Ann: 6.6MWh US project recommended for grant funding, page-25

"Because I refer to the efficiency to manufacture electricity.
ie : Mining, processing, shipping, manufacturing logistics , erecting construction , harnessing and storing renewable is extremely inefficient way to produce electricity.
Fossil fuels have already been harnessed processed and stored by nature . Thats about as efficient it can get. ;o) Merely dig it up and burn it...."
A bit selective here. You count the infrastructure cost of renewables, but ignore the infrastructure costs of fossil fuels. Let's look at a few:
Mining, processing, shipping, manufacturing, erecting and constructing a power station, plus demolition and safe disposal of rubble and toxic substances at the end if its life.
Manufacturing equipment to create a coal mine, then using that equipment to relocate towns, roads, waterways before clearing millions of tons of overburden before the coal can be accessed, plus moving millions of tonnes of overburden back to fill the holes and make something that can actually grow grass again at end of life (a very complex and expensive task that requires construction of artificial strata within the overburden to try to stop rain seeping down to the bottom of the hole and leaving the surface bone dry)
Planning and construction of handling machinery, washeries, dust control equipment, facilities for workers, etc.
Manufacture and operation of heavy machinery to mine the coal and deliver to railways.
Construction of railways, rail cars and locomotives for shipping coal from the mine to the power station, then ongoing operation for 30 years to ship tens of thousands of tonnes of coal every day.
Managing environmental damage from the coal mine, such as changing the microclimate and lowering the water table leading to parched and dry landscapes
Managing the health costs of coal mine dust and toxic chemicals from power stations.

Fossil fuels do not look so efficient when all this is included.