Key takeaways
- Geothermal drying delivers up to 95% lower Scope 3 carbon intensity per kilogram of dried ingredient versus freeze-drying, and 88-93% lower versus conventional fossil-fuel hot-air drying — making it the single highest-impact supplier-side lever for food brands targeting science-based emission reductions.
- Scope 3 Category 1 (Purchased Goods and Services) accounts for 70-80% of total emissions at most food companies. Within that category, post-harvest processing energy — specifically the drying step — dominates the embedded carbon of dried fruit, herbs, and botanical ingredients.
- EU CSRD, CDP Climate, and SBTi FLAG guidance now require or strongly encourage disclosure of Scope 3 processing emissions. Switching to geothermal-dried suppliers gives you auditable, cradle-to-gate emission factors that survive third-party assurance.
- A single sourcing decision replaces years of incremental efficiency gains. Swapping a conventional dried-fruit supplier for a geothermal-dried equivalent can remove 800-1,100 kg CO2e per metric ton of finished product from your Scope 3 inventory.
- Co-benefits extend beyond carbon: lower drying temperatures preserve 25-40% more vitamin C, eliminate the need for chemical preservatives, and deliver weather-independent 24/7 production that stabilises supply chains.
Introduction
For any food brand serious about decarbonisation, the arithmetic is uncomfortable. Scope 3 emissions — indirect emissions across the value chain — represent 70-80% of total greenhouse gas output for the average packaged-food company. Within Scope 3, Category 1 (Purchased Goods and Services) is almost always the largest single bucket. And within Category 1, it is not freight, not packaging, and not warehousing that dominates — it is the energy consumed during post-harvest processing of raw agricultural ingredients.
Geothermal drying and Scope 3 carbon reduction are now inseparable conversations for procurement and sustainability teams sourcing dried fruit, herbs, spices, and botanical extracts. When the drying step alone accounts for 55-70% of a dried product's cradle-to-gate carbon footprint, the choice of drying method is not a technical footnote — it is a strategic emission-reduction decision that can move your corporate carbon inventory more than any other single action in the ingredient supply chain.
This guide provides the data, the regulatory context, and the accounting methodology that ESG managers, procurement leads, and brand sustainability teams need to evaluate, quantify, and report the Scope 3 benefits of switching to geothermal-dried ingredients.
Understanding Scope 3 emissions in food supply chains
What Scope 3 Category 1 (Purchased Goods) means for ingredient buyers
The GHG Protocol Corporate Value Chain (Scope 3) Standard defines Category 1 as all upstream emissions associated with the production of goods and services purchased by the reporting company. For a food brand, this includes every kilogram of CO2e embedded in the agricultural cultivation, post-harvest processing, and pre-shipment handling of every ingredient lot.
In practice, Category 1 is where ingredient procurement meets climate accounting. When you buy 20 metric tons of dried apricots, your Scope 3 inventory must capture not just the farming emissions but the full energy profile of how those apricots were dried, sorted, and packed. The drying step is where the numbers diverge most dramatically between suppliers.
A representative emission breakdown for one metric ton of conventionally dried fruit delivered to an EU warehouse:
| Supply chain stage | kg CO2e per ton | Share of total | | --- | --- | --- | | Farm operations (cultivation, irrigation, harvest) | 80-150 | 7-10% | | Post-harvest drying (natural gas / LPG) | 850-1,200 | 58-68% | | Sorting, grading, packing | 50-100 | 4-6% | | Inland transport (origin country) | 20-55 | 2-3% | | Ocean freight and EU inland logistics | 90-180 | 8-12% | | Warehousing and cold chain | 40-80 | 3-5% |
The drying line is not just the largest — it is the most variable. A supplier using geothermal heat reports 20-60 kg CO2e for the same step. That single line-item difference reshapes the entire product footprint.
Why processing method matters more than transport
A persistent misconception in sustainable sourcing is that food miles are the primary carbon driver. The data tells a different story. Ocean freight from Turkey to Rotterdam generates approximately 15-25 kg CO2e per metric ton of dried product. The drying step in a fossil-fuel facility generates 850-1,200 kg CO2e. That means the processing energy embedded in a single container of dried fruit exceeds the transport emissions by a factor of 40 to 60.
For procurement teams building Scope 3 reduction roadmaps, this means the highest-return intervention is not nearshoring supply or optimising container fill rates — it is switching the energy source of the drying process.
The regulatory push: EU CSRD, CDP, SBTi
Three regulatory and disclosure frameworks are converging to make Scope 3 processing-energy data non-optional:
EU CSRD (Corporate Sustainability Reporting Directive). From financial year 2025 onward, large EU companies and non-EU companies with significant EU revenue must report under the European Sustainability Reporting Standards (ESRS). ESRS E1 (Climate Change) requires Scope 3 Category 1 disclosure, including the calculation methodology and data sources. Estimated or industry-average emission factors are accepted but flagged; supplier-specific data from auditable sources (such as a geothermal operator's energy metering) earns a higher data-quality score.
CDP Climate Change Questionnaire. CDP's scoring methodology increasingly penalises companies that cannot break down Scope 3 by category with supplier-specific or product-level data. In 2025, the Climate module explicitly asks respondents to identify their largest Scope 3 hotspots and describe reduction actions. A documented switch from fossil-fuel to geothermal-dried ingredients is a concrete, auditable action that scores well.
SBTi FLAG (Forest, Land, and Agriculture) Guidance. Companies setting science-based targets in the food and agriculture sector must now include FLAG emissions in their near-term targets. The FLAG pathway emphasises real emission reductions over carbon removal, and processing-energy switches are among the most defensible reduction levers because they are measurable, permanent, and not subject to reversal risk.
Carbon footprint of drying methods compared
The following table compiles life-cycle assessment data from published studies and operator-reported energy audits, normalised to one kilogram of dried product (starting from fresh fruit at approximately 80% moisture, dried to 12-15% moisture).
| Drying method | Energy source | kWh per kg dried product | kg CO2e per kg dried product | Availability | Key limitation | | --- | --- | --- | --- | --- | --- | | Conventional hot-air | Natural gas / LPG | 2.0-3.5 | 0.85-1.20 | Year-round | High emissions, nutrient degradation | | Freeze-drying | Grid electricity | 4.0-7.0 | 0.80-1.40 | Year-round | Very high cost, energy-intensive | | Solar drying (open-air) | Solar radiation | 0 (direct) | 0.01-0.03 | Seasonal / weather-dependent | Food safety risk, inconsistent quality | | Solar-assisted (hybrid) | Solar + electric backup | 0.8-1.5 | 0.15-0.35 | Partially seasonal | Requires backup energy, variable output | | Geothermal drying | Subsurface thermal | 0.05-0.15 (pumping only) | 0.02-0.06 | 24/7/365 | Geographically constrained |
Conventional hot-air drying (fossil fuel)
Conventional tunnel and tray dryers fire natural gas or LPG to push air at 65-90 degrees C through the product bed. The thermal efficiency of these systems typically ranges from 35-55%, meaning that nearly half the fuel energy is lost as exhaust heat. At an emission factor of 56-62 kg CO2e per GJ for natural gas, the carbon intensity is high and structurally unavoidable within the fossil-fuel paradigm. Incremental efficiency improvements (heat recovery, insulation upgrades) can reduce emissions by 10-20%, but the fundamental combustion chemistry sets a floor.
Freeze-drying (electricity-intensive)
Freeze-drying (lyophilisation) uses vacuum sublimation to remove moisture at sub-zero temperatures. While it preserves cell structure and nutrients exceptionally well, the energy cost is substantial: compressors, vacuum pumps, and condenser plates consume 4.0-7.0 kWh per kilogram of water removed. On a typical national grid mix (EU average: 0.25 kg CO2e per kWh, or higher in coal-dependent grids), freeze-drying can match or exceed the carbon intensity of conventional hot-air drying. For a deeper comparison, see the freeze-dried vs geothermal comparison.
Solar drying (weather-dependent)
Open-air solar drying has negligible direct energy input and very low carbon intensity. However, it operates only during daylight hours in clear weather, requires large open-air surface areas exposed to dust and insects, and produces highly inconsistent moisture levels. For export-quality product meeting EU food safety regulations, solar drying alone rarely meets the required standards for water activity control, microbial limits, and batch traceability.
Geothermal drying (renewable, continuous)
Geothermal drying taps subsurface hot water or steam — typically at 65-110 degrees C at the wellhead — piped through heat exchangers into enclosed, sanitary drying chambers. The only electricity consumption is for circulation pumps and fans, typically 0.05-0.15 kWh per kg of dried product. Because the heat source is renewable and continuous, geothermal dryers operate 24 hours a day, 365 days a year, independent of weather, season, or fuel markets.
Life cycle assessment data (kg CO2e per kg of dried product)
The emission factors above reflect cradle-to-gate boundaries: from raw material intake at the drying facility through to packed, palletised product ready for shipment. They include upstream energy supply emissions (grid mix for electricity, well-to-burner for gas) and operational emissions (combustion, refrigerant leakage for freeze-drying). They exclude farm-gate emissions, transport, and end-of-life, which are common across all methods.
| Emission metric | Conventional | Freeze-dried | Solar | Geothermal | | --- | --- | --- | --- | --- | | kg CO2e per kg dried product | 0.85-1.20 | 0.80-1.40 | 0.01-0.03 | 0.02-0.06 | | Reduction vs conventional (%) | Baseline | -14% to +17% | 97-99% | 93-98% | | Reduction vs freeze-dried (%) | — | Baseline | 97-99% | 93-97% |
How geothermal drying achieves 95% emission reduction
The physics: subsurface heat at 65-85 degrees C, zero combustion
The fundamental reason geothermal drying is so low-carbon is simple: there is no combustion. No fuel is burned. The thermal energy exists as a natural endowment in the subsurface — hot water heated by radioactive decay and residual planetary heat, available at the wellhead at temperatures that are directly useful for drying (65-85 degrees C in the Aegean geothermal fields of western Turkey, higher in volcanic zones).
A geothermal drying facility replaces the entire fuel-combustion chain (extraction, transport, storage, burning, exhaust treatment) with a single well-to-heat-exchanger loop. The only carbon-emitting input is the electricity to run circulation pumps and ventilation fans, which typically draws 0.05-0.15 kWh per kg of product — a trivial amount even on a fossil-heavy grid.
This is not an incremental improvement over fossil-fuel drying. It is a categorical change: from a combustion-based thermal process to a geologically sourced thermal process with zero on-site emissions.
Energy cost comparison
Beyond carbon, the energy economics of geothermal drying create structural cost advantages that stabilise pricing for B2B buyers:
| Cost metric | Conventional (gas) | Freeze-drying | Geothermal | | --- | --- | --- | --- | | Energy cost per kg dried product (USD) | 0.08-0.18 | 0.35-0.70 | 0.01-0.03 | | Sensitivity to fuel price | High (gas index) | Medium (grid tariff) | Very low (fixed well cost) | | Capital intensity | Low-medium | Very high | Medium (well + exchanger) | | Operating cost trajectory | Rising (carbon pricing) | Stable to rising | Flat to declining |
The marginal fuel cost of geothermal heat is essentially zero once the well infrastructure is in place. This means geothermal operators can offer stable, multi-year FOB pricing that is decoupled from global energy markets — a significant procurement advantage in an era of volatile gas prices and escalating carbon levies.
Operational uptime: 24/7/365 vs seasonal alternatives
Solar drying operates 6-10 hours per day and shuts down entirely during rain, cloud cover, and winter months in many regions. Geothermal heat is available continuously, regardless of time of day, weather, or season. This translates to 3-4 times higher annual throughput per square metre of drying area, more consistent batch quality, and the ability to fulfil large B2B orders on predictable timelines.
For procurement teams managing just-in-time inventory or seasonal product launches, the reliability of geothermal drying eliminates a category of supply-chain risk that plagues weather-dependent alternatives.
Arovela's facility — real-world data
Arovela operates geothermal-powered drying and processing facilities in the Sindirgi district of Balikesir province, Turkey — one of the richest low-enthalpy geothermal fields in the eastern Mediterranean. Our facility data for the 2025 production year shows:
- Drying temperature: 45-65 degrees C (product-dependent)
- Annual operating hours: 8,400+ (96% uptime)
- Electricity consumption for pumping and ventilation: 0.08 kWh per kg of dried product
- Calculated carbon intensity: 0.04 kg CO2e per kg of dried product (using Turkey 2024 grid emission factor of 0.47 kg CO2e/kWh)
- Reduction versus conventional gas drying: 96%
- Reduction versus freeze-drying: 95-97%
This data is available to buyers as part of our standard product documentation and can be provided in formats compatible with CSRD reporting, CDP questionnaires, and SBTi target-tracking tools. For full technical specifications, see the geothermal drying technology guide.
Integrating geothermal-dried ingredients into ESG reporting
How to calculate Scope 3 reduction from supplier switch
The calculation follows the GHG Protocol's supplier-specific method (preferred) or the hybrid method:
Step 1: Establish baseline. Determine the emission factor of your current supplier's drying process. If supplier-specific data is unavailable, use the industry-average emission factor for the product category and processing method (e.g., 0.95 kg CO2e/kg for gas-dried apricots).
Step 2: Obtain new supplier data. Request the geothermal supplier's cradle-to-gate emission factor per kg of product. At Arovela, this is 0.04 kg CO2e/kg, documented with energy metering records and the applicable grid emission factor.
Step 3: Calculate reduction. Multiply the difference in emission factors by the annual purchase volume:
Scope 3 reduction (tonnes CO2e) = (baseline EF - new EF) x annual volume (tonnes)
Example: Switching 50 tonnes of dried apricots from a conventional supplier (0.95 kg CO2e/kg) to Arovela's geothermal operation (0.04 kg CO2e/kg) yields: (0.95 - 0.04) x 50 = 45.5 tonnes CO2e annual Scope 3 reduction.
Step 4: Document the methodology. Record the data source, boundary conditions, and emission factors used. This documentation is required for third-party assurance under CSRD and for CDP scoring.
Documentation requirements for auditors
Third-party assurance providers (under CSRD limited or reasonable assurance) will require:
- Supplier-specific emission factor with calculation methodology
- Evidence of the energy source (geothermal concession documentation, energy audit reports)
- Metering data for electricity consumption at the drying facility
- The grid emission factor applied (source and vintage)
- Confirmation that the emission factor boundary matches the reporting boundary (cradle-to-gate, gate-to-gate, or other)
Arovela provides a standardised Scope 3 data package that includes all of the above, formatted for direct integration into carbon accounting platforms (Persefoni, Watershed, Sphera, Plan A, and others). Visit our certifications page for the full list of available documentation.
CDP Climate questionnaire — where this data fits
In the CDP Climate Change questionnaire, Scope 3 processing-energy data fits primarily in:
- C6.5: Scope 3 emissions by category (Category 1 breakdown)
- C4.3b: Scope 3 emission reduction initiatives and quantified savings
- C12.3: Engagement with value chain on climate-related issues
A documented supplier switch from fossil-fuel to geothermal drying, with quantified annual CO2e savings, demonstrates tangible value-chain engagement — one of the factors that separates B-score companies from A-list performers.
CSRD double materiality — processing energy as material topic
Under CSRD's double materiality assessment, ingredient processing energy is likely material for food companies on both dimensions:
- Impact materiality: The drying process has a significant actual impact on climate change through greenhouse gas emissions.
- Financial materiality: Rising carbon pricing (EU ETS expansion, CBAM), investor ESG screening, and retailer sustainability requirements create financial risk from high-carbon supply chains.
When processing energy is assessed as a material topic, ESRS E1 requires disclosure of the transition plan, targets, and actions taken. A geothermal-sourcing strategy directly addresses this requirement with measurable, time-bound actions.
Building a credible sustainability narrative
What claims you CAN make (with data)
When you source geothermal-dried ingredients and hold the supporting documentation, the following claims are defensible:
- "Dried using 100% renewable geothermal energy" (if the facility operates without fossil-fuel backup for the drying process)
- "X% lower processing carbon footprint compared to conventional drying" (with cited emission factors and calculation methodology)
- "Scope 3 Category 1 emissions reduced by Y tonnes CO2e through supplier selection" (with auditable documentation)
- "Processing energy from a certified renewable source" (with geothermal concession and energy audit documentation)
These are process claims supported by physical measurement data — the strongest category of environmental claim under both EU Green Claims Directive proposals and existing Unfair Commercial Practices Directive (UCPD) case law.
What claims to AVOID (greenwashing risk)
- "Carbon neutral" or "net zero" product claims — unless the entire product lifecycle (farm to end-of-life) has been assessed and residual emissions offset under a recognised standard (PAS 2060, ISO 14068). Drying-step reductions alone do not justify whole-product carbon-neutral claims.
- "Zero emissions" — geothermal drying still consumes grid electricity for pumping. The intensity is very low, but it is not literally zero.
- "Sustainable" without qualification — the EU Green Claims Directive will likely prohibit generic sustainability claims without specific, verifiable substantiation.
- Comparative claims without methodology — "95% lower carbon" needs the baseline, the boundary, and the data source to be defensible. Avoid vague comparisons.
The safest path: make specific, quantified, bounded claims and always cite the methodology. For guidance on aligning these claims with broader ESG goals, see the geothermal ESG guide.
Case example: switching from conventional to geothermal-dried apricots
Consider a European snack brand purchasing 200 metric tons per year of dried apricots for its trail-mix product line. The current supplier uses natural-gas tunnel dryers in the Malatya region of Turkey.
Baseline Scope 3 (drying step only): 200 tonnes x 0.95 kg CO2e/kg = 190 tonnes CO2e/year
After switch to geothermal-dried (Arovela, Sindirgi): 200 tonnes x 0.04 kg CO2e/kg = 8 tonnes CO2e/year
Annual Scope 3 reduction: 182 tonnes CO2e (96% reduction in the drying-step emission line)
Full product-level impact: If drying represents 62% of the product's total cradle-to-gate footprint, the overall product carbon intensity drops by approximately 59%.
This single supplier decision delivers more Scope 3 reduction than most food companies achieve across their entire supply chain in a given year through efficiency programmes. It is auditable, permanent, and does not require offset purchases.
Marketing the sustainability advantage to end consumers
For brands communicating to retail consumers, the geothermal drying story offers several advantages over typical sustainability messaging:
- It is concrete and physical, not abstract or financial (consumers understand "dried with underground hot water" more intuitively than "verified carbon credits").
- It is verifiable at origin — factory visits, energy audit documents, and geothermal concession records provide a transparent chain of evidence.
- It pairs naturally with other product qualities: better taste, better colour, better nutrient retention, and clean-label positioning.
The most effective consumer messaging connects the drying method to tangible product benefits (taste, nutrition, naturalness) and mentions the carbon reduction as a co-benefit — not the other way around. Lead with quality, substantiate with sustainability.
Beyond carbon — co-benefits of geothermal processing
Better nutrient retention (lower temperature)
Geothermal drying operates at 45-65 degrees C — well below the 70-90 degrees C range of conventional hot-air dryers. This temperature difference has measurable consequences for nutrient preservation:
- Vitamin C retention: 70-85% (geothermal) vs 28-45% (conventional hot-air)
- Carotenoid retention (apricots, peach): 75-88% vs 40-60%
- Polyphenol retention (berries, pomegranate): 80-90% vs 50-65%
- Essential oil volatile retention (herbs): 85-92% vs 55-70%
For brands positioning products on nutritional density or functional-food claims, this nutrient advantage translates directly into label claims, marketing differentiation, and premium pricing justification. For a complete analysis, see the freeze-dried vs geothermal comparison.
Cleaner label (no chemical preservatives needed)
The controlled, low-temperature, enclosed-environment process of geothermal drying produces a product with consistently low water activity (0.55-0.65 aw) and low microbial counts. This eliminates the need for sulfur dioxide (SO2) treatment — the most common chemical preservative in conventionally dried fruit — and allows brands to market products as "no added sulfites" or "preservative-free."
In markets where clean-label positioning commands a 15-30% retail price premium, this is a material commercial advantage in addition to the sustainability benefit.
Supply chain resilience (not weather-dependent)
Unlike solar drying, which halts during rain, cloud cover, and winter months, geothermal drying operates continuously and predictably. This resilience has three practical implications for B2B buyers:
- Consistent lead times and delivery schedules, even during peak demand seasons
- Stable product quality across batches (no weather-driven variation in drying conditions)
- Reduced inventory buffer requirements (reliable supply means less safety stock)
For brands managing complex multi-ingredient supply chains, the operational predictability of a geothermal supplier reduces procurement risk in ways that go beyond the sustainability narrative. Explore Arovela's geothermal-dried fruit range and sustainable agriculture products for available SKUs and specifications.
FAQ
How much can switching to geothermal-dried ingredients reduce my company's Scope 3 emissions? The reduction depends on your current supplier's drying method and your purchase volume. For most dried-fruit and herb categories, replacing a conventional fossil-fuel-dried supplier with a geothermal-dried supplier reduces the drying-step emissions by 88-96%. If drying represents 55-68% of the product's cradle-to-gate footprint, the total product-level Scope 3 reduction is typically 50-65%. For a 200-tonne annual purchase, this can translate to 150-190 tonnes CO2e removed from your Scope 3 inventory.
What documentation does Arovela provide for Scope 3 reporting and CSRD compliance? Arovela provides a standardised Scope 3 data package that includes: the product-specific emission factor (kg CO2e per kg), the calculation methodology and boundary conditions, geothermal concession documentation, annual energy audit reports, electricity metering data, and the grid emission factor used. This package is formatted for direct integration into carbon accounting platforms and meets the documentation requirements for third-party assurance under CSRD limited assurance.
Is geothermal-dried product more expensive than conventionally dried? The FOB price of geothermal-dried product is typically comparable to or marginally higher than conventional equivalents — the energy cost savings from geothermal heat largely offset the infrastructure amortisation. However, when you factor in the Scope 3 reduction value (avoided carbon credit purchases, improved CDP scores, retailer sustainability compliance), the total cost of ownership is often lower. The price stability advantage is also significant: geothermal operators are insulated from gas price volatility, so multi-year contracts carry less price-escalation risk.
Can I claim "carbon neutral" on products made with geothermal-dried ingredients? No — not on the basis of the drying step alone. A product-level carbon-neutral claim under PAS 2060 or ISO 14068 requires a full lifecycle assessment covering cultivation, processing, transport, packaging, retail, and end-of-life, plus offsetting of any residual emissions. Geothermal drying dramatically reduces the processing emission line but does not eliminate emissions from other lifecycle stages. The defensible claim is a quantified processing-emission reduction, not whole-product carbon neutrality.
Where is geothermal drying available, and can it scale? Commercial-scale geothermal drying for food products is concentrated in regions with accessible low-enthalpy geothermal resources. Turkey's Aegean basin (particularly the Sindirgi, Germencik, and Salavat fields in Balikesir and Aydin provinces) is the dominant global cluster for geothermal food drying. Iceland, New Zealand, Kenya, and parts of Italy also have geothermal resources suitable for drying applications. Scaling within existing geothermal fields is straightforward — well capacity in the Sindirgi field supports significant expansion beyond current utilisation. For a complete overview, see the wholesale dried fruit guide.
Reduce your Scope 3 emissions
If your CSRD submission, CDP response, or SBTi target pathway depends on measurable Scope 3 reductions in your ingredient supply chain, geothermal-dried sourcing delivers the largest single-action impact available. Browse Arovela's geothermal-dried fruit range, review our certifications and Scope 3 data packages, or request a quote to get supplier-specific emission factors for your product categories.