new architecture.jpg


The Riversimple vehicle is conceived within an innovative 
new architecture for cars that we call a Network Electric platform.

It embodies various key features:Screen Shot 2012-11-28 at 15.30.50.jpg

Four electric motors, one in each wheel

Regeneration of electricity by these motors when the     car is braking – known as regenerative braking

Super-capacitors to store this energy and provide most of the power for acceleration

Low powered hydrogen fuel cells (although other primary energy devices could be used) and

A body made of lightweight composites

However, these alone do not explain the step change in energy efficiency achieved.  Although novel in the industry, they are not unique and none make economic or performance sense on their own.  The breakthrough really comes through the synthesis of them all– the synergies between them yield a step change in energy efficiency.

The two principles that really are new (conceived by Amory Lovins and the Rocky Mountain Institute) and that make this synthesis so powerful are: 


1. Decoupling acceleration and cruise demands;

2. Mass decompounding



Decoupling acceleration and cruise.jpg


Decoupling acceleration and cruise power requirements means that the fuel cell needs only to be sized to meet the maximum steady demand when cruising.  This is usually only about 20% of the maximum power required when accelerating.


In a conventional car, the engine provides the power for both acceleration and cruising; but as a car is only accelerating for about 5% of the time, and the power needed then is five times what it is when cruising, it means that for 95% of the time, the car is carrying around an engine and transmission that is five times larger than necessary.


In our network electric vehicle, almost all braking is done by the electric motors, capturing the energy of the car in motion, rather than using conventional brakes that just waste the energy as heat.  This energy is then stored in a bank of super-capacitors.  Because super-capacitors can be both charged and discharged very rapidly, they can provide 80% of the power required for acceleration.  Therefore, in our cars only a fifth of the power is required from the fuel cell that would be required if it alone was replacing the engine in a conventional car, which leads to an immense reduction in its cost. 


Mass decompounding.jpg


Mass decompounding is an emergent property of “whole system design”, designing the car as a whole system - rather than attempting to squeeze a fuel cell into a car architecture that is designed for a combustion engine and then trying to persuade it to behave like one.  The reduced size of the fuel cell, and elimination of a gearbox and driveshafts, results in a weight reduction.  This leads directly to a lighter chassis, as this is usually designed to hold on to a heavy engine and gearbox in accidents.  This in turn means less power is needed, which means lighter components, and so a lighter chassis, meaning less power and so on, and this effect is magnified by using lighter materials, composites, for the chassis as well.  Furthermore, all these weight reductions lead to narrower tyres and make power assisted systems for brakes and steering redundant; this virtuous circle of mass decompounding leads directly to significant improvements in efficiency.

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