Microalgae Biofuel LCA: Real-World Data from the InteSusAl Facility

Note: Below280 undertook this work while operating within Narec (National Renewable Energy Centre) and subsequently Decerna

Background

Microalgae attracted real research interest as a biofuel feedstock for good reasons. They grow far faster than terrestrial energy crops, do not compete with food production for agricultural land, and farmers can cultivate them on non-arable land using seawater. Early research initially suggested high oil yields and greenhouse gas savings compared with fossil fuels. By the early 2010s, the European Commission was co-funding a cluster of demonstration projects to test whether those promises held at industrial scale.

The problem was that most LCAs supporting those claims were based on laboratory data, mathematically scaled up to hypothetical industrial facilities.

InteSusAl was a European Commission FP7 project running from 2011 to 2016, co-funded by DG Energy, designed to test the integrated production of microalgae for biodiesel at a real demonstration facility. Six consortium partners across four countries each contributed specific expertise: CPI (UK) as project coordinator, providing heterotrophic cultivation technology and IP; Necton S.A. (PT) hosting the demonstration facility and contributing phototrophic cultivation expertise; NIOZ (NL) for algae strain selection; DLO-FBR (NL) for industrialisation and separation technology; EUREC (BE) for dissemination; and Narec (UK), the organisation from which Below280 later emerged, responsible for validating the environmental and economic sustainability of the whole system.

That sustainability role sat within a dedicated work package running throughout the project. The project embedded the LCA from the start, using it during the design phase to guide decisions on system configuration and compare the InteSusAl approach against fossil fuels and other biofuels.

The Facility

The project partner Necton S.A. built a facility in Olhão, Portugal. This comprised 16 km of tubular photobioreactors with a combined volume of 60,000 L across four systems growing Phaeodactylum tricornutum and Nannochloropsis salina, alongside three 1,000 L low-cost steel fermenters supplied by CPI producing Chlorella protothecoides heterotrophically. A fourth fermenter ran at the CPI site in Teesside.At the time of publication, no other peer-reviewed LCA covered an integrated real-world photobioreactor and fermenter system.

The system combined heterotrophic and autotrophic growth, with CO₂ from the fermenters feeding the photobioreactors and O₂ from photosynthesis feeding back into the fermenters. Growth productivity trials ran from October 2015 to June 2016, providing the primary data for the LCA.

The LCA

Below280 conducted an ISO 14040 and ISO 14044 compliant, well-to-wheel LCA using primary operational data from the Olhão facility. The team modelled it in GaBi with secondary data from Ecoinvent. The functional unit was combustion of 1 MJ (Lower Heating Value) of algal biodiesel in an internal combustion engine. This allowed direct comparison with petroleum diesel.

Below280 modelled three electricity scenarios… The team assessed each scenario with and without infrastructure impacts.

Impact categories covered the full ReCiPe midpoint set alongside IPCC AR5 GWP100, GWP20 and Global Temperature Potential. This represented a broader climate characterisation than most biofuel LCAs at the time.

Applied Energy published the harmonised LCA methodology used across all three Algae Cluster projects in 2015.

What the LCA Found

Including infrastructure, algae biodiesel produces higher climate change impacts than petroleum diesel across all three electricity scenarios. Specifically, on PV power, 1 MJ of algae biodiesel emits 1.48×10⁻¹ kg CO₂eq against 8.84×10⁻² kg CO₂eq for petroleum diesel on GWP100, and the gap widens over shorter timescales due to the methane burden from yeast production.

Under grid electricity, electricity dominates operational impacts. Under PV, yeast extract becomes the primary source, accounting for 68.2% of AR5 GWP100 operational impacts. Reducing electricity therefore does not resolve the system’s environmental profile; it shifts it.

Beyond climate change, the picture is more difficult. Under the 2020 grid scenario, freshwater ecotoxicity impacts were 1,320% those of petroleum diesel and freshwater eutrophication was 1,610%. Under PV, water depletion was 2,350% greater. A PV-powered system reaches climate parity with petroleum diesel at productivities above roughly 25.6 tonnes per hectare per year. Most other impact categories, however, remain substantially worse at that level.

In conclusion, the InteSusAl system is not viable as a biofuel production system at current productivity and process configurations.. Instead, the LCA pointed toward high-value products from microalgae. In particular, nutraceuticals, pigments, proteins and specialty chemicals carry far higher value per unit of biomass, making the cultivation energy investment easier to justify.

What Happened Next

The LCA findings fed directly into how Necton developed the facility after InteSusAl. The energy impacts identified in the assessment informed Necton’s decision to construct a photovoltaic installation at the Olhão site. The nutrient findings, informed attention to feedstock sourcing and production system design.

Below280 continued working with InteSusAl consortium partners on the subsequent EU Horizon project MAGNIFICENT. That project investigated high-value products from microalgae.The conclusion the InteSusAl LCA pointed toward became the focus of the next project.

That thread continues in REALM, the current EU Horizon project where Below280 is an active partner. The project applies and extends the microalgae LCA methodology to next-generation food production systems. The relationship with Necton, which began with InteSusAl, runs through all three projects.

The Published Work

Applied Energy published the harmonised LCA methodology developed for the Algae Cluster in 2015. The paper, Unified approach to Life Cycle Assessment between three unique algae biofuel facilities (Bradley, Maga & Antón, 2015), lists Below280’s lead practitioner as lead author.

The International Journal of Life Cycle Assessment published the full InteSusAl LCA in 2023: Life cycle assessment of microalgae-derived biodiesel (Bradley et al., 2023). At publication, no other peer-reviewed LCA covered an integrated real-world photobioreactor and fermenter system.

Why It Matters

The InteSusAl LCA produced a result that challenged the assumptions of the project it was part of. For investors and developers evaluating bio-based technologies, results from real facility data are more reliable than scaled-up laboratory projections.

About Below280

Below280 is a specialist LCA, EPD and carbon due diligence consultancy. The team has a long track record in microalgae LCA, biofuel life cycle assessment and bio-based materials. Below280 conducts ISO 14040/44-compliant assessments for renewable energy technologies, sustainable materials and low-carbon systems. This includes independent verification of environmental claims for investors, developers and regulators.