A clean source of heat has the potential to extend the lifetimes of the thermal plants that deliver stability in the grid.
A quick look at the National Electricity Market will tell you Australia is deeply commited to coal. Over the past 12 months about 65% of supply of electricity relied on the combustion of black and brown coal. Those plants will not be switched off tomorrow, but the outlook for them is bleak … unless, of course, they could be reengineered to run on a clean fuel.
It sounds like a fantasy, all those reliable turbines being reborn in a deep shade of green. In a world where variable sources of generation – wind and solar – are being touted as ideal power sources to manufacture hydrogen as well as supply the grid, could renewables indirectly fuel the generators in coal plants?
Sydney-based company Star Scientific says yes, if that hydrogen is combined with oxygen using its Hero technology.
Hero is the company’s name for a thin catalyst coating which, when exposed to hydrogen and oxygen, creates a condition where the atoms are joined.
It’s a purely chemical interaction, but when water is made from hydrogen and oxygen a large amount of excitation energy – the speeding up of atoms – results. “Per kilo, it’s five times more energy than coal,” says Star Scientific global group chairman Andrew Horvath.
When the coating is applied to a substrate material, be it a metal, ceramic or Inconel [a family of superalloys], all of that heat is transmitted to the substrate and then directly to whatever it is you want to heat. “In the case of a power station,” says Horvath, “it would be water to make steam.”
The Hero technology is what’s known as a “true catalyst”, or a home for a process to happen. It doesn’t get used in the process. A demonstration unit in the company’s facility at Berkeley Vale, NSW, has clocked up thousands of hours’ run time, Horvath says, with no wobbles. About 20 other units are being tested, all set to slightly different temperatures. The largest one is producing supercritical steam on a daily basis, suitable for running a turbine.
“With Hero, we can move 90% of the energy out of the hydrogen into whatever you want to heat,” Horvath says.
The world relies on thermal generation plants with working lives ahead of them measured in decades. The only problem is that they rely on fuel which produces pollution when burned. “There is nothing wrong with them, you just need to replace the CO2-emitting part.”
Horvath looks at this existing energy infrastructure as an enormous opportunity to apply the Hero solution as a primary heat source. Plants fuelled by Hero need only be half the size they are today, once the coal front-end and pollution back-end are removed. “It saves an enormous amount of money a year; it turns the plant green and they’ve got their business model back.”
Beyond those benefits, of course, the well-known strengths of thermal generation are allowed to work their wonders guilt-free, with spinning mass bringing automatic stabilisation.
Every electron is valuable
It sounds ideal, but where will the hydrogen come from? “Our line has always been that the solar guys and the wind guys should be making hydrogen, because then no-one will tell them when they can and when they can’t [generate] – every electron is valuable in that game.” Hydrogen is the best storage mechanism, Horvath says, outperforming batteries 100 to one. “It is so much better than batteries.”
Around Australia and the world some industries are finding that hydrogen manufactured and utilised on-site offers the best value solution. Horvath is looking further ahead, where hydrogen is distributed from multiple points of manufacture to wherever it is needed, whether that means through pipelines or in liquid form. He says the alternative option of combining hydrogen with nitrogen to make ammonia is a complicated process that won’t be economic in a world overflowing with hydrogen.
The phone is running hot, he says, with requests from power utilities in the United States to individual companies looking for clean heat processes. In the beginning of this year Star Scientific announced a deal on the sovereign scale, signing a memorandum of understanding with the Philippines to convert more than 10 coal plants to clean fuel. Solar and wind have struggled in the South-East Asian archipelago nation and the idea is to develop offshore wind to power electrolyzers at thermal plants where Hero’s solution is installed to replace coal and oil.
The transitioning of dirty generation to clean is part of a strategy to prepare the county for a step up the value ladder. “They have 108 million people, and half of them are between 15 and 21,” Horvath says. “There’s a big population about to get a job and they’ll all want to move to Manila at once.” The government wants to sidestep this bottleneck by building new cities and becoming a green manufacturer to attract business from regional competitors.
It’s part of a global trend, he says. “We’ve got very big connections with a lot of the big youth groups around the world and the theme that’s about to swamp us is they are about to make a big call to say we’re not buying something unless it’s zero emissions, recyclable and slave-free.” A clean grid will put the Philippines on course to become the next South Korea, perhaps. “And they’re not the only country we’re talking to.”
From here to 800°C
The Hero process takes about three minutes to reach 800°C, but it can be specced to lower temperatures. At the 8,500-square-metre laboratory in Berkeley Vale engineers are working on designs for modules between 30-50MW that can be linked to suit tasks up to hundreds of megawatts in scale. “It can be scaled to whatever you need; it doesn’t make any difference.” All engineering is completed in-house.
Star Scientific is also about to start work on an alkaline electrolyzer. “It’s a very unique, very clever system out of Chile, and we’ve bought into that,” Horvath says. The water produced by the Hero process can be run back through an electrolyzer, with about a 20% loss. “It really doesn’t use as much water as people think it does to make hydrogen.”
As renewables connect to the grid dispatchable generation and storage will become vitally important. The grid cannot operate without them. But thermal generation assets are not attractive in the eyes of the renewables crowd. The attitude seems to prevail that the sooner they are retired and their smokestacks dynamited, the better.
Energy security isn’t a topic where ideology should go unchallenged, and coal plants that have been converted to a clean fuel can make a mighty fine contribution.
“Solar and wind are unreliable,” says Horvath, only stating the facts. “You’re never going to get the same energy at any point from the sun. What you have to do is grab that energy and store it. Spinning mass, however, form the electricity systems and the way everything is designed to work. Every resistor, every capacitor, is designed to work at stable frequency. Having frequency-stable power is the key.”
As large generators are inevitably switched off, perhaps after their lifetimes have been lengthened thanks to Hero technology, Horvath says the grid might evolve to rely on distributed supercritical CO2 generators that will be able to solve localised problems with predictable supply. “Thermal heat is going to be the key to all those, but it’s way more efficient – up around the 60% mark. It’s a closed loop system and the only fuel going in is hydrogen.”
Closer to home
If the objective is to deliver a reliable grid, there’s no point taking a reactionary stance against turbines. Owners of wind and solar plants shouldn’t be worried if it sounds as though thermal assets have a reason to dig their heels in. They will make just as much money if their purpose is adapted to manufacturing hydrogen instead of a sole focus of supplying the grid, Horvath says.
“Mr X makes hydrogen from his solar farm and sells that green hydrogen in under his blockchain into a bank somewhere. It means you can sell that hydrogen somewhere else out of another bank. It can be used as a commodity, it can be pumped around; it moves way quicker than natural gas in a pipe. We know how to pipe it, we know how to transport it. It’s not hard.”
In this future scenario no wind or solar plant will ever be curtailed. Every electron will be used. Storage of hydrogen will also be an option, he says, with three to four days’ capacity possible in underground vessels at generation sites.
The agreement with the Philippines Department of Energy will likely see Hero put to work on power stations between 600MW and 50MW, where hydrogen will be produced by electrolyzers powered by “deep offshore” wind plants.
Closer to home, Horvath admits he has his eye on a local coal plant. “I’ll say yes but I won’t tell you where,” he says. “There is no shortage of offers on the table.” Inquiries are also coming from economies that are far more energy-hungry than ours, including parts of the United States where the story runs a little like: ‘We don’t want to shut down our coal [plants]; the assets are brilliant. If we can keep them running it’s going to make running the state a heck of a lot easier.’
Horvath can see the logic in that. “Why scrap trillions of dollars of working infrastructure – power lines, connections into the grid – when you can just run it the same as you did the day before but it’s just running on a new fuel source. It just makes more sense. It also makes the transition away from CO2 a lot, lot faster.”