Sunday, August 6, 2017

Digitalized Gas Plants and Battery Storage on the Grid: Integration, Collaboration, Competition, and Implications for Cost-Saving, Dealing with Demand Spikes, and Optimizing Gas Peakers



Digitalized Gas Plants and Battery Storage on the Grid: Integration, Collaboration, Competition, and Implications for Cost Saving, Dealing with Demand Spikes, and Optimizing Gas Peakers 

Green Tech Media just put out an interesting analysis of the integration of digitalized gas peaker plants and energy storage, typically lithium-ion based batteries, for dealing with peak demand at low cost. General Electric (GE) is leading the charge at digitalizing the gas plants so they can have faster response times and automated switching. Linked here:


GE recommends full digitalization of utility generation sources through their ‘asset performance management (APM) system’ and their Predix platform. From the article:

“Digitally assisted, flexible gas plants can handle both peak power and grid stability, calling into question the need for lithium-ion in those roles, said Niloy Sanyal, chief marketing officer for GE Power Digital, in an interview at the company's San Ramon campus.”

Advantages to this are that the often under-utilized gas peaker plants can be better utilized and optimized giving them better economics. Storage advocates claim building new gas peaker plants could become stranded assets. While lower storage costs do make an economic case against building new gas peaker plants, digitalizing existing ones makes even better economic sense.

The near-instantaneous response time gives batteries an advantage and the gas peakers take several minutes to fire up. However, with good predictive software it can be known in advance when they will be needed. Small storage can be added to existing peaker plants for near-instantaneous response times giving the plants the minutes needed to come on-line. Sanyal pointed out that storage by itself is better for certain applications like storing peak mid-day solar generation for evening use.

Small and often under-utilized gas peaker plants are utilized around the world as necessary back-up for intermittent and unpredictable solar and wind generation. Digitalizing them and equipping them with small battery storage allows them to have the response-time of utility-scale battery storage and improves their economics by increasing their utilization and capacity factors. The batteries serve as a ‘ramping resource,’ allowing the gas peaker plant to be responsive to short-time (5-15 min) power demands. Overall, this makes grid integration of renewables cheaper for utilities by providing flexibility. One might see it as a symbiosis of sorts. AES Energy Storage notes that 1 MW of battery storage provides 2 MW of flexibility. However, with digital hybrid gas plants a smaller amount of storage can provide even more flexibility.

Also mentioned in the article is another factor – incentives. Renewable standards and goals as well as energy efficiency standards incentivize batteries and other storage for utilities. This gives storage by itself an advantage in some areas. Utilities will need to compare their incentivized savings from adding storage to the savings from more optimized digital gas plants. This will likely be the competitive aspect.

GE and SoCal Edison just turned on this spring two of these hybrid electric gas turbine plants in California. They are small at 50 MW. The batteries can provide up to 10 MW and 4 MWh of power. They set these up in a hurry to help deal with the Aliso Canyon gas storage field being off-line. What is fascinating is that these fully digital/automated hybrid plants are complementary – the limitation of batteries is that they can only run for a short time before needing to be recharged while the limitations of the gas plants are that they need a little time to start up (even though they are considered ‘quick-start’ compared to older gas plants or even slower to start coal plants). The digitally controlled hybridization with coordinated control systems overcomes both limitations for seamless operation. SCE also noted that digital controls and associated equipment can drastically reduce water consumption and fuel consumption thus reducing pollution and greenhouse gas emissions as well. This is cutting edge technology at the grid edge!

References:

GE Digital Gas Plants vs. Utility-Scale Batteries – by Julian Spector, in Green Tech Media, Aug. 3, 2017

The Emerging Boom in Utility-Wide Asset Analytics – by Jeff St. John, in Green Tech Media, Feb. 21, 2014

Inside GE and SoCal Edison’s First-of-a-Kind Hybrid Peaker Plant with Batteries and Gas Turbines – by Jeff St. John, in Green Tech Media, April 18, 2017



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