Newfie wrote:Came across this about wind turbines and hurricane. Seems like they don’t do so good force 3 or above.
I always wonder who pays for the fixes and who pays to have them removed at their end of life. Which is what? 30 years?
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3295275/
Newfie wrote:Vt
There are economic reasons for density. It keeps the land connection costs down. Spread them out and they become much more expensive with many more connecting links drive maintenance up and reliability down
Then it also impacts a much larger area.
O free lunch as usual.
It seems to me that storage addresses the issue of voltage and frequency support even better than the issues of intermittency and dispatchability. The pay is better and storage responds faster than traditional sources. The grid is already starting to feel the loss of primary frequency regulation from all those large rotating machines going offline. Thus the growing interest in the secondary frequency regulation market.NWMossBack wrote:Rock - Storage addresses the issue of intermittency and dispatchability but not necessarily the other two power quality issues of voltage and frequency support. Of course that's just an engineering problem, but right now the grid is designed to have a stable base load of rotating machines with very high inertia. Stable frequency and voltage are inherent in the design of the things, and the technology is very mature (over 100 years). The battery power from storage schemes would be fed into the grid via massive solid state inverters, which could in theory be designed to supply voltage and frequency support, but this is uncharted territory at that scale. Also the generally accepted EROEI numbers for wind (around 5) and solar PV (around 3) do not include the enormously complex task of DC storage, conversion to AC, and redesigning much of the grid to support that change. Ever since the 2003 east coast blackout a major effort has been under way to improve grid reliability for a grid based on large rotating machines - solid state devices throws a major curve ball into that effort.
Energy storage good option for frequency responseEnergy storage is a good option for frequency response, a storage trade group will tell the Federal Energy Regulatory Commission this month. Markets would be less efficient and "system costs greater than necessary if resource owners are mandated to provide frequency response service from generators more suited to provide energy and capacity.” Requiring generators to provide frequency response could produce an oversupply of frequency response headroom, imposing additional system costs. The group noted that many generators are not well suited to provide frequency response because doing so can lower operational efficiency, which will eventually result in higher system costs. Additionally, requiring all generators to provide frequency response would fail to create a market signal.
On the other hand, energy storage, particularly batteries, are well suited to provide frequency response, ESA said. They are fast responding and do not lose efficiency by needing to reserve headroom. In its comments, ESA cited studies by the Electric Reliability Council of Texas that found 1 MW of fast responding resources could be substituted for 2 MW of primary frequency response resources during some system conditions.
Primary frequency response should not be confused with frequency response, which could also be called secondary frequency response. Primary frequency response is an automatic, nearly instantaneous response by generators to deviations in frequency. Frequency regulation is a second line of defense in balancing the grid — at least in organized wholesale power markets, it is provided as a paid service.
Not designed to address storage
For purposes of primary frequency response, frequency deviations are measured by metrics such as “droop” and “deadband.” If a generator trips offline or a large load leaves the grid, frequency can drop enough to create instability and even cascading blackouts. Generators and motors with large, heavy rotors add inertia to the grid and can help dampen the effect of dips in frequency, and many generators have mechanical or electrical governors that can help return frequency to balance. But the spread of variable speed motors, the retirement of baseload, synchronous generating stations, and the proliferation of non-synchronous electrically connected variable energy resources such as wind and solar power has resulted in a “significant decline in frequency response in the Eastern and Western Interconnections,” FERC’s NOPR states.
Fast-Responding Energy Storage Digs Into Frequency Regulation MarketShort Acting Storage
With more intermittent generation, fast-responding energy storage is becoming essential to maintaining grid reliability. PJM Interconnection was the first system operator in the U.S. to take advantage of FERC Order 755, which recognizes the value provided by resources that deliver fast-responding and accurate frequency regulation service. PJM offered higher payments for fast-responding assets, such as batteries, flywheels and other quick-acting load control systems, compared to the fossil power plants that have traditionally performed the ramping up and ramping down to help stabilize frequency across the grid.
There's now about 110 MW of fast-responding assets online in the PJM frequency regulation market, with another 100 MW or so in the pipeline.
Batteries and flywheels can ramp to full power virtually instantaneously, so they respond faster to grid operator signals than coal or gas peaker plants, but they cannot last as long. Their fast response means batteries actually provide some real competition – but only to peaker plants.
Wind farms providing secondary frequency regulationSecondary frequency regulation, where participating generators track a power signal sent by the ISO over tens of minutes, is an area of growing interest. Recent work has shown that wind turbines can effectively provide secondary frequency regulation by reducing their operating power production setpoint to allow turbines to increase production levels while following the regulation signal.
These results provide important insights into the possible strengths and limitations of the proposed approach to wind farm control for frequency regulation. First, these results suggest that wind farms may be better suited to act as a quickly responding resource for grid regulation services. The consistently passing composite performance score for the RegD signals indicates that these controlled wind farms are able to provide this service reliably. Further work, however, is needed to improve the performance of the method in providing slower regulation services. The lower RegA scores are partially explained by the controlled wind farm’s inability to provide prolonged periods of up-regulation.
First Solar Proves That PV Plants Can Rival Frequency Response Services From Natural Gas PeakersLast summer, First Solar and California grid operator CAISO ran a set of tests to show that utility-scale solar PV, instead of being a disruptive influence on the power grid, could actually help stabilize it. Over a series of days in August, First Solar slightly curtailed power output at a 300-megawatt solar farm in California, enabled its array of inverters, and plugged into CAISO’s system. It then orchestrated the plant’s output to follow CAISO’s automatic generation control (AGC) signals, respond to its frequency regulation commands, and use inverters for voltage regulation, power factor regulation and reactive power control.
The results, according to a report released last week, showed that First Solar was able to meet, and sometimes exceed, the frequency regulation response usually provided by natural-gas-fired peaker plants. First Solar was also able to provide inverter-based services throughout the day -- and possibly even at night.
It turned in a respectable performance matching CAISO’s wholesale market price signals -- even when clouds appeared on the afternoon of the second day of testing, reducing First Solar’s capacity to shift its load.
All told, the data from CAISO, First Solar and the Department of Energy’s National Renewable Energy Laboratory (NREL) indicates that a utility-scale solar farm, equipped with standard inverters and software controls, can serve to smooth out grid fluctuations from the solar itself or from other sources.
NWMossBack wrote:Newfie - I don't know how the end of life work fits in to EROEI, but I would guess the scrap value is a positive number. There are rare earth elements as well as copper, electronics, aluminum, etc.
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