Que: How is hydrogen retrofitting emerging as a practical and scalable pathway in India’s clean-energy transition?

Ans: India’s energy transition has to deal with a hard fact: for the next 15–20 years, diesel engines in trucks, buses, construction equipment, marine vessels and DG sets are not going away. Transport already accounts for around 12 percent of India’s energy-related CO₂ emissions, and diesel dominates freight and heavy duty use. We are not including mining, marine and DG sets that add up to much higher CO2 emissions. If we wait for full fleet replacement by EVs or fuel-cell vehicles, we will miss a crucial window.

Hydrogen retrofitting offers a bridge solution: instead of scrapping existing assets, we upgrade them. By injecting controlled quantities of hydrogen into the air intake of a conventional diesel engine, we can improve combustion, extract more useful energy from every litre of diesel, and cut emissions significantly. Global research on dual-fuel hydrogen–diesel engines consistently shows higher brake thermal efficiency and lower CO, HC and particulate emissions when hydrogen is used correctly and that is repeatedly demonstrated by the use of our system too.

At the policy level, India’s National Green Hydrogen Mission explicitly recognises transport and hard-to-abate sectors as key demand centres, with a target of 5 MMT of green hydrogen per year by 2030 and an expected reduction of around 50 MMT of CO₂ annually. Retrofitting allows some of that hydrogen to flow into existing diesel engines rather than only into new fuel-cell platforms.

The practical and scalable part comes from three things:
1. Compatibility with a wide base of existing engines.
2. Quick installation and fast payback from fuel savings.
3. No disruption to current operating patterns for fleets and DG users.

In short, hydrogen retrofits turn the giant installed base of diesel engines from being a climate liability into a transitional decarbonisation asset.

Que: Can you explain the science and engineering behind Saarthi GreenTech’s hybrid innovation that integrates hydrogen with existing diesel engines for cleaner mobility?

Ans: At Saarthi Green, our approach is to keep the diesel engine architecture intact and layer a smart hydrogen system on top of it.

We generate hydrogen on-board and feed a calibrated hydrogen–oxygen stream into the engine intake. Hydrogen has a very wide flammability range and high flame speed, which helps the diesel spray burn more completely. In a conventional diesel engine, a fraction of fuel leaves the cylinder as unburnt or partially burnt hydrocarbons, soot and CO. When we introduce the right quantity of hydrogen at the right load and RPM, we improve the local mixture formation and flame propagation, which:
• Increases combustion efficiency resulting in more brake power per unit diesel.
• Reduces incomplete combustion products, lowering CO, HC and particulate matter.
• Improves cylinder cleanliness over time, because deposits are progressively burnt off, resulting in better fuel efficiency as well as better engine life and lower cost of maintenance.
Engineering-wise, our systems – GreenDrive™ for vehicles and GreenX™ for DG sets – combine:
• A robust electrolyser optimised for automotive/industrial duty cycles.
• A closed-loop control unit that looks at engine signals (RPM, load, sometimes CAN data) and decides how much hydrogen to generate and inject.
• Multi-stage safety architecture with sensors, flashback arrestors, pressure control and automatic shutdown logic.
• A non-intrusive interface with the air intake, ensuring no modification of pistons, injectors or compression ratios.

Because the diesel injection strategy is preserved and hydrogen is treated as a combustion enhancer, our hybrid system works across a wide range of engines and applications without requiring OEM re-designs.

Que: Why do measurable outcomes such as fuel savings and emission reductions matter more than sustainability pledges in ESG reporting?

Ans: ESG is moving from storytelling to scorekeeping. Investors, regulators and customers are no longer satisfied with declarations like “we are committed to net zero by 2050” unless they can see hard data: how much fuel did you save this year, and how many tonnes of CO₂, NOₓ and PM did you actually avoid?

In India, transport and diesel-intensive sectors are a major source of CO₂ and local air pollutants. Road transport alone accounts for a sizeable share of energy-related CO₂ emissions and is a key contributor to urban air quality problems. For a company operating fleets or DG sets, the real ESG story is in litres of diesel avoided and grams of pollutant reduced per kWh or per tonne-km, not just in future targets.
Measurable outcomes matter more because:
1. They are auditable where external agencies can verify lab reports, stack tests and fuel baselines.
2. They connect directly to P&L as fuel savings show up as real operating cost reduction.
3. They de-risk greenwashing since regulators worldwide are tightening rules on unsubstantiated claims.

Our philosophy at Saarthi is that every ESG claim must ride on a data trail: baseline tests, intervention, and post-retrofit performance. This makes decarbonisation not just ethically desirable, but financially credible and reportable.

Que: What key insights have emerged from Saarthi GreenTech’s pilot deployments, and what does real-world data reveal about performance and return on investment?

Ans: Across multiple pilots – trucks, buses, industrial DG sets and telecom power – three clear insights emerge.

First, fuel savings are real but application-dependent. In steady-state DG applications with good loading, we see highly consistent savings; in road fleets, the number varies more with duty cycle, driver behaviour and route profile. Across use cases, we have repeatedly demonstrated 3 to 25 percent diesel savings with appropriate tuning, along with over 50 percent reduction in key exhaust pollutants, validated by NABL-accredited labs and field measurements.

Second, the ROI is faster than most people expect. When diesel prices are high and utilisation is strong, paybacks as low as 3–12 months are feasible. That shifts the narrative from “sustainability cost” to “efficiency investment.”

At the same time, we understand that high upfront Capex often discourages businesses from adopting new technologies, even when the economics are favourable. To solve this, we created a Decarbonisation-as-a-Service (DaaS) model. With a simple security deposit and a small monthly fee—always structured to be lower than the value of diesel saved—companies can adopt hydrogen retrofitting at scale without financial burden. Saarthi manages the full lifecycle: installation, maintenance, and continuous IoT-based performance data, ensuring customers clearly see their fuel savings, CO₂ reductions, and operational benefits. As carbon markets mature in India, this verified data will also help businesses claim carbon credits, adding an additional revenue stream.

Third, there is a progressive engine-health benefit. As combustion quality improves, we observe cleaner exhaust, reduced visible smoke, and gradual reduction in carbon deposits. This has positive implications for maintenance intervals, oil life and engine longevity.

Real-world data essentially tells us that hydrogen retrofits, when engineered correctly, can deliver simultaneous gains in cost, compliance and asset life, which is rare in heavy-duty applications.

Que: How does IoT-enabled monitoring bring real-time transparency and accountability to decarbonisation efforts?

Ans: IoT is the truth layer on top of any decarbonisation claim.

In our GreenVision™ platform, every retrofitted engine is connected through an IoT device that streams parameters such as run-hours, load, fuel rate (directly or via calibrated models), hydrogen utilisation and emissions proxies. That allows customers to:

• See before-and-after fuel performance at the level of each truck, bus or DG set.
• Track CO₂ reduction in real time, using standard emission factors (2.68 kg of CO₂ per litre of diesel for DG sets, for example).
• Trigger alerts if a system is bypassed, having issues, under-utilised or under-performing.
For ESG and sustainability teams, this data plugs directly into Scope 1 and Scope 3 reporting. Instead of manually collecting spreadsheets from dispersed sites, they get a live dashboard of litres saved, tonnes of CO₂ avoided and uptime metrics. For operations teams, IoT brings predictive maintenance and early detection of anomalies.

In essence, IoT converts decarbonisation from a one-time project into a continuous, measurable process – and that is what serious investors and regulators increasingly expect.

Que: In your view, how ready is India in terms of infrastructure, policy, and industry adoption for hydrogen-based retrofitting and mobility solutions?

Ans: India’s Green Hydrogen Mission targets nearly 50 million tonnes of CO₂ reduction annually by 2030. Retrofitting may not replace the need for large-scale hydrogen production or fuel-cell mobility, but it can address a very large part of the low-hanging fruit.

Today, India operates one of the world’s largest installed bases of diesel engines — trucks, buses, DG sets, earthmovers, marine engines, and construction equipment. If even a portion of these engines adopted hydrogen-assisted retrofits, the national impact would be substantial.

To illustrate the scale with a hypothetical assumption that every diesel asset uses Saarthi Hydrogen Retrofit:
• A conservative 5 percent efficiency improvement across India’s diesel base would save ~3.7 billion litres of diesel per year, avoiding nearly 10 million tonnes of CO₂.
• A more realistic 10 percent average saving that we expect from Saarthi retrofits on diesel engines, would save ~7.4 billion litres and avoid ~20 million tonnes of CO₂ annually, while reducing national diesel expenses by ₹30,000–60,000 crore.

This single category of combustion efficiency improvement in existing engines, could contribute meaningfully toward the 50 MMT annual CO₂-reduction aspiration of India’s hydrogen roadmap.

That’s why I believe retrofitting is not a side story but an essential transition pathway, one that accelerates decarbonisation today while the long-term hydrogen ecosystem is still being built. At the same time, we must acknowledge that India is only at the very beginning of the hydrogen-retrofit curve. The absence of clear policies, standards, and governance frameworks can slow early adoption. But, as we have seen with every transformative technology, regulatory systems eventually evolve to support what delivers real value. I am confident that this sector too will receive the attention it deserves and will enable India to achieve meaningful and measurable emission reductions.

Que: What is your vision for the future of hydrogen technology in India, and how can Indian innovators contribute to the global green-tech movement?

Ans: I see hydrogen playing three complementary roles in India:
1. As a strategic fuel and feedstock – for green ammonia, steel, fertilisers and refineries, aligned with the Green Hydrogen Mission.
2. As a combustion enhancer and transition fuel – upgrading existing diesel engines in road transport, rail, marine and power backup.
3. As a core element of future mobility – in fuel-cell vehicles and hydrogen combustion engines in segments where batteries alone are not optimal.

Indian innovators have a unique opportunity to design frugal, rugged, and scalable hydrogen solutions for the realities of the Global South: mixed-age fleets, unreliable grids, cost-sensitive customers, and challenging operating environments. If we can prove technologies here – at Indian cost structures, on Indian roads, with Indian operating patterns – the same solutions can be exported to Africa, Southeast Asia and Latin America, while getting readily accepted in the developed economies of the world.

My vision for Saarthi GreenTech is to help make India not just a consumer of global green tech, but a creator and exporter of hydrogen-based decarbonisation solutions. If we combine India’s engineering talent, manufacturing base and policy momentum, we can turn hydrogen from a buzzword into millions of tonnes of CO₂ avoided, year after year – in India and far beyond.