Right before writing this article I was not a huge advocate for wind power. I knew that wind turbines have one problem: supply and demand. Electrical energy needs to be created at the very moment it is needed. wind power can only When you turn on your washing machine, your lights, your dishwasher - you need power right then and there. Wind power can only be generated when there is wind. Therefore, you no matter how many extra windmills you put up, you still won't have enough power during the right times.And Solar won't help (at least in the winter). Solar has a lot of capacity in the summer, but in the winter not so much. When do we need power you ask? well look below (this is for sounthern Canada, courtesy NRCAN):You can see that energy demand is the least in October and April, and currently the most in January with a growing peak in July. For an idea of how energy demand changes during the day:You can build your wind farms, but unless you build some way of storing the energy, you will still need conventional (hydro-electric, coal, oil, natural gas, nuclear) power plants. Ways of storing power are:- batteries- water damnsTo build batteries would be just silly. You want to save the environment, so you create toxic waste? Batteries also do not have that much capacity. Building damns limits the locations you can build wind turbines to:- places that have a high frequency of wind (and)- places that are hillyThis combination is a hard find.But one thing did not click in my mind. Europeans are not idiots. Why build so many wind turbines, when they know that wind energy will not be able to suffice their power requirements?The answer is high voltage DC power lines. Yes, DC, this is not a typo. A list of advantages can be found here. AC transmission is used because of historical reasons: When we were installing AC power lines, we didn't know about the advantages of HVDC, and we had just switched from (Lower-Voltage) DC power lines because of their inefficiency. HVDC lines are standard (in Europe) at 500KV. This means much larger insulators are required, and more ground clearance. (Many) thyristors would be needed to change over to HVDC, and adaptations to current lines. Regular transmission lines are 125KV AC in North America.What does this have to do with wind energy???Winds are strongest in the winter in Scandinavia. THey are strongest in the summer in the Sahara. Europe wants to interconnect the whole continent with HVDC power lines, install (a lot) of wind turbines, and supply clean energy to the whole continent year round. This would not have been possible with much less efficient AC power lines.They are investing $80Bn US into this infrastructure. This kind of investment makes sense for other reasons: peak oil:Once oil supplies have sufficiently run out, we will inevitably need to use renewable resources. Having an efficient energy distribution system like this will allow for adding more (green) power sources and not worrying about local / regional power users, since power can be transmitted efficiently over (ridiculous) distances.I wasn't for wind power. Now I am. BUT North America needs a more efficient, and more importantly, more interconnected power distribution system than it has for this to work.Go green but go green smart.
No comments:
Post a Comment