What is the real cost of the food we produce in aquaponics? We often talk about the cost of setting an aquaponics system but what we will see here is the cost of running it from a power consumption point of view.
Cost of power consumption in aquaponics
We run our small aquaponics systems with 20 watts pumps. It means we consume 20 watts per hour. There are 24h per day so 20*24= 480watts per day. 365 days per year so 480 watts x 365 = 175KW.
The price of a KW is approximately (depending on your location) $0.2 AUD so the annual cost of running a system is 175×0.2 = $35
Now this type of water pump allows to run a 500L growbed but if we take the example of an IBC system, it is 1square meter (approx 300L of media).
It is extremely difficult to evaluate the annual production in a one square meter aquaponics system but we can guess an average production of 5kg of fish and 20kg of vegetables.
Cost of plants produced in aquaponics
This mean that if we leave the fish production aside to cover the cost of the fish food plus setting costs we have: $35 AUD / 20kg veggies = $1.8 / kg of vegetables.
We can challenge the numbers taken for this calculation, but it gives us an idea of the cost of aquaponics food.
The interpretation of this result can be different for each person. My point of view is that this cost is still acceptable comparing to the price of the food from the supermarket. Also the quality of the food produced is significantly higher. I will not develop this point any further here but as you know I see many other advantages. Let me know your point of view in the video comments.
Here is the original inquiry received:
Hi Jonathan, my name is Saeed, I am living in Melbourne and I recently finished your book of ‘The Art of Aquaponics”. I read it as I became interested to the concept of growing safe, nutritious, and less expensive food and wanted to do it. However after reading your book, I got this impression that it might be safe and nutritious approach to get your food, but it is not a less expensive one and am writing to check and confirm this matter as explained below:
What I understood from reading your book and specifically in FAQ section, page 144 is that maximum fish biomass is 1kg for each 50 litres of growbed and also 5kg vegetable for each 1kg of fish annually. Assuming I make the cheapest set up with IBC with 300 litre of growbed, my maximum fish biomass is (300/50=)6 kg and maximum vegetable qty will be (6×5=)30 kg annually. To be safe I consider 20 kg vegetable annually to leave some clearance for system.
Ignoring all initial cost for set up and regular maintenance (minerals, iron powder, fish food…) and only looking on the electricity that is consumed for a 20 watt pump for this set up, that runs non stop through the year, I’ll have:
20 watt × 24 hours daily × 365 days annually = 175.2 kWh
I pay ¢20.79 for each kWh to electricity retailer for my home and therefore my electricity charge for 20kg vegetable will be about (¢20.79×175.2 kWh/100=) $36 wich means it will be about $1.8 for each kg of vegetable.
As pump capacity and wattage goes linearly up with bigger system, this price will not change if I double the size of my family feeding purposed system.
Can you please confirm this calculation is right as to me it doesn’t looks a very less expensive solution to grow your vegetable?
Cheers,
Saeed
You will probably be interested to discover Jonathan’s six steps to build and manage an Aquaponics system. Click here to access for free! Thanks and good reading 🙂
