Are off grid wood gasifiers a new technology?

No. During WWII over 1M cars and trucks in the US ran on wood gas - which is produced by a wood gasifier. http://www.robertsarmory.com/gas.htm

So rest easy this is a well proven technology that has been in use for over 100 years! We have taken this technology and packaged it into a simple energy - turn key system. Our off grid wood gasifier kit includes everything you need to get started.