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What is the savings potential for a battery dry room?

With the right dehumidification strategy, a battery cell manufacturing plant could cut electricity consumption by up to 42,7GWh/year and CO2 emissions by 14,900 tonnes/year.

Cotes Exergic Technology would be able to lower electric consumption by up to 88%. But what would it mean in absolute numbers?

As a rule of thumb, the electricity consumption (Wh of dehumidifying 1m3) would be:

Fresh air rate 100% 50% 25%
Conventional one-stage 11,2 7,8 6,1
Cotes Exergic waste/district heat 2,4 1,7 1,4
Cotes Exergic Heat Pump 4,3 2,7 1,9

The above is based on a -40°C dew point (but -60°C would almost be the same for Cotes Exergic Technology).

If the Giga factory has an air supply need of 500.000m3/h, the annual consumption for 24/7 operation would be (GWh/year):

Fresh air rate 100% 50% 25%
Conventional one-stage 48,8 34,0 26,6
Cotes Exergic waste/district heat 10,5 7,4 6,1
Cotes Exergic Heat Pump 18,7 11,8 8,3

The above would leave an annual electricity saving potential of up to 38,4GWh if waste heat is available and utilised. An extra 4,4GWh could be saved if the fresh air rate could be reduced to 25% by improving filtration and reducing leaks in the clean room. That would together lead to a reduction of 43,7GWh.

If waste heat is unavailable, an alternative would be replacing the chillers with high-temperature heat pumps. That would reduce the annual consumption by 30,1GWh/year. Lowering the fresh air rate to 25% would save another 10,5GWh/year, totalling 40,5GWh/year.


With electricity prices going rocketing high, the saving potential is enormous. At an electricity price of EUR200/MWh, a reduction of 42,7GWh/year would lead to an annual saving of EUR8,5mio. 


The German average CO2 emission is 349g/kWh electricity, meaning the change from a conventional dehumidifier to a three-stage dehumidifier would cut emissions by 14,900 tonnes of CO2/year, equaling emissions from 3.131 trips around the world in a standard car – every year.