I was wondering if there are permaculture related sites that I could visit on an upcoming visit to Bangkok? I am not sure what is available but I am interested in all best practice sustainability sites including community gardens, food forests, aquaponics, solar power. Do such things exist in the capital?

There is a permaculture training group in Chaing Mai with facility, you can find them on the net, google; permaculture Chiang mai.

anyone knows how to say Permaculture in Thai language

You may get some useful information through the Thai Visa 'Farming in Thailand' forum and the 'organic' subforum. There was a recent discussion on a new basic training program in the north.

It's doubtful that you will find much 'permaculture' in Bangkok, but as Animatic has suggested, there is more activity and training in Chiang Mai and the north.

http://www.panyaproject.org/

http://www.fairearthfarm.com/