Bio-gas coupled with conversion of its waste bio-slurry into bio-fertilizer would benefit India in the field of both energy and agriculture. The Government seems to have made up the mind to move in this direction. The newly floated schemes are a clear indication. When1 kg of biogas is produced, nearly 100 Ltr of waste bio-slurry is also produced. This bio-slurry is actually “Brown Gold”, which can give up to 5X returns to bio-gas owners as compared to the bio-gas. Experts calculate the potential of bio-slurry to save on imported chemical fertilizers to be to a tune of INR 6000 – 11,000 Cr every year. However, our work on value addition of biogas slurry suggests that it could be at least 10 times more. A simple model of operations which is “tested at scale”, points out, that at least half of this sum earned by the bio-slurry can go into the pocket of farmers - those farmers who set-up and effectively run a household biogas plant of 2 m3 capacity. This economics of bio-slurry will build a strong circular economy. It will also pave new ways to raise the initial capital for bio-gas plants and reduce the subsidy burden on the Government