GRA wrote:The issue here, ISTM, isn't that they are having teething problems. That's to be expected.
Not by some... Or perhaps are both expected and a reason to celebrate. Hard to tell.
GRA wrote:It's that this system was proposed and sold as a way to reduce the need to import most of their diesel fuel, resulting in lower electricity costs and improved air quality, not as a dem/val to gather performance and economic data with no expectation that it would save money.
I don't disagree, and perhaps I should go back and find some of the discussions I had with "A" on this subject.
GRA wrote:As it is, with the info we now have, early misgivings about the size of the pumped storage capacity, even if it's being fully used which it apparently isn't, have now been confirmed. Even if the system operates at 100%, it simply lacks enough storage capacity to cover low wind season and offset significant genset usage.
Three issues with the system according to:http://euanmearns.com/el-hierro-complet ... operation/
The GdV wind park consists of five 2.3MW Enercon turbines capable of generating up to 11.5MW, but during the first year of operation wind generation never exceeded 7.5MW.
This is a puzzle, why did they throw away all of the power potential between 7.5MW and 11.5MW from the wind park?
A 2012 study conducted before GdV started operations concluded that power generated by the wind turbines could be admitted to the El Hierro grid without compromising grid stability provided three of the Pelton turbines in the hydro plant were maintained as a spinning reserve:
The results show that, to ensure system stability in the worst network contingency, the best option is to hold three hydraulic units in spinning reserve mode
This approach has clearly not worked, and as a result GdV has had to resort to other measures.
Grid stability is a well documented worry with high levels of renewables. A known unknown. If they solve it, this might be a valuable outcome.
Here we come to GdV’s fundamental (and unsolvable) problem. GdV was built because of the existence of an inactive volcanic crater 700m up the hill, which it was believed would provide enough energy storage when filled with water and linked to a lower reservoir to smooth out fluctuations in wind generation. Unfortunately no one bothered to do the sums and check the wind records. Had they done so they would have found that the storage was adequate to fill El Hierro’s demand for only about two windless days and that low-wind periods on El Hierro can last for months.
Here I disagree. 65%, the design goal, should be achievable with a few days of energy storage. Only if the goal is near 100% do you need storage for months. The real issue on energy storage is that it wasn't being used, for some reason.
The hydro system does not seem to be working as planned either. Hydro generation to date has been minimal,
Again, a puzzle without enough information to solve.