Spain is preparing to introduce a new deposit-return system for drinks containers, with consumers paying an extra 10 cents when they buy certain drinks and getting that money back when the empty container is returned.

The idea is straightforward: put a small value on an empty bottle or can, encourage people to return it rather than throw it away, and increase the amount of packaging that gets recycled.

But there could be an unexpected side effect — Spain’s rubbish bins could become a little more valuable.

What is Spain’s 10-cent deposit scheme?

Under the new system, a 10-cent deposit will be added to eligible drinks containers.

When the bottle or can is returned through the appropriate collection system, the consumer gets the deposit back.

For someone buying a single drink, 10 cents is hardly a fortune. But throw away several bottles or cans every day and the value starts to add up.

And that creates a completely different situation from today’s recycling system.

At present, if someone sees a plastic bottle in a rubbish bin, there is normally little financial reason to retrieve it. Once the deposit system is operating, that empty container will effectively have a small cash value attached to it.

Could people start looking through rubbish bins?

This is where things could get interesting.

Spain’s streets, parks, beaches and public spaces generate plenty of empty drinks containers. Some end up in recycling bins, but others are simply thrown into general waste.

Once every eligible container carries a 10-cent deposit, those discarded bottles and cans effectively become something that can be exchanged for money.

That could encourage some people to collect containers from places where they have been thrown away.

It isn’t difficult to imagine someone walking through a park or along a beach and picking up discarded bottles before taking them to a collection point.

Ten cents doesn’t sound like much.

But 50 containers would represent €5.

Collect 100 and that becomes €10.

For someone willing to spend time collecting them, the incentive is very different from simply picking up rubbish for the sake of recycling.

It could also mean cleaner streets

There is another side to this.

If empty bottles and cans become financially valuable, people may become less likely to leave them lying around — particularly in busy tourist areas.

Spain receives millions of visitors every year, and during the summer months huge numbers of drinks containers are consumed on beaches, promenades, in parks and around tourist attractions.

A bottle that previously had no value once it was empty could soon be worth 10 cents.

That gives people a reason to return it rather than abandon it.

It could also encourage people to pick up containers that somebody else has discarded.

But there is a potential problem for rubbish bins

The change could create an unusual situation around public rubbish bins.

People looking for containers may concentrate on bins where bottles and cans are likely to have been thrown away.

That doesn’t necessarily mean people will start emptying every rubbish bin in Spain. However, where there are large numbers of valuable containers, there could be an incentive to retrieve them.

And that could make public bins messier if people search through them and leave other rubbish behind.

Whether that actually happens on a large scale remains to be seen.

The experience of other European countries will be useful here.

Spain isn’t the first country to try it

Deposit-return schemes are already well established in several European countries.

Germany, for example, has a long-running system in which consumers pay a deposit on eligible drinks containers and recover it when the container is returned.

Similar schemes operate elsewhere in Europe, with the aim of encouraging higher collection and recycling rates.

The basic principle is the same: give the empty container a monetary value and people have a reason to return it.

Spain is now moving towards the same model.

What does this mean for consumers?

For most people, the biggest change will simply be remembering that the extra 10 cents isn’t necessarily a permanent cost.

Buy a qualifying drink and the price will include the deposit.

Return the empty container and you get the deposit back.

That could require a small change in habits, particularly for people who are used to throwing empty bottles into the nearest recycling or rubbish bin.

Instead, consumers will need to keep eligible containers and return them through the new system.

For households buying large quantities of bottled drinks, the difference could become noticeable.

A shopping trip involving 20 eligible containers would potentially mean €2 in deposits.

Tourists will need to understand the system too

There is another challenge for Spain: explaining the system to visitors.

Tourists arriving for a week in Spain aren’t necessarily going to know that a 10-cent deposit has been added to their drinks.

Hotels, holiday apartments, campsites, bars and supermarkets will all have a role to play in explaining how the system works.

For visitors, the simplest message will probably be:

Don’t throw the bottle away — it’s worth 10 cents.

That could eventually become as familiar as recycling instructions are today.

Will Spain’s bins really become a source of money?

It is too early to say.

The idea that people will routinely search rubbish bins for bottles is certainly possible, but it remains a prediction rather than an established consequence of Spain’s new system.

What is much more certain is that Spain is trying to change the economics of waste.

Instead of an empty bottle being something with no value, the system gives it a small financial incentive to be returned.

That could mean more bottles and cans being collected, higher recycling rates and potentially less packaging ending up in general waste.

And if some people decide that collecting discarded containers is worth their time, Spain could discover a rather unexpected side effect of its new recycling rules.

Suddenly, the empty bottle in the bin isn’t just rubbish. It could be worth 10 cents.