Wednesday, April 08, 2009

Germany First Fully Renewable Energy Economy... by 2050?

The Reichstag in Berlin will be fully powered by renewable energy, in the iconic intention that the rest of Germany will become the first fully renewably powered industrial nation. By projecting current momentum toward renewables, it is reckoned that by 2050, 100% of Germany's energy will be so provided. Immediately I wonder how they will get around the problem of replacing liquid fuels for transportation, or do they think they will be all-hydrogen or all-electric by then?

The total quantity of energy used in Germany is reckoned as the equivalent of 472 million tonnes of coal in 2007, which amounts to:

472 x 10^6 tonnes x 29.3 x 10^9 J/tonne (coal) = 1.38 x 10^19 J (13,842 PJ).

For some reason, in Britain we tend to cost our energy in terms of oil equivalents, rather than coal, which amounts to 226 million tonnes of crude oil, with an accepted energy content of 42 GJ/tonne:

226 x 10^6 tonnes x 42 x 10^9 J/tonne = 9.49 x 10^18 J (9,490 PJ).

Roughly the ratio of energy used in these two countries is that of their relative populations (82 million/61 million), but ca 8% more energy is used per capita in Germany, probably because of relatively more industry and colder winters.

It is planned to reduce the amount of energy used in Germany from 13,842 PJ (2007) to 12,000 PJ in 2020, and to 10,000 PJ in 2030 (a total reduction by 28%), by implementing energy efficiency strategies, which will save billions in terms of imported energy sources, the price of which is predicted to rise. Indeed it is debatable how much oil will be available let alone what it will cost by 2030, and by 2050 there may be precious little of it left, even at prices of $200 or more a barrel in today's money, as has been predicted.

In 2008, 7.3% of Germany's total primary energy came from renewables, and it is expected that this will rise to 33% by 2020, well in front of other European nations. By 2020, 30% of German electricity is forecast to be generated from renewable sources: wind energy is the principal player in the mix at 15%, with 8% bioenergy (biomass and biogas) and hydropower at 4%. It is anticipated that photovoltaics will be cheap enough by 2015 that a price parity will be achieved with other electricity sources.

Up to 10 GW is expected to be generated from wind turbines placed across the northern German coastlines and offshore wind-farms placed in the North Sea. The electricity is to be conducted from the north and east or south and west using high voltage direct current fed into a smart national grid and that by 2030 50% of German electricity generation will come from renewables, feeding into an entire European trans-continental grid.

Electric cars powered by batteries charged by electricity from renewable sources are planned to provide transport across the nation and so curb dependence on imported oil (around 40% of the total primary energy budget - about the same as in the U.K.) and its greenhouse emissions. Some of this electricity is expected to be made from biogas, derived from compost and waste, pumped into high temperature fuel cells that run at 850 degrees C. and converts the gas to electricity with an efficiency of 40 to 55%. These I presume are solid-oxide fuel cells. If the heat can be recovered too the combined thermal and electrical efficiency of the fuel cell amounts to nearer 85%.

It's a big job, but the Germans seem to be throwing all their technology at the critical issue of providing future energies which other nations, e.g. Britain are not. Good luck to the Germans - even if they only match half their energy requirements by renewables it will be a major achievement and secure stability for the country. I have my doubts about all those electric cars hurtling up and down the autobahns though, and whether enough of them will be made even by 2050, or if the supplies of liquid transportation fuel will fail long before then; before an equivalent scale of substitution can be made.

Related Reading.
"Germany: The World's First Major Renewable Economy," by Jane Burgermeister:

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