5th generation district heating is a way of changing from fossil fuel heating to highly efficient carbon-free climate control in urban environments. This is done using serial heat pumps and harvesting excess heat – and excess cold – that otherwise would go to waste. All in all, creating a circular heating and cooling system that makes it possible to switch from fossil in all kinds of urban developments.
But – how does it really work? Qvantum’s Sofia Akhlagi has a long experience of low temperature networks, and she gives you the rundown:
1. LOW-TEMPERATURE HEATING CIRCUIT
5th generation district heating systems typically run at temperatures of about 10 – 20° C. When used as an energy source for heat pumps, it is, therefore, possible to use them both for heating and cooling – as they can do both things. When used for heating, they return cooler water. And when used for cooling, they return warmer water. So one person’s warm water becomes another person’s cool breeze and vice versa.
The low temperature also reduces the need for wide insulated pipes in deep trenches, as the energy loss is low at these temperatures since they are not very different from the temperatures in the surrounding ground.
2.NARROW PIPING IN BUILDINGS
The circuit is led to and through each connected building. In each building, the circuits are connected to each apartment or workspace. As the pipes are so narrow, installers can often use existing holes.
3.SMALL IN-APARTMENT HEAT PUMPS
In each apartment, small 4-6 kW heat pumps, connected to the circuit, replace gas burners. The heat pump reduces the temperature of the circuit water when it heats the radiators. And it warms the circuit water when it is used for cooling via fan convectors or underfloor cooling. So, heating the shower water in one apartment balances the cooling of another.
4.COLLECTING EXHAUST HEAT
Excess heat is often generated from the ventilation of buildings, underground transport, or garages. Food stores also generate a lot of exhaust heat from cooling equipment. All this is harvested on the circuit, aiding in keeping the temperature at the desired level.
5.CENTRAL HEAT PUMPS
Large centrally located heat pumps (up to 1,5 MW) collect energy from ambient air, closed loop and/or open loop boreholes. They balance the temperatures and ensure the water in the circuit always holds the right temperature.
6.THERMAL ENERGY STORAGE
Boreholes connected to central heat pumps are used for thermal energy storage. That means that they can store large quantities of heat or cold. In the winter, when the heat pumps use the heat in the ground, the ground is cooled down. In summer when the heat pumps are used for cooling, the rejected heat warms up the ground.
7. POWER COMPANIES LOVE THERMAL INERTIA
It takes time to heat a house, and it takes time to cool it down – this is an effect of thermal inertia. Qvantum customers can use this to their favor in dealing with power companies. As they can control all heat pumps in their circuit, they can offer the power companies to ”charge up” when there is little demand for power. In return the customer can lower their energy cost. Moving peak hour need an hour or two can reduce costs by up to 50%.
8. TURN ONE SOLAR PANEL INTO FIVE
By using Qvantum heat pumps in low temperature systems, users generally get more than 5 kWh of heat for every 1 kWh of electricity. Making every solar panel or windmill generate five times more than they would have if the power was used in a traditional way. In the Scandinavian countries, heat pumps have been the primary
heating source for private homes for the last 20 years. Now we combine it with new tech and bring it to the cities of Europe.
and after sales at Qvantum.
