The ŠKODA OCTAVIA G-TEC runs on carrots and onions

When you get into an OCTAVIA G-TEC and start the engine, you won’t be able to tell from the engine noise or the car’s behaviour that you’re running on natural gas. The only giveaway is the digital fuel consumption readout with units in kilograms rather than the traditional litres per 100 kilometres.

But closer inspection will reveal two fuel gauges on the instrument panel – the car has two fuel tanks. The larger tank holds CNG, the smaller one petrol. The car uses petrol at specific moments: when the engine starts after refuelling with natural gas, if the outside temperature falls below -10°C, or if the natural gas tank is so empty that the pressure in the tank falls below 11 bar.

The ŠKODA OCTAVIA G-TEC comes with a 96 kW (130 hp) 1.5 TSI engine that generates around 25% lower CO₂ emissions than petrol engine versions.The car also emits much less nitrogen oxides (NOx) and no particulate matter.

A tank that can store 17.33 kg of natural gas allows a range of up to 500 km in the WLTP cycle when the car runs on natural gas. The 9-litre petrol tank increases the range to 690 km*. With the fuel tank housed beneath the luggage compartment floor, the boot size is 455 litres in the liftback version and 495 litres in the estate. *This information is provisional and subject to change.

Incidentally, filling up the car with natural gas is practically the same as for petrol. There is a piston right beside the fuel tank aperture. The piston is connected to the gas filling hose, which you use just like at a petrol pump.

The drive is made even greener if you fill up with clean biogas, which is produced at biogas stations using natural materials.The OCTAVIA G-TEC stopped at one of these stations near Vienna.At the pump you can read that you’re filling up with horse manure.Though not literally: there are several industrial processes horse manure, or carrots and onions, has to go through on their way to a car’s fuel tank.

The secret of converting manure and vegetable scraps into fuel at EVM Biogas Margarethen was explained to ŠKODA Storyboard by Lukas Malaschofsky.

“We don’t use any food,” he makes clear right away. Most of the vegetable matter we can see in the storage areas would never have made it onto the supermarket shelves for various reasons, such as insufficient quality, so it’s waste that would be thrown away otherwise. Like the remains of stripped corn cobs and husks lying on the floor.

Lukas Malaschofsky
EVM Biogas Margarethen

But this waste is great for making biogas. “In spring, when there were major restrictions due to coronavirus, we even had potatoes here that had originally been intended for a fast food chain,” Lukas Malaschofsky adds. The plant also uses mown grass from its grounds not far from Vienna airport.

OCTAVIA model G-TEC comes with an eco-friendly CNG engine that generates around 25% lower CO₂ emissions than petrol engine versions.

All the biowaste then goes into huge tanks. Bacteria are let loose on it, and soon methane is being emitted. The methane is purified using carbon filters or various processes to remove contaminants like sulphur (the methane tends to be sulphur-rich if it comes from onions, for example) or CO₂. This multi-phase purification process results in biogas that meets the standards for public gas mains and gas-powered cars.

Part of the gas generated in this way goes to the refuelling station on the edge of the site; part goes into a public gas pipe. The plant produces 2,800,000 kilos of biogas a year. That would be enough to fill 161,569 tanks of the new ŠKODA OCTAVIA G-TEC.

Not all the methane is sent through the purification process: some is fed into a generator that produces 5,200,000 kW/h of electricity a year and supplies heat to around 70 households in the area. And the natural cycle comes full circle – the material that was used as a source of methane production can subsequently be used as fertiliser.