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Workshop/5 min exploration

A hot rock reservoir can drive a power cycle

How can underground heat become electricity without burning fuel?

A geothermal plant moves a working fluid through a hot underground reservoir. The returning hot fluid transfers energy to a turbine cycle; a condenser cools the loop and the injection well returns fluid underground. Change the reservoir temperature and mass flow to see why both matter.

Explore the model and follow its moving parts.

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Select a part. Change a control. Follow the motion.

More mass flow or a larger temperature drop carries more thermal power; only a fraction becomes electricity in this idealized cycle.

With the same temperature difference, what happens if mass flow doubles?

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How the parts work together

  1. Start with a warm reservoir

    The orange path rises from the deep reservoir to the turbine. Blue fluid returns through the condenser and injection well.

  2. Raise reservoir temperature

    A larger temperature difference means each kilogram can carry more heat: Q̇ = ṁ cₚ ΔT. Watch the thermal and electric readouts rise.

  3. Increase mass flow

    Doubling the flow doubles the ideal heat rate at the same temperature difference. The animation shows more moving markers, not a fluid-dynamics solution.

  4. Separate heat from electricity

    The selected efficiency is applied after heat rate is calculated. Real plants lose energy in wells, heat exchangers, turbines and generators.

The main parts

Hot reservoir
A porous rock zone supplies heat to the circulating fluid. The rock is drawn as a single uniform block, not a site model.
Production well
The hot fluid rises through this well. The arrow direction is the prescribed flow, not a pressure calculation.
Turbine
Thermal energy is represented as shaft work. Blade shape and two-phase flow are omitted.
Generator
The shaft drives an ideal generator with the selected conversion efficiency.
Condenser
The loop rejects heat and returns a cooler fluid to the injection side.
Injection well
Cooled fluid returns to the reservoir, closing this simplified circulation loop.

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