Luxury headphone makers Monster and Beats Electronics have announced that they will be ending their relationship when their current contract runs out. Beats and Monster together have been extremely successful, and, according to researcher NPD Group, their products gained 53% of the $1 billion annual headphone market in 2011. The companies have collaborated since 2008.

But their partnership will now end, as Beats Electronics has chosen not to renew the contract for another five years. According to Businessweek’s sources, the split occurred because of disagreements about fair profit sharing.

Beats will keep the rights to the bass-heavy sound technology, the prominent circular design and the brand. It is majority owned by gadget-maker HTC and had collaborated also with HP.

Seen that Beats is very popular among young people, Monster is going to target athletes, women and business professionals. One $200 pair of in-ear headphones has the name of the ’70s soul act Earth, Wind & Fire. A Miles Davis line has earbuds shaped like trumpets and a volume controller that looks like a piston valve. There are also eight new lines in 50 different styles.

The OTEC permit office in the US was opened between 1981 and 1994, having issued not a single OTEC permit. When oil prices went down after the 1970s, the incentive to invest in OTEC faded. Renewable energy sources are now fashionable again, and there are several companies interested in this technology, from giants such as Lockheed Martin to smaller companies like the Ocean Thermal Energy Corporation of Lancaster, located in Pennsylvania.

Lockheed Martin is doing an experiment in Hawaii in collaboration with a smaller firm, Makai Ocean Engineering, to build a ten megawatt (MW) pilot plant that should be operational by 2015. If that gives positive results, the idea is to build a 100MW power station by 2020.

Ocean Thermal Energy Corporation is working on a smaller project with the Bahamian government to build a fully commercial OTEC plant. Initially the idea is to provide cooling for a holiday resort and then to build a 10MW power station.

If you are interested in renewable energies, read also Deep Heat.