Now more than ever, environmental issues are forcing us to think and build intelligently.
Protecting the environment and our heritage has, over the past few years, become a global issue, synonymous with our responsibility towards future generations. Is this the world we want to leave our children and grandchildren?
We need to think differently and find alternatives for the various energy sources we all need. For over a decade now, we have seen that the growth in renewable energies has contributed to a structural fall in CO2 emissions.
In 2016, CO2 emissions linked to power and heat generation were 21.9% lower than in 1990.
So what do heat networks have to do with all of that, and how can they be optimised?
The University of Aalborg in Denmark and the University of Halmstad in Sweden show how these networks are evolving towards a fourth generation of urban heating, demonstrating the considerable potential of distributing “low-temperature” energy to integrate renewable energies and surplus heat.
This is a genuinely sustainable solution, with the maximum distribution temperature maintained at around 70°C.
In fact, heating systems need a maximum of 55°C, while for underfloor heating just 35°C is enough.
The environmental impact
Today, less energy is required to produce a PER-a pipe than a steel pipe.
It thus has a better carbon footprint.
The lambda value of the reticular polyethylene foam remains constant over time, which means it follows the building’s thermal evolution as closely as possible, however it is used. Which is not the case of other polyurethane type materials. Nonetheless, polyurethane has a better “ex-works” lambda value and can be selected in most cases when we do not have a “Operation and Maintenance” approach to the project.
The piping is made up of a PER-a coolant pipe, reticular polyethylene foam and a PEHD sheath, and remains more attractive in terms of financial cost, logistics, implementation and the high level of flexibility required.
These benefits respond to future project design requirements and the fourth generation developed by the universities mentioned above.
In urban areas, they are seen as the only way of making large-scale use of energies such as biomass, geothermal heat or waste recovery heat.
These national orientations are part of a European framework that is also keen to mobilise efficient heat networks in the different Member States.
In 2013, the national debate on the energy transition confirmed this key role for heat and cooling networks, a tool that local authorities can use to bolster local energy independence, reduce greenhouse gas emissions and increase the share of renewable and recovered energies.
This is thus the fourth generation (4G) of heat networks.
3 key facts to keep in mind:
- Emergence of insulation with a lambda value that remains constant over time;
- PER-a polyethylene piping, perfectly suited to this function (max. temp.: 95°C);
- Highly flexible pipework that is easy to install.
In the next episode: 5/5 – Heat networks – Energy efficiency
