The money saver

Traditional heating systems use expensive fossil fuels. A heat pump boiler works much more efficiently and conserves more energy than a traditional heating system based on fossil fuels or electricity. You are only charged for a small amount of electricity, but that’s an investment that pays. From 1 kilowatt of electricity Daikin Altherma produces 3 to 5 kilowatts of available heat.
Money Saver graph.
Legend money saver 1.Running cost
Legend money saver 2.Primary Energy Efficiency
Fuel boiler   Gas boiler       Daikin Altherma

* Source

How do we reach 168%?
We compared the primary energy consumption, to come to a cumulated efficiency
= Efficiency of electricity generation (0,42) x COP of heat pumps (4)