Guest post by Rud Istvan,
Here we are again on another Charles request, this time just summarizing the essence of several previous related and much more detailed renewables dissections at Climate Etc. Those previous posts were co-authored with electric utility ‘Planning Engineer’– (who after his recent retirement is invited to comment on this here also).
The specific issue Charles highlighted for possible comment was a newish article at the ‘irrefutable’ Atlantic. It claimed that but for President Trump’s intervention, the ‘Green New Deal’ (GND) grid could have been stabilized by nationwide grid connected GND renewables.
This article is more ‘fake news’ nonsense for several separate technical reasons, independent of the fact that the sun sets nationally so night is still a big solar problem as California is finding with its rolling blackouts, whether or not there is national grid—although AOC might think it helps.
First, voltage sags with distance thanks to resistance (a bit more complicated in the alternating current Tesla domain, but still true as the main reason Nicola Tesla (Westinghouse alternating current) beat Edison direct current (GE) for our present several large regional grids. Even a very high voltage national AC grid would lose some of its electrical energy: per regional experience, transmission grid energy losses would be on the order of 15%. That is why very long links tend to invert to HVDC, then revert to AC, as the Scandinavian/EU interconnectors do. There are inverter losses, but less than AC losses at higher distances. There are several other practical engineering reasons the US high voltage grid is still NOT nationally interconnected, even though it theoretically could have been from a purely technical perspective. None have to do with President Trump.
Second, wind and solar lessen grid stability because they lack grid inertia. So the more renewables penetrate, the less the needed grid inertia provides voltage (manifested as AC frequency) stability. More renewables means less grid inertia, thus more grid frequency instability (evidenced as (‘brownout’ voltage sag) that can shut the entire grid down to protect all the classic spinning generators. Massive rotating steam/gas turbine generators (several hundred tons each) also store kinetic energy for the grid via their simple rotational momentum. The grid demands more energy, they offer up the momentum and begin to slow down, and the ‘steam/gas’ turbine responds and powers them back up to keep their rotational frequency generating speed ~constant.
Neither wind nor solar have this inherent kinetic energy momentum ‘capacity’, since both are asynchronous. They lack ‘grid inertia’. So their addition to any existing grid increases its potential frequency instability. That is not a problem if asynchronous penetration is a small percent of the total generation. It is a BIG problem if their penetration becomes significant (>~10% or about equal to conventional rotational momentum spinning reserve standby capacity).
There is a grid inertia solution, but at great additional grid cost ignored by GND. You can add synchronous condensers in an amount equal to renewables. These are essentially big undriven (no attached turbine) generators spinning synchronously with the grid AC. They can provide the grid inertia renewables lack. But are ONLY necessary with renewables; wind farms and solar operators need subsidies BEFORE the added costs of underutilized backup power and synchronous condensors. They are hopelessly uneconomic. In Climate Etc. essay “True cost of wind” we redid the grossly erroneous Obama era EIA estimate of onshore wind compared to coal and gas. The lifetime cost of energy (LCOE, an annuity calculation) of CCGT is about $56/MwH. The true cost of wind, using the Texas ERCOT grid for some of the specifics, is about $146/MwH. About 2.6x higher. Not a little bit higher, more than two and a half times higher. And that was without adding synchronous condensers.
Third, a nationally connected grid still does not solve three other separate renewable intermittency problems.
(1) First, the sun always sets, albeit about 3 hours later on the US west coast than on the east coast. There is still much mutual night on both coasts. So there is always insufficient solar offset for the evening hours (dinner cooking, AC, laundry) on a US national grid. Florida cannot save California.
(2) Second, energy demand is always seasonal. The sun sets early in winter when additional energy is needed for heating. No national grid can solve northern hemisphere seasonality.
(3) Third, wind is still highly variable by location. There is no mathematical assurance that on average it will ever be average across the US. The windiest places in the US (north Texas, western Iowa) still have capacity factors averaging about 32% of nameplate capacity. So 2/3 of the time, not enough wind even in the best locations. No different than the same meteorological problem covering much smaller Europe. But for French nuclear and Scandinavian variable hydro, German wind renewables would already be toast.
The Atlantic should have stuck to its previously justified fame, satirical political cartoons. Rather than now becoming several itself.
Addendum from Charles Rotter:
I believe this tweet thread below from David Reaboi sums up nicely what happened in this instance covered by the Atlantic.
Reaboi is talking about issues at DHS, not the EPA, but this pattern has been repeated for the last four years throughout Federal agencies. If anyone wants to do some FOIA leg work, we’d all love to see this brilliant plan to ease renewable energy issues.
(1) ANATOMY OF AN INFO OP. You’re a Democrat career civil servant somewhere, and you hate the president, who’s a Republican. You want to undermine him, and also advance your own political and ideological goals. How do you do it?
(2) You write a report that dovetails with your ideological thinking, but one that has no support from your bosses, the administration, or even reality. It doesn’t even have to be coherent or factually sound.
(3) When it’s laughed out of the room, you leak it to the media–as you’d always planned to do. The media runs the initial story like, “see, even Trump’s own DHS doesn’t think Antifa and far-left terrorism is a priority, or even a problem!”
(4) Then, once the DHS report is scrutinized inside government and subsequently rejected–guess what? Media has another story: “Truthful report censored by Trump!”
(5) When a legit report comes out–say, about Antifa and its documented anti-American activity and violence–the media casts it as “politicized.”
(6) The people who do this are loathsome. They know exactly what they’re doing, and that it’s an effort to undermine. The media knows it, too– they’ve got the whole story arc of these pieces already planned out before the first one runs.
via Watts Up With That?
September 10, 2020 at 08:42AM