post-oil city Göteborg

May 2010

6. On site design proposal

May 30, 2010 9:29 AM
Natalie Adelhoefer

Above: Sketch on combined cistern and pipe system for algae cultivation using the existing structures to be found at the Ryahamnen site today.

The algae production could take place on the exterior of the cisterns as well by a system of tubes as a façade device. That way, the algae particles can flow from the interior pond into the tubes on the outside at a certain growth stage to collect natural light on the outside which they require for growth. In that way, the tubes could make most use of the scarce daylight situation in the Gothenburg region. They are also a very effective production device with a lot of advantages comparing to algae pond systems (see list below the reference project).

Regarding the connections of cistern and turning them into a network of several cultivation steps, a tube system between the former oil cisterns as the connection device will improve the cultivation process by having several steps of algae growth. By this connection method, the algae particles would be kept in a steady flow which they need for an efficient growth rate as they need to be stirred or mixed with nutrients and water. In addition, when they move, the risk of algae particles blocking sunlight from each other is deminished.

The tube system could not only serve as a logistic algae transportation device but as well as a infrastructural link between the cisterns as well, for maintainance as well as for educational purposes.

Below: Sun angle and intensity on site throughout the year.

from left to right: sun angle in summer, fall+autumn, winter in Gothenburg

Below: sun intensity rate and duration in Gothenburg throughout the year.

Below: Conceptual section through a cistern located on site.

The new cistern operation could work as a system described in the section above. The cistern could function in several layers, using water input and output pipes. As algae can only efficiently grow on the top 6mm layer of a water pond due to the light they need to grow, this pond can be kept quite low in depth. The carbon dioxide needed for algae growth could be injected through pipes from below, as gas is lighter than air and would have a natural tendency to flow upwards.

Above: Reference project (student project by Karuga Koinange, Chris Bowler, Daniela Krug, University of Cambridge ).

Advantages of tube-based algae production:
- non-invasive
- cylindrical shape allows for even distribution of light
- closed system means no evaporation
- controlled productive environment
- not depended on surface growth like a pond system
- easy to harvest (easier at least than in a pond)
- easy to monitor and maintain a stable temperature


5. Visions for a future use

May 30, 2010 8:33 AM
Natalie Adelhoefer

The transformation of the oil cisterns located at Ryahamnen today would require taking care of the contamination caused by the oil. The new usage of them as algae production facilities would turn them into a system of input and output, consisting of a network system of pipes and ponds.

The system input would be wastewater and biomass (organic material) from the close to Ryahamnen located wastewater treatment plant Gryaab. (
That way, the amount of wastewater coming from the city and coming into the cleaning process steps of Gryaab wastewater treatment plant would be reduced. Also, the stormwater treatment could be seperated from the wastewater treatment by setting up a second, parallel treatment process plant, the algae cultivation.
The water will get in a sense cleansing treatment by algae cultivation as those algae cultures will process the nutrients and organic material and in that way, filter those substances out of the wastewater coming into the system.

In that way, the algae cultivation wouldn‘t only have a positive effect for the city of Gothenburg by being a green production and research hub but also as a support for the municpality in terms of reducing the amount of wastewater needing treatment and therefore saving energy and making the metabloic flows of the city more efficient.

Above: Transformation of the site. Step 1_Site Programming

Above: Transformation of the site. Step 2_Algae patches

Above: Transformation of the site. Step 3_Algae dimensions

Above: Longitudinal section through site today

Above: Longitudinal section through site tomorrow

As the algae production needs a lot of water running through the system (an average of 1% of algae particles in 98-99% volumn of water), there will be huge amounts of water as an output product of that production system. The water will be filtered and the algae in several steps extracted from it. But this step in the process is still quite difficult and so I plan on having a series of extraction steps along the “chain“ of cisterns and finally let the discharged water which can still contain algae particles into a open pond system which is located on the lower levels of the site. Gravity will help the water flow towards the sea.

But as the direct discharge of the algae water could cause eutrophication in the sea, the water quality has to be monitored and through the opening of the algae-water, outside bacterias will eventually settle on the open ponds and help the water to get free of algae particles again. That way, the water discharged again into the sea can be treated by pretty much only natural processes.

Below: sketch and site model


4. The Concept of Intervention

May 30, 2010 6:10 AM
Natalie Adelhoefer

As a result of investigations of today's material flow in the city of Gothenburg, a lot of water and energy is not being used in an efficient way and the liniar system of metabolism that is existing now could be turned into a circular system again, closing the material flow and leading to a sustainable, rather self-sufficient and resilient city in the future.

Above: Diagramme of material flow in Gothenburg today and future improvements in the system marked red.

The situation today is basically, that water is taken from the river up North of the city, receives treatment and then is consumed by the city and goes back into a wastewater treatment plant to get just enough treatment so that the water can be led back into the sea without harming nature. Although, there are already a few improvements in the water cycle today, there is still a lack of efficiency and big amount of energy needed for the process. Improvements today are for example using the sludge of the wastewater treatment plant by fertilizing soil for farming purposes and using the natural gas produced in the treatment process for biogas cars.

Below: Statistics on Sweden's Wastewater treatment. Figures from 2006. Source: EPA Sweden.
Sources of Nitrogen and Phosphorus and their discharge rates into water in Sweden.

Above: Nitrogen and Phosphorus cycle in urban metabolic systems.

Above: Diagramme of Algae Production. The input material for algae growth is basically carbon dioxide, Nitrogen, Phosphorus and other organic material which are contained in the sludge and waste water of the city's output.
By introducing algae as a new component in the material flow of the city, the metabolistic cycle can be closed again in a green, renewable and biodegradable way.

Today Algae are used by humans in many ways, for example as fetilizers, soil conditioners and livestock feed as well as a pollution control in sewage water and as a source of pigments and stabilizing substances in milk products. One of the most interesting facts though is that algae species contain 2-70% in their weight as oil which can be extracted and converted into biofuels that can already be used to run engines in our existing technologies.

How does Algae production and conversion into biofuels work?

Below: Diagrammes of algae biofuel production process steps

Algae, the Master of Photosynthesis. Photosynthesis in Cyanobacteria generally uses water as an electron donor and produces oxygen as a by-product.Cyanobacteria are found in almost every conceivable environment, from oceans to fresh water to bare rock to soil.
Production through the natural process of photosynthesis requires sunlight, water and carbon dioxide, supplemented with nutrients.

Bio-oils from algae can be used to manifacture a full range of fuels, including gasoline, diesel fuel and kerosene.
The production chain consists of 6 phases: algae development and growth, algae harvesting, recovery of bio-oil produced by alage, transport and storage, conversion of bio-oil to biofuel, production of commercial products.

Closed carbon loop. The carbon dioxide produced by burning the biofuel will be fed back to the algae resulting in a zero carbon dioxide emission.

Below: Parametric components. Influences on Algae production rates

Below: Case studies of Algae Technologies

4 examples of different algae production technologies.

Below: Reference projects

Advantages of Algae biofuels:
Algae: the 3rd generation Biofuel. Comparing algae to other biofuels: the downside of normal biofuels is that they cover large areas of land and therefore push up the prices for food and crush our economy.
Algae grows rapidly and all years around and produces 10-200% more oil per acre than soy. As Algae has a harvesting cycle of 1-10 days, it permits several harvests in a very short time frame, a differing strategy to yearly crops.
Algae can also be grown on land that is not suitable for other established crops, for instance, arid land, land with excessively saline soil, and drought-stricken land. This minimizes the issue of taking away pieces of land from the cultivation of food crops. Moreover, it is non-toxic, biodegradable and can be grown in any type of water. Algae can be grown in open or closed systems, in horizontical or vertical cultivation methods.


3. The Concept of Transformation

May 28, 2010 7:27 AM
Natalie Adelhoefer

My proposal for the transformation of the site is basically structured in several steps over a time period of at least 10 years. It takes that long to treat contaminated soil in a natural way through wetland plants.

I imagine the site to transform into a green production and research hub, a centre of educational implementation into a production site. A faciltity to test biofuel production technologies and methods and its large scale production to become a major source of renewable energy for a post-oil future of the city of Gothenburg.
With the new ferry link, the new research centre on algae production and products could be linked with the Science Park Lindholmen (existing site of research and company collaborations and become a part of this educational hub.
The open pond system I plan through re-using the cistern shells and implementing them into the ground, could become part of the recreational wetland on the lower part of the site, connected with the water edge and in that way become a fusion of both programmes and a soften up the edges of the patch areas.

1. Existing patches on site today

In the first transformation steps, the lower parts of the site which are closest to the water edge and most likely to be flooded with the rise of the sea level, will be turned into a constructed wetland. The soil will get cleaned. The water edge will in that way get accessible for the public and the site re-connected to its surroundings. (see a and b marked in the map below)

2. First step in the transformation process

In a second step, a new public ferry link can be started, replacing the dock function of today's use by oil companies. Turning the site into a rather public site over time, new walkways and cycle paths can be set up, serving as leisure spaces for the residential neighbourhoods.

3. Second step in the transformation process

In third and last step, after the contaminated soil has been cleaned and new public infrastructural links have been set up, new programmes could be integrated which make the site into a relevant district for the city of Gotheburg again.

4. Third step in the transformation process

New programmes could range from a café/restaurant on the water edge, overlooking the river and the city's skyline across it to an open air cinema under the bridge.
The main new programme though, will be a green production and combined research centre about algae biofuels. With the existing dock and a new public ferry terminal point, the site could be easily connected to the existing ferry link ("Älvsnabben") and therefor become integrated into the eduction and research site Lindholmen, located as well on the Northern Riverbank and only a 5-10min ride away.
The algae research centre could become an eductaional as well as a productive hub for Gotheburg and its new renewable source of energy.


2. Status Quo, The existing situation today

May 28, 2010 6:41 AM
Natalie Adelhoefer

The site I was working with called Ryahamnen belongs to the Port of Gothenburg and is after the harbour moved westwards, out of the city and towards the ocean in the 1980s,  today the part of the harbour which is located closest to the city centre of Gothenburg.

Maps below showing analysis of the site's urban layers today.

1. Topography and Green Spaces

2. Infrastructural Links

3. Flooding Scenario

4. Built Structures, Industrial Use

5. Built Structures, Residential Use

6. Overlayering of all existing layers found on site  today

Regarding the decline of fossil fuels, this site will undergo a major transformation after peak oil.

Above: Natural surfes on site today.

Above: Hard surfaces on site today. Contamninated soil.


1. Gothenburg as a post-oil city, An Introduction

May 24, 2010 8:20 AM
Natalie Adelhoefer

Post-oil City Gothenburg

An idea of how to transform an existing fossil oil and natural gas plant into a green production hub with research facilities and a source of energy for an entire city.

The project:
Working with existing built structures and infrastructure systems to create a new green energy  production facility for Sweden's second biggest city.

Gothenburg, located on Sweden's West Coast, along the way between Oslo and Copenhagen. Gothenburg is characterized by its large harbour site, the biggest running sea port f the Nordic Countries.

See also drawings 1, 2 and 3 below.

1. Location. Sweden, Gothenburg (2.)

2. Location. Gothenburg. Site (3.)

3. Site. Ryahamnen marked in red.

Above: Overview on Gotheburg with most important parts marked in red.
Isometric view on Gothenburg an the site's characteristics.





1. Gotheburg as a post-oil city, An Introduction
2. Status Quo, The existing situation today
3. The Concept of Transformation
4. The Concept of Intervention
5. Visions for a future use
6. On site design proposal

RSS feed