Hawaii shuts down its last coal-fired power plant in bid to fight climate change | Hacker News Reader

Hawaii shuts down its last coal-fired power plant in bid to fight climate change

cnbc.com

34 pointsgbenga4real17 comments

Hawaii is in an excellent position to try out the full range of storage technologies and discover which work best for them.

They have underground cavities that used to be full of lava, for compressed air, hydrogen storage, or pumped hydro. They have mountains pumped-hydro reservoirs would be easy to build on. They have deep ocean trenches just offshore for undersea compressed air and buoyancy.

Choices for renewable generation include not just solar and wind, but also undersea currents and wave air pumping.

Volcanic cavities and mountains are not necessarily stable enough and impervious enough to be relied on as reservoirs.

Undersea CAES may be worth trying, but I don't know why it hasn't yet been tried.

Seabed-mounted buoyancy seems to me most promising, but I doubt anybody is working on it.

What is "Seabed-mounted buoyancy"?

Screw a pulley down to the seabed. Run a cable from a float through the pulley to a reel on a winch driven by a motor-generator. (Could be on shore, in a boat anchored out there, or bolted to a wind-turbine post.)

Crank the float down toward the seabed when you have power to spare. Let the float reel back out when you need that power back.

For extra credit, attach a whole series of reels to one winch, with clutches, so one winch can crank down as many floats as you have reels, one or two at a time. (Floats, pulleys, and reels are cheap, motor-generators expensive, so it pays to share.) Maybe, instead of a winch and clutches, the reels are driven with hydraulics.

Size the floats so the winch is a catalog item, say <1000-ton capacity. Use as many motor-generators on winches as you need for the MW you must generate. Use as many pulleys/floats as you need for the MWh you need to store.

The deeper the pulleys are, the more MWh each float can store. Keep adding floats until you have enough.

They should be doubling down on solar farms and off shore wind -- they have plenty of both.

Zero interest loans to install solar on every residence and business possible as well.

https://www.hawaiianelectric.com/clean-energy-hawaii/our-cle...

With all those volcanoes, why not geothermal?

They're just switching from coal to oil, and the oil will be a lot more expensive and the sourcing less reliable.

They say they'll eventually get enough intermittent online, but that is many years away.

This is a poorly thought out, haphazardly executed plan.

> They say they'll eventually get enough intermittent online, but that is many years away.

> This is a poorly thought out, haphazardly executed plan.

The facts don’t support these assertions. The higher oil consumption is temporary until delayed utility scale solar and geothermal projects come online [1] (supply chain issues). A recent battery project with Tesla Megapacks [2] replaced AES’ coal plant for grid services.

The price of oil pushes renewables adoption velocity in this situation, as clean energy options are cheaper than burning oil for electricity. Before this closure, Oahu had roughly equal coal vs solar generation capacity (~200MW). It’s obviously cheaper to replace that coal generation with batteries that can charge from renewables.

> “It is really unfortunate that we are having to rely on oil for a short period of time to transition from coal to the solar and battery projects,” Glenn said. “[But] it underscores the whole reason we need to make this change. Because oil is incredibly volatile. And we have to pay for it in a way that you don’t have to with solar battery.”

> He said the state is expected to close some of its oil power plants in the coming years, including part of the Waiau power plant on Oahu.

> Sandra Larsen, market business leader for AES in Hawaii, said the company supports the shuttering of its coal power plant and is now working on six renewable energy projects across the state’s four island counties. One of its projects, Kuihelani, is expected to generate power for about 27,000 homes on Maui.

> “The coal plant was needed to help stabilize Oahu’s electricity rates and the economy … 30 years later, it’s time to move on,” she said.

[1] https://www.theguardian.com/us-news/2022/aug/31/hawaii-close...

[2] https://www.kapoleienergystorage.com/

> The higher oil consumption is temporary until delayed utility scale solar and geothermal projects come online

Then why not keep the plant online until solar is running. Increasing energy costs will affect the poorest and most vulnerable. There’s no pressing need to shut down the plant sooner than its replacement is ready.

Because coal plant retirements (and the coal deliveries those plants require) are planned quite a bit in advance. Average electric bill will go up $15/month (~4%) in the interim (not trivial, but also not catastrophic). It’s a political issue to subsidize that unexpected short term cost, not a technical issue to keep an aging plant running.

Energy transitions aren’t easy. There will be missteps.

(I would agree the local and or state government should provide support for low income electric users impacted by this until rates come back down from more renewables online pushing out oil generation; cut the utility a check and define the means testing)

To me it’s a clear case of bad policy. Good goals don’t magically make for good policy.

> Average electric bill will go up $15/month

What does bad policy look like in your opinion, if not this? It’s an avoidable fuck-up.

If a 4% increase seems like bad policy to you in a high inflation (~9%) macro environment, your expectations are likely unrealistic. There would’ve been a cost to keep the coal plant running, including buying coal on the spot market at highly elevated (compared to long term contracts) prices (~300-400%).

https://markets.businessinsider.com/commodities/coal-price

https://www.wvpublic.org/energy-environment/2022-07-12/coal-...

It’s an avoidable 4% increase. That’s why I think it’s poor execution.

If my city increased by utility price by 4% because they messed up the sequencing on a contract it would be a sign of poor planning.

Sure, but the cost of really good planning that never messes up sequencing is likely to add a lot more than 4% to your utility bill.

How much more are you really willing to pay for completely flawless sequencing?

Part of the issues were due to an unforeseen pandemic that messed up the supply chains and increased prices drastically. However keeping the plant running may not have been feasible. There's some coal plants on Maui were parts suppliers shutdown or simply don't produce spares anymore. The energy producer there is faced at trying to get custom fabricated parts and hoping they work or building a whole new plant to provide interim power. A lot of these projects were planned years in advance and major disruptions (like a global pandemic) can wreak havoc on plans.

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