domenica 14 marzo 2021

Energy storage and alternatives

And what are the different forms that energy can be currently stored in?

We have the traditional ones, because if you talk about energy storage in relation to electricity, people will think about hydro, because it is stored in the water. And that is a very good way to store for very long times. You can store for days, weeks and even years. Compressed air is another form that has been used, where you also can store for quite a long time. But these two forms always have limitations. 

And particularly, if you want to store for shorter times, we can see that the batteries have become very competitive technology. With batteries, you can store for hours, days, but maybe not longer. But you can also store in very different scales, which is not so possible with the bigger ones, like hydro dams.

And the different scales that you are talking about. What are those scales?

Well, we have two scales. One is in power, and the other one is in time. And if you look at the hydro dams, then you can store very large amounts of power. You can serve the whole country of Sweden.

You can serve for a month with the hydro dams we have in Scandinavia. And you can provide the entire power for the country. For the compressed air -which is, by the way, not so common up here, but I would say worldwide it is used- then you talk about, again, a few days, maybe up to a week. For batteries then, then you have a much wider range. So, you can talk about everything from, I would say, minutes, up to hours and days. And in power terms, you usually talk about then powers that is, you can have power similar to a car. You can have hundreds of kilowatts, maybe up to two megawatts. And there you see development also, that now you can see, battery stores up to hundreds of megawatts. But that is a very recent development.

And a lot of the benefits seem quite obvious by using this type of energy storage. But what do you think are the benefits that people might not necessarily realise? Or can you let us know what they are, just to differentiate from ordinary energy storage, which is not battery related?

Well, if I take one example from the power sector, it is quite interesting, because of course people realise that you can store energy. People realise if you have PV panels, you can store it during the day and use it in the night. But what people maybe don not realise, you can also use the battery to reduce the power consumption, because how much power you use can be quite important. It's not the energy only, but the power. And you can drastically reduce the power need. And this is not so well-known. 

Can you explain what the different types of storage are based on time, duration, and delivery of power?

We mentioned some of them already, and then I covered the batteries. If you want to store energy for very short times - and now we're talking about seconds, minutes, and maybe 1/10 of minutes - we have a technology called supercapacitor, which is very good because these capacitors have, I would say, almost unlimited lifetime. And you can charge in this kiosk as many times as you like. And you can also release very high amounts of power. For longer storage, if you do not have the hydro storage or compressed air, of course hydrogen storage has emerged as one very interesting technology, because then you transform the electricity to gas and the gas you can then store basically as long as you like. So that is why we believe in hydrogen storage, because that you have no limitation in how much you can actually use. And you can also locate it wherever you like.

Tell us a bit about how lithium batteries are representing electrochemical storage. How are they also being used?

Well, as you mentioned, electrochemical is chemistry. So that means that you store the electricity in a chemical process. And you can release it in a chemical process. The advantage with lithium batteries is that they can store, compared to other battery technologies, very, very high amount of energy. That is in a given space and for a given weight. For stationary storage, as we say, where space is not so important, then you can have other forms of batteries. But everything that is moving, then you have lithium batteries. That is why you have lithium batteries in the smartphones also. You do not want to carry batteries as big as the phone.

And where do you see the lithium battery going to? So, what is the future of the lithium battery? It's currently in incredible use in a lot of technology these days. But what's the future of the lithium battery? And is it going to change, or is it going to stay the same?

Well, first of all, let us take us back a little in time. I do not think people are aware of how many lithium batteries you have in your home. I made a little quick count and said, 10 years ago, I had one lithium battery in my home. Today, I have 20. You have lithium batteries in your shaver, in your toothbrush, you have it in the speakers, in electric toys and you have electric bikes. And you can go on and on. And so over the last 10 years, we have started using the home quite extensively. And the new thing now is that we are starting to use batteries also for other applications, where we use bigger batteries and more batteries. And the typical example, of course, is the electric car, but also in the power sector. Again,people see that we start use batteries together with solar panels, I mentioned that already. But we also can see that you will have the batteries to make energy use more efficient in a home. So, you can decouple, so to say, the use from the energy you draw from the grid. And I personally believe that is an application that will grow very, very fast, once people see the value you can bring with the batteries.