“The quickest and easiest way to reduce our carbon footprint is through energy efficiency. Energy efficiency is not just low-hanging fruit; it is fruit that is lying on the ground.”

Dr. Stephen Chu, US Secretary of Energy 

One thought on “Quote of the Week”

  1. Wow. Improve efficiency. What in the world have we been doing the last hundred years?

    I remember when trains were pulled by coal burning locomotives using non-condensing steam engines. They likely attained 3% to 7% thermal efficiencies. Diesels get over 30% thermal efficiencies.

    Most houses had no insulation in walls or attic – none. Household furnaces were woefully inefficient largely because all the controlling depended on the operator. Inside warm air went up the chimney, replaced by outside air. There were no thermal windows. There were no heat pumps. No florescent lamps.

    Cars would get about 10 to 14 mpg in the city and maybe 15 to 20mpg on the open road. It had long been know that efficiency could be increased by raising the compression ratio but this couldn’t be done until higher octane gasolnes could be supplied. (By 1930 the world use of oil had risen to 3 million barrels a day, mostly in the US. Today about 85 million B/D of liquid fuels is burned – more efficiently.)

    The efficiency of electricity generation increased as higher steam pressures were used. Our fired power plants today operate at about 34% thermal efficiency, against the limit for a conventional plant. Multiple cycle plants do better and better use can be made of “waste heat” i.e. low temperature heat.

    So only now, after making most of the improvements that the Laws of Thermodynamics will permit, are we scolded to improve efficiencies by those to whom an energy problem has been revealed.

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