"The October 2021 week featured the highest rate of change in CCGT generation of nearly 120 MW/minute. Meanwhile, the total CCGT output rose from ~5,000 MW to ~17,000 MW, that is about 12,000 MW in a little under 2 hours."
October - so the weather would probably have been coolish but not excessively cold for that morning's ramp-up.
But that is to meet only *existing* electricity demand!
To achieve that 'NetZero', some expect to switch many millions of gas boilers *serving un- time-shiftable* space-heating demand over to heat pumps.
An indication of the magnitude of short term natural gas vs electricity demands and ramp rates is given by UKERC in "Challenges for the decarbonisation of heat: local gas demand vs electricity supply Winter 2017/2018"
Another great detailed post that takes two reads. One to skim, and one to read slowly to assimilate the details.
The first is done, hence this response before I forget:
"My analysis in this post quantifies the variability of current gas generation. Whatever replaces gas has to be able to ramp by at least +/- 12,000 MW in 2 hours, and by
+/- 120 MW/minute. Current nuclear technology cannot do this. Neither can electrolysers cope with these power flows or levels of intermittency, so there can be no ‘green hydrogen’ to feed instead to the gas turbines."
That latter point might be a blessing in disguise ;-)
Apparently, a literature search "Injecting hydrogen into the gas network –
Prepared by the Health and Safety Laboratory for the Health and Safety Executive 2015" exposes 'concerns':
<blockquote>"3.7.1.9 Gas turbines
A combustion system particularly sensitive to variations in gas composition is the lean premixed gas turbine. Gas is mixed with high pressure and temperature air and the resultant expanding flames impinge on the turbine blades. Unwanted spontaneous ignition before reaching the burner and flashback of the flame into the burner can both have potentially disastrous effects on the integrity of the machine. At the other extreme, flame blowout is equally unwanted, and even partial flame lift can result in undesirable acoustic instability. A particular concern regarding ignition is the presence of hydrogen; since this gas ignites easily, there is concern that even small quantities of hydrogen in natural gas would be catastrophic for turbine behaviour. To illustrate this apprehension one major turbine manufacturer allows only traces of hydrogen in the fuel gas, while another manufacturer allows only 8.5% of hydrogen (64)."</blockquote>
Comment #2 - Ramp Rates
"The October 2021 week featured the highest rate of change in CCGT generation of nearly 120 MW/minute. Meanwhile, the total CCGT output rose from ~5,000 MW to ~17,000 MW, that is about 12,000 MW in a little under 2 hours."
October - so the weather would probably have been coolish but not excessively cold for that morning's ramp-up.
But that is to meet only *existing* electricity demand!
To achieve that 'NetZero', some expect to switch many millions of gas boilers *serving un- time-shiftable* space-heating demand over to heat pumps.
An indication of the magnitude of short term natural gas vs electricity demands and ramp rates is given by UKERC in "Challenges for the decarbonisation of heat: local gas demand vs electricity supply Winter 2017/2018"
Table 1 shows Peak Hour & Peak Day, and, 1-hour & 3-hour Ramp Rate ratios
Gas vs electrical ramp rate ratios were 7.6 and 7.3 respectively!
Their Figure 3 shows gas vs electricity 3-hour difference in demand over a year
https://d2e1qxpsswcpgz.cloudfront.net/uploads/2020/03/ukerc_bn_decarbonisation_heat_local_gas_demand_vs_electical_supply_web.pdf
Feeding heat pumps will triple / quadruple / quintuple existing peak Hour & Peak Day, and, 1-hour & 3-hour Ramp Rates.
(Assuming also, that those millions of EVs will be ramp-rate neutral)
Hi Chris
Another great detailed post that takes two reads. One to skim, and one to read slowly to assimilate the details.
The first is done, hence this response before I forget:
"My analysis in this post quantifies the variability of current gas generation. Whatever replaces gas has to be able to ramp by at least +/- 12,000 MW in 2 hours, and by
+/- 120 MW/minute. Current nuclear technology cannot do this. Neither can electrolysers cope with these power flows or levels of intermittency, so there can be no ‘green hydrogen’ to feed instead to the gas turbines."
That latter point might be a blessing in disguise ;-)
Apparently, a literature search "Injecting hydrogen into the gas network –
Prepared by the Health and Safety Laboratory for the Health and Safety Executive 2015" exposes 'concerns':
<blockquote>"3.7.1.9 Gas turbines
A combustion system particularly sensitive to variations in gas composition is the lean premixed gas turbine. Gas is mixed with high pressure and temperature air and the resultant expanding flames impinge on the turbine blades. Unwanted spontaneous ignition before reaching the burner and flashback of the flame into the burner can both have potentially disastrous effects on the integrity of the machine. At the other extreme, flame blowout is equally unwanted, and even partial flame lift can result in undesirable acoustic instability. A particular concern regarding ignition is the presence of hydrogen; since this gas ignites easily, there is concern that even small quantities of hydrogen in natural gas would be catastrophic for turbine behaviour. To illustrate this apprehension one major turbine manufacturer allows only traces of hydrogen in the fuel gas, while another manufacturer allows only 8.5% of hydrogen (64)."</blockquote>
Page 32, here:
https://www.hse.gov.uk/research/rrpdf/rr1047.pdf