Energy-conscious to an extreme, Olaf Taeuber relies on just a single 5-watt bulb that gives off what he describes as a ''cozy'' glow to light his kitchen when he comes home at night. If in real need, he switches on a neon tube, which soaks up all of 25 watts.

Even so, he found himself seeking help last week to fend off a threat from Berlin's main power company to cut off his electricity, one of a growing number of Germans left unable to pay their soaring energy bills. He is among those feeling the immediate effects of Chancellor Angela Merkel's most ambitious domestic project: Germany's energiewende, or energy revolution, under which the country is shutting down its nuclear power reactors, discouraging coal-fired plants and encouraging a near-complete shift to renewable energy sources.

''Often, I don't go into my living room in order to save electricity,'' said Mr. Taeuber, 55, who manages a fleet of vehicles for a local social services provider. ''You feel the pain in your pocketbook.''

''Energy poverty,'' as Germans now call it, is just one of the many problems confronting Ms. Merkel's plan, the likes of which has never been tried - not just in Germany, but in any major industrial country. Energy prices in Germany - the highest in Europe - have spiked 30 percent over the last five years as costs have risen with the transition. Providers pulled the plug on an estimated 312,000 German households unable to pay their bills in 2011, according to official figures.

Newly constructed offshore wind farms churn unconnected to an energy grid still in need of expansion. Carbon emissions actually rose last year as oil- and coal-burning plants were fired up to close gaps in energy supplies. Energy-intensive industries have begun to shun the country for fear of the even steeper costs ahead.

David Fuller's view Arguably, this is a brave move by Mrs Merkel and Germany but is it entirely rational? Opinions will obviously vary on the emotive topic of expensive green energy versus fossil fuels such as crude oil and, increasingly, natural gas. These are obviously much cheaper if produced domestically. However, with a troubled Middle East and other energy exporters keen to see prices just below levels that could weaken global demand (crude oil Brent and WTI), we have not yet reached the point where energy costs are likely to be permanently lower in real (inflation adjusted) terms, due to increased global supplies. Upside breakouts from these trading bands shown above would certainly be a headwind for the global economy.