Electricity from low-grade heat

The RED-Heat-to-Power project adopts a game-changing approach that generates electricity from low-grade heat in the temperature range of 40 to 100^oC. This clean source of electricity is very flexible and can cover base load or peak load at a very competitive cost, having all the characteristics for contributing to the mix that will form the backbone of the future energy system.

The concept is based on the generation of electricity from salinity gradients using a Reverse Electrodialysis (RED) device in a closed-loop system. In this concept, limited amounts of artificial saline solutions are used as working fluids. The solutions exiting from the RED unit are then regenerated, in order to restore the original salinity gradient, by means of a separation step, which uses low-temperature heat as its energy source.

Competitive electricity generation

Using artificial solutions provides the flexibility to choose the salts and the conditions that maximise the productivity of the Reverse ElectroDialysis process, generating up to 10 times more electricity than when using natural water streams. RED Heat-to-Power is on track to achieve the highest efficiencies and lowest costs for converting low grade heat to electricity.

Exploiting widely available low-grade heat

The system can be installed practically anywhere in the world as low grade heat can come from renewable sources like solar or geothermal at very low cost. A very attractive application is to install the system at industrial sites where there is need for electricity, while waste heat is and its disposal is an issue that the industry has to deal with.

Offering flexibility to the power system

The technology is a fully controllable source of electricity: the regeneration step can be operated to match the heat availability profile and the saline solutions can then be stored at no cost in simple tanks for as long as required. This flexibility is a distinctive advantage over variable renewable energy, but also against conventional thermal technologies, which are not very flexible.

A safe and clean source of energy

The technology involves only simple circulation pumps and any noise will be minimal, while it is modular and can be housed in any kind of building raising no visual or aesthetic issues. There are very low requirements for operation and maintenance, making it suitable for any kind of application. It is operated at atmospheric pressure reducing the risks for accidents.