By Iain Riddell, principal consultant at SAC Consulting, part of SRUC
INDUSTRIAL hemp is cultivated globally – around 35,000 hectares in the EU alone – with a market value projected to quadruple to £13 billion by 2030. While end uses for the crop are wide ranging, including automotive parts, bioenergy, paper and textiles, in Scotland an opportunity is emerging to use hemp as a sustainable alternative for traditional construction materials.
As it stands, the construction sector is one of the largest contributors to carbon emissions, with concrete responsible for around 8% of global CO₂. An increased use of hemp-based products could support the sector’s efforts to reach net-zero targets, while still maintaining the performance and quality of traditional products.
Hempcrete, for example, is a bio-based alternative to concrete comprising a mix of hemp shiv – the chopped-up, woody core of the hemp plant – and lime, used as a binding agent. Studies have shown that homes built using hempcrete are structurally equal to those built using conventional materials, but are better insulated and less prone to damp.
Thermal insulation panels using hemp fibre are another example, offering a natural, environmentally friendly alternative to synthetic insulation materials. These products maximise carbon capture and energy savings and, at the end of their life cycle, panels can easily be reused or reprocessed into new products.
While not necessarily suitable for the same applications in a building, analysis of the carbon footprint of hemp-based alternatives is compelling. One square metre of timber-framed hemp-lined wall sequesters around 35.5kg for the lifetime of the building, effectively locking in the carbon emissions. The use of one tonne of reinforced concrete, by contrast, results in 198kg of CO2 emissions, largely through its manufacturing process.
Scotland has a suitable climate for growing industrial hemp, and Jedburgh-based IndiNature is a great example of a pioneering company capitalising on its potential. However, there is scope to take that much further and ensure that home-grown Scottish hemp is used as the foundation for these products, rather than imports from other parts of the UK or overseas.
Currently, there are only a handful of producers growing hemp at any meaningful scale in the UK, but with a strategic and collaborative approach, this could quickly change. SAC Consulting recently completed a feasibility study, supported by the Industrial Biotechnology Innovation Centre (IBioIC) and Scottish Enterprise, to explore the possibilities for a new supply chain with a farming cooperative at the heart of the plans, supporting 2,000 hectares of hemp.
Five Borders farmers have sown hemp crops already this year, which will provide opportunities to promote the crop to others at upcoming events and meetings. However, on the whole, farmers remain understandably cautious about exploring a new crop.
Though fibre crops were previously grown in Scotland, today’s farmers face challenges ranging from legal requirements to uncertain market pricing. There is also still a misconception that hemp crops have narcotic properties, which needs to be challenged. The crop varieties used for industrial applications have negligible amounts of tetrahydrocannabinol (THC), the psychoactive compound. The process for obtaining a license to grow hemp can also be a barrier in terms of cost and complexity, as well as the requirement for regular checks and renewal.
It is important that we make more farmers aware of the benefits of using hemp as a break crop, such as improved soil health. UK growers have reported the hemp can boost the yield of subsequent cereals by 15%. Hemp also offers potentially better pricing than alternative break crops such as wheat, barley, and oats.
Growing hemp also has significant benefits for the environment in terms of its ability to capture carbon. Production is carbon negative, and studies have shown it to be more effective than trees. Industrial hemp absorbs up to 15 tonnes of CO2 per hectare per year, compared to up to six tonnes per year for forests, after a period of 30-50 years to grow. Meanwhile, the carbon cycle for hemp is just 12 months, making it a powerful tool in the fight against climate change.
Nations like the Netherlands and Germany provide a strong evidence base which Scotland can learn from. With supportive policy, cooperative models and targeted subsidies, we could also have a thriving hemp sector. Investment in processing facilities and clear market incentives are also needed for the construction industry to adopt sustainable materials and in turn, we can create more demand.
The market is still in its infancy, but the potential is there for Scotland to become a first mover in the UK’s industrial hemp market, with a particular focus on opportunities for the construction sector. The groundwork exists, but with farmers, government and industry working together, hemp could become the core material for new, fossil-fuel free products that are made in Scotland for years to come.
