Found an article at Sustainable Design Update (the site seems to have disappeared) about Sintex Industries making a prefabricated biogas digester which turns waste and garbage into cooking fuel. Nothing new about the technology but constructing a tank has always been the biggest headache. Now, you can just get it ready-made and install it. According to some reports, it costs about Rs. 17,000 for a tank that’s 1m³ in size which is enough for a family of 4 and the payback period is 2 years.
Interestingly, most references to Sintex call it a “plastics and textiles manufacturer”. I didn’t know they did textiles. Here in Bombay, Sintex is to tanks what Xerox is to photocopiers. In the meanwhile, not a single Indian newspaper or website had picked up on this. Yet…
The Sintex website makes no mention of this product and it’s still probably a pilot project because only 100 have been installed as of date. They do plan to increase production tenfold but 1000 tanks is still merely a drop in the ocean. If other manufacturers copy this design with as much alacrity as they did the Sintex loft and overhead tanks, then we might get somewhere.
Edit: Since this was written, Sintex has updated their website and you can see septic tanks listed as one of their products.
Edit #2: The page itself has disappeared so, for the moment, the link above points to an archived version on Wayback Machine.