5G Heat (Fifth Generation Heat!)

In my blog ‘How will energy look in 2030? My 10 predictions for the next 10 years!’ I predicted that by 2030 all city centres will have some form of fifth generation heat network – taking heat networks share of heating beyond the 18% currently forecast by the government! In the article I didn’t go into too much detail about how exciting fifth generation heat network technology really is so I thought I would elaborate in a follow up post….

1.     What do we really mean by fifth generation?

The fundamental premise of 5th generation heat networks is that the distribution temperatures drop substantially to around twenty five degrees (typically 4th Generation systems run at around 50-60 degrees).

At this temperature the system integrates with heat pumps enabling energy sharing – for example using the ‘low grade’ heat energy emitted from cooling systems to be redistributed round the network.

To achieve high efficiencies, data is used to constantly optimise the total system – modifying the network temperatures and flows to provide the overall optimised position for all users. Whereas existing networks may have summer and winter temperature settings the fifth generation constantly change to deliver the optimum temperature…driving the coefficient of performance (how efficiently heat pumps converts electricity into cooling or heating) up across the system.

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Fifth Generation heat networks have some unexpected (positive) consequences over other heat de-carbonisation options which matter when it comes to building future smart cities most notably in freeing up roof space to live in (and not for big cooling rejection units from air source heat pumps!) and ensuring local cooling effects don’t make our city centres more than a little chilly! They also don’t have the local emissions issues which a switch over to Hydrogen still won’t achieve…

2.     I didn’t even know we had been through third and fourth generation what did I miss?

The trend in heat networks has been to reduce in system temperature. Older networks use steam to transmit heat, with more recent systems using water at around 80 degrees. Thinking from academia and industry has recently seen a shift towards fully integrated heat systems with temperatures as low as 40 degrees in networks (with issues such as Legionella control resolved more locally to the consumer).

Bad news for cats - radiators might not be quite as warm

In practice fourth and fifth generation networks are likely to merge. Unlike your phone you don’t get a little logo in the top left corner of your screen saying you are using 5G Heat. Fifth generation is something that can happen quietly in the background with the end user not really knowing!

3.     What is happening to make fifth generation heating technology mainstream?

There remain some significant challenges with fifth generation technology. How you deliver a system for the ‘greater good’ and share the carbon and cost benefits will present some interesting challenges!

There are several case studies in operation now such as E.ON’s medicon village which are showing some interesting performance. There is also some research being lead by South Bank University (amongst others) around the Bunhill cluster in London.

Some great examples of using ‘low grade’ heat such as using the London underground, sewage and cable tunnels are already being looked into and the potential really is out there!

There is also some really interesting research from the likes of Lot-Net where universities are working together to deliver some fascinating insight into how fifth generation heat networks can and will work.

4.     What will need to happen to make it work?

Collaboration is key to fifth generation networks. Parties need to look to share the carbon saving and produce a system where everyone benefits. Opportunities for energy sharing exist in many places and its only through open dialogue that these can be turned into reality.

Sharing economy

Also systems need to be designed ‘future proof’… lower temperature networks and heat pumps ned systems that rely on much lower temperatures. A good example is using underfloor heating instead of radiators (or higher capacity radiators). Some simple choices like taps and show heads with a low temperature differential can make a huge difference down the line.

5.     How can I get involved?

The great thing about Fifth Generation networks is that they are all about collaboration. So we are all going to have to work together to come up with some great ideas.

Some really good ways of getting involved are:

  • Follow some of the Fifth Generation Twitter feeds such as Lot-Net and E.ON’s ectogrid.
  • Take Part in conferences on the future of heat and ask plenty of questions about the future of heat! (I will be at the Future of Utilities Conference in March 2020 banging the heat drum!)
  • Talk to people about the future of Heat! It matters… 50% of carbon emissions are from heating – an area we have made little headway in reducing carbon intensity.
  • Ask plenty of questions… where does the heat come from to heat this building? Why aren’t we using the cooling from next door? Have we thought about collaborating?


Pipe by Martin Adams on Unsplash

Sewer Photo by Martin Brechtl on Unsplash

Sharing Photo by Sophie Elvis on Unsplash

Data Photo by Franki Chamaki on Unsplash

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