Climbing into a car that's been parked for a while on even a moderately sunny day can be an uncomfortable experience and is likely to provoke full-blast operation of the air conditioning, using up fuel and increasing emissions. Toyota has solved the problem with a new solar-powered ventilation system that keeps the interior cool, with no need for the engine to be running. And to make sure the temperature is just right before you get inside, it has produced the world's first Remote Air Conditioning control, operated using the car's key fob.

The two innovations form a Solar Pack that is available as an option on T Spirit versions of new Prius.

Solar panels, neatly integrated into a sliding sunroof, power the electric air circulation fan. Running independently from the engine, it can cool cabin temperature down from 80 to 45°C, so there is less need for the air conditioning to be used to achieve a comfortable level when you return to the vehicle.

The system can be activated as the driver leaves the car. One minute after the ignition is turned off, the air intake mode switches to "Outside Air Ventilation" and the blower mode switches to "Face" to ensure the most efficient performance. To avoid cabin air that has already been cooled being vented straight away, the system starts operating after 10 minutes, continuing until it is switched off, or the ignition is turned on.

Toyota's Remote Air Conditioning is a world-first. Thanks to the power available from Prius's large capacity hybrid battery, it can run for up to three minutes before the car is occupied (such a system could not be supported by a conventional 12V car battery). It is activated by pressing the A/C button on the key fob for one second.

New Prius is on sale from 1 August, priced from £18,370 on the road. The Solar Pack option costs £1,450, including VAT.

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