Germany today likes to boast a total of 36,000 megawatts of installed photovoltaic capacity and over 30,000 MW capacity of wind power. Theoretically at noon on a sunny, windy day Germany could cover almost all of its electric power demand, which at noon on a workday is roughly 70,000 megwatts.
But anyone familiar with Germany’s climate knows the country’s weather is often gray and sees about as much sunshine as Alaska does. Germany has a fair amount of windy days, but periods of windless days are also frequent enough. They can’t be avoided and must be reckoned with. In a nutshell, solar and wind power production are often AWOL and so conventional power systems (coal, gas, nuclear) always need to be on standby, ready to deliver on a minute’s notice.
To illustrate, the following chart depicts German electric power production and consumption over the 6-day period 14-19 July: conventional power (gray), solar production (yellow), wind (dark blue), hydro (light blue) and biomass (green). German consumption is shown by the red line.
Image: agora-energiewende.de
Readers immediately notice the huge fluctuations in solar and wind power outputs. At night there’s no sun and the wind appears only sporadically.
The data from the above chart show, for example, that at 9 p.m. on July 16 total wind power output was a mere 0.334 gigawatts and the day’s last rays of sunlight were delivering only 0.103 gigawatts of power. That means the two sources of wind and solar combined were putting out only [(0.334 + 0.103)/65]100 = 0.7% of their rated capacity. That in turn means the remaining 99.3% had to come in large part from the conventional coal, nuclear and gas power plants.
Germany’s installed wind/solar systems on average operate roughly at about 15% of their capacity.
Moreover the chart shows that wind energy output was close to zero for a period of three days (July 16 – 19). Little wonder that wind and solar have yet to replace a single conventional coal power plant in Germany. No matter how much installed solar/wind capacity the country has, it still has to rely on conventional power on windless nights, which are frequent enough.
The result is that the economics of wind/solar energy are just plain awful. To illustrate, imagine the costs involved in being forced to own two cars: an expensive one that runs on average only 1 random day a week, and a cheaper one that can run anytime. Whenever you want to drive, you are first required to drive the expensive/unreliable one. Only when it doesn’t start up are you allowed to drive the cheaper, always operable car. Obviously such a model of personal transportation (being forced to own, maintain, insure and repair two cars) would bankrupt most working-class households.
Today’s green wind/solar energy makes little economic sense.
Good analogy, Pierre (two cars per household vs. one).
Most voters should be able to grasp the argument.
Ought to be effective in getting SOME of the citizens to question the sillier of the Cleantech initiatives.
Thanks, a very informative and illustrative piece. Highly useful when debating those alarmists who seem to believe (outside of Germany, anyway) that Germany operates happily on sunny, windy weather.
People need to remember that power production is a full time job, and not one that can be done by someone (or something) who shows up for work only one day a week.
it is not only an anaalogy ,some would like people to buy an electric car to store electricity in ace of peak in production…
A kWh that you store in a Li-Ion battery and later get it out again costs you one Euro. Given battery wear, battery prices, assuming a car battery is designed for a lifetime of 100,000 km, with the care consuming about 20 kWh/100km, and a 5 cent/kWh source price of the kWh.
Nothing that subsidies can’t fix though.
… for bragging rights with their neighbors…
Question for you: I recently saw commentary on German renewables, in which the person commenting claimed ‘green’ energy now had a ‘75%’ share of the German market.
I’m not quite sure what they meant, but from what you wrote above, Germany has apparently put up quite a bit of wind and solar, but even more apparently is barely getting a fraction of that in reality, yes?
From time to time demand is weak – on public holidays – and the sun is shining and in those moments, yeah, there’s a spike, and the fossil plants and nukes have to throttle as fast as they can.
This is always accompanied by jubilations by our esteemed quality journalists. Who know everything about energy, the economy, and numbers.
[…] To illustrate, the following chart depicts German electric power production and consumption over the 6-day period 14-19 July: conventional power (gray), solar production (yellow), wind (dark blue), hydro (light blue) and biomass (green). German consumption is shown by the red line. Continue reading here….. […]
Sigmar Gabriel (Ministry of Energy, left CSU) is the only politician honest enough to accept the reality: Energiewende is a hoax, a money black hole and a technical disaster, period. He voiced this in front a an assembly of Wind Industry from which he escaped alive…
ALL the others right and leftwing politicians, having “taken the AGW train running” for electoralism reasons, are now trapped and cannot make the necessary political U-turn to save the economy of their country: They carry over and dim any legal attempt to issue a law reducing exhorbitant renewable fundings. Spanish politicians have been more courageous.
With 24B€ renewable fundings paid by population (about €800/annum per couple) we can bet that all these parasits be expelled by next polls….
“He voiced this in front a an assembly of Wind Industry from which he escaped alive… ”
Yet the government he is in as vice chancellor simply perpetuated the subsidy orgy, thanks very much, social democrats. The so called “reform” of the subsidy law didn’t reform anything. The SPD MP’s have their shares in wind parks just like the members of the other Bloc parties. They need to fund their metamphetamine habits after all.
And for those geniuses who say that the wind is always blowing somewhere and everything will be fine once massive interconnectors are in place, please check out
the UK wind for the last few days or even two months. Installed wind approx. 8Gw.
http://www.ukpowergeneration.info
Another way of looking at the graph could be that solar power fits in quite nicely with the larger demand for power during the day… Therefore, the power produced by conventional powerstations seems rather constant (on a larger scale).
I agree that windpower is totally useless but judging from this graph there might be a case for solar power.
To limited degrees – good for air conditioning.
Solar power suffers from the cumulus effect. Cumulus clouds moving in a clear sky on a sunny day lead to vertical power cutoffs and restarts for individual fields of solar cells: quite vicious, and not at all what the grid of villages is designed for.