Tag Archives: Sustainability

Project Sponge: Cool Heating and Hot Cooling


The Netherlands lives with water. The world-famous water management techniques have proven invaluable for a country with 26% of its territory below sea level and another 29% at risk of river flooding, as taken from PBL. And in the face of climate change, these systems will become even more urgent.

The Dutch waterworks have found their way to all landscapes, except for one. The city. There is the last landscape that still experiences a risk of regular flooding. Albeit not life-threatening, flooding in a city the size of The Hague will cause substantial damage and associated repair costs. But what if the city could create a massive water storage capacity, making it in essence a large sponge, while simultaneously reducing heat stress and energy demand.

water-waterwarmtepomp grondwater
TK Warmtepomptechniek

Mainly designed on the well-proven principle of a water-water heat pump, some neat hypothetical additions can be added. The system boils down to a series of insulated underground water storage tanks and above-ground pipes. The pipe grid will run both through the building’s interior and as a trickling waterfall through the façade. The logic behind it is very simple. During summer, cold water from the tanks will be pumped through the building’s façade, cooling both the building and reducing the heat-island effect felt on the street by absorbing and transporting the sun’s heat away from the surface. This practice of transporting heat is very common in space applications and could also have large benefits in civil applications. By using this technology, the water will heat up, creating a buffer of thermal energy. Come winter, this thermal energy can be used to heat the connected building, reducing further need for gas or electric heating. In this way buildings will have a positive effect on the temperature of their surroundings as well as reduce their energy bill sustainably.

Waterfall in glass panes at The Clarendon Hotel and Spa, on Tripadvisor

Besides the heat-island effect, cities of tomorrow (especially in the water country that is the Netherlands) will also have to deal with heavier rainfall. At the moment, cities scramble to create water retention capacities to store the water in such an event. Enter the system described before. By connecting the system to the storm sewer, a massive water retention capacity can be realized, for very little extra cost. Now the system has the added bonus of reducing nuisance from heavy rainfalls combined with limiting the effects of summer droughts.

According to the International Energy Agency (IEA) water has a minimum energy storage capacity of 2000 kWh/ton and is capable of storing this energy for up to a year. Given that thermal energy storage is well proven, yet bulky, underground applications should be well possible. In addition, cooling buildings by waterpipes through the roof has also been proven efficient back in the 1970s in New Delhi, India.

Where climate adaptation is now mainly seen as a necessary pain to keep the city livable in the face of climate change, implementing project Sponge will transform this into an opportunity. Creating revenue by tapping a new renewable energy source, while simultaneously installing all required climate adaptation measures with innovative green and blue technology.


Two ways to find out how sustainable you live in your house

On 12 December 2015, 171 political leader signed an international climate policy in Paris, the Paris Agreement. This agreement also meant a reversion for Leiden in the field of CO2- emissions: a reduction of 49% in 2030 compared to 1990. In order to achieve this, the trias energetica was included in the policy plan of the municipality. The trias energetica is based on the following: ‘First, we need to reduce the demand for energy. Second, we need to use sustainable sources in stead of fossil fuels. Third, we need to produce and use fossil energy as efficient as possible.’ Despite the fact that the trias energetica is included in the policy plan, there are two issues, which make the target more difficult to achieve:

  1. The mandatory energy label (Dutch: Energielabel plicht)
  2. The green certificates from abroad (GOs = Guarantees of Origin)

1. The mandatory energy label 

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An energy label is a label that indicates how many measures for energy- savings have been applied to a house. Houses can no longer be sold without a label because of the mandatory energy label. This measure aims to reduce the demand for energy. With this measure, the government has set a step in the right direction. However, this obligation does not apply to all houses. Protected monuments* do not need to have a label, while protected monuments form a significant share in the housing market in Leiden. It is possible that Leiden is not going to achieve its target for 2030 because of this legislation. If you do not live in a protected monument, see if your house contributes to achieving the climate agreement. Below, you can find out what your label is. Label A is the best and G the worst.

*According to the Heritage act (Dutch: Erfgoedwet) or in the provincial or municipal regulation (Dutch: verordening)

Step 1. The website: https://www.rijksoverheid.nl/onderwerpen/energielabel-woningen-en-gebouwen/vraag-en-antwoord/hoe-kom-ik-aan-een-energielabel-voor-mijn-woning

2. The green certificates from abroad 

The next step requires an explanation about green certificates from abroad. What are green certificates anyway? The video below gives a good explanation. A green certificate  proofs that 1 MWh of renewable energy has been generated from sources such as solar panels and windmills. The green certificate is sold to the energy provider and therefore  the energy provider can provide the consumer with green energy. This is done, because it ensures the consumer that he or she contributes to the production of green energy on the general energy network.  Since the general energy network also contains energy from fossil fuels, such as coal-fired plants. There is often no direct connection between the source of the renewable energy and the consumer, for example between a windmill and a specific building. This direct connection is only made on paper because of the green certificates. The purpose of the certificates is to use more and more renewable energy and less fossil fuels.

It is therefore regrettable that some energy providers have found a way to use green certificates, but on the other hand do not contribute to the energy transition. This is due to purchased green certificates from abroad, for example from Norway and Iceland. Inhabitants of Norway and Iceland are sure that they receive green energy from the hydropower plants. They do not necessary need a green certificate to believe that they are receiving energy from renewable resources. On top of that, these countries can sell  green certificates to other countries, because they have enough certificates to reach the climate targets. Therefore, the green certificates from Norway and Iceland can be sold to countries such as the Netherlands. Inhabitants of the Netherlands also want to contribute to a more sustainable world, but because we do not automatically purchase electricity from renewable resources, we buy green energy with the green certificates. The behavior of some energy providers is misleading. It is cheaper for them to buy green certificates from abroad than actually produce renewable energy themselves. The hydropower plants in Norway have been running there for decades. Unfortunately, this does therefore not contribute to the energy transition. So see if your energy provider also participates in this. You can see this below.

Step 2. The website: https://wisenederland.nl/energievergelijker


Local initiatives will lead to a climate proof Leiden

I have been living in the city of Leiden for three years now and fell in love with the canals, the old streets and buildings and the little parks here and there. This beautiful scenery will however not last very long. The streets are subsiding, the city centre is heating up and water related problems are occuring. And these problems will only become more intense since the climate is changing due to global warming. There will be more tropical days, meaning that the heatstress problem will become dangerous to weaker people, such as small children and the elderly. Next to more tropical days, there will also be more heavy rainfall. Currently, with all the stone and little green in cities the amounts of water get to large and streets and buildings will flood, giving large damage costs. So, it is necessary that Leiden becomes climate adaptive.

This climate adaptation can be done by the munincipality who will force rules on the citizens to change. That however will be very hard and will not make the munincipality popular amongst their citizens. It is probably a better idea to have the initiatives come from the locals themselves. The munincipality can then help the citizens with expertise and subsidies.

There are already some local initiaves in the Netherlands that show great effort from within the local community. One of them is Amsterdam Rainproof, an initiative to decrease the water problems due to heavy rain in the city centre of Amsterdam.  For instance, people can put rain barrels in their garden to collect the water. And the project encourages the citizens to add more green to their gardens so the ground and the plants can hold on to the water longer. More information can be found on their website. https://www.rainproof.nl/

Another local initiative is Operatie Steenbreek, it literally tries to break the stones in the city of Leiden. So, replacing stones by plants, the same kind of idea as Amsterdam Rainproof. Because, plants don’t only hold water but also lower the temperature of an area. This is important since we will have more tropical days and the heatstress will cause great problems. In the current situation, people still have a lot of stone in the gardens or balconies. If everyone would more their houses and direct environment greener, then the water and heat problems will drastically decrease.

This video below explains Operatie Steenbreek.

These are just two examples of local initiatives in communities to battle the problems that arise because of climate change. It shows that little changes can eventually solve a large problem. These kind of bottom up actions lead to more awareness amongst the citizen. This is a very important aspect in climate adaptation. The more people that think and act on possible solutions the faster we can solve the big issues. Because heatstress and water issues are serious problems that must be solved before they become a threat to our health.

Smart Batteries may be the solution for a sustainable The Hague

Do you want to reduce your annual energy bill while you’re helping The Hague become future proof? Many steps have to be taken to minimize and eventually completely eliminate our carbon footprint. Using green energy in our houses, workplaces, school and other buildings is a clean and easy way to do our share for the environment. A company based in California, Green Charge Networks, might have developed the golden trick to facilitate this process, namely Smart batteries. This allows solar energy to be stored for later consumption. The company is specialized in creating predictive software and energy-storages, enabling households and local enterprises to lower their energy demand during peak hours. The project’s main goal is to promote energy-efficiency and in the meantime encourage more households, local businesses and public organisations to go solar.

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A picture of the smart lithium-ion batteries released by Sustainia. http://solutions.sustainia.me/solutions/smart-batteries-reducing-peak-power-consumption/

How does it work? The corporation provides lithium-ion batteries accompanied by big analytical data software. When solar energy is affluent during the day and the grid demand is low, the installed lithium power cube will automatically store the surplus energy. This technology, doubtlessly user-friendly, enables us to use green and free energy when the demand is high and the prices increase.

This video posted on Youtube by the company gives a short and clear visualization of the installation. https://www.youtube.com/watch?v=bVE0qazg8qM


A “two birds with one stone” solution. In addition to financial benefits, this innovation also empowers the use of locally produced green energy allowing cities to make big steps towards the carbon neutral goal. Currently, many cities are thriving in becoming fully green and carbon neutral before reaching half way the 21st century. The Hague makes no exception here. Reducing energy generated by non-renewable sources such as coals, oil and gas will definitely help us achieve this sustainable goal. Considering the current expansion of households, corporations and public organisations are eager to invest in green energy. Bearing in mind that in 2016 only 5,9% of the Dutch electricity bill was generated from renewable sources. The installation of smart lithium batteries in The Hague will be the golden opportunity to upscale the green energy consumption and to decouple the demand from the supply chain. Enabling other futuristic and green energy-efficient innovations to progress. Another unneglectable green aspect induced by this modernization is the fact that solar panels will account for higher production levels than ever before, meaning that raw materials are better invested. On the long run, this could also mean that less raw materials will have to be extracted for the production of solar panels. The only downside to this is that the amount of raw materials needed for the batteries will increase.

We-share-solar.jpgBe cool and share. The lithium-ion energy storages could form the base to new social projects. For example Solar share, allowing the extractionof energy stored by different consumers. Meaning, you could use green energy produced by your neighbour’s solar panels when he or she is not home. This share of renewable energy is already set in place in different municipalities in Australia and in the United States. Green Energy Cooperative, an association developing and financing different energy-efficiency projects that involve local communities, claims that inducing full engagement and responsibility of citizens in energy production is the key to a sustainable future.


Visualization of energy share.

I agree that much more will have to be done if we want to fight back climate change fully.  Yet I do believe this modern installation could be an easy way to facilitate the transition to green energy, as it brings along a broad range of benefits and opportunities. I especially like the fact that it could makes individuals more independent, seeing as they would not have to fully rely on the volatile prices of energy. It also strengthens local communities.


Waste is not the end

For the last couple of decades, climate change is all over the news and slowly but surely people are getting more involved in this issue. Sustainability is our savior, our hero against climate change. However, this specific hero of mother earth is still far away. Once it will be nearby, it should embrace the earth and protect her from exploitation and pollution.


Difference between linear and circular economy. Source: World Economic Forum    https://www.weforum.org/agenda/2016/05/can-the-circular-economy-transform-the-world-s-number-one-consumer-of-raw-materials/

How to solve the everlasting problem like climate change then? And where to begin? First of all, we need to change our way of using and producing things. Our economy is based on linearity. We extract resources, produce, distribute, consume, and dispose, for me also known as ‘waste’ or  ‘rejected leftovers’. Instead of rejecting it, we must re-think about the meaning of waste. Just start calling it ‘leftovers’ rather than ‘waste’ .  If I have enough leftovers from my lovely diner that I cooked, I’ll save it for the day after, because it is cost saving and at the same time the quality is still excellent enough for using it again. Leftovers from the production in a company or factory should be used as a secondary resource for themselves or for another company, like a contributor to a circular economy.

Video showing the challenges and opportunities for companies. Source: The Guardian

this video states that companies should start with the circular economy. The two examples following up perfectly describe where to begin on a small scale.

I work in a do-it-yourself shop. One of the services we deliver is sawing wood in the preferred size for the customer. The waste we leave behind is sawdust. Instead of labelling it as waste and throw it away, we provide our sawdust to a farmer, who is using it again for the pigs for rooting. Another example is a company in The Hague, buying leftover  wood briquettes from furniture companies to heat up his own building and even other buildings surrounding him. The advantage of burning wood briquettes is that they release less carbon dioxide compared to fossil fuels.  These two examples do present a solution for reducing the extraction of raw materials and to save energy by using leftovers instead of using new raw materials.

These two cases do not present a circular economy on a large scale, but they perfectly describe a small starting circular economy. These examples can be a great practice for companies in The Hague. Why The Hague? The Hague is a city with lots of citizens and companies. The chance of companies working together is more likely to be in a city like The Hague. Businesses helping each other like these examples in industry areas like ZKD and Binckhorst would tremendously reduce the impact on climate change and exploitation of materials in The Hague. If the Netherlands wants to achieve their goal of being a circular economy in 2050, more cities should introduce a circular economy. The more cities, the closer we will be towards a better and sustainable earth.

Making the energy transition easier

The municipality of The Hague has set the goal to be climate neutral in 2040. On energy transition level, this means two things. On the one hand, the energy usage has to be minimized. On the other hand, the energy demand has to be supplied with sustainable energy coming from renewable sources. In short, energy transition can be defined as the transition from fossil fuel based energy to a renewable form of energy. For the majority of the citizens of The Hague this transition may seem as a huge step. This blog is not going to argue that it is not, but it will provide a tool that can be useful during the transition.

First of all, this step does not need to be taken in one go. The distance from the starting point to the endpoint can be chopped up into smaller pieces. In this blog I will focus solely on the first part, namely the reduction of energy use. According to Linda Steg and colleagues, the reduction of energy use will enhance the efficiency of sustainable energy systems. Individuals can either invest in sustainable initiatives or avoid certain daily energy actions. The average energy use of households in The Hague is forty-four percent of the total energy demand. This percentage is the highest of the six stated sectors.

The tools and information to reduce energy use at the household level are openly available. The top five tools for reducing energy provided by Harvard University states that shutting down electronic devices, choosing for LED light, unplugging electronic devices, shutting down power strips and turning off the lights are the main tools to reduce energy use. These tools are publicly known, however why bother when you are convinced that your energy usage is already low?

Currently, there are multiple initiatives that are trying to make the visualization of the energy use of households more accessible. One of these initiatives is a Kickstarter funded project called Glow. Glow is an energy tracking device which measures the energy usage of a household and creates an overview of the gathered information. This gathered information is visualized in an app. When connected, the device shows different colors of light. When it is green, the energy use is low, when it turns orange or even red, the energy use is (too) high. This energy tracker can be a useful device to monitor and eventually reduce energy use.

With this blog I am not posing the magic key to a successful energy transition, but I think that the majority of the people living in The Hague are not aware of their daily energy use and even if they are, it might be too expensive to make the transition. This expenses could be partly subsidized by the municipality. Or the municipality can try to create an similar app as the one from Glow, with which the citizens can see their daily energy use. When the energy use information is available to the households, they are already a few steps on their way to the finish; a fulfilled energy transition. The Hague wants to be CO2 neutral in 2040. Let us try to decrease the energy use of the sector in which the demand is highest, namely the households.

Waste or Energy – What do we find in local restaurants’ waste bins?

For more than 5 years now, I’ve seen the hospitality industry and many of its facets. From high-class hotels and fancy restaurants to cafeterias in zoos and museums, one thing strikes me time and time again: how can such a big industry be so unsustainable? As a student interested in sustainability, the unsustainability of the industry kept bothering me. The Dutch Circular Economy week (16 to 24th of January 2018) and Leiden’s 2020 goal to have a 50% waste separation, and ambition to be completely circular by 2050 are an inspiration to rethink our use of waste. From my point of view, it is time to tackle one of the main distributors if it comes to waste, namely: the hospitality industry.

In a Circular Economy, waste does not exist because all resources can be reused. This video from the Ellen MacArthur Foundation briefly explains the concept of the Circular Economy. A way to reuse stuff is through recycling. Especially the recycling of organic waste can be interesting for the municipality of Leiden. There are approximately 162 restaurants and cafeterias in Leiden, including big chains as for instance McDonald’s. A small change in the recycling policy of organic waste in such a restaurant can already provide a big amount of material that can be reused in a profitable way. Hence, there is plenty of potentials to recycle organic waste in Leiden’s local restaurants.


A short illustration of how the Circular Economy works, with on the left side the recycling of organic waste

In the hospitality and restaurant scene, food remainings are already scraped from the plate into a bin. Then, the plates and cutlery are put into separate places, waiting for the washing machine. Therefore, with the introduction of garbage bins for organic waste, it is only a small effort to recycle the food remainings. A short explanation of how organic waste is recycled and can be reused in various ways is shown in this video20161208_foodwaste_news_featuredFirst of all, organic waste can serve as a cheap fertilizer for the farmland surrounding Leiden. Moreover, the remaining organic waste can be transformed into food for livestock. Hereby, Leiden can reach its goal of 50% waste separation by 2020. Secondly, recycling food waste produces biogas, which can Leiden help to achieve its ambition of Circular Energy by 2050.

For sure, neither Leiden nor the Netherlands is the only place where the issue of organic waste separation in the hospitality industry occurs. Best practice case studies in other countries, such as the United States, illustrate how to reuse organic waste from this industry. In San Francisco, it is forbidden by law to not separate organic waste. Instead, the waste is collected and transformed into profitable fertilizer. Moreover, in New York around 300 restaurants and hotels are already obliged to separate its organic waste in order to recycle and reuse it. A local example is at the University of Leiden – Campus Den Haag (Wijnhaven), where organic waste is already separated.

A cook throws away leftovers in the 'Auf da Muehle' restaurant in Soell636372896323838453-636366774865832683-uscpcent02-6uf4nti61x1100qtirj-original

Examples of organic waste separation in restaurants

Next week, the Circular Economy week in the Netherlands starts. Maybe it is an idea to be inspired by those examples and make the circle round in Leiden. Other cities are showing us how to cope with waste in a sustainable way. Let’s not waste the potential to profit from the food thrown away in the hospitality industry. It is a win-win situation for all parties. So, it is about time to start acting on this opportunity.