Thursday, February 29, 2024

Reader is Skeptical of Pumped Storage

Dear Editor,

I am still skeptical of TC Energy’s (TCE) claims about a new inlet and outlet port design for the proposed Ontario Pumped Storage (OPS) project. John Mikkelsen stated, “We have and will continue to undertake studies to test the proposed design, including computer modelling and sediment mapping”. This seems to indicate that there is no existing experience data or previous studies for this “new design”.

In the first decade of operation, the Ludington, Michigan PSP killed approximately 150 million fish every year, when drawn through the turbines. An environmental lawsuit settlement mandated use of a four-kilometre net to protect fish. Jim Roush, director of environmental compliance at Consumers Energy (the Ludington PSP operator), told The Narwhal, “The net is 91 per cent effective in saving fish greater than five inches”.

This still allows 9% of the larger fish to enter the turbines and what about the millions of fish 5 inches and under? These fish are the juvenile future generation of the larger fish and also several mature species of bait fish. Both groups provide food for the larger fish. How would TCE’s “new design” compare to the Ludington PSP upgrade and other pumped storage plants currently in operation? I certainly hope it would perform far better.

Battery storage projects also create many job opportunities for Ontarians and use locally sourced materials, just as the OPS would. Many supposed “local” suppliers of hydro-electric project equipment are divisions of global corporations that manufacture elsewhere. The OPS could be using these suppliers as well.

It is true that pumped storage projects currently account for about 95% of the worldwide energy storage but this dominance could be eclipsed in the future. China is investing in several pumped storage projects. However, China is also investing in other energy storage technologies, such as lithium-ion battery energy storage systems (BESSs), a first-ever sodium-ion grid-scale BESS, gravity storage and compressed air storage.

Battery storage will be part of the $7 trillion investment opportunity in power generation, batteries, and grids by 2040 in China, by Goldman Sachs (GS) estimates. “GS Research predicts China will require about 520 gigawatts of storage, more than three-fourths of which will come from batteries – 70 times higher than 2021. The remainder of the storage increases will come from pumped hydropower facilities,” Goldman’s analysts wrote.

Most of the U.S. pumped storage hydro capacity was built between 1960 and 1990, and no new projects have come online since 2012, according to the U.S. Energy Information Administration (EIA). In the U.S., significant barriers hamper pumped storage development. Some are environmental impacts, geographical dependence, market conditions, large capital investment required over long time periods and long licensing timelines. Like any large hydro-electric infrastructure, pumped storage plants require periodic inspections, major refurbishments, equipment replacements and upgrades over time.

Currently, lithium-ion battery energy storage projects do have a maximum battery lifespan of about 20 years; however, newer battery technologies will have longer lifespans, and be more efficient, less costly and safer.

Superior efficiency and short-term construction times are battery storage advantages. A Tesla Megapak battery unit has a 93.7% round-trip efficiency compared to TCE’s 72% round-trip efficiency claim for the Ontario PS project. The TCE claim doesn’t include long 2-way transmission line losses that a battery energy storage plant wouldn’t have, if located close to the grid. These transmission losses could lower the Ontario PS efficiency down to 65% or less.

Using TCE’s efficiency claim, the OPS would require an input of 11,111.11 MWh at 72% efficiency to supply the 8,000 MWh of energy stored in the OPS reservoir. A Megapak battery plant would require 8,537.89 MWh of input at 93.7%. The efficiency difference is 2,573.22 MWh (2,573,220 kWh). This 2,573.22 MWh of energy would be lost to the OPS pumps/generators, etc. At the average Ontario household electrical consumption of 26 kWh per day, the wasted energy could power 98,970 houses for 24 hours (2,573,220 kWh/26 kWh) and 296,910 houses during an 8-hour output cycle. At the average rate of $0.141 per kWh, the retail revenue loss would be $362,824 per day and $132.43M per year.

Megapaks are infinitely scalable. For the same 8,000 MWh capacity as the OPS, 2,043 Megapak units would be required for a capacity of 8,000 MWh and 1,000 MW of power. A 2023 Megapak volume cost of $3,956B Cdn (plus supporting infrastructure cost), is still less than the 2019 $4.3B cost projection of the OPS, which is outdated and unrealistic. The actual OPS cost could easily be twice that projection or more by the anticipated 2030+ in-service date.

Megapacks are pre-assembled, including battery modules, bi-directional inverters, a thermal management system, AC main breaker and controls. Each Megapack requires minimal maintenance over its lifespan. At the end of its useful life, it can be returned for recycling.

If an 8-hour output cycle is required, a Megapak 4-hour battery plant could be split into two banks that would deliver 1,000 MW and 4,000 MWh each. These two battery bank output cycles could be staggered to produce the same 8-hour output cycle as the OPS.

In many areas of the U.S., only a 4-hour output cycle is utilized due to demand, climate, electricity markets, etc. Government energy credits are issued to clean energy projects for 4-hour cycles or less. Any output cycle under 4 hours is prorated and a 4-hour cycle receives full credits. Any output cycle above 4 hours does not receive additional credits, so there isn’t an economic incentive for it.

Why is this archaic, expensive, centralized and potentially environment damaging open-loop Ontario Pumped Storage proposal still progressing when the IESO recommendation to the Minister of Energy was that it was of insufficient value to the ratepayers of Ontario?

Why is the Ontario PS proposal being sole-sourced by TC Energy, and not submitted to the IESO Long-Term Request for Proposal (LT RFP) to compete with other energy storage companies and technologies in the submission approval process?

Something smells!


Mike McTaggart, Meaford

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