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Cycling through a sustainable Leiden

The city council of Leiden is working on a liveable and promising city through the years.
At the moment they set up a plan for 2016 until 2020 to focus on a more sustainable city even more. The idea seems really nice, but the big question is: Will it be  achieved?

To realise such an achievement, you will need the contribution of the citizens.
Because they are the biggest player in the sustainable game. To make them act towards the sustainable plan of the council, you will first have to show them that it is really possible to do something for a more sustainable city.
And people in the city are allready on the right track actually!
I would like to give you a short preview on how citizens make Leiden more sustainable starting with a small contribution.

Everything in Leiden is very close to each other, this makes it very attractive for people to take the bike instead of their car. Actually almost fifty percent of the people takes their bike to go to work or school.
And that school part is very important in Leiden, because there are a lot of students living in the city. Almost every student has one bike (or more). But you would be a fool to buy the most beautiful bike you can afford, because the chance that it will be stolen is very high.

But a lot of students on crappy bikes also means a lot of bikes which break down. Those bikes will often not be repaired, because its easier to buy a cheap new bike.
Bikes that broke down will stay where they are, which most of the time means next to a canal (and after an amount of time end up in the canal)
Those bikes have a large impact on the environment because they release iron while rusting. Once a year these bikes have to be dragged out of the water, which costs a lot of money.

Two students in Leiden thought that something should be done about this problem.
They wanted to offer a very quick bike fixing service and also to stop waisting old bikes which aren’t used anymore. A new company arose at that moment, EasyFiets.
They started to collect old bikes through the city which owners could address themselves. Those bikes were repaired and put back on the market again for leasing, or renting for a day. You can easily recognise them on the red handles and saddle. 

Remarkable red saddle and handles (EasyFiets)

This is an example of a small start to contribute to a circular economy.
Ofcourse not all the old bikes will be collected by the company and re-used. But still, once you know about the concept you see the remarkable bikes everywhere you go.And every time you see one, you will be remembered about the easy way to contribute to a more sustainble city.

It’s only one example of a contribution by citizens, but ofcourse there is more. This example is just to show that people are willing to change and work with the council to make the city of Leiden more liveable and promising.



Energy Transitions past and future

As we begin to come to terms with the serious effects of climate change, it is now more than ever that we must look back into the past to ensure mistakes made in previous generations are not repeated in our current transition period. One such mistake that seems immediately obvious is an over investment in one pathway for transition. For example, while not exactly an energy transition (but nonetheless relevant to sustainability), the change from open sewage system to underground sewage removal in modern cities was a transition that has left us with no easy way to again adapt to changes. In the future if our sewage systems should prove incapable of dealing with novel problems we can of course try to alter it to overcome these challenges, however the heavy investment in infrastructure during the transition period was done in a way that has left us locked into the current sewage system with little possibility of a radical overhaul. While we may not yet be in a position where the sewage system requires a radical overhaul, the same cannot be said for our energy production and unfortunately, the same “lock-in” effect seems so have taken effect. When society transitioned to a fossil fuel economy little care was taken to ensure the new system was adaptable and versatile. Huge investments were made without pausing to thing about how a complete reliance on fossil fuels could hinder us in the future. Of course, people back then had no idea that the carbon dioxide given off would cause the environmental issues we see today, but the problem I want to highlight is not that they were unaware of future problems but that they did not appear to even consider the possibility of future problems arising.

So, what does this mean for our current energy transition? I think these lessons from the past show us the importance of investing in multiple different energy alternatives and not relying on one single source such as solar or wind to solve our problems. We see in ecological and biological systems alike that diversity increases resilience. With a large array of renewable energy sources powering our future societies, we will be less vulnerable to unforeseen problems. If years later we find out wind turbines are having damaging effects on the Earths air circulation it will not be nearly as challenging if we have a vast array of alternative energy sources ready to fill the energy deficit while we transition once again. Furthermore, transitions in the past show us that while we should design our future energy production systems to survive well into the future we should design them with the knowledge that one day they will change once more. Whether this be changes to make the systems more efficient or changes that ultimately see them dismantled, we need to thing not just about the life of the infrastructure but also its death. Technology is constantly evolving and if something is not made obsolete by technological advancements making it function redundant, then it will soon be superseded by a more advanced and more efficient version of itself.

In the real world there is no silver bullet. A successful energy transition for the future will require innovative and new sources of energy designed to exploit the different environments in which they operate. We should take heed of the mistakes made in the past and never slip into thinking that the solutions for today’s problems will be the solution for the problems in the future.

District Heating: Not a hottie, but I’d still do it

When it comes to the energy transition of Leiden, it is vital to explore new ways to heat the city without gas, the good old gas that has been something oh so convenient, but also deceptive. It has betrayed Leiden, and many others. Now it tries to explain things for the better: “Come on, carbon capture and storage will fix this. And how about condensing boilers?! Hey, at least I am not as bad as oil and coal!”

But Leiden has started to realise that it needs to look for a new source of warmth. Now it seems that the best bet for Leiden is to opt for―no matter how unsexy it sounds―an extensive district heating network. Others, like many cities in Denmark, have already fallen in love with it.

Simply put, in a district heating system heat is distributed in the form of water or steam from the site(s) of production to a wide range of users. The system, like any other, has its pros and cons. A top-down imposed centralized system might raise objection, and the initial changes needed in the infrastructure will be costly. Nonetheless, a district heating system would offer substantial long-term benefits for Leiden.

District heating systems are energy efficient and highly flexible as they can utilize various sources of heat for optimal energy use.

To start with, surplus or waste heat from different processes could be pumped in the network. For instance, cogeneration plants that produce both electricity and heat (for a network) are significantly more energy efficient than conventional thermal power plants that merely waste the by-produced heat. Surplus heat can be connected to the district heating network from various local, or more distant sources, such as the Rotterdam harbour. Using waste or surplus heat would result in significant total energy savings, which is positive for the environment, and perhaps even for the wallets of the Leidenaars.

Apart from waste heat sources, the system can be fed by almost any current (and likely future) heat production forms. Some of the renewable examples are geothermal heating, biomass, central solar heating, and various types of heat pumps that can harvest heat from air, ground and water. In Duindorp, for instance, the district heating is fed by warmth harvested from seawater.

District heating system’s flexibility and compatibility with different forms of heat production makes sure that Leiden will not be dependent on only specific sources of energy. This, in turn, provides energy security. In order to make the district heating system even more flexible, it is recommended to pair it with (seasonal) thermal energy storages that act as a buffer and solve the intermittency problem of certain renewable energy sources. The storages can also help to optimize the energy efficiency of the system and its financial returns.

In short, it is time for Leiden to leave its smelly old gas system and move on. District heating—even if it remains unsexy—is a perfect fit for Leiden in its longevity and adaptability. It will open endless possibilities to keep the city warm and cosy—now, and in the future.


Photo: Bill Ebbesen

Sources and further reading:

State of Green: New White Paper on District Energy

The Guardian: Lessons from Denmark: How District Heating Could Improve Energy Security

Sustainable Cities Collective: The Heat is On for Sustainable District Heating and Cooling

UNEP: District Energy in Cities

The Energy Collective: Holland: Pioneering Sustainable District Heating Innovations

Review of District Heating and Cooling Systems for a Sustainable Future

Towards Next-Generation District Heating in Finland

The ADE: What is District Heating?


Leiden’s canals charging your phone

Everybody is familiar with the beautiful scenery of canals in old Dutch cities like Leiden. But below their surface, the key to a green Leiden is hiding. Those beautiful canals contain a huge amount of silt.
The silt from those famous canals might launch a huge transition in energy generation in Leiden, and make Leiden an example to all other cities with water flowing through them.

Silt contributes to the overarching term biomass, that is composed of vegetable, garden and fruit-waste, vegetable oil, wood, fertilizer and plant-rests from agriculture. Biomass can be used in many ways to increase sustainability. Biomass is capable of lowering relative CO2 levels emitted by power plants. When a part of the power plant’s ‘fuel’ (mostly coal) is replaced by biomass, it lowers the usage of fossil fuels and thus reduces the relative CO2 emission. Furthermore biomass on its own can be used to produce electricity, when it is burnt down, steam is produced that will enter a turbine in order to generate electricity. Another way of using biomass is by fermenting it, in this way biogas is produced. Biogas is composed of methane and carbon dioxide. After fermentation a wet digestate is left. The methane that is formed by fermentation can be burned in power plants and create green energy.
Biomass can also be gassed. This means; burned down under certain conditions (low oxygen level). This generates biosyngas, that is composed of mostly carbon monoxide and hydrogen. Hydrogen can be used to generate energy in a hydrogen fuel cell.

All these techniques need to have a huge biomass input. Luckily enough, in the Netherlands we’ve got a big amount of biomass available. Of course the silt which was named already. Furthermore waste from people’s homes, restaurants and supermarkets can be used. Especially when accurate advertising is done, a lot of people will join and collect their organic waste. Leiden is near to the Westland, which means a huge amount of greenhouses. In these greenhouses there is a lot of organic waste, because only the fruits/vegetables of the plants are being used. The rest of the plant is perfect for creating green energy. Almost the same counts for ‘Het groene Hart’, where a lot of farming is done. Not everything that grows on the land, is being used.

For turning silt into energy, fermentation to biogas seems to be the most appropriate technique. For cities like Leiden to kick-off such a project, investments will have to be made. A fermenter needs to be installed and a power plant that can transfer biogas (methane) into electricity  as well. This is a huge investment, however, cities can work together and share their resources.

Leiden to kick-start the transition!



People as Energy Source

Wouldn’t it be amazing if we could create energy by just performing our everyday activities? This is not a mere dream, it is already possible. In 2009 the idea was presented for the first time: an energy generating tile. Pavegen creates just that, energy generating tiles, producing energy every time someone steps on it. Even though the tiles only produce 5 watts per step, I believe this new form of renewable energy can play a vital role in future energy generation and save our Earth.

These energy generating tiles can be used everywhere people walk. Areas bustling with life are great sources of energy, think about office buildings, train stations, airports, schools, restaurants and sports grounds. People spend many hours a day walking around, travelling from A to B. There is no need for them to change their behavior. For an idea on how the tiles produce energy, please watch this video. The tiles have other capabilities as well. For example, they can gather data on how people move in a certain area. The data gathering possibilities is interesting for many companies interested in behavior. The tiles are relatively new, so there is still a lot of room for improving their energy producing capabilities. If the tiles are improved and placed with many in a lively area I am sure they can become an acknowledged energy source. Saving on your energy bill by just playing soccer, that’s killing two birds with one stone.


Shell soccer pitch, Nigeria, using energy generating tiles

This sounds very nice, but there are a few downsides. The tiles don’t produce much energy yet. Financially placing the tiles is also a tough decision to make, as a single tile still costs £600 per square meter. However, the producer aims to sell the tiles at almost the same price as regular tiles in the future.

The municipality of Leiden, the Netherlands, wants to be 100% energy neutral by the year 2040. Meaning the want to produce as much energy as they use within their own borders. This is an admirable goal and a tough challenge. There is only so much that can be done within the boundaries of the municipality. There is not enough room to start very big projects within a city. Perhaps the energy generating tiles will not be very profitable at this point, but I would advise the municipality of Leiden to keep an eye on this renewable energy source. For now I hope they can get as far as possible with reaching their goal by using existing renewables. Hopefully a part of Leiden’s need for energy can be covered by the movements of its own population in the future.

Whenever we think of renewable energy, we often think about wind turbines and solar panels first. However, I don’t think we can become energy neutral by just using those two methods. We need other methods like geothermal energy and hydropower. I hope people will come up with more innovative ideas, such as the energy generating tiles. In this new age where climate change is a huge threat to mankind, it is of great importance to switch to renewable energy as fast as possible. We need to protect our Earth and our future, but we only have limited time.


Solar power, answer for Leiden’s renewable energy source?

Our primary energy generation still relays on fossil fuels. Approximately 80% of the world’s energy supply comes from fossil fuels. However, fossil fuels will soon or later depleted. Therefore, energy generation by non-fossil fuels should be implemented on large scale. Solar energy has a large potential to generate a considerable amount of energy in the world. The potential of solar energy can be seen in figure 1.

Figure 1. Solar energy potential in the world.

Energy generation still also relays primarily on fossil fuels in The Netherlands. In 2014 only 5.5% comes from renewable sources. The government has set a target of 20% renewable energy sources in 2020. In the next coming years we have to increase our renewable sources by 14.5% of our total energy generation. Currently, biomass and wind energy accounts for the majority of renewable energy in the Netherlands. Solar power has relatively a small share in comparison to biomass and wind energy. This can be seen in figure 2.

Figure 2. Shares of renewable energy sources in the Netherlands.

However, in recent years the use of solar power has significantly increased from 88 MW in 2010 to 1405 MW in 2015. Solar power will contribute a significant amount of renewable energy. In order to reach the target of 20% renewable energy sources in 2020, solar energy has to expand in The Netherlands. Solar power has potential to generate energy as can be seen in figure 3.

Figure 3. Solar power potential by annual sun hours.

The potential is not that high as in countries with more sun hours per annum e.g Australia. However, Germany installed an enormous number of solar power systems. In 2015 the installed capacity was 40782 MW.[i] This accounts for approximately 7% of the total energy generation in Germany. The amount of solar energy generation is almost neglectable. Germany has a similar sun energy potential as in the Netherlands; we have a similar climate and sun hours per annum. Therefore, it is likely to implement similar solar systems in the Netherlands as in Germany to increase the share of renewable energy sources.

Solar energy has a small share in renewable energy in the Netherlands. However, let’s zoom further in local municipalities in the Netherlands. The city of Leiden has an ambitious target to reduce CO2 emissions by 40% compared to 1990 in 2030. They also want to increase the use of renewable energy sources. The percentage of renewable energy was 6.1% in 2014 in Leiden according to klimaatmonitor. The share of renewable energy usage is slightly higher than the national average. However, Leiden has less solar polar per inhabitant than the national average. This can be seen in figure 4.

Figure 4. Comparison Leiden-the Netherlands solar power per inhabitant

This suggests the city does not invest enough in solar systems. According to figure 3 Leiden has a higher solar potential than other cities in the Netherlands. Moreover, Lots of roofs are suitable for installing solar panels. In order for Leiden and the Netherlands to reach its targets, solar energy could attribute significantly more to renewable energy sources than our currently capacity of solar energy.


Energy Producing Flooring: a steppingstone for Sustainability

Step by step by step by step we move forward. Each and every one of us makes thousands of steps every single day. Be it frantically running around the bedroom to find that last clean shirt or walking down to the shops to get a cold beer you earned for putting so much effort into finding a clean shirt. In total a person walks up to 150 million steps in their lifetime. Whether you live in Sweden, Zimbabwe or Guatemala: walking  is unarguably the most common way of transport.

So what if I told you that each and every single one of those steps has the potential to generate sustainable energy; that we can move away from fossil fuel-based energy simply by walking?


 Making this vision reality is exactly what Laurence Kemball-Cook, the founder of Pavegen is trying to achieve. In 2009 he engineered a flooring tile that can transform the kinetic energy that is released through a step into energy and save this energy in a battery. This battery can then be utilized to power street lighting, advertisements or charge phones for example. A big asset of this kind of energy is that it is off-grid and, not like solar or wind energy, independent from weather developments.

As Kemball-Cook explains in a TEDx talk in Rio, first trials were successfully made in a school, and public awareness rose rapidly.  Newspapers started writing and politicians and celebrities stated their support for the idea. With this positive response the start-up started growing. By 2012 they had built a football field in Brazil  lighting is now powered by the movement of people playing or walking on it. Today several big places such as train stations, airports and commercial sites are already equipped with the floor, producing energy every day. Moreover, similar firms such as energy-floors are already developing which is an indicator for the economic viability of the idea for producers but also for consumers

The exact cost information is currently not released to the media but in an interview with Forbes  Cook claims that “ a standard square meter of decent flooring that would be used in a building such as a train station would cost around 1000 pounds and Pavegen will be sold for around that price”. Furthermore, even if the cost still is slightly higher it will be compensated for by the energy saved while it is in use. In the long run the tiles are expected to become even more affordable for several reasons. The production is going to be less pricy when done on a larger scale and the batteries, a crucial component, will become cheaper with the help of Tesla’s gigafactory. Seeing these developments, there is reason to be optimistic about the future of energy-producing flooring.

Pavegen secured his market position by releasing a new tile: V3. The V3 produces 200 times more energy than its predecessor and also collects data about the steps made on it. This double function makes the flooring even more attractive for the interconnected, data driven city of the future. However, in addition to green energy and data collection the tile might be able to fulfill a third very important function: spreading awareness and involving people in sustainability on a personal level.

Harvesting human power as an energy source has the potential to show that every individual can contribute. The flooring can make this connection visible in a way that only few other solutions can. Be it by charging your own phone by dancing at a festival or lighting your own way when walking home.

e65cef9812e64fe5f0eb5247a629afe3The immediate response to your own action is an empowering and motivating experience. It basically sais: you can make a change. Since we all walk and all use public spaces such as train stations, clubs, shopping streets or airports this will permeate every level of society and hopefully give a more accessible image to the sustainability debate. Because for you it might only be a small step but if we all make it, it is one giant leap for mankind.