Can a country produce all its energy renewably?

At this time of year, it is very common to see news of major heat waves and, consequently, strong increases in energy demand. But we also see that the advancement of renewable energies is not only strong but can become the main energy production in the near future. However, is it possible that one day we will have fully sustainable countries? The answer might be very close to our country.

During the past month of July, Portugal's National Electricity Grid announced a fact that many will find incredible: 104% of its energy production was generated from renewable sources. It was referring to the month of March of this same year. 55% of the production was achieved solely with hydropower, reservoirs, and waterfalls. And 42% through wind energy. The rest and the surplus were obtained through other types of energy solutions that are also green.

In light of this news, the question to ask is clear. Can we depend solely and exclusively on renewable energy sources? Unfortunately, we must say that (still) not. Sustainable systems are much more complex than polluting ones and, furthermore, depend on external factors that make them less secure. However, in the near future, this may change.

When we analyze the case of Portugal, the first thing we must consider is that this Atlantic country has a great strength in hydropower resources, which is a relatively stable source of energy production and also favors a high penetration percentage. But the trick of March in Portugal is not related to its excellent hydropower and wind installations - which they certainly are - but with the heavy rains that hit the peninsula and also with the strong winds that moved the water.

This is precisely the great problem of renewable energies, that they depend on weather conditions. And we cannot always expect it to rain or that the wind be strong. In March, for example, the weather conditions were devastating for the Portuguese, but fantastic for energy production.

Does this mean that it will not be possible for us to have countries that produce their energy solely sustainably? Not at all. Moreover, it is advancing that Portugal will be able in 2040 to meet all its energy demand solely and exclusively with renewables.

Challenges of future sustainable countries

The next challenge of green technology is that it is electrical, so it cannot be stored: what is produced is what is consumed. Normally, traditional energy can be used to adjust consumer demand.

The example of Portugal tells us that we are on the right track, but that there is still much to go to have countries that are completely sustainable in their energy. On a smaller scale, in the Canary Islands, we have the example of Hierro, where there was an attempt to create an island whose energy production would be 100% clean. However, it has only been achieved during some temporary periods.

The future lies in understanding the hydrological and wind systems - the two that generate the most energy - so that we can store it. In countries like Denmark, systems are oversized to reach a point where demand never runs short. As we said, the energy generated is what is consumed; demand sets the total consumption. If it could be stored in some way, a giant step would have already been taken. The evolution of systems is expected to evolve so that we can generate better production, especially during peak hours.

Right now, we must continue to maintain a mixed system, where we combine renewable energy with traditional energy. The good news is that the presence of green technology is increasing. But for now, we will have to wait and see if by 2040 countries like Portugal can rely solely and exclusively on renewable systems.