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</o:shapelayout></xml><![endif]--></head><body lang=EN-US link=blue vlink=purple style='word-wrap:break-word'><div class=WordSection1><p class=MsoNormal>Thank you, Harry. I am amazed that I did not know about the Northfield facility. Pumped water storage still represents over 90% of all the world’s electricity storage. The world’s largest such facility is in Virginia, or was the last time I looked. I don’t know what China has done very recently. Unfortunately, there is not a huge growth potential of pumped hydro as we know it, because you need certain geography to make it feasible: an upper reservoir and a lower reservoir or running water source, with enough of a height differential. There is some interest in using the height difference between underground caverns and the ground, but so far it has not had much traction.<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Yes it is wasteful of energy, as is electrolyzing water to make hydrogen as an energy storage medium and later oxidizing the hydrogen in fuel cells. However, if you have excess solar and wind energy production at some times of the day/year, it is less wasteful to convert it to something than to just throw it away.<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>-- Carl<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><div style='border:none;border-top:solid #E1E1E1 1.0pt;padding:3.0pt 0in 0in 0in'><p class=MsoNormal><b>From:</b> LCTG <lctg-bounces+carllazarus=comcast.net@lists.toku.us> <b>On Behalf Of </b>Harry Forsdick<br><b>Sent:</b> Tuesday, May 17, 2022 8:58 AM<br><b>To:</b> LCTG@lists.toku.us<br><b>Subject:</b> [Lex Computer & Tech Group/LCTG] New England's Largest Battery Is Hidden Inside A Mass. Mountain | WBUR News<o:p></o:p></p></div><p class=MsoNormal><o:p> </o:p></p><div><p class=MsoNormal>Here is a large scale battery based on the differences in cost of electricity between high and low periods of demand. Right here in Massachusetts!<o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>— Harry<br><br><br><a href="https://www.wbur.org/news/2016/12/02/northfield-mountain-hydroelectric-station">https://www.wbur.org/news/2016/12/02/northfield-mountain-hydroelectric-station</a><o:p></o:p></p></div></div></body></html>