Response to "The Engineer" article on grid-scale storage

I attempted to post this response to this article on The Engineer, a UK-based Energy website, but it failed, so I'm posting it here.


First, the article reverses power and energy in this excerpt quote:
"This removes the link between the power density and the energy density of the system; the power density is determined by the size of the storage tanks, and the energy density by the size of the reactor."

Second, it is not nonsense to consider multiweek storage schemes. Aggregated wind output from entire regions...such as North America or all of Europe, varies on about a three-week cycle. In current thinking, the remainder that cannot be balanced by pumped storage will have to be made up by dispatchable generators.

There are a few potential pumped storage sites around the world that can store energy over multiweek periods, such as the Lake Erie-Lake Ontario system in the US, which can store 1300 GW-hours of energy if one allows the lake level of the smaller lake (Lake Ontario) to shift only 30 cm/cycle. I presented a paper on this to the Energy Storage Association in May 2009; there is no chance of implementation any time soon, but also no doubt it will work. There are also no comparable lakes in Great Britain.

There are also three particular sites in Africa that allow for the possibility of high capacity pumped storage operating between the ocean and a depression that is below sea level: the Qattara depression in Egypt, the Danakil depression in Eritrea, Ethiopia and at Lake Assal and the surrounding Afal depression area in Djibouti. I have a blog post on this that might interest some of you:
http://www.elpipes.com/2011/01/pumped-storage-at-danakil-depression-in.html

Japan has built a sea water-based pumped storage system with an elevated upper reservoir, which I also did not see mentioned in the article. The advantage of such a system is that one needs only one reservoir, though the need for corrosion resistance increases equipment cost.


I have so far found that US-based venture capital investors will not take an interest in the elpipe because it is "too big, too long term." I have therefore put my startup Electric Pipeline Corporation onto Wefunder: https://wefunder.com/elpipes 
in hopes that I can get started on this important (and expensive) development soon. It would help me move this forward if you will "follow" me on Wefunder; I expect the US Securities and Exchange Commission will be issuing rules by May that will allow me to raise funds though Wefunder (this is not legal yet, but by following EPC, you will help move me to the front of the queue when the final rules are announced).