How much diesel is saved by not importing sunflower husks?
Our warehouse is occasionally replenished with 22.5 tons of hulled sunflower seeds from Bulgaria. But how much diesel are we actually saving by not transporting all the hulls? Let's follow this calculation!
Since half the weight and volume consists of the hulls of the sunflower seed, this means only one truck needs to go back and forth instead of two. But how much diesel does it require?
There is a useful unit called kWh/ton-kilometer, where there are tables showing how much energy different modes of transport consume. Long-haul truck transport uses 0.18 kWh/ton-km. The distance to Bulgaria is 2716 km, so the number of ton-kilometers is 22.5 x 2716 = 61,110 ton-km. The energy consumption is then 0.18 x 61,110 = 11,000 kWh. What does this mean? Well, one liter of diesel contains about 10 kWh. So, it requires 11,000/10 = 1,100 liters of diesel for such a transport.
We have thus consumed 1,100 liters of diesel for transporting 22.5 tons of sunflower seeds. At the same time, we have actually saved 1,100 liters by choosing not to transport the hulls here!
But wait a minute! The 22.5 tons of hulls that remain in Bulgaria are used as biofuel! Assume that they actually replace fossil energy, how much is saved compared to transporting the hulls to Sweden to rot on a lawn? It's not entirely fair - you can't fuel directly with sunflower hulls - but you can burn them to produce electricity, and this is still largely done with coal and lignite.
The energy content in sunflower hulls is about 4 kWh/kg (comparable to, for example, birchwood, about 4.4 kWh/kg). 22,500 x 4 = 90,000 kWh!
90,000/10 = 9,000 liters of diesel! That's a lot!
That corresponds to 9,000/1,100 = 8! In other words, the energy amount equivalent to driving 8 full trucks from Bulgaria to Linköping!
We can thus say it's 9 times more energy-efficient to use hulled sunflower seeds!
To avoid any appearance of green-washing, we must also inform you that this is a more significant saving at the corporate level - consider that it's 900 25 kg bags that save these 1,100 liters of diesel + an additional 9,000 liters worth of energy in the sunflower hulls.
As a private individual, however, the saving from forgoing a trip to Thailand for one person still corresponds to 700 liters of aviation kerosene (and if you calculate the carbon impact with the high-altitude effect, around 1,400 liters!). Plus, every mile you choose not to drive is an incredibly efficient way to reduce carbon emissions.
Why calculate the transport emissions?
Now we know in black and white the energy consumption of a product for our warehouse. Long-distance transports are often more environmentally damaging than short ones, provided the same amount is transported. But consider the calculation example below! People are often mistaken about the environmental impact of long transports.
It also becomes very interesting to calculate when, in some cases, we can factor in that it takes more energy to dry a crop grown nearby than one grown far away. As in the case with our own sunflowers. We can also account for the energy in the sunflower husks, which are used as biofuel instead of being transported long distances and subsequently becoming waste in gardens.
Comparing a product's transportation emissions to our warehouse with the transportation emissions from the warehouse is also intriguing.
What do the numbers on our labels mean?
Let's take white millet as an example:
Transport emissions to our warehouse: 0.17 kg CO2 eq./kilo
How far can you drive by car to pick up that sack from our warehouse without your car trip becoming the most environmentally impactful part of the transport?
Yes - the CO2 emissions from the transport of a sack from the farm in China to our warehouse require 0.17kg Carbon Dioxide x 25kg (seeds in the sack)= 4.25kg carbon dioxide.
When driving, just under 3kg of carbon dioxide is emitted per liter of diesel or gasoline (see explanation below).
With a car that consumes just over 0.5 liters per 10 kilometers, you can roughly drive 10 kilometers one way to pick up a sack of seeds from China to achieve similar emission levels!
Facts about Carbon Dioxide
CO2 is carbon dioxide - a greenhouse gas that is produced when we breathe and burn. Burning old oil and coal increases the amount of greenhouse gases, likely warming the earth. From a cautious perspective, it is unwise not to assume so.
From 1 liter of gasoline, just about 2.65 kilos of carbon dioxide is produced during combustion. Why? Well, what weighs in gasoline is almost only carbon atoms, and when it burns, 2 oxygen atoms that weigh about as much each attach to every carbon atom. CO2 means: a carbon atom and 2 oxygen atoms
When we burn oil and gasoline, it's easy to calculate CO2 emissions based on how many kWh are used. It's not as easy when using electricity, as there are many ways to calculate how much carbon dioxide it results in. We won't delve into that here...
We have chosen the energy agency's calculation of 100g carbon dioxide/kWh Nordic electricity mix.
CO2-equivalents are a unit often used when comparing different greenhouse gases with each other. When electricity is converted into carbon dioxide emissions, CO2-equivalents are usually used. That's why it appears on our labels. Sometimes the goods travel by electric train and sometimes an electric fan for drying sunflowers or other things has been running.
We also list emissions measured in kWh on the items on the website, what is kWh?
1 kWh is the energy required for a thousand watts in an hour. For example, having a hotplate (about 1000W) on for an hour. Or 100 ten-watt lamps for an hour.
Or running out 1 deciliter of gasoline in the car. 1 liter of gasoline is about 10 kWh.
Transporting a 25 kg sack from the farm in China to our warehouse requires, therefore, 0.61x25=15 kWh
In a fair world where every person can emit an equal amount without risking climate impact, figures between 0.5-2 tons CO2 per year per person are usually mentioned. How much gasoline is that? How many kilos of bird seeds? The average Swede today emits between 5-15 times the fair share (depending on how one calculates).
How do you calculate?
We use established figures for energy consumption for different modes of transportation. If you're curious, we can send you an Excel sheet where you can see all the measurements and values. You can also use this to calculate other types of transportation.