Biomass is renewable plant material that has been grown using energy from the sun. It includes wood, and other cellulosic plant fibres. Wood is favoured as a biomass fuel due to its low ash content and a relatively constant heating value. Unlike wind and solar power, wood chip biomass electricity generation is not intermittent but is a reliable baseload power source. In 2013, biomass accounted for about half of all renewable energy consumed and 5% of total energy consumed in the United States.
After a century of established use around the world, biomass electrical power production is a renewable technology that is currently witnessing a substantial increase in uptake, given global pressures on environmental performance and sustainable practices, carbon constraints and corporations’ desire to enhance their social licence to operate. Biomass power is the only renewable power source that is storable, transportable and dispatchable on demand.
The PNG Biomass project involves the development of 16,000 hectares of FSC certified tree plantations, using underutilised Kunai grasslands in the Markham Valley, and the development of a 30 MWe Biomass Power Plant to generate electricity for supply to the Ramu Grid.
The plantation establishment will require the planting of more than 20 million trees and will be managed in an internationally sustainable manner. The plantations will provide a dedicated fibre source for the power plant, which will require the annual supply and harvesting of 160,000 – 180,000 bone dry metric tonnes of wood to support the 30 MWe power project. The trees will be harvested every 4-7 years.
The trees will be harvested in the plantation and then transported in large trucks to storage facilities at the power plant where they are dried and turned into wood chips for fuel. The chips will then be burned in the power plant to generate high-pressure steam that drives a turbine. When the wood chips are burnt they release carbon dioxide (CO2) into the atmosphere. This CO2 is in turn consumed again by the trees in the surrounding plantations. This process is known as photosynthesis, the by-product of which is oxygen. The electricity generated from the turbines will then be transferred directly into the nearby Erap substation to provide power into the Ramu Grid.
This excellent video from EDF shows how a biomass power plant works.
Biomass power generated from certifiable sustainable feedstock is internationally recognised as one of the most efficient and proven renewable energy sources. Biomass power is a “carbon cycle” in which PNG Biomass will have 20 million trees planted and grown in under-utilised Markham Valley areas in an internationally certifiable sustainable manner and then harvested every 4-7 years. Over 200,000 BDMT of wood will be harvested annually to support the 30 MWe biomass power project. The trees regrow after harvesting and new planting will also occur to maintain the tree supply indefinitely.
The trees will be harvested in the plantation and then transported in large trucks to storage facilities at the power plant where they are dried and turned into wood chips for fuel. The chips will then be burned in the power plant to generate high-pressure steam that drives a turbine. When the wood chips are burnt they release CO2 into the atmosphere. This CO2 is in turn consumed again by the trees in the surrounding plantations. This conversion of CO2 to wood is a process is known as photosynthesis, the by-product of which is oxygen.
Biomass power using certifiable sustainable feedstock is internationally recognised as one of the most efficient and proven renewable energy sources available.
Using biomass (wood) for power is a centuries-old technology – it is based on the use of a boiler to burn the wood and make high-pressure steam to turn large electricity turbines.
Biomass power is attractive because of its proven and simple technology, cost competitiveness and ability to supply the energy needs of major industries, households and rural communities. The use of Biomass Power Plants around the world is increasing rapidly as the costs of fossil fuels go up and the need for renewable energy and greater positive environmental impacts are increasing.
Biomass plants have increased in popularity globally as both stand-alone power generation and as cogeneration facilities with other agricultural processing plants and coal. Biomass plants can use dedicated feedstock as well as crop residue and waste to generate power. This can which result in additional revenue for the agricultural industry such as palm oil, forestry and sugar.
Global Biomass Electricity Capacity is around 62 GW, which is around 200 times the size of all the grid connected generation in PNG. Shell (2014) forecast that Biomass will provide over 15% of the world’s energy needs by 2050, most PNG people are familiar with the use of biomass (wood) to generate heat for cooking.
Biomass is widely used in the Pacific region. Thailand has an installed biomass capacity of over 700 MW of which 240 MW which is connected to the utility grid. Malaysia is estimated to have over 500 MW of installed biomass power and Australia has 450 MW installed capacity of biomass generation of 10 MW or greater.
Biomass plants are generally less than 100 MW but large-scale plants are now being built in Europe where they have secured long term supply contracts for biomass feedstock.
Biomass Power Plants are ideal for PNG because they can support power generation from 5 – 50 MW at a price that is lower than diesel and Heavy Fuel Oil (HFO) and which is complementary to the cost and time to deploy hydro and gas power solutions of the same size. The key to success for Biomass power (and for any power) is having a secure fuel supply and PNG’s sustainable plantations can provide this in abundance.
The following are examples of biomass power plants around the word that use basic technology and at various scales.