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Why everyone should know that 'Baldies' can help save the planet

OPINION | 'Build-anywhere long-duration intermittent-energy storage' can silence renewables' baseload sceptics, argues Leigh Collins

They could save the planet, but hardly anyone knows they exist.

Governments still believe that wind and solar power are too intermittent to become the backbone of our energy system. “Oil and gas will be needed for decades to come,” they cry, like overgrown children scared to give up their security blankets.

Even climate campaigners discuss the need for expensive nuclear power, or that long-promised mirage that never seems to get any closer — carbon capture and storage (CCS).

What they do not seem to know is that we can store wind and solar power to make reliable 24-hour baseload energy. The technology already exists, and it will probably be a whole lot cheaper than carbon-emitting fossil fuels, nuclear or CCS.

And I’m not talking about utility-scale batteries. They don’t hold charges for long enough and cannot produce enough power, at least not at an affordable price. As Jereme Kent, CEO of US wind developer/installer One Energy, recently wrote in an article for Recharge: “I am tired of hearing about batteries being the future of the power grid... Only in the modern world of venture-capital hype could it be possible for this much error to perpetuate… The biggest battery in the world right now can’t power one of my customer’s factories for an afternoon, let alone help them flatten their load.”

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There doesn’t seem to be an agreed name for the group of emerging technologies I’m talking about, but for the purposes of this article, I will refer to them as “build-anywhere long-duration intermittent-energy storage” — just so I can use the amusing acronym, Baldies.

And the “build-anywhere” part of the name is key — the reason why they will be far more important than pumped hydro or compressed-air storage, which can only be built in certain locations as they require mountains and air-tight underground caverns, respectively.

Baldies are flexible, modular energy-storage systems that can be built anywhere and at any size required, and used for a variety of purposes, including 24-hour wind and solar, grid balancing and reducing the need for expensive grid upgrades.

The two main Baldies technologies are thermal energy storage and liquid-air storage, which as their names suggest, store electricity as heat — in volcanic rocks or molten salt — and as cryogenically frozen air.

UK-based Highview Power has already commercialised its liquid-air CRYObattery system, after a privately-funded 14-year research and development programme, having recently completed optimisation work at a commercial-scale power plant near Manchester, England.

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Siemens Gamesa Renewable Energy — which you may know as a wind-turbine manufacturer — has completed its hot-rock thermal-storage commercial pilot plant, and is expecting to offer the technology commercially in 2021; while Stiesdal A/S is due to begin operation of a 1MW/24MWh hot-rock commercial pilot next year, with a view to commercialising its hot-rock system within the next two years.

And then there is Google X spin-off Malta Inc, whose molten-salt energy-storage system is still at the design stage, yet is backed by a host of big-name billionaires, including the world’s richest two men, Jeff Bezos and Bill Gates.

All of this technology is based on well-known, well-established processes that largely utilise off-the-shelf equipment. The challenge for these companies is not to create new pieces of kit, but to integrate existing technology into new, innovative, cost-efficient and optimised systems. Like, say, combining Lego bricks in a way that no-one has ever done before.

So it’s not really a case of ‘can it be done?’, it’s more a case of ‘who can do it best and how much will it cost?’

As Malta technical lead Adrienne Little recently told me: “It's difficult to say at this point, given the level of development of all these different ideas, which one is going to be the best.”

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Now let’s talk about money. Nothing happens in this world unless someone is willing to pay for it.

To start with, wind and solar power are less expensive than other energy sources in a wide range of markets, and they will only get cheaper.

And Baldies are less expensive than you might think, despite not yet being established technologies.

The cost of Highview’s system — the so-called levelised cost of storage over the 30-year lifetime of a plant — is close to $100 per MWh today, with chief executive Javier Cavada telling me that this cost should fall to $50/MWh within ten years.

By comparison, a new pumped-hydro plant would have an LCOS of $152-198 per MWh, with a comparable lithium-ion battery system costing $285-581/MWh, according to analyst Lazard.

And with a new gas-peaker plant having a levelised cost of energy of $156-210/MWh, and wind power at $30-60/MWh (also according to Lazard), it may already cheaper to balance the grid using wind-powered liquid-air storage than fossil-fuel technology.

And Henrik Stiesdal, the Danish wind-power pioneer and bona fide genius who heads Stiesdal A/S, believes that his hot-rock thermal storage system could make offshore wind a 24/7 energy source for an additional cost of only €17 ($19) per MWh within five years.

"Baldies will not only enable round-the-clock wind and solar, but will almost certainly be cheaper than the alternatives."

So Baldies will not only be very clever solutions that will enable round-the-clock wind and solar, but they will almost certainly be cheaper than any of the alternatives — especially as the cost of wind and solar energy is falling all the time, and the price of fossil fuels are probably only going to go up, especially if and when an adequate carbon price is slapped on them.

But while Baldies are a much-needed part of the energy transition, and could help to enable a 100% clean energy system, they will not be able to do this alone.

For example, in the European winter, we simply could not produce enough wind and solar energy to provide the demand for energy from the heating, transport, power and industrial sectors. And let’s not forget, the world also needs to decarbonise these sectors too — either through electrification (and then the use of clean energy) or by CCS.

So, rather than having to fall back on fossil-fuel plants to get us through the cold European winter, we’d need a way to store wind and solar power during the hot summers, and send that stored power back to the grid in winter. The only realistic method to do this is green hydrogen — created by splitting water molecules into hydrogen and oxygen inside an electrolyser powered by renewable energy. This hydrogen — whether stored as compressed or liquid hydrogen, or inside ammonia or a so-called liquid organic hydrogen carrier — can be stored indefinitely and used to generate electricity (by burning it in a power plant or by using a fuel cell). Either generation method results in zero carbon emissions.

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Electrolysers exist, but they are currently expensive. Hydrogen made via electrolysis can be five times more expensive than so-called grey hydrogen, which is produced by cracking methane into hydrogen and carbon (which combines with oxygen in the air to create CO2).

The price difference between grey and green hydrogen will depend on many things, including local prices of natural gas, electricity and carbon, and in some parts of the world, the cost of green hydrogen is within touching distance of its identical grey twin. Plus, as demand for green hydrogen grows, economies of scale could result in the price of electrolysers falling at a similar speed to solar panels over the past decade.

And demand for green hydrogen will not just come from the power sector, it could also be used for heating in people’s homes — transported along existing gas networks (with new polyethylene pipes) — and for the high-temperature heat needed for many industrial processes.

Baldies and green hydrogen are also likely to be supported by a third energy-storage source — electric-vehicle (EV) batteries.

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Laszlo Varro, the highly intelligent chief economist of the International Energy Agency, told me two years ago that there will be so many EV batteries plugged into the grid in the years to come that “we will have roughly ten times as much battery capacity as what we would conceivably need, even in the very worst case scenario to integrate a very high share of wind and solar into the power system”.

A meteoric rise in the uptake of EVs seems inevitable, and certainly some kind of smart charging will be required to stop the grid crashing when scores of EV owners try to simultaneously charge their cars on the same distribution network. Whether this will be one-way staggered overnight charging or a so-called ‘vehicle to grid’ system where EVs will send energy back to the grid when required, is still up for debate.

But my point is that we will soon have all the technology we need to completely decarbonise our energy system — whether that involves electric heating, EVs, or industrial processes.

Every part of the energy system can be decarbonised — and our politicians, as well as climate campaigners, need to know this. We have to start planning for our future energy system now if we are to stand any chance of keeping climate change within manageable levels.

The coal- and gas-fired power plants that governments are commissioning now are not needed to keep the lights on.

And yes, we will need to massively increase the build-out of wind and solar projects, Baldies and electrolysers, and build up our grids and digitalise them, and maybe put solar panels on every roof and enable demand-side response in every home.

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And yes, this will cost money, but as Stiesdal recently told Recharge: “Who says that when we are saving the planet from the dramatic risks of climate change that it has to be, by default, at no cost? Why should it be, if we want to solve the biggest problem of humanity?”

Also, we can offset the costs through a revenue-neutral carbon tax like in Canada, where polluters are charged for how much carbon they emit and consumers get a rebate, paid for by the carbon tax, to compensate them for any additional costs resulting from the polluters’ increased costs.

Technology and cost are not preventing us from creating a clean energy system. The only things stopping us are a lack of knowledge about the technology available and a lack of political will.

It’s time to re-envisage our energy system. And we must start now.

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