Energy efficiency is an integral part of a smart city. How you reduce resource consumption and how you produce resourceful innovation while you advance the city stands as the fundamental foundation for every city infrastructure.
But why talk only about energy efficiency? Well, if you have a closer look, from the sensors to the big data and vehicles to the buildings every bit of infrastructure has a link with energy. And if this energy is pulled out of exhaustive resources there wouldn’t be anything to rely on by 2050.
Today, the cities around the globe are consuming 80% of the total energy present on earth which is an alarming situation. That is why focusing on investments in energy efficiency and building up smart management solutions involving ‘resourceful consumption’ is indispensable for sustainability of smart cities. Among all these, innovation plays the key role in offering efficient sustainability solutions. So, to inspire the cities to adopt energy efficient innovations here are some examples of the smart cities around the globe that are thriving to become carbon neutral.
Example Of Efficient Waste Management – Sweden
Sweden is already on the road to becoming a ‘zero waste’ nation in the near future. From 38% in 1975 to more than 99% in 2017, the household waste is recycled and reused in the form of energy. Being a strict rule, every recycling station is found just 300 metres away from a residential area.
Either the waste is thrown in recycling stations or is disposed of in the facilities available to the residents. The residential apartments are facilitated with a stationary vacuum system in which the residents throw the waste through inlets. Here the waste bags are stored temporarily until full and are emptied regularly through a network of underground pipes.
The residents segregate the waste before sending it for recycle. The newspapers, plastic, metal, glass, electric appliances, light bulbs and batteries all are separated. Even more, the municipalities urge citizens to separate the food waste before throwing it.
Bottles – reused or converted to new items, newspapers – converted to paper mass, plastic materials – converted to raw plastic, food – composted, chemically processed to biogas and soil, waste water – converted to 100% potable water and larger waste items such as TV, furniture – recycled in the outskirts. Every single thing is recycled, reused or composted.
Furthermore, rubbish trucks use biogas or recycled electricity as fuel. Pharmacist takes back remaining medicines.
The incineration plants in Sweden burn 50% of household waste to produce energy. Sweden has learned to produce cheap energy from profitable yet efficient waste management.
After incineration, 15% of ash still remains. Thus, metals are recollected from ashes and sent for recycling. Porcelain and tile (which are noncombustible) are processed through sifting to extract gravel used in the construction of roads.
More importantly, incineration sites emit smoke that comprises 99.9% non-toxic carbon dioxide and water. Yet, the smoke is again filtered using dry filters and water. The resultant precipitate from the dirty filter water helps in the refill of vacated mines.
Further to prevent waste production, Hans Wrådhe at the Swedish Environmental Protection Agency ( Naturvårdsverket ) has created an action plan in collaboration with government departments and corporations: encouraging producers to manufacture products with longer shelf life and tax deduction on repairs.
“Government-sponsored ads on how to avoid food waste might also help”, Wradhe says. “And less toxic substances used in production would mean fewer products that require expensive treatment”.
Contribution from Swedish Companies
H&M takes used clothing from customers and offers rebate coupon in exchange for the initiative called ‘Garment Collecting’.
Coloured waste bag separation machine has been distributed by the Optibag company. Food waste is disposed of in a green bag, paper in red and different colour bags for metal and glass. This helps in minimising on waste sorting stations.
Helsingborg (a city in the south of Sweden) has equipped the city with waste bins that play very pleasant music that encourages people to recycle and reuse. In Helsingborg, more than 40% of homes use recycled energy for heating.
- 2.3 million tonnes of household waste in Sweden turned into energy in 2015
- More than 1.3 million tonnes of waste imported from Norway, Ireland, and the UK in 2015
- Emissions of heavy metals reduced by 99% since 1985 (despite the fact that Sweden incinerates waste three times more than before)
Example of Efficient Housing – Hamburg
In 2013, Hamburg constructed the first ever building in the world with a bioreactor facade.
This innovation proved to be successful in terms of delivering a self-sustainable building.
The building known as ‘BIQ’ has a cladding that supports the growth of microalgae that is used to produce high amounts of biogas. The microalgae are cultivated in bioreactor panels made out of glass built around the facade. Sunlight and constant turbulences stimulate growth of microalgae inside bioreactors. The algae are provided water and other elements essential for photosynthesis. The microalgae produce 5 times more biogas compared to other terrestrial plants.
Bioreactors generate heat and biomass which is transported through energy management system. From here, the water-algae solution is treated in a heat exchanger to produce heat simultaneously harvesting biogas. The harvested biogas can then be used by the residents in cooking, as a fuel or for any other heating application. For storage, a gas engine can be deployed that converts biogas into heat and electricity.
The building is integrated with the system in such a way that surplus heat produced in photobioreactors pre-heats domestic water, warms the interior of the houses or is reserved in an aquifer present underneath the building.
The heat generated through this system has 38% efficiency compared to 60-65% in a conventional solar thermal source. The biomass has 10% efficiency when conventional PV gives 12-15%.
This innovation has been recognised as competent with existing technologies. However, the idea still remains debatable as the construction of such buildings is more expensive. And, there are other factors such as leaks in the panels that may cause odour. Contamination due to neurotoxins and hepatotoxins present in some algae is another point discussed. As a whole, the concept has a more positive impact on the experts and professionals who’ve analysed the pros and cons of the system.
Example of Efficient Transportation – Medellin
Medellin, the city of Colombia has witnessed a great improvement in terms of smart city innovations and implementations.
Recently, the extremely crowded traditional buses running on exhaustive fuels were replaced by six cable car lines that run on electricity. The ride is convenient, eco-friendly and safe. It reduces carbon emissions, greenhouse gases and enhances the air quality of the city considerably.
The new cable car line with 3 already established in April 2015, was integrated with the metro lines of the city. And so, the entire cable car line transport system is managed by the metro.
The local public finds the cable car line highly reasonable and is being constantly appreciated by the city. The line seamlessly connects the hilly areas to the city centre. The people living in hilly areas are from the lower income families of the city and for them, the transport turns out to be cheap in terms of travel cost and travel time.
The reduction in emissions is calculated considering the average of the traditional vs new transport system. The cable car line project has proved to be efficient in reducing carbon emissions as well as improving the air quality.
The benefits of energy efficient innovations showcased by different smart cities can help other cities emulate the ideas to build a sustainable future.