Engineering360: "Old Diesel Engines Resurrected for Renewable Energy Storage"

So, they want to burn diesel to store energy via compressed air? Not sure I see the advantage to that? Taking diesel off the road, to burn it in a centralized location, while driving up the cost of the energy conversion-storage cycle?

And how is this an advantage? Is this just a way of funneling money into unneeded research?

"Researchers at the University of Nottingham, UK are converting end-of-life Volvo Truck engines into machines that compress air using renewable energy. The air can then be expanded to generate energy when needed."

Renewable energy, not more diesel.

Where does the energy come from to compress the air?

Well, the quote is: Renewable.

My guesses: hydro-electric, windmills, biomass burning, tidal.

Oh, now I see. Low power resources.

Why are they 'low power' resources?

If, for example, hydro is available all 24 hrs a day, why not store the energy at low demand times and use it later, even if the conversion efficiency is not the greatest? Same for wind farms and tidal.

T-Boone Pickens once commented that Wind Energy was his biggest mistake. It looks cheap until you consider the low amount of power per acre of land, plus the maintenance cost of windmills.

Mr Pickens was a mystery as far as I was concerned, so I had to look him up.

A take-over king and (presumably) asset-stripper?

Energy is still expensive in the world in general, so the logic applied inside the USA to investment in energy generation does not necessarily apply elsewhere.

In Europe (with a population roughly equivalent to the USA) Government grants often apply to generation projects but, ultimately, business processes must apply and the cost of generation ultimately has to meet commercial criteria.

Windmills: population densities in Western Europe are high and, as a result, big wind farms are often built off shore, allowing very large arrays in areas too shallow for larger ships and where disruption can be limited.

Europe's finances are a mess. And for a reason.

...and how much indebtedness is there between the USA and China?

I was thinking more about income tax.

?

Why are wind farms quoting the cheapest KwHr?

One windmill uses only a few M square. Irrelevant the acreage - it can go on growing cows.

What current info do you have on maintenance? I imagine they must be getting very good now - perhaps an annual grease & oil change, bearings abt 5 - 10 years?

From:

http://www.instituteforenergyresearch.org/analysis/the-hidden-costs-of-wind-power/

"According to the American Tradition Institute, there are numerous hidden costs to wind power, including the cost of back-up power, the cost of extra transmission, and the cost of favorable tax benefits. And, the assumption of a 30-year life used in government calculations for wind power is optimistic given reports from European countries that have invested early in wind power.[vi] Including these hidden costs in calculating the cost of wind power increases its cost by a factor of 1.5 or 2, depending on the power system that is used as back-up. The Institute calculates that ratepayers are paying an extra $8.5 to $10 billion a year for wind power compared to natural gas-fired generation, and this will only grow as more capacity is added. Add to this the more than $12 billion that the American taxpayer is paying for the ‘one-year’ extension for the PTC, and one can see that the wind industry is getting a real boondoggle at the expense of taxpayers and ratepayers."

& fossil fuels get no subsidies?

Storage ain't gunna be cheap. Then there is the efficiency -