Coal power is dirty – but abandoned mines could help create a clean energy future

Pushing on into a bright future: the Old Meadows Coal Mine, Bacup, Lancashire, 1936. Image: Hulton Archive/Getty.

Energy from coal is now being linked to global warming and pollution on a global level. In fact, it has been estimated that coal contributes to 25 per cent of green house gases.

Coal use has caused severe negative environmental impacts, from its mining and processing, to its transportation and combustion, leading to high levels of pollution. In October 2017, a United Nations weather agency report indicated that levels of carbon dioxide surged at “record-breaking speed” compared to 2016.

Around the world, coal mining contributed historically to the industrial revolution and played an important part in the development of modern society. But many mines have since been closed in the UK and Europe. In the UK, this led to hard financial times and unemployment in many communities, including the miners’ strikes of the 1970s and 1980s, an impact recorded in the 1996 movie Brassed Off.

But what happens inside the coalmines after their closure? Surprisingly, most disused coalmines start producing methane – known as Coal Mine Methane (CMM) – which can be a clean source of energy. It can be used to generate electricity via gas engines or, with some technical processing, be fed into the gas grid. Over time, however, the mines will begin to fill with water and the methane will almost entirely disappear.

Water, water everywhere

But this will create yet another opportunity. The UK’s historic coal mines have an approximate residual void space of a billion cubic metres. When flooded, that’s the equivalent of 400,000 Olympic swimming pools of water at a stable temperature. This vast volume of water can be used for efficient heating and cooling applications and reduce carbon emissions.

But how? A recent publication by the team at Nottingham Trent University explains. The water in the coalmines is generally at a stable temperature – normally between 12C and 20C depending on the location – which makes it perfect for warming, or cooling, buildings or industrial processes.

We developed and tested a new technology for several years using two systems, one at Markham Vale and one at the National Coal Mining Museum for England, and found it can use this water to provide green, sustainable energy to homes and businesses in the UK.


Opportunities and challenges

The technology, which is based on using water source heat pumps, is simple and straightforward and works along similar lines to a refrigerator or air-conditioning system. It produces no noise or local air pollution and is also three or four times more efficient than a standard electric heater or gas boiler.

To understand how heat pumps in general work, consider the refrigerator in your kitchen. This extracts the heat from the food and drinks inside it, and diverts it into the surrounding environment via a condenser (which is simply a radiator) on the fridge’s exterior. Our technology employs a similar system. In this case, we extract the heat from the coalmine water and use it to warm buildings.

In the UK, coal mining technology programmes already pump nearly 112m megalitres of water for environmental reasons, such as avoiding the pollution of drinking water, springs and rivers. The new technology could use this water, which is being pumped anyway, potentially generating 63 megawatts of heat per year.

But the technology has its own challenges, specifically a lack of investment and “champion” organisations to lead the process. In part, this is because it remains a little-known or understood technology by many investors.

There is also a lack of a clear model to follow in the UK when implementing new technologies such as this, not just commercially, but contractually and legally as well. Most housing developers in the UK and Europe, for example, prefer to rely on well-established technologies such as gas boilers or electric heaters, even in areas where coalmines are available. If such new, green technologies are to succeed, comprehensive strategies are needed to get developers – and the general public – on board.

Hot topic

On the positive side, the technology can be integrated with other heating technologies, and in many cases existing building infrastructure can be used to implement it. The technology can also reduce carbon emissions and energy use and support compliance with the EU Energy Efficiency Directive and UK ESOS regulations.

We also have excellent, large-scale case studies, showing how effective it can be. In Asturias, north-west Spain, for example, a hospital and a university building are already being heated using coalmine water.

The ConversationOur research shows this technology could give the world’s disused coal mines a new, green, lease of life. What a fitting legacy for the industry that would be.

Amin Al-Habaibeh, Professor of Intelligent Engineering Systems, Nottingham Trent University.

This article was originally published on The Conversation. Read the original article.

 
 
 
 

Barcelona’s car-free “superblocks” could extend lives. So will they catch on elsewhere?

Barcelona. Image: Getty.

The world’s biggest cities have larger populations and higher economic outputs than some countries. But as they grow in size and complexity, cities are also facing thorny challenges that threaten the health and happiness of residents. Congestion, pollution and a lack of community spaces have become major drags on people’s aspirations and experiences of urban living.

In response, cities must manage their resources and priorities to create sustainable places for visitors and residents, and foster innovation and growth. Enter Barcelona – the capital of Catalonia, in Spain – where a bold stroke of urban planning first introduced “superblocks” in 2016.

Image: ISGlobal/FAL.

Superblocks are neighbourhoods of nine blocks, where traffic is restricted to major roads around the outside, opening up entire groups of streets to pedestrians and cyclists. The aim is to reduce pollution from vehicles, and give residents much-needed relief from noise pollution. They are designed to create more open space for citizens to meet, talk and do activities.


Health and well-being boost

There are currently only six superblocks in operation, including the first, most prominent one in Eixample. Reports suggest that – despite some early push back – the change has been broadly welcomed by residents, and the long-term benefits could be considerable.

A recent study carried out by the Barcelona Institute for Global Health estimates that if, as planned, 503 potential superblocks are realised across the city, journeys by private vehicle would fall by 230,000 a week, as people switch to public transport, walking or cycling.

The research suggests this would significantly improve air quality and noise levels on the car-free streets: ambient levels of nitrogen dioxide (NO₂) would be reduced by a quarter, bringing levels in line with recommendations from the World Health Organisation (WHO).

The plan is also expected to generate significant health benefits for residents. The study estimates that as many as 667 premature deaths from air pollution, noise and heat could be prevented each year. More green spaces will encourage people to get outdoors and lead a more active lifestyle.

This, in turn, helps to reduce obesity and diabetes and ease pressure on health services. The researchers claim that residents of Barcelona could expect to live an extra 200 days thanks to the cumulative health benefits, if the idea is rolled out across the city.

Space to play. Imag: Mosa Moseneke/Unsplash.

There are expected to be benefits to mental health, as well as physical health. Having access to such spaces can stave off loneliness and isolation – especially among elderly residents – as communities form stronger bonds and become more resilient.

Stumbling blocks

It was Salvador Rueda, director of the Urban Ecology Agency of Barcelona, who first championed the introduction of superblocks – and he argues that the idea could be used in any city. Even so, authorities looking to expand the concept in Barcelona or beyond will need to be mindful of some concerns.

Changes like these require capital investment. Even as the car-free streets are transformed with urban furniture and greenery, the remaining major roads will likely have to accommodate heavier traffic.

Nothing comes for free. Image: Zvileve/Flickr/creative commons.

Further investments in local infrastructure – such as improving surrounding roads to deal with more traffic, or installing smart traffic management system – could be required to prevent serious congestion. Then the question remains, how to finance such investments – a higher tax rate is unlikely to be popular.


What’s more, whenever a location becomes more desirable, it leads to an increase in property demand. Higher prices and rent could create pockets of unaffordable neighbourhoods. This may lead to use of properties for investment purposes and possibly, displacement of local residents.

It’s also worth noting that Barcelona is an old and relatively well-planned European city. Different challenges exist in emerging global cities across Asia, Africa and Latin America – and in younger cities in the US and Australia. There is a great deal of variation in scale, population density, urban shape and form, development patterns and institutional frameworks across the cities. Several large cities in the developing world are heavily congested with uncontrolled, unregulated developments and weak regulatory frameworks.

Replicating what’s been done in Barcelona may prove difficult in such places, and will require much greater transformations. But it’s true that the basic principles of superblocks – that value pedestrians, cyclists and high quality public spaces over motor vehicles – can be applied in any city, with some adjustments.

Leading the way

Over the history of human civilisation, great cities have been at the forefront of innovation and social progress. But cities need a robust structure of governance, which is transparent and accountable, to ensure a fair and efficient use of resources. Imposing innovation from the top down, without consultations and buy-in, can go squarely against the idea of free market capitalism, which has been a predominant force for modern economies and can lead push-back from citizens and local businesses.

Citizens must also be willing to change their perspectives and behaviour, to make such initiatives work. This means that “solutions” to urban living like superblocks need to have buy-in from citizens, through continuous engagement with local government officials.

A man speaks at a public consultation on the Eixample superblock in Barcelona. Image: Ajuntament Barcelona/Flickr/creative commons.

Successful urban planning also needs strong leadership with a clear and consistent vision of the future, and a roadmap of how that vision can be delivered. The vision should be co-developed with the citizens and all other stakeholders such as local businesses, private and public organisations. This can ensure that everybody shares ownership and takes responsibility for the success of local initiatives.

There is little doubt that the principles and objectives of superblocks are sound. The idea has the potential to catch on around the world – though it will likely take a unique and specific form in every city.

The Conversation

Anupam Nanda, Professor of Urban Economics and Real Estate, University of Reading.

This article is republished from The Conversation under a Creative Commons license. Read the original article.