The PR assertion of wind power advocates that geographic diversity smooths the variability of wind power was put to a stern test by Finnish physicist Jani-Petri Martikainen in this recent post. Martikainen’s analysis obliterates the assertion that distance between wind farms solves the problem of variability.
Martikainen starts his analysis by creating a synthetic wind farm by merging synchronized real time production data from actual wind farms in Southeastern Australia, Ireland, and the U.S. state of Oregon. He assumes a superduper grid that connects these three sites without any line losses. Even with these heroically generous assumptions in favour of wind power, it turns out that the output of this synthetic wind farm is still so variable that it would require almost 1:1 backup by reliable generation. He notes “the combined system has about a 7% probability of producing less than 10% of the installed capacity.”
Martikainen then goes on to analyze what capabilities would be required of electrical storage devices to allow wind power to make a large contribution to meeting primary electricity requirements. The answers he comes up with are obviously unaffordable.
I participated in a contribution to the literature on the benefits of geographic diversity for smoothing wind power. In 2009, when our analysis was published, the assertion that geographic diversity solves variability seemed worth debating. Martikainen’s debunking of the assertion is so powerful that only ignorant or dishonest folks will continue claiming that more transmission and storage will make high wind reliance a practical and reliable option for modern industrialized economies.
Can demand flexibility be made scalable, practical and consumer-friendly enough to make a meaningful dent in the need for generation dispatchability? That seems to me to be a question worth investigating. However, I have doubts about whether energy storage can be practical and economic on any significant scale in Ontario, particularly in light of the dodgy economics of the existing pumped storage in the province.
A future post will address safety concerns associated with a pumped storage proposal for Eastern Ontario. Safe above-grade water storage on a significant scale will be costly if it is to be located uphill of people.
His model is deeply flawed on many levels. He takes the same “aggregate” approach to arrive at capacity reserve requirements (looking at yearly production models). Plainly stated, we don’t schedule operating reserves on a year to year basis, but on a day ahead, hourly, and minute by minute basis (to more closely correlate with daily load). His approach is an incredibly wasteful use of generation resources and inefficient standby reserves (which is why “it appears” so impractical and expensive in his analysis). He also only choses to use wind when it matches demand, and discards (or curtails) wind when it is not needed or when there is overproduction (despite discussing supergrids and energy storage alternatives). In his model, therefore, he is willing to shed up to 5.3 TWh of energy generation per year, and I can’t think of any business case where a utility or independent operator would find this acceptable, and run their generation sources in this way (thus forgoing profits and return on investment on equipment by selling energy to neighboring regions or storing the energy for use at peak intervals). So “stern test” and “debunking” of assertions, not quite. If anything needs curtailing, it’s his analysis, and not the abundance of energy being produced by wind power and meeting societal needs to 30% of total production in his modeled system.
EL, you gave me a chuckle with “In his model, therefore, he is willing to shed up to 5.3 TWh of energy generation per year, and I can’t think of any business case where a utility or independent operator would find this acceptable, and run their generation sources in this way.”
Ontario is likely to require that amount of generation curtailment (almost entirely of carbon free sources)of about that amount by 2014. One government body, the IESO, is working on how to pay more producers for generation the grid can’t accommodate, while another is telling the first one to work quicker (the OEB market surveillance committee).
Now you can think of one.
You are welcome.
Moreover, the analysis combined the large and disparate regions it combined, in order to create a “sampled” model of a WORLD that built wind generators to meet its energy needs! Finding “neighboring regions” to buy surplus energy is still a challenge when you’re discussing the whole planet Earth as the seller of the surplus, no? And the issue of “or storing the energy for use at peak intervals” is actually addressed extensively in the article — and addressed excessively generously, i.e., way more than fairly, as far as I can see. (With >50% actual turn-around energy losses from our pumped-storage facility at Niagara Falls — rather than the 20% assumed in the article — I doubt that Tom’s safety arguments will be necessary to limit the future role of pumped storage here. And compressed air and flow batteries and flywheels all look as bad, at least when I look at them. Maybe millions of plug-in hybrids will turn things around. . .)
The tenuous relationship between Ontario’s real-world electricity needs on the one hand, and the financial inputs to the “business cases” that our utilities and independent operators must be calculating these days, on the other, could make a sensible Ontarian weep.