How does gas get to our homes

Gas is undoubtedly one of the leading energy sources used in homes and companies in our country. Many of the heating, cooking and hot water systems in our homes use gas, mainly natural gas.

This is due to its many advantages. It is the least polluting fossil fuel, contaminating far less than coal and oil derivatives like diesel, and it is one of the most economical sources of energy and is also easy to transport, which allows Spain to import practically all the gas we need to supply not only homes, but also many businesses and even industry. 

Gas extraction

Like oil, gas pockets were formed millions of years ago, from the decomposition of different components, mainly mud and other organic matter. This fact, coupled with the heat of the earth's crust and the pressure forces of the earth, formed gas pockets.

Therefore, the first step is to explore these gas fields, not only to discover where they are, but to determine how much gas they contain before starting to exploit them.

Remember, there are gas deposits both on land (onshore) and also under the sea (offshore), which are exploited by means of platforms in the same way as oil. In both cases, gas is usually found at depths between 1.5 and 4 km.

There is also a big difference in the condition in which this gas is found. There are two possibilities: it is either free, in which case it is extracted independently or in a compound state, when it is mixed with other hydrocarbons (such as oil) or other gases. In this case, all the usable fuels and components are extracted, either as a source of energy or as raw material for other industrial processes.

Where does the gas used in Spain come from?

Virtually all the natural gas in Spain is imported from other countries. Spain's own gas production - mostly from the Viura field in La Rioja - accounts for just 0.10% of the total supply, which makes Spain one of the largest importers in Europe

Another important aspect is that, unlike many European countries, whose gas comes mainly from Russia, our main gas supplier country is Algeria. Spain benefits from the large Algerian deposits and their proximity, which makes it cheaper to transport while guaranteeing a large, continuous supply with two direct connections with North Africa through Tarifa and Almería. For all these reasons, although its importance has decreased slightly in recent years, Algerian gas accounts for around 50% of the total imported by Spain.

So as not to depend only on a single source, we also import gas from a dozen other countries. Algeria is followed, although at a great distance, by countries such as Nigeria, Norway, Peru and Qatar with approximately 10% each, according to data from the National Commission for Markets and Competition (CNMC), with minor imports from countries like France, the United States, Trinidad and Tobago and Angola.

How gas is transported to Spain

Gas reaches Spain in two ways, either through gas pipelines or in liquefied form on huge ships.

Most important are the gas pipelines, huge pipes that transport gas on a large scale under high pressure to facilitate this process, usually 72 or 80 bar on its way overland. These massive steel pipes cross land and sea and are coated with a layer of polyethylene that prevents direct contact with the ground and protects them from corrosion.

In undersea sections, such as the international connection that brings us Algerian gas, one of which comes in through Almería and the other one that connects Denia in Spain to the Balearic Islands, the pressure is even higher, 220 bar, to facilitate transport in an environment where the pressure of the sea itself hinders its movement.

The other option is to transport the gas on ships in a liquid state. In this case, so-called Liquefied Natural Gas (LNG) is carried on large ships called LNG carriers or gas carriers that have structures in the form of half spheres on deck that serve as storage space for the gas.

These ships call into different ports (in the Canary Islands it is the only route of entry for gas), injecting further quantities of natural gas into the supply from the North African gas pipelines.

In both cases, the gas has been processed to enable its transport and for subsequent use in companies and homes. So, for example, for its transport in liquid state, any components that interfere with its cooling are eliminated and, if it is transported by pipeline, corrosive elements that can harm the pipes are removed.