How we could become energy autarkic. And what it's worth.

An autarkic lifestyle - not depending on any external party to live our lives. A dream for many. And especially in ever more insecure times like this, an idea that becomes more and more popular.

Russia's attack on Ukraine and the exposure of Europe's dependency on Russian gas have created another boost to this topic. Finally, the question of how to be independent of gas import got more urgent. And therefore also the question of energy autarky became incredibly important and interesting.

So let’s dive a bit deeper into what this would actually mean. And how we could achieve this goal.

How to make a single-family home energy autarkic

Before we get into what we would need to make Europe energy autarkic as a whole, let’s start small. We begin by investigating, what we would need to make a single-family home autarkic.

Let's suppose we are a homeowner in Austria. As we already mentioned in other blog posts, the yearly electrical energy demand is  5000 kWh/year (which is the average demand of a 4-person household according to CO2 online.de). At current price levels (~0.2 €/kWh), this would cost us €1100. For simplicity's sake, we assume that we do not need any heat. (Yeah, that's probably wrong. But this is going to get really complicated very soon anyway. So bear with us here.)

The seemingly obvious way to reduce these costs is to install a PV plant. pvgis, an online tool to simulate PV plants, helps us calculate the appropriate size of our PV Plant. We discovered the necessary size for a plant large enough to cover our own demand, which is 70 m².

But what is not so obvious when it comes to the installment of a PV plant: Almost no one can use electrical energy at the same time as their plant provides it. Depending on the individual usage profile, probably only ~15-40 % of the energy is used by the producer. Mattia Marinelly published a super relevant post on this here just a few weeks ago.

So at best, this plant could reduce the amount of energy we need to buy from a provider. Thereby, our electricity bill would be decreased to  3000 kWh or €660 per year. One way to increase the amount of energy we can use is to buy energy storage. Specifically, batteries. Using the “Independence Calculator” by htw Berlin, we find that even the largest amount of storage would not be enough to make us fully autarkic. The best we can do is 69 %. Bummer. But let’s roll with that.

Autarky is incredibly expensive

Using the setting described above, we reduce our dependency on externally provided energy and become to ~70 % self-sufficient. That means we save 70 % of our initial energy costs: €770. An additional €110 per year compared to the scenario without storage.

But the costs for our system are high. Prices for PV plants are in the order of 2€/Wp (see, for example, this randomly selected module). In our case, this results in ~€10.000 for PV. With a current price tag of~500€/kWh, a battery pack large enough to bring us as close as possible to self-sufficiency adds ~€10.000 to our bill. Totaling to an overall cost of €20.000. Therefore, the time until we have saved enough money to pay for our investment (ROI) for this system would be ~26 years.

To evaluate the real costs of autarky, we need to consider the fact that a battery of this size is not the cost-optimal solution for us. To illustrate this, let’s investigate a scenario where we buy more PV modules instead of battery storage and sell excess energy to the grid.

For €10.000 (the estimated price for a battery), we could buy additional PV modules that provide us with an additional yearly yield of 5000 kWh. Without a battery, we are very likely to use only approximately 15 % of the energy produced by our plant. In our case, that means we are using 1500 kWh by ourselves. This leaves us with a residue of 3500 kWh that we need to buy from our provider. Our electricity bill is now €770 per year.

Seems to be on par with our battery scenario, right? But there is another point for our mini power plant. We can simply sell the excess energy provided by our PV plant back to our neighbors and other surrounding consumers. Let’s assume the currently low rates of ~0.04€/kWh. We would make a yearly revenue of about €340.

If we take this into consideration, our annual electricity bill is now reduced to €770 - €340 = €430. This sounds like a pretty amazing deal, but only if there is a network of other consumers that buys our electricity. However, this contradicts the concept of autarky to a certain point.

Communities are efficient

The example above shows how sharing energy results in reduced costs. Well-designed networks lead to better utilization of resources. Energy communities are another tool that allows us to build such networks for smaller systems. We have to agree with our friend Ricardo Wickert from Hakom, who recently stated in this discussion, that communities are a great tool and help us to become more efficient.

What does this mean for our aim to become energy autarkic?

If we say autarky, we actually mean sustainability

We started this text with a specific trigger. The current war in Ukraine. And the looming danger of a disrupted gas supply. The independence from Russian gas, or fossil energy sources, in general, is more relevant than ever and needs to be addressed. Today, cheaply imported fossil energy is still the most attractive energy source. But this is about to change.

That's why we started looking into autarky. Now we established, that this may seem attractive at first sight, but it is not a sustainable answer either. Autarky is just a green washed term that seems to describe that we want to operate our society in a way that is not leading us into one or many catastrophes. To become sustainable.

But now we understand that autarky is an inefficient and relatively expensive concept even for small systems. Large, self-sufficient systems, especially in industrial contexts, are even more inefficient and expensive.

Is everything lost now? We don’t think so. Not even a bit. We just have to reframe the problem to arrive at a solution. And this can be easy. For each individual case, the question boils down to how to design an energy system that is efficient and sustainable for the user.

How that might look for different scenarios is something that we will cover in future posts soon. And if you want to look into your individual path to a sustainable energy system - get in touch with us!