That sounds like an awful lot of power for something which does not involve any heating!My Flymo sucker/blower is 3 kW, ....
Whether a sucker/blower, a chain saw or any other sort of power tool, the average householder/DIYer is going to use them for such relatively short periods of time, and probably only very occasionally, that their use will surely have minimal impact on the totality of their electricity bills, won't it?but I will still use it to clear the leaves rather than using the chain saw attachment and going down to get petrol and mixing it with oil for the chain saw, and still likely cheaper to use electric to using petrol as for one the electric is more powerful so used for less time.
Kind Regards, John