Frequently Asked Questions
Does burning biomass emit more harmful greenhouse gases than coal?
No, biomass is part of a closed cycle involving the atmosphere and biosphere. Trees take carbon from the atmosphere when they are growing and release it again when they decay in the forest or are burned. This is known as the Carbon Cycle and is shown in the diagram below. In contrast, when fossil fuels are burned, carbon is released that has been stored for millions of years, which increases carbon in the atmosphere. This carbon would have continued to have been stored if it was not burned. Instead, the burning of fossil fuels adds to a net increase in the amount of carbon in the cycle, which adversely contributes to the Greenhouse effect.
Do wood pellet plants create emissions that pollute the air around it?
Highland Pellets uses the best available technology to ensure that any emissions are within the strict limits and regulations of our Air permit.
Highland is incorporating a green grinding process to produce a very precise, smaller particle size distribution. By grinding to a smaller particle size, Highland is assured to get full penetration of the dryer heat through the cross section of the wood particle resulting in a uniform moisture content through the particle when dried. Uniform and thorough drying reduces the difference in the shell and core moisture content assuring that any Volatile Organic Compounds (VOC’s) are released at the dryer where they can be destroyed by the Regenerative Thermal Oxidizer (RTO). Managing this process minimizes the release of VOC’s in the downstream processes.
A Wet Electrostatic Precipitator (WESP) is used to clean particulate from the dryer air so it can be further processed to remove VOC’s. Half of the dryer conveying air is recycled within the dryer, half travels through a stainless-steel quench duct where it is sprayed with water to separate the large solid particles. The moisture laden air passes through collection tubes where they are introduced to an electrostatic field which pulls the fine solid particles from the gas stream. Once the solid particles have been removed, the moist air is transferred to an RTO (Regenerative Thermal Oxidizer).
The moist air contains VOC’s that have been driven from the wood fiber as it is subjected to high temperatures in the dryer. The VOC laden air is conveyed through a ceramic media bed heated to 1,500 degrees F. The air is subjected to these high temperatures for approximately 2 seconds which destroys 99.9% of the VOC’s. After passing through the high temperature medial beds, the cleaned air is exhausted to atmosphere.
Why do we need biomass if other forms of renewable energy provide zero carbon?
Biomass power stations are available to be ramped up or down when needed by the System Operator. Biomass is therefore an alternative to dispatchable fossil fueled energy, which intermittent wind and solar are unable to replace. In the last few years, many European countries have significantly changed their energy mix away from fossil fuels to include a much greater proportion of renewable energy. The prior high dependence on coal has largely been replaced by a combination of solar and wind, while natural gas remains an important dispatchable source of power for balancing the networks.
However, with most European countries now committed towards a net-zero carbon economy by 2050, natural gas remains part of the emissions problem until Carbon Capture Storage (CCS) technology becomes commercially available and enables natural gas to become carbon neutral. Applying CCS to Biomass (Biomass Energy Carbon Capture Storage or BECCS) would move biomass energy from carbon neutral (existing carbon cycle) to carbon negative (most emissions captured and used in other production of goods or stored underground). BECCS technology is being developed by Drax in the UK and could be commercially available within the next 10 years.
Biomass is therefore important today as a carbon neutral form of dispatchable energy that is cleaner than natural gas and more controllable than alternatives forms of renewable energy. In future, Biomass with BECCS will be essential if the UK is to reach its legally binding net zero carbon targets by 2050.
If a tree burns in seconds but a replacement tree takes years to re-grow to the same size, is there a ‘carbon debt’ until the new tree has reached the size of the tree it replaced?
An assessment of the carbon stock of a forest must include the whole forest and not just a single tree. As trees are harvested in one area of a managed forest, there will be several other areas with new trees growing. The carbon stock therefore needs to look at the region in question and assess whether there are as many trees absorbing carbon than is lost through the harvest of trees, so that there is no net loss of carbon. Sometimes the “Growth to Removal” ratio is used to assess the balance of harvest versus new growth. If the ratio is equal or greater than one, then there will be more trees absorbing carbon than carbon lost through the harvest of trees. Healthy demand for wood stimulates supply and ensures forests remain as forests. That is why forest cover in the U.S. is growing year on year and has been growing for each of the last 50 years. Highland follows stringent sustainability criteria that ensures our supply of pellets does not lead to a net increase in carbon levels.
Does the biomass industry contribute to deforestation around the world?
No, biomass provides an additional market for wood fiber that is otherwise uncommercial. This additional demand creates new value to the forest and helps to further stimulate investment in sustainable forests. In fact, wood thinnings are created as a consequence of good forestry management aimed at stimulating forest growth and development, thus maximizing carbon reduction.
Highland Pellets only harvests from forests with responsible forest management practices to make sure that forests are being maintained and not contributing to deforestation.
How can it possibly make sense to ship wood pellets up to 3,800 miles to generate electricity when there are other alternatives available?
The economies of scale are a big advantage as we are able to ship our biomass in vessels as large as 60,000 tonnes capacity. We measure the carbon footprint of every step in the supply chain, so we know exactly how much carbon is emitted during harvest, processing and transport. Even when this entire life cycle is taken into account, savings relative to coal are around 80%. Wind power cannot be relied upon to respond to changes in demand when needed. Other renewables are important, but on their own they cannot meet our electricity needs.
Is the production of biomass tightly regulated?
Yes, Highland is independently audited against stringent sustainability standards covering a range of issues including protection of biodiversity and conversion of forestland to other uses. Highland puts feet on the ground to have firsthand knowledge that any material coming to Highland follows State best forest management practices. At the federal level in the U.S., forestry is regulated by the Clean Water Act, Clean Air Act, Endangered Species Act, Migratory Bird Treaty Act, Coastal Zone Management Act and the Lacey Act. At the State level, it is regulated by a range of water quality management regimes, established industry best practices, wetlands protections and zoning and landscaping ordinances. See our Sustainability section for more information.
Does Highland produce pellets from whole trees?
Highland only uses residual parts of trees (branches, tops and sawdust) or trees that have low commercial value because they are diseased or damaged or cut down to thin the forest and encourage growth, but are too small to be sold into any other market (“thinnings”). It makes no commercial sense to use good quality mature whole trees for biomass since the mature tree has substantially more value being made into saw logs or furniture – we simply cannot afford to use whole trees to make pellets because the wood is too expensive. The forest owners will maximize their value by selling the best wood into the highest value markets. Biomass provides a valuable additional source of revenue to forest owners by providing a market for wood fiber that would otherwise be non-merchantable. This helps forests stay commercially viable as forests, where many managed forests are under threat of being developed into other land uses because of the global collapse in the demand for paper caused by technical innovation.
Will industries that use wood be competed out of the market, including the furniture and construction industries where the carbon in the wood continues to be stored in the end product?
Forest owners typically supply a range of markets including sawmilling, panel board, pulp & paper, energy and heat; therefore, wood for energy is just one use amongst many. The forest owners will sell the best wood to the highest value markets such as saw logs. Large diameter logs from the trees’ lower trunks are usually the most valuable part of a tree. It is typically sawn and used in construction, joinery and furniture-making.
Biomass often uses the leftover fiber that is low value, because it has no alternative market. It is often the case that a new pellet facility will locate in an area where there was once a paper factory but has since closed due to the dramatic decline in the demand for paper in recent years due to advances in technology. Pellet facilities therefore help to replace old industries and provide new value into forests, enabling them to remain commercially viable and preserve local employment.
Wood pellets make up a very small amount of the overall wood products industry. Wood pellet production made less than 2% of total production of US forest products in 2018. Wood pellets therefore do not have a strong impact on the furniture and construction industries because they are much larger markets and use higher quality saw logs rather than the low-quality fiber for pellet production.