The Microbial Challenge Behind Renewable Energy Performance

How biofouling and biodeterioration affect offshore, solar, and geothermal infrastructure, and how molecular tools can improve monitoring

Renewable energy infrastructure is designed to operate in demanding environments. Those same environments also support microbial communities that can accumulate on surfaces, trap deposits, alter local chemistry, and contribute to deterioration. For offshore wind, terrestrial photovoltaic systems, and geothermal facilities, understanding the microbiology behind fouling can help teams move from reactive cleaning and repair toward more informed monitoring.

Biofouling and Biodeterioration Are Related, but Different

Biofouling is the unwanted accumulation of microorganisms, biofilms, and larger fouling organisms on a surface. Biodeterioration occurs when biological activity contributes to the physical or chemical degradation of the underlying material. The two processes often overlap: a mature biofilm can restrict flow or block light while also creating localized conditions that promote corrosion, mineral deposition, coating damage, or surface dissolution.

The practical consequence is that a visible deposit may be only part of the story. The microbial community within the deposit may influence whether the condition remains a maintenance problem or develops into a material-integrity risk.

Where Renewable Energy Systems Are Vulnerable

Offshore and Marine Renewable Energy

On submerged infrastructure, organic molecules can condition metal, plastic, glass, concrete, and microelectronic surfaces within minutes. Bacteria and other microorganisms then attach and produce extracellular polymeric substances, or EPS, which stabilize the developing biofilm. Early marine communities may include strong biofilm-forming genera such as Pseudoalteromonas, Alteromonas, Vibrio, Pseudomonas, Flavobacterium, Marinobacter, and Alcanivorax.

As the biofilm matures, it can encourage attachment by larger organisms. The accumulated material may change turbine-blade lift and drag, obstruct light reaching floating solar systems, interfere with sensors or microfluidic components, and increase inspection, cleaning, and maintenance requirements.

Terrestrial Photovoltaic Systems

Solar-panel glass can support subaerial biofilms containing bacteria, fungi, algae, and cyanobacteria. These communities help retain dust, debris, and pollen, creating a combined biological and particulate layer that limits light transmission. Protective pigments produced by phototrophic organisms can further scatter incoming radiation.

Microbial colonization may also affect plastics, sealants, coatings, and other polymeric components. Fungal growth, extracellular enzymes, and corrosive metabolites can contribute to localized pitting, surface dissolution, or coating deterioration. Because the community changes with climate and operating environment, monitoring should be designed around the specific asset and location.

Geothermal Energy Systems

Geothermal fluids naturally contain thermophilic and thermotolerant microorganisms. Biofilms can form on heat exchangers, pipelines, wells, and other wetted surfaces, restricting fluid flow and reducing heat-transfer efficiency. Biofilms can also capture or promote silica, calcium carbonate, iron-bearing, and iron-sulfide deposits as temperature, pressure, pH, and fluid chemistry change.

Sulfur- and iron-cycling microorganisms are especially important. Sulfate-reducing bacteria can produce sulfide, sulfur-oxidizing bacteria can generate sulfate and acidity, and iron oxidizers and reducers can transform iron minerals and corrosion products. These linked processes can contribute to scaling, under-deposit corrosion, and deterioration of metal infrastructure.

From Fouling to Material Damage

A biofilm creates steep chemical gradients across a very small distance. Oxygenated and oxygen-limited microniches may occur next to one another, supporting different organisms and reactions. On metal, these conditions can promote microbiologically influenced corrosion through sulfide production, acid generation, electrochemical interactions, and transformation of protective corrosion products.

Concrete can be affected when biologically produced sulfuric acid dissolves calcium-bearing phases and weakens the cementitious matrix. Glass may experience localized alkaline-ion leaching, micropitting, or dissolution of the silica network. Some microorganisms also possess enzymes associated with polymer hydrolysis. Importantly, detecting an organism or gene associated with a process identifies potential; detection alone does not demonstrate that active degradation is occurring under field conditions.

Matching the Molecular Tool to the Monitoring Question

CENSUS^® qPCR: Targeted Quantification

CENSUS^® uses quantitative polymerase chain reaction to measure selected genetic targets directly in DNA recovered from an environmental sample. Unlike culture-dependent methods, qPCR does not require organisms to grow under laboratory conditions. The selected marker may represent a specific organism, microbial group, or functional capability.

Targets relevant to renewable energy infrastructure may include sulfate-reducing bacteria, iron-oxidizing bacteria, iron-reducing bacteria, sulfur-oxidizing bacteria, radiation-tolerant Deinococcus species, a Bacillus-associated PET-esterase gene, and the broader QuantArray^®-MIC panel. Results are most informative when they are evaluated with chemistry, operating data, material assessments, and trends over time.

Next-Generation Sequencing: Broad Community Characterization

NGS profiles bacterial, archaeal, or fungal communities without requiring prior selection of individual organisms. It is particularly useful when the project needs to determine which microorganisms are present and how community composition differs among locations, materials, operating conditions, seasons, treatments, or time points.

NGS results are generally compositional and reported as relative abundance. They should not be interpreted as absolute cell concentrations. Diversity indices, principal coordinates analysis, dendrograms, taxonomic bar charts, and heatmaps can reveal changes in community structure and help identify targets for routine qPCR monitoring.

WGS and Shotgun Metagenomics: Taxonomy Plus Predicted Function

Shotgun metagenomic sequencing analyzes DNA fragments from across the microbial community rather than amplifying a selected marker region. The approach can provide higher taxonomic resolution and direct detection of genes associated with metabolic functions. Outputs can summarize bacteria, archaea, fungi, functional groups, genes, and pathways across samples.

As with other DNA-based methods, gene detection indicates predicted functional potential rather than gene expression or confirmed activity. Functional interpretations should therefore be evaluated with supporting chemistry, operating history, targeted measurements, and evidence of material condition.

A Practical Monitoring Strategy

A strong biofouling and biodeterioration program connects molecular results with the part of the asset that is changing. A practical framework includes:

1. Define the operational concern, such as reduced heat transfer, blocked light, restricted flow, deposit formation, or material loss.
2. Collect representative samples from relevant water, biofilm, deposit, corrosion product, soil, sediment, or component surfaces.
3. Use NGS or WGS for broad characterization when the community or mechanisms are not well defined.
4. Use targeted CENSUS^® or QuantArray^® testing for quantitative surveillance of selected organisms and functions.
5. Interpret microbial trends with chemistry, process conditions, inspection findings, corrosion data, cleaning history, and asset performance.
6. Evaluate the response to corrective actions and refine the monitoring plan as system-specific relationships become clearer.

Sample Quality Matters

Meaningful comparisons depend on consistent sample collection, preservation, and documentation. Samples should represent the component or condition under investigation, be kept cold at approximately 4°C, and be shipped promptly under chilled conditions. MI will incorporate the appropriate controls and quality-assurance procedures which are essential throughout extraction, amplification, sequencing, and data review to ensure both precision and accuracy throughout the processing of samples.

Turn Microbial Information into Asset Intelligence

Renewable energy systems are not microbiologically passive. Microbial communities can influence deposits, flow, heat transfer, light transmission, corrosion, and the long-term condition of metals, glass, plastics, coatings, microelectronics, and concrete. Molecular biological tools provide a way to characterize those communities before extensive damage is visible and to track how microbial conditions change over time.

The most defensible interpretation combines molecular data with field observations, chemistry, operating information, and material assessments. Used together, these lines of evidence can help asset teams identify emerging risks, select targeted monitoring approaches, evaluate control measures, and make more informed maintenance decisions.