A few random thoughts: 1. There are symbiotic relationships between different sources of energy. In order to suck petrol out of the earth we need coal (used in

A few random thoughts: 1. There are symbiotic relationships between different sources of energy. In order to suck petrol out of the earth we need coal (used in steel manufacturing). In order to mine coal we need petrol (used by diggers and for transport). We still don't know how to manufacture solar panels and wind turbines without fossil fuels. The mining, steel forging and international transport of these products is still based on fossil fuels. 2. Electricity consumption represents only about 30% of total energy consumption. A lot of people seem to underestimate the difference in energy density between petrol and lithium batteries. This difference makes it highly unlikely that we'll move to electric ships and aircraft in the near future. 3. The mining activity associated with manufacturing solar panels, wind turbines, batteries, smartphones and electric cars is highly demanding in energy, is highly polluting, and demands great quantities of fresh water as part of the process of refining the different metals. With the rise of electric cars, the continuing demand for smartphones mining is expected to demand even more energy and fresh water, and pollute even more our rivers and soils. This, in a period of constrained energy sources, droughts, and an already degraded environment. 4. Judging by the comments on here people demand an always-on supply of energy, be it electricity, petrol or gas, which is a privilege only some countries enjoy today, and is relatively recent in human history. I think the idea of intermittent energy supply is worth exploring, and might make it easier to achieve 100% renewable energy production, in conjunction with a lower energy consumption.