Exergy Loss Minimisation

If exergy describes the potential of an energy source to generate work, and exergy efficiency is a measure of how well the exergy is extracted then it follows that we want to minimise the loss of exergy. When we look to nature for inspiration we see a series of thermodynamic systems. They have an exergy input - the Sun - they have a network of cells which utilise, convert and store this exergy - chemical structure of the trees, shrubs and animals - and a method for losing energy - respiration, evaporation and radiation. Studies have shown that the most exergy efficient ecosystems are those that are most diverse. The best example being a primary rain-forest.

Figure 1 shows an exergy cycle comparison between a rainforest and a grassland habitat. By having a variety of methods for capturing and storing the exergy, losses are minimised, the system becomes more robust. If one plant fails then there are others to take it's place. In fact the ecosystem's primary goal becomes the pursuit of exergy efficiency and minimisation of the exergy loss.

At Exergy Devices we're taking this ecosystem model as the basis for our view of how a domestic energy system should work. By increasing the diversity of exergy capture devices (say solar panels, wind turbines and CHP boilers) the system can be optimised to minimise exergy loss. This is not only good for the occupant, but for the environment, by reducing demand on grid power (generated largely from coal or gas fired power stations).