Energy Policy Makers

As a policy maker you must work with many conflicting demands. These include technical constraints, integrating energy plans with other related political policies, time deadlines and societal expectations. It's not easy navigating these.

From a technical perspective, most cities that are trying to develop policies and strategies to decarbonise are all facing similar issues. There needs to be coordinated planning of the energy transition at national, regional and city scales. Coordination of which buildings will be transitioned in which order of priority, with coordination of these associated demands on city electrical networks, flows of financing, people resources, equipment etc.

The constraint which is rapidly becoming critical is time. A good analogy is the famous 'square peg in a round hole' scene from the  Apollo 13 movie, where CO2 levels in the spaceship were reaching dangerous levels (sound familiar?). The managers threw a collection of items on the table and staff were told to come up with a solution because time was  limited. It's the same situation here on our spaceship (Earth) where we are in space and CO2 levels are reaching dangerous levels. The collection of items we have available are: people, equipment, money, limited energy and limited time. Failure is not an option!

Decarbonisation of the built environment will require a large shift to electrification, but transportation is also shifting to electrification, so you have these competing demands. City electrical supplies and distribution networks are coming under increasing pressure to cope with these electrification shifts and changes in demand. And time keeps ticking away....

But cities have wastewater networks carrying huge amounts of free low grade heat. This heat energy is reliable, predictable, stable and already where it is needed by buildings, and the infrastructure collecting and transporting this heat is already there (the sewer network). In most cities this heat energy is sadly just ignored and flushed away every day. The favorable temperatures of wastewater allow wastewater source heatpumps to operate more efficiently than air source heatpumps, so capturing and recycling wastewater heat allows electrification of more buildings to be achieved using less electricity (so helping manage the growing demands on the electrical infrastructure).

There are also other benefits of wastewater heat recycling heatpumps which are particularly relevant within cities locations. These include:

• Smaller equipment size – sometimes inner-city buildings simply do not have enough space to accommodate air source heat exchangers (these are typically mounted on the roof of a building). The size of wastewater heat recycling equipment is normally smaller and installed within the basement or just outside the building.
• Noise generation – air source heatpumps require fans to move air through the outdoors heat exchanger. Naturally these fans create some noise which can be problematic in urban locations where there might be people sleeping or working/learning. Wastewater heat recycling systems do not have fans outside. The equipment is all mounted within the basement or room and so noise is contained.