Is energy always conserved?

Well imagine this wavelength /\/\. It has a duration of 4 characters and a frequency of 0.5 cycles per character. Imagine I stretch this out. /-\-/-\- now it has a duration of 8 characters and a frequency of 0.25 characters. This has a lower frequency, but to compensate, has a longer duration. The product, characters times frequency, is 2 in both cases.