Posted: 8 May 2014

A greener vision?

Ebbsfleet, garden cities, smart heat, district heating, CHP plants, heat pumps, National Grid


Will the Government’s announcement of a new garden city be the dawn of a new era for energy and a vindication of smart-energy principles – or an expensive pipe dream? Stephen Marland, National Grid’s Gas Demand Manager, looks at the concept of communal heating networks and weighs up the pros and cons.

Stephen Marland, National Grid Gas Demand Manager

Stephen Marland, National Grid Gas Demand Manager

George Osborne’s plans for the ‘first garden city in Britain for 100 years’ is something everyone in our industry should be observing closely. The creation of 15,000 homes in the Thames Estuary at Ebbsfleet presents an opportunity for all those with an interest in the future of energy and a low-carbon economy.

The ‘garden city’ concept originates from Ebenezer Howard; founder of the 20th century Garden City movement. His aim was for ‘co-operative ownership of the underlying land, with the community benefiting from development that takes place on it’. Howard’s original goal was a self-contained egalitarian community, consisting of residential, industrial and agricultural sectors and its legacy can be seen today in places like Letchworth and Welwyn Garden City.

Useful testing grounds

Why is this a such a great opportunity for the energy sector?

Today, the concept refers to communities that are largely self-sufficient in managing their energy needs, by using a localised district network founded on ‘smart’ technology. There is good reason for such innovation: the need to reduce greenhouse gas emissions, to help consumers manage rising energy prices and have a say in future energy developments – all this makes community schemes worthy of detailed exploration.

They’re also useful testing grounds for the latest energy technologies too. The Government’s Heat Strategy, published in 2013, envisages a rapid growth in district heating to make use of waste heat energy and to work in tandem with the power sector as a means of using excess electricity from low-carbon generation.

In a world where our energy needs are met predominantly by nuclear and renewables, district heat networks could take their excess power, convert it to heat and store it as energy for when it would be useful. This makes district heating a valuable resource to the wider market as well as the local community – and potentially more economic and sustainable.

‘Smart heat’ systems can come in many forms, but in this case a district heating network opens up the opportunity of integrating largescale and highly efficient ground, sea and air source heat pumps, These can soak up excess electricity, coupled with short and long-term heat storage. The principle also opens up the potential for other sources. For example, a local manufacturer that creates a lot of residual heat could be harnessed to further feed the network.

This vision builds upon the overall energy efficiency improvements from Combined Heat and Power (CHP) plants and, in the future through smart metering, enabling local communities and individuals to adopt a range of new heating appliances to meet their own needs and to feed into the network. Ultimately the aim is to help consumers use energy more efficiently.

Commercial viability

So what are the practical challenges we face in establishing these types of communities?

As it stands, district heating forms only a small part of the energy market (just over 200,000 of the 27 million homes in the UK are connected this way). Gas, electricity, LPG and oil all have much wider use. There’s a simple reason for this: smart heat networks are expensive when compared to existing infrastructure.

Successful examples usually come about when the organisation behind them – often a local authority that has to hit challenging environmental targets – sees such schemes as the most effective way of doing this. However, schemes driven by local authorities tend to start small, with council buildings, social housing developments and local council controlled developments. Developing to wider communities has a number of barriers, ranging from the lack of regulation, community awareness and appetite for change, and crucially the costs compared to incumbent utilities.

For example, gas networks have been in place for a long time and have recovered a good portion of their construction costs, so developing district heating networks that can compete economically remains a challenge. The location of such developments is another major factor in their commercial viability.

What’s more, it’s much easier to put such a system in a new-build development. There is less chance of a resident switching energy source when there’s no pre-existing infrastructure there to begin with, and the costs and practicalities of developing the network are far less challenging.

So doesn’t it make sense to focus our efforts on any new ‘garden cities’?

There are also legitimate questions about long-term sustainability. Although heat grids have zero emissions at the point of use, this still requires low-carbon heat production at source for the long-term. To cite an example, Gas CHP plants are great for reducing CO2 today but, as power generation decarbonises by the mid 2020s, they will start to become more carbon intensive than centrally supplied power and heat from a gas boiler.

At some point, the district heat will need to be supplied either from bioenergy, waste heat or electrical heating such as heat pumps, again influencing the location and economics of such developments. So the future viability of smart heat systems are inextricably linked with wider challenges and trends across the energy industry.

Theory into practice

Nevertheless, such factors don’t outweigh the huge benefits potentially on offer. The fact that heat grids can store energy for long periods of time and the simplicity of converting low-carbon power gives them an advantage over more common sources of energy.

At some stage, we also need to demonstrate that theory can become reality – that heat networks can be integrated and can help balance a low-carbon power network – test the operational practicalities of largescale heat pumps, store large volumes of heat between seasons and, ultimately, find a market model that consumers will adopt.

So what are we to make of the Chancellor of the Exchequer’s plans? Time will tell, of course, but this does feel like an opportunistic moment. The next few years may be the perfect time to put theory into practice, and we’ll be a step closer to knowing whether the vision of communal, low-carbon, smart energy systems really does have a future.

Read more:

Stephen Marland, National Grid Gas Demand Manager on the implications of alternative technologies to our homes and the energy sector. Click here to read more.

The future of heating: meeting the challenge was published last year and sets out specific actions to help deliver low carbon heating across the UK in the decades to come. Click here to read more.

Creating garden cities and suburbs today was a report published by the Town and Country Planning Association, highlighting ways in which sustainable new communities can be delivered using Garden City principles. Click here to read more.

GRAID passes toughest tests yet
“Successful examples usually come about when the organisation behind them, a local authority say, has to hit challenging environmental targets and such schemes are seen as the most effective way of doing this.”

Stephen Marland, National Grid’s Gas Demand Manager,