- Renewable & Alternative Energy
Wind Power: Acting Responsibly
Wind Power: Acting Responsibly
Green energy is a priority these days but just what does that mean? I live in the province of Alberta which hosts both the tarsands (oilsands is the preferred local term) and Wind Farms. Internationally it is known that the tailings ponds at the tarsands kill thousands of birds (two thousand actually). What is less known is that the wind farms kill about the same number of birds that the tailing ponds do. What makes this a serious problem is that the tailings ponds belong to a mature industry, the wind farms are an emerging industry that is expected to grow much larger, that means even more dead birds.
Dead birds (and bats it must be added) are not the greatest drawback to wind farms. The great drawback to wind farms is the grid, that is, the electrical grid which distributes electricity throughout North America. The grid is used to even out spikes in supply and demand. Too much demand and areas experience brown outs and even black outs as there is not enough electricity to go around. Too much supply and power generating stations start to shut down.
Wind turbines operate when the wind is blowing, too little wind and no electricity can be generated. But too much wind and the same is true, the wind turbines must be shut down to prevent damage. Wind turbines are not an on-demand producer of electricity. This becomes difficult when wind speed and demand peaks are unsynchronized, which is especially true of mornings. The morning is one of the high demand times for electricity. We are just getting out of bed turning on lights, heating up stoves for breakfast, turning on coffee brewers and toasters. We get to work where someone has turned on the lights and we now turn on our computers, printers, fax machines and copiers. Demand is high, but morning is a time of day when the wind doesn’t blow enough to meet demand. A similar problem occurs both in summer and winter, when it is very hot and demand is high, wind speed tends to be insufficient to meet demand. When it is cold and demand is high wind speed is low and generation cannot meet demand.
With wind turbines providing a small percentage of electricity this is not a big problem. But as the amount of electricity generated by wind turbines grows so does the problem. It means that somewhere there will have to be another kind of generating facility to provide the necessary electricity, it means redundancy. While there is already a certain amount of redundancy in the current grid, wind generation will require greater amounts and these facilities will not simply be able to be switched on and off but will need to be in standby mode.
Wind power also creates the problem of surges. When the wind blows wind farms generate electricity, if this is when demand is low then power surges into the grid. To level out the surge other facilities must scale back their generation of electricity, they go into standby mode.
In some areas, like Alberta, where there is little hydroelectric generating capacity, we depend on thermal generation, primarily coal and natural gas. This method requires heating water into steam to drive generators. When the electricity generating facilities go into standby mode they continue producing heat and CO2 but not electricity. Hydroelectric generation simply requires opening water channels to start turning the turbines, as generation facilities in Norway and Sweden do when Denmark supplies them with wind generated electricity.
What this means is that as we come to depend more on wind generated electricity the grid becomes more unstable. Not simply in the morning when the wind doesn’t blow, but also in winter when storm winds blow too hard (wind turbines operate best at a wind speed of 34 mph and must operate between 22 and 44 mph), just that time when demand runs high.
The nice thing about winter is that the birds will have gone south and not be killed by the wind turbines. The industry (the wind turbine industry) says that the number of deaths is not significant, the published numbers suggest 6 animals (some are as high as 40/turbine) will be killed per turbine per year. On a 5000 turbine wind farm that’s 30,000 (or 200,000!) birds and bats a year, a significant difference from the amount of birds killed on the oil sands tailing ponds. I wonder why the deaths on the tailing ponds are significant when the deaths on wind farms are not, especially when we take into account the kinds of birds being killed at the wind farms.
Wind turbines kill a lot of raptors, those are eagles, hawks, and vultures. These are birds that have already been menaced by human activity and have a harder time making a come back than other birds. The solution is not to simply cancel the wind farms, but to site them properly. Not only are the wind farms being built where the raptors fly, some of them are being built on land essential for habitat of other birds. The requests of the bird lovers is that more care be taken in siting of the wind farms.
Wind turbines also kill bats, which aren’t as cute as birds but ecologically are just as important. Bats are slow reproducers having only 1-2 offspring a year. Destroying hundreds of them a year will impact the environment.
Some have stated that it is possible with fewer larger wind turbines to reduce the number of bird and bat deaths, but that reduction comes with another price. Large wind turbines create noise, both audible and sub-audible. Standing underneath the wind turbine it is difficult to hear, but from a distance it is noticeable and bothersome. One writer noted how a wildlife area he frequented no longer had wildlife after the installation of wind turbines nearby. It would appear that it is not enough to consider the birds and bats in placing wind turbines.
I can recall when recycled paper became popular. My neighbour managed the local recycling plant and mentioned that a significant bleaching was necessary to make the recycled paper usable to the consumer which led me to ask, to save a tree are we killing a river? Are we making the same mistake with wind generated electricity?
While it is true that the number of bird and bat deaths by other human means are substantially greater than what is currently being caused by wind turbines I would suggest that it does not constitute a reason to ignore the hazards of wind turbines. Before we rush to implement an energy strategy based on wind farms (or have we already?) a more careful appraisal may need to be undertaken. Can we afford the redundancy required for large scale dependence on wind farms? Can we sustain the ecological damage from an expanded industry? I’m not suggesting that we throw the baby out with the bath water, but maybe if we recognize that the bath water is dirty we won’t lose sight of the baby.
What do we do then with wind turbines and wind farms? We do our homework. Wind turbines need to be sited where they do not interfere with wildlife, either in the air or on the ground. The complaints that have been made about their environmental impact generally comes with a complaint that the government ignored siting concerns during the approval process, and that is true regardless of what country the complaint comes from. We may have to limit wind turbines to off grid use. It should come as no surprise that some of the biggest investors in wind farms are companies involved in natural gas thermal electric generation. They will push for large wind farms which have to be backed up by large thermal generation plants, plants that have to be kept running even when the wind is blowing.
Wind power may hold promise for the future but it requires us to act responsibly now to prevent the death of bats and birds, and discomfort to people and animals on the ground.