How an ElectraTherm ORC works: inside the PM75

An Organic Rankine Cycle (ORC) Power Module turns heat you already produce into electricity. This short video shows how it works: first as a simple diagram, then as a 3D model of the open-frame ElectraTherm PM75, built from the factory drawings, with the expander-generator cut open so you can see the screws and generator inside.

One sealed loop, four steps

Inside the Power Module, a working fluid with a low boiling point (R-1233zd(E)) circulates in a closed loop. Your waste heat never touches it directly; the two only exchange heat through plate heat exchangers.

1. Evaporation. Hot water from your site, between 65 and 132°C, flows through the evaporator and boils the working fluid into high-pressure vapour.

2. Expansion. The vapour spins a twin-screw expander, which turns an induction generator sealed in the same housing. The vapour leaving the expander also cools the generator.

3. Condensation. Cooling water carries the leftover heat away in the condenser, turning the low-pressure vapour back into liquid.

4. Pumping. The feed pump sends the liquid back to the evaporator at pressure, and the loop starts again.

The PM75 at a glance

• Up to 75 kW of electricity

• Runs on hot water from 65 to 132°C

• Working fluid: R-1233zd(E), in a sealed loop

• Only three moving parts: the expander-generator, the bypass valve and the feed pump

• About 2.5 m × 1.8 m × 2.2 m

Got waste heat?

Fill in our Request for Information form and send it to sales@koolbricks.co.uk. We’ll show you what your heat could generate, backed by real UK fleet data.

Download the RFI form (PDF)