t$$