The ways that the grid can't handle the amount of PV generation is typically not on national grid scale or even regional grid, although that may theoretically happen when the transmission line capacity is reached. Most likely is a problem on local scale, where you have pole pigs (25kW) serving blocks of houses which can create an overload on the pole pig when all houses airco's.kick on, so a utility tends to set the output voltage of the pole pig a little "hot", say 245V instead of 240 to account for the expected (over)load. Now assume a mild and sunny day after 3 of the homes have had PV installed to compensate for their pool heater or their EV charging. However, if not much load is present and all PV systems crank out between 5 and 10kW then the opposite overload problem happens: the pole pig struggles to feed all that PV power back into the Mid Voltage (usually 11-22kV) line. Buuut - the low voltage was already a little "hot" to account for the overload situation, so when now the PV is cranking away, the voltage drifts up and up and reaches the limit that the "anti-islanding" protection is set to, so the PV either cuts out completely or throttles back from the overload voltage, whatever it is set to: 250V or 255 or even the max permissible on a low voltage grid 264V (240V +10%). This is the most likely reason that PV will cut back, simply bottlenecks in the local grid, causing the inverter to run into its safety limits and cutting back to avoid overvoltage in the home. Cor.
On Thu, Sep 2, 2021 at 5:03 PM Michael Ross via EV <[email protected]> wrote: > > In today's local paper is an article about FlexGen in Durham NC, they're > raised $150M. They build "software that helps grids manage energy storage." > > Doesn't sound exactly like market and also not hardware management > software. " FlexGen's energy storage solutions bridge the gap of > reliability for the grid, and help accelerate the adoption of renewables by > shifting renewable power to times when it is needed the most." > > Source is the Raleigh News and Observer. Thursday 9.02.21 page 6A. I get > this in paper form, but there is an online version. > > On Tue, Aug 31, 2021, 8:30 PM EVDL Administrator via EV <[email protected]> > wrote: > > > From what I've read, California now has so many PV installations that > > they're actually deliberately cutting output - there's more supply than > > demand. Springtime is a particular problem because there's ample > > sunshine, > > but the weather is mild, so there's little need for heating or aircon. > > > > Long-term storage would seem to be the real answer, I guess (I"m not an > > expert), and maybe the legislature needs to revisit their RE goals. > > > > But for the immediate situation, more EVs => more demand => more efficient > > use of installed PV, no? > > > > Since charging tends to be at night, short-term storage would be a factor, > > I > > suppose. Seems easier to implement than long-term storage, but again, > > what > > do I know? > > > > David Roden, EVDL moderator & general lackey > > > > To reach me, don't reply to this message; I won't get it. Use my > > offlist address here : http://evdl.org/help/index.html#supt > > > > = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = > > If at first you don't succeed, skydiving probably isn't for you. > > > > = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = > > > > _______________________________________________ > > Address messages to [email protected] > > No other addresses in TO and CC fields > > UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub > > ARCHIVE: http://www.evdl.org/archive/ > > LIST INFO: http://lists.evdl.org/listinfo.cgi/ev-evdl.org > > > -------------- next part -------------- > An HTML attachment was scrubbed... > URL: > <http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20210902/c9d37f11/attachment.html> > _______________________________________________ > Address messages to [email protected] > No other addresses in TO and CC fields > UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub > ARCHIVE: http://www.evdl.org/archive/ > LIST INFO: http://lists.evdl.org/listinfo.cgi/ev-evdl.org _______________________________________________ Address messages to [email protected] No other addresses in TO and CC fields UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub ARCHIVE: http://www.evdl.org/archive/ LIST INFO: http://lists.evdl.org/listinfo.cgi/ev-evdl.org
