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.”

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.

As Recharge explains over the next ten pages, in interviews with top executives at the four leading players, 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 having recently completed optimisation work at a commercial-scale power plant near Manchester, England.

Siemens Gamesa Renewable Energy 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, 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?’

And Baldies are less expensive than you might think, despite not yet being established technologies. As our article about Highview Power setsa out, the levelised cost of energy for a CRYObattery plant powered by wind turbines may already be cheaper than new gas peakers and pumped hydro plants.

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.

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.

Green hydrogen can solve many of these issues, while electric-vehicle batteries and demand response will also be able to help deal with the intermittency of wind and solar.

In short, we will soon have all the technology we need to completely decarbonise our energy system — including heating, transport and industrial processes — and our politicians, as well as climate campaigners, need to know this.

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. Any extra costs associated with this build-out can be offset through a revenue-neutral carbon tax like in Canada, where polluters are charged for how much carbon they emit and consumers get a rebate 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.