Alex Bardell and members of the BCS Green IT Specialist Group explore and explain the sustainable technologies that will make tomorrow’s smart cities pleasant places to live.

As the digital revolution progresses, its influence is already affecting how we live our lives. Its effect is particularly prevalent in areas with large populations where access to fast and reliable compute services is already an essential part of life.

A typical smart city dweller day would include online:

  • networking with work colleagues, family and friends;
  • re-ordering food;
  • purchases;
  • using transport from taxis, buses, metro, trains;
  • seeking locations and services;
  • booking accommodation, transport, entertainment, restaurants;
  • maintenance and repair work;
  • control of dwelling light, temperature and ventilation;
  • access to information and news.

In all these activities, technology provides the means to do them quickly and accurately, and enables us to lead smarter lives in more crowded cities.

But how do we ensure that the resulting so-called ‘smart cities’ are also sustainable cities?

Forward looking

Across the world cities are preparing and publishing blueprints that outline their plans to deliver carbon neutral, waste neutral, and green and clean smart sustainable environments.

Technology will be, and already is in some of these cities, an essential enabler of these blueprints. In turn, we need to be aware that technology has its own sustainability impacts and we need to be sure, through guidance, standards, and the adoption of best practices, that this tech is carbon neutral, waste neutral and sustainable.

For cities to become smart and liveable, to meet their nation’s commitments to reducing greenhouse gas emissions, waste and pollution, we need to use technology in all its guises. Its sources of energy need to be zero carbon-based, if not entirely renewable.

Transport has to move from the internal combustion engine to either fuel cell or EV vehicles. Domestic heat and hot water from our gas boilers have to be provided by electric heating sources such as solar, wind, and geothermal.

Current renewables’ dependence on the weather means they suffer from erratic levels of supply, and without smarter energy grids - with suitable energy storage facilities to smooth those peaks and troughs - they are not well placed to deliver the increase in demand from the move to electric vehicles and domestic electric heating systems.

Technology will support this transition by providing information to consumers enabling behavioural patterns and energy tariffs to better manage demand. Smart buildings and smart houses currently exist and can be integrated through application programming interfaces (APIs) to interact directly with the grid. Where supply issues exist, energy stores will be able to provide electricity back into the grid. Electric car owners can drive for free by letting energy firms use their car batteries as a source of supply as well as power for the vehicle (Guardian online, 2 October 2017).

The world’s largest lithium ion battery has recently begun dispensing power into an electricity grid in South Australia. The 100-megawatt battery, built by Tesla, was activated at the start of December 2017 and, when fully charged, the battery can power up to 30,000 homes for an hour. The battery, which is paired with a wind farm, is designed to improve the security of electricity supplies across South Australia.

An ever-changing world

There is a huge migration of people from rural to city locations across the world: it is expected that the population of London will be 11 million people by 2050. The demand for transport services will grow with people still needing to move around the city for commerce, work, education and leisure requirements.

Infrastructure projects are expensive and time-consuming (Crossrail was first envisaged in 1943). We simply do not have the space in our densely populated cities to fit in more infrastructure. Can smart technology help ease the movement of people?

Generating data

As well as moving people around, our smart cities need to move information and data around. You could almost say that data is the fourth utility.

As our cities are becoming smarter in many ways, they need access to information and to data about things they manage including: buses, metros, vehicle movement, parking spaces, waste collection and green spaces. To get that data we need things to tell us where they are, how hot or cold they are, queues, their weight and volume.

Objects which were previously passive and mechanical - from waste bins to buses - now include computer processors and sensors, the data from which is communicated through common APIs to control and management systems.

We have come to define the structure to achieve this as the internet of things - a term that is becoming universally understood as the means for connecting sensors across the internet with systems and applications that, in turn, manage and control things and environments over the internet.

The internet of things (IoT) is a fast growing IT sector. In a recent UK Government report, predictions range from 20 billion to 100 billion sensing devices being deployed globally by 2020. This is equivalent to the number of neurons in the brain.

Then there’s the problem of bandwidth (both private or public). For the smart city to deliver on all its promise, huge amounts of data will need to be moved around.

But we must not forget the sustainability impacts of these IoT systems themselves. They may, for example, be cheap and easy to build. It is possible to construct a simple website that stores and displays data from a multi-sensing device.

It could possibly provide temperature, position, moisture and light data, using TI and Raspberry Pi / Arduino type technologies for less than £150. However, this is not so cheap in terms of the environmental resources needed to build and implement them though.

For example, we need to consider:

  • That there needs to be sufficient supply of the metals and minerals required to meet those huge predicted sensor volumes.
  • That during operation, and once they reach end of life, they must be prevented from polluting the environment in which they have been working.
  • That they can be retrieved and disposed of/re-used in line with the waste hierarchy.
  • That the hosting capacity we are building into the end systems, for example, data analytics/presentation, is being built sustainably.

We are also building IoT systems on which we will need to rely if they are to fulfil their promise. To ensure success, we need to address important considerations such as:

  1. Reliability: is the data I am getting ‘true’; can we verify it?
  2. Security: is the data I’m getting also being sent elsewhere? Is the route over which I am getting that data vulnerable to attack and useable, and could it possibly corrupt the sensor, its data or hack into my systems?
  3. Coherence: can I relate one sensor data stream with another, for example, alignment in time, to understand what is going on where the sensor(s) are located?

Green and open spaces in the sustainable city

A sustainable city is a pleasant city - people need green open spaces. More people are living in densely populated areas and do not have access to open spaces and the opportunity to learn, first-hand, about nature.

Many studies have confirmed both the mental and physical value to one’s well-being of growing, tending and harvesting your own produce. Connecting with nature is both natural and fulfilling, and as a species, it’s part of our DNA.

So, as an allotment gardener, the thought of how you might replicate a 10 pole allotment of trees, soft fruits and vegetables in a smarter city is challenging.

The standard size for most allotments is 10 poles, or 50 metres. Forty allotment holders would, therefore, require one hectare of land, which is a sizeable area and would primarily be used for housing, offices, manufacturing or transport. So, in a smarter city of many tens of thousands of horticulturalists, how could you establish and engineer an allotment society when space is such a premium?

One such approach is to think vertically and not horizontally. Might it be possible to grow vegetables vertically, utilising the sides of buildings as land?

Charlie Guy and his team at LettUs Grow ( have designed an irrigation and control technology for vertical farming. Aeroponic technology is utilised to deliver consistently high yields for vertical growing.

Aeroponics is a methodology of growing plants without soil, where the roots are watered using a fine mist. Not only does this allow greater oxygenation of the roots, delivering better flavour and faster growth, but it uses up to 95 percent less water than traditional agriculture, and with water an ever more scarce commodity, conserving water is essential in the cities of tomorrow.

So that takes care of the vegetables, but what about the trees? Planting trees in containers is not a new idea and is becoming more popular, especially in landscapes with little or no outside space. Growing trees in containers is ideal for small gardens or where space is limited, such as on a patio or terrace. Vertically hung containers planted with sapling trees can grow to bring height, fruit, bark, seasonal colour and fruits. But how do you maintain vertically planted trees on buildings?

Working with fellow foresters at the Small Woods Association (SWA), Richard Lanyon-Hogg is leading a project which draws upon the IoT technologies to monitor the health of trees. By utilising sensors and other IoT technologies a tree’s temperature, moisture, humidity, light absorption and sap movement is monitored.

This is then interpreted to provide a qualitative view of how the tree is feeling. The internet of trees service provides both tree owners and arborists with an insight into the health of the tree and a suggested prescription for possible ailments.

For our future smarter city allotment holders, a possible solution, therefore, exists: a combination of LettUs Grow and the internet of trees service ( enables a simple, efficient and sustainable way to grow, tend and harvest your own produce, albeit vertically. It remains to ask the question, where do you put your shed?

The data centre of the future

Smart cities are dependent upon technology to deliver digital transformation. This requires a large amount of compute power needed for data analytics and smart applications. Compute and datacentres cannot be seen to support a sustainable smart city, if they are not themselves sustainable.

When we talk about the data centre of the future, we must ask two questions. The first: what is a data centre? A second: what do they look like today?

What is a data centre? We should adopt the EU COC (EU Code of Conduct for Data Centres - energy efficiency). It defines a data centre as: ‘[including] all buildings, facilities and rooms which contain enterprise servers, server communication equipment, cooling equipment and power equipment, and provide some form of data service (large-scale mission critical facilities, all the way down to small server rooms located in office buildings).’

What do we have presently? Given the above, we can consider that there are many different options, from hyperscale warehouses, all the way down to a server room in a building. These will be classified under either the tier or EN50600 (building regulations) class concepts and will get progressively more expensive to build and operate, depending on the resilience and risk profile of an organisation. Almost all datacentres are standalone and air cooled, which uses lots of power.

What does the data centre of the future look like? It all depends on how far in the future. Conventional thinking on data centre design and build indicates that the building fabric should last between 60-75 years, the mechanical and electrical infrastructure for 20-25 years, and the IT equipment between 3-7 years. So, given the above criteria and the pace of current construction we could say that the data centre of the future looks very much like the data centre of today.

However, that would be failing to look at various technologies and concepts that are slowly gaining ground and adoption. The EU COC contains many best practices that look towards the data centre of the future we look. These include the use of ISO management standards in sectors such as environmental, energy and asset management, life cycle assessment, liquid cooled IT equipment, green coding, renewable energy systems, free cooling, waste heat reuse, the capture of rainwater etc, and monitoring and measurement.

The most important best practices are the intangible best practices. These point toward a strategic and cultural change approach that may mean faster adoption by enterprises and by commercial co-location and cloud organisations to be future ready.

In the next five years it is expected that data centres will use renewable energy. This could be either on site (biogas / combined heat and power (CHP) / solar / hydro) or procured via green tariffs. Waste heat could be sold to local communities via district heating systems too. This clearly means that liquid cooling IT systems will become more prevalent as they have higher heat transfer capabilities. Higher rack densities could become a regular fixture too.

This maximises the heat recovery opportunities. We may also see better monitoring and measurement offering ‘burst’ pricing and the ability to shift IT load to the lowest cost areas, perhaps based upon wholesale electricity pricing and weather conditions.

In addition, we may see a lot more ‘roadside’ edge data centres like mobile cell towers containing IT equipment to service the growth of the IoT. These may be constructed in factories and dropped into place, connected to power and communications and ready to go immediately.

It’s clear that the global data centre industry has a bright future, but will require regulation to meet the Paris 2015 Greenhouse Gas reduction commitment.

The authors: Denise Oram BA MSc MEd MBCS FHEA, John Booth BSc (Hons) Tech (Open) MBCS CDCAP,Richard Lanyon-Hogg CEng FIET FBCS, Professor Colin Pattinson BSc (Hons) PhD MBCS, Bob Crooks MBE, Alex Bardell BA MBCS

Ethics questions for smart cities

Smart cities will revolutionise our lives and we need to ensure this revolution is a positive one. Early recognition of ethical, regulatory and related issues can save time and money, support user acceptance and promote beneficial aspects of the technology. Issues of control, division of responsibilities, the right or ability of individuals to exercise personal control, accountability, ownership, monopoly, privacy, and governance should all be taken into consideration.

If we get it right we can look forward to a brighter, sustainable future. Smart cities will revolutionise our lives and we need to ensure this revolution is a positive one. Early recognition of ethical, regulatory and related issues can save time and money, support user acceptance and promote beneficial aspects of the technology. Issues of control, division of responsibilities, the right or ability of individuals to exercise personal control, accountability, ownership, monopoly, privacy, and governance should all be taken into consideration. If we get it right we can look forward to a brighter, sustainable future.

No more landfill: turning waste into something useful

Smart cities use smart devices, which in turn require natural resources and some of these materials are difficult and polluting to manufacture. What can be done to address the challenge of e-waste management?

The circular economy replaces the ‘cradle to grave’ product life cycle with a model where products, components and materials are retained in the system, and rarely, if ever, lost to landfill or other forms of disposal.

The circular economy is actually more like a series of loops. In the most complete example, a product might be refurbished and be returned to its original use, probably with a different user. If this is not possible, a product might be reused in its complete form, but for an alternative purpose.

Alternatively, sub-components might be recovered and put back into use. The process can be carried out to increasing levels of deconstruction, up to and including the recovery of basic materials. The greatest effectiveness comes from taking entire products back into use, since that requires the least extra input. Longer loops are preferred – more time spent in the use phase relative to the make/remake phases means more time in operation to recoup the energy and resource costs incurred in manufacture.

In 2017, e-waste volumes were predicted to reach 65.4 million metric tons. In 2014, only 15.5 percent of global e-waste was estimated to be recycled in the formal sector, despite the estimated $52 billion USD of precious materials contained within. Much of the rest found its way to landfill, incinerators or informal disassembly operations threatening the health of workers and local communities.(Source: Green Peace).

To deliver the circular economy requires that products are designed to be reused from the outset. Reusing subcomponents implies modularity in design - not the increased integration common in IT devices. Manufacturers need to design devices which are easier to repair and use standard parts. Software updates should be available to extend the life of older products. Where possible hazardous chemicals should be removed from technology products, which will, in turn, make end-of-life handling safer and promote closed-loop production cycles.

Manufacturers should be encouraged to make their devices recyclable and to incorporate recycled components into their future products, reducing the requirement for additional materials and moving towards a greatly reduced waste footprint.