Gas controls a lot of our thinking. The word seems to be absent from our conscience and consciousness. Speakers claiming to protect the greenhouse argue that if the world stops burning coal, global warming would stop. What they are omitting is the phrase, AND GAS.
Also omitting "AND OIL", but even so they're wrong. Climate warming will continue for way, way too long even if we stop emitting fossil carbon today. The heat currently disappearing into the oceans cools the globe, and until they come to equilibrium heating will continue. Then there are the effects from things like methane from thawing permafrost.
Anyone ready to consider geoengineering yet? I suspect we're going to need some megatons of SO2 in the high stratosphere shortly to prevent the phenomena of 2020 Australia being repeated world-wide.
CSIRO states their opinion that SMRs will be more expensive ...
Well, it isn't CSIRO engineers saying that. The GenCost 2019-20 report (currently a draft report) does not consist of peer-reviewed work by CSIRO scientists, much as the article in the renewables trade journal, RenewEconomy would have us believe, but by a group of renewables enthusiasts largely in AEMO and elsewhere. Years ago, an anti-school government required that CSIRO publish work partnered with industry. Consequently there are "CSIRO reports" on nonsense like carbon sequestration etc. On the flyleaf, as publisher, CSIRO inserts "Important disclaimer... CSIRO ... excludes all liability ... arising directly or indirectly from using this publication (in part or in whole) and any information or material contained in it." Reader beware!
The GenCost report compares the costing for instantaneous renewable electricity without including the cost of firming the ragged supply for 24-hour use as electricity on demand. (Are we going for 100% non-fossil power, or not?) Costings for coal with carbon sequestration are included, despite it being purely hypothetical. The costing for SMRs is somehow set at 16 $/W, contradicting NuScale and MPower estimates of 5 $/W. They don't discuss the revolutionary drop in cost expected of the transition between FOAK and NOAK of SMRs, although they concede that their estimate of 16 $/W may decrease, but never to less than twice the cost of renewables. No mention is made of the much lower (than 16 $/W) cost for established large nuclear.
Post by engineerpoet on Mar 21, 2020 10:28:35 GMT 9.5
Organic Rankine cycles are generally aimed for low-temperature applications and have similarly low thermal efficiencies. I found nothing in the article or at the RayGen site which goes into anything close to scientific detail, so I have to consider this a half-baked scheme. Yes, it can generate some power after dark. I saw nothing to support the claim of 4 MW/50 MWh.
Post by engineerpoet on Apr 12, 2020 1:37:17 GMT 9.5
1 megawatt at 2% of final capacity. This comes to 50 megawatts when complete. This compares to the ~450 MW drop in wind-farm output which was the penultimate event in the S.A. blackout.
A Powerwall is rated at 13.5 kWh of capacity. This is enough to make a good PHEV, maybe 2 if they're small. In V2G use, PHEV batteries would make a perfectly fine VPP and decarbonize transport. Tesla's stunt is just that, a stunt.
"Tesla Virtual Power Plant In Australia Outperforms Expectations" ... This is a sizable battery.
The article reports that the "Virtual power plant" was able to supply 828 kW for several minutes, about 0.1 MWh. That is big for a distributed battery and might be useful as replacement for some of the spinning reserve on the system, but it does not rank as a power station. The use of the term VPP is a clear innuendo that it does rank.
A solar farm might boast of having a battery to continue supply for a few minutes when the sun goes behind a cloud. A coal-fired power station keeps a stockpile of weeks of coal in case of disruption of supply. By way of example, an Indian stockpile of 450 tonnes (of 20 GJ per tonne coal burned at 40% efficiency) represents 1000 MWh. That ten-thousand fold difference is the ballpark for storage that renewables fail to achieve.
PS – That reference to 450 tonnes did not quote the size of what must be a tiny power station so its endurance is unclear. I have an old memory of three months being set for a reserve supply of coal, but it seems to predate the Internet. I did find a modern reference with a graph that indicates that US stockpiles vary between 50 and 100 days of burn. Matching that level of energy storage (again, a ballpark of 10,000 fold shortfall) for renewables seems to be an impossible pipedream.
An Indian stockpile of 450 tonnes (of 20 GJ per tonne coal burned at 40% efficiency) represents 1000 MWh. That ten-thousand fold difference is the ballpark for storage that renewables fail to achieve.
Indeed. Batteries provide minutes to hours, when we need weeks and months.
One of the things I'm looking into is the possibility of refuse-derived fuel (char, actually) as a "renewable" solid fuel which can be stockpiled. My initial numbers suggest that it would be small compared to current use of coal, but significant. However, I'm given to understand that biochar is chemically reactive and tends to auto-ignite in large masses. It doesn't help much if you can't store it cheaply, and it's hard to get cheaper than piles on the ground outdoors.