Biomass, renewable CO2-neutral energy source obtained from biological processes (wood, straw, etc) for the production of alternative energy etc. ( alternative energy sources). The proportion of biomass in primary energy use rose from 3.4% in the 1970s to 12% in 1995 and is still growing. 99% of bio-energy is obtained from biomass: 70% from fire wood, 14% from wood shavings, bark and chippings, 14% from waste lyes from the paper industry and 1% from straw. 1% comes from waste-tip gas, sewage gas and methane. The proportion of biomass in electricity production is still clearly below 1% but is hoped to be increased in the immediate future. Amongst the Austrian Federal Provinces, Upper Austria obtains the most energy from biomass.