In 2014, Germany produced 56 TWh of electricity by wind power (BP Statistical Review of World Energy June 2015).
Over the last 10 years Germany produced 422 TWh by wind power. At the end of 2014, the country had 39.2GW installed nameplate capacity (EWEA: Wind in power 2014 European statistics), which looks like a capacity factor of 16% (this understates the factor as the wind power installed in December 2014 can’t contribute very much – if instead we use installed capacity at end 2013 – 34.3GW – this gives a capacity factor in 2014 of 19%, so the correct value is in the range of 16-19%).
If this windpower replaced coal-fired power stations at about 900g/kWh of CO2, this last 10 years of wind has reduced Germany’s CO2 emissions by 380M tonnes CO2. And over the next 20 years (assuming 17.5% capacity factor) this installed base will produce 1,200 TWh, reducing CO2 emission compared with coal of 1080M tonnes CO2.
At current costs (see last article), which understates the country’s expense, Germany has spent a capital cost of €39BN, plus some considerable O&M costs.
As wind power increases in grid penetration, the benefits reduce a little – basically you will be ramping up and down conventional generation more, as windpower gets priority. This ramping up and down reduces efficiency (how much is a question we will look at in another article). Even though Germany has about a 10% average penetration of windpower, at peak windiness times, wind power might easily be over 50% of the power in the network, leading in fact to curtailment at certain times (see V – Grid Stability As Wind Power Penetration Increases).
So, well done Germany.
However, CO2 is a well-mixed GHG. So CO2 emissions from Germany are exactly the same as CO2 emissions from the US. That is, whether the US or Germany reduced their emissions by 380M tonnes of CO2 over 10 years makes zero difference to the climate.
Suppose Germany had installed this 39GW of nameplate capacity in the mid-west of the US:
The average capacity factor in Oklahoma in 2011/2012 was over 41%.
Let’s assume that the capital costs outside of buying the turbine are the same (grid connection, land cost, access roads, regulatory compliance, etc). In that case German windpower investment of 39.2GW of nameplate could have produced 2.3x the energy (41%/17.5%).
Instead of reducing CO2 emissions by 380M tonnes CO2 to date, and a potential 1,080M tonnes over the next 20 years – the reduction would have been 870M tonnes to date and 2,500M tonnes over the next 20 years.
Just add a page to the national energy production figures which shows the benefit. It’s not hard to understand.
I don’t want to pick on Germany, but it’s a nice concrete example. When you spend over €40BN on something it’s no longer a hobby. Why not get two and half times the environmental benefit?
It’s a serious question.
Articles in this Series
Renewable Energy I – Introduction
Renewables II – Solar and Free Lunches – Solar power
Renewables III – US Grid Operators’ Opinions – The grid operators’ concerns
Renewables IV – Wind, Forecast Horizon & Backups – Some more detail about wind power – what do we do when the wind goes on vacation