Grid is key to selling wind's benefits

The US and China may be the biggest generators of wind power, but they are also the two worst polluters. It is this fact that has enabled other countries resisting the drive towards renewables to argue that there is no point in reducing their carbon emissions.

 The result: much dragging of heels and further exploitation of dirty fuels.

Last month, this argument looked on shakier ground when presidents Barack Obama and Xi Jinping signed an agreement to combat climate change by cutting carbon emissions. At last, the two main players appeared to be leading the way. Except there was rather less to the agreement than met the eye. The US pledge to cut carbon pollution to 26-28% below 2005 levels by 2025 is a promise to continue to do what it is already doing - it has already cut levels by 10-15% over 2005 levels, and they are falling by around 1.5% a year.

China's pledge that 20% of its energy will come from low-carbon sources by 2030 sits alongside its admission that its carbon pollution will go on rising until then. Once the details were out it was hard to raise more than two faint cheers.

But two faint cheers are better than none, given that there has been little cause for applause on the political front for wind recently. Even countries with the financial muscle and political stability to push renewables seem to be wedded to fossil fuels.

Grid stability

If we are to look to energy users to persuade politicians, then we must address the comments that the variable nature of wind power makes it impossible to integrate it successfully on the grid.

This is less about what to do when the wind doesn't blow, as about how to manage the grid to incorporate power from a wide variety of resources, including nuclear and thermal, to ensure that the lights stay on at reasonable cost.

And there are real examples to show it works. As UK green-energy firm Ecotricity highlighted in its Nothing Happened advertisement campaign in the national press, Britain's wind energy took up the slack one day in October after four nuclear reactors shut down and a fire at a gas plant forced it offline. Wind delivered almost 25% of the electricity across the country with no loss of power to end users.

Spain and Denmark continue to deliver high proportions of electricity from wind energy that their grids can comfortably manage. We can hark back to December last year when 54% of Danish electricity was provided by wind. In 2013 wind outstripped all other forms of electricity generation in Spain, producing 21.1%.

There is no simple sliding scale of how much reserve power must ramp up in relation to an increased proportion of renewables. Energy storage systems may play a growing role in facilitating their integration in coming years, but we should be clear on just what storage can do for the network now, given many examples currently prove to be costly and inefficient.

Control systems have moved a long way from simple low-voltage ride-through technology, and most new projects now actually help to protect and manage energy flow so much that expensive switch-off of large power plants can be reduced - renewables can benefit grid balancing.

While technology advantages continue to help wind play a pivotal role in electricity production, we must shout loud the clear examples where wind power is already doing just that.

Jacki Buist is editor of Windpower Monthly