We have the task or turning an area of Barcelona into a self-sufficient neighbourhood. So, what is self-sufficiency? The dictionary says it’s “needing no outside help to satisfy our own needs”. So, which dependencies does our neighbourhood have? Namely Energy, Food, Water, and Others (such as social, technological, or cultural dependencies).
Let’s start with energy. To achieve an energy self-sufficient neighbourhood we need to make the result of this equation be one:
Local clean and renewable energy production/ total energy consumption.
Right now Barcelona uses only 13% of renewable energies to power itself. If we look at the sectors, we realise buildings are responsible for over 75% of the energy consumption in the city. The rest is mostly transportation.
So the current reality of Barcelona gives us a result of 1.7%. That is 0.017, so there’s an awfully long way to go, and very few poles of energy production in the city.
When getting our hands in our study area, the numbers look even worse. We are going to go through a series of interventions to try and bridge that deficit gap, starting with trying to lower the bar for the consumption of energy. It only seems fair to start trying to bring the energy consumption of the buildings, that spend most of the energy heating and cooling themselves.
A green coat for Barcelona.
Barcelona has mostly flat roofs, and underused, too. Through equipping these roofs with greenery, we reduce considerably the consumption of energy of the building for both heating and cooling, on one of their weakest façades. The only other façade that is weaker are the party walls, the “mitgeres”, mainly because they are unintended and therefore underinsulated façades. We will retrofit them too, in both stacked up greenery and climbing greenery, improving considerably their performance.
This will somewhat keep the consumption under control, but it has the potential to tackle another one of the big dependencies of the neighbourhood.
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Since 1950s the import of food has been a growing industry. In spain, 25 million tons of food are imported every year, producing 4.2M tons of CO2. This is done mainly by boat, and secondly by trucks. The food travels an average of 3.828km to reach the consumer.
Right now the production of food in BCN is still very limited and more a hobby than anything else. However, the fact that it is perceived as a hobby can be used to our advantage. We will make the neighbours farm the city.
Farming the city
Neighbours will grow food self-configuring their roofs with the help of the modular planters, and even modular furniture, to turn the roofs not only into productive spaces, but also liveable ones.
The walls will also be equipped with stacked planters for the growth of spices and other herbs.
The city is determined on making the courts the next conquered space for public activity. We envision these public courts to also incorporate green, where bigger vegetables and trees can be grown in the soil.
At last but not least, a number of underused warehouses will be transformed into indoors vertical farms, where planters are stacked up and can be soil-based, but also water-based or aero based, where nutrients are sprayed directly onto the roots of the plant. Vertical farms have proved to be very efficient, with control on the parameters, no use of pesticides, and an exponentially lower use of water.
Which brings us to water.
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A green neighbourhood will signify an unavoidable increase in the consumption of water and water is a scarce resource in this climate. So, we will have to turn our block into water sponges.
A sponge block
Blocks will incorporate a system to collect water from rain, grey water (while using these resources to first water the stacked up planters on party walls, which will filter it) and at last when these two are unavailable or insufficient, pulling water up from the phreatic level, which is very shallow in this area, and helping to regulate its level at the same time.
This water is stored in a water tank located in the court, to then be redistributed around the block.
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We have decreased the consumption of the area, and achieved a localised production of food and water. What about producing energy, what about the blue bar?
The first answer is obvious and can’t be denied. The highest potential of energy production in Barcelona still lies in the sun. The only challenge, in a highly dense city like Barcelona, is the space, as we can’t extend a carpet of solar panels, since there is no room for it.
We will therefore add a layer literally on top of the activity, allowing life to happen underneath it.
A photosynthetic umbrella
Using flexible and semi-transparent PV, we’ll overlay a grid of triangular movable solar panels, easily hookable to telescopic vertical posts that help them adjust their position to different scenarios, whether it is towards efficiency or in service of the activity and liveability of the roof.
The amount of energy they can produce will depend on both the usable surface on the roof and the implemented area.
Then we will provide the triangular fabric pieces with two levels of transparency, that result in two different performance levels and giving us a total amount of energy produced, that will be added to our bar.
The same system will be applied to the south facing party walls, but vertically achieving their highest efficiency right when the roof ones cannot, and protecting the green behind them from excessive radiation.
Even the court will be populated with them.
We won’t stop there. Windows can be retrofitted with the same technology in the form of an awning / blind.
Solar is still not enough, so we’ll scrape for any clean energy we can find locally.
Scraping energy
Two lines of metro and a Rodalies train run underneath our area. Using cylinders placed in between the tracks, L.A. is already collecting energy from the wind generated in the passing of the trains.
We add those numbers to our equation.
Adding a Biomass bin in our court might not have been very efficient before, but with the increased green comes a huge increase on the organic waste in the area, making it definitely a useful addition. Plus, the outcome of the burning isn’t just the energy, but the ashes produced with it can be very beneficial for the plants.
Biophotovoltaics are not (yet) achieving the numbers of others, but they benefit from an easy implementation on the one hand, and a consistent reliable production on the other.
Still, we’re not there yet!
What other players do we have on our block that we haven’t considered yet, and that can help us achieve our goal?
The people.
The human network
How can we engage people to help us get to our goal? If information is power, then sharing readable understandable data with and amongst them will empower them and lead them to a significant behavioural change.
The beacon
We call it the beacon and it will display the energy consumption of the block in real time, on the one hand, the energy production on the other (imagine shifting the posts of your roof PV and see the change in the beacon immediately), and will be equipped with an app activated electronic board for the neighbours, where they can display messages when they need or have something to give, when they organise an activity in the court, etc. This will encourage self-organisation from a bottom up approach.
Even when thinking about the possible designs of the beacon, we concluded it was better that the neighbours design it, through local design competitions and collaborations with local schools and universities.
Through all this, we are not only heading towards a self-sufficient neighbourhood, but one that is more cohesive, and hopefully one that reduces levels of loneliness in the city, through a progressively scaled neighbourhood building, from the interactions with the direct neighbours, through the block neighbours to the neighbourhood and the city, through the implementation of a rotating system of food markets.
The farmer’s market
With the implementation of a rotating system of food markets, we will consolidate a cohesive neighbourhood, where neighbours gain this feeling of belonging, whether it is by watching over your neighbours cherry tomatoes or attending the market on the neighbouring block where you know, even though you won’t admit it, they have better aubergines that your block has.
Management
We envision three ways of managing this system. In one building, the neighbours have decided to manage it themselves. They move and maintain the PV, and do their own gardening, and they love it.
On a bigger community, the neighbours simply can’t be bothered, so they associated with Farmbite, a local restaurant committed to Km0 food. They do the maintenance, grow their food, and provide the neighbours with a sweet deal in their restaurant.
Macrosoft is a local 22@ tech company that has decided to automate the system for their roof and walls. They have integrated sensors to supervise the growth of plants and are experimenting with an algorithm that moves the pergola posts automatically to shape it in the most efficient angle at all times.
Beyond the self-sufficient city.
So welcome to a self-sufficient city. These systems, and these interchanges, don’t only boost the biodiversity in the city, the self-sufficiency of the neighbourhood, decrease pollution and therefore the heat island effect (that reduces cooling consumption even more), but we believe they walk towards a more cohesive and resilient city.
And why stop there? This could be only the beginning. Imagine streets full of lettuce, working areas outdoors, among clementines, a public transportation acting like bees, and transporting greens from one block to another, maybe even chickens running around in our block court.
There is definitely a long way to go, but every journey starts with a single plant.
GREENIFYING BCN is a project of INTERNET OF CITIES – SELF-SUFFICIENT ENERGY DISTRICT of IaaC, Institute for Advanced Architecture of Catalonia developed at Master in City and Technology in (2018/2019) by: