This assumption is incorrect; there is no problem with cost of electricity as regards mining with our new algorithm. There is some confusion between hashpower and hashrate. Power consists of GPUs doing work. Rate is a measure of solutions per second.
We often estimate hashpower in hashrate. This works well to compare one GPU to a different GPU when both are using the same algorithm.
However, you can not use hashrate to compare power between two different algorithms, because the algorithms have different hashrates when powered by the same GPU.
We know that the same GPU, with the same power profile, will produce about 12 times as many solutions with the old <200,9> as with the new <144,5>. This means equivalent hashpower will produce 1/12th as much hashrate with the new <144,5>.
We can see from historical data that the change to the new algorithm on July 3rd resulted in no material loss of hashpower on the BTG network. (Click link for detailed FAQ with graphs.)