Adenosine triphosphate (ATP) is the universal unit of energy used in all living cells. This molecule is produced and broken down in metabolic processes in all living systems.Known as the ‘energy currency of life,’ ATP can store and transport the energy we need to do just about everything that we do. Essentially all metabolic functions of living cells require energy for operation and obtain it directly from stored ATP.
That's the stuff going on in our cells.
But the more I look into the issues I believe there is a justification to state that energy is the currency of the world at large. It is energy that flows from the sun, that starts the whole cycle of life, and all our life is dependent that. In addition, all farming is about yielding energy, and ultimately our whole industrial society is based on access to cheap fossil fuel. If it were not for the coal pits in England, there might never had been an industrial revolution nor capitalism.
There seems to be a rough overall correlation between GDP/capita and energy/capita. This is understandable, since higher productivity per individual will cause a higher energy need for each. Due to the very rapid expansion in financial "services" and housing booms in many countries there was seemingly a bigger disconnect the last twenty years than we can see historically.
Source: the World Bank.
I believe this very strong correlation is what makes the energy issue to such a hot political issue more than a technical issues. It IS about our lifestyles and it IS about our economic system at large. To challenge energy use is fundamentally to challenge capitalism. That's why even proponents of wind and solar or biomass have this tendency to oversell those technologies, because it is only if they can show that they will be adundant and cheap that you can get political acceptance for them.
But as well as sugar is energy in our body, and more energy makes a stronger person, ultimately it also leads to diabetes and obesity. Our societies are obese, not only the people.