Waste not, want not: start-up takes on the green energy problem (2024)

Despite climate change and the need to move away from fossil fuels dominating the global conversation, one of many technical challenges that receives little attention in the media is the storage problem.

Storage of energy, that is. Renewable power has gone mainstream. Even Ireland, which was ranked the worst country in the EU for combating climate change this week, is producing about 27 per cent of its power at any one time from renewable sources. But stockpiling that power is a problem. When there’s no wind or the sun isn’t shining, nothing is being produced. When there’s no demand from the grid the generated power goes to waste.

A self-funded Dublin start-up says that it has come up with a solution to the problem. It’s a renewable technology based on a combination of gravity and the exertion of pressure from compressed air on water flow. Crucially, it’s available on demand, to some extent negating the issue of storage.

Static Hydro Energy (SHE) is the brainchild of Owen McElroy, a 60-year-old civil engineer, and his founding partner Eddie Rooney, 50, together with their fellow director Barry Metcalfe, an electrician running his own business in the Leinster area.

Both from north Dublin — Mr McElroy is from Swords, Mr Rooney from Malahide — the pair have known each other for more than 20 years. The past five of those have been spent developing the company helped by a €500,000 injection from personal funds. Mr Rooney is the salesman of the two, endlessly enthusiastic, eager to talk, with a background in insurance and property development in eastern Europe. Mr McElroy is the business owner, and the ideas man. The technology behind SHE is his creation. It is a product that the pair claim will be worth billions — an estimated $41.2 billion, according to one interested investor, one of the largest manufacturers of compressed air systems in the world.

“Basically, how it came about, I’d always had a general interest in wind power and generation, but the most efficient form of renewable energy are dams, hydro power. All the best places in the world for that are long, long gone. I was walking along Portmarnock beach wondering about the concept, and what would happen if you had a constant tidal flow of water into a hole in the ground, for example, what would the applications be,” Mr McElroy says.

His idea, which he calls Capo, for compressed air power optimisation, involves using a rotational supply of water. First a chamber with a turbine is submerged in a tank, in a pool or similar. Water then pours down on the turbines, turning them, and once it collects beyond a certain point it is fired using compressed air, which is fed into the chamber, via a “snorkel” effect back to its starting point. “Think of a bottle rocket and you’ll be thinking along the right lines,” Mr Rooney says.

“Capo represents a total departure in that it’s the first apparatus to transfer the pressure in waste compressed air into force, then to use that force to drive a turbine, thus rendering the whole operation much more efficient,” Mr McElroy says.

What results is a clean, renewable form of energy, dependent upon an abundant supply of compressed air. “Ten per cent of the world’s energy is used to manufacture compressed air for giant industrial manufacturing plants, and 40 per cent inefficiency is typical in many installations” Mr McElroy says. He estimates that the energy potential of waste compressed air released into the atmosphere each year equates to roughly $260 billion. “This is the size of the potential market.”

The success of SHE’s concept is thus dependent on gaining access to waste compressed air from industry. Mr Rooney and Mr McElroy say that is a requirement that has now been satisfied. “There are over 77,000 centrifugal air compressors in operation around the world, 15,000 in the US alone,” Mr Rooney says. “Each one as big as a house. Each one producing enough in waste to power multiple of our own machines. Fifty of our machines would be sufficient to power 10,000 homes.”

SHE has filed patent applications for its prototype machine, known as the Powerstar, or Aquairo, in 13 regions “equivalent to coverage for about five billion of the world’s 7.5 billion population,” Mr McElroy says. Their Chinese patent has now been granted, they say, with Indonesia expected to fall also in short order.

There is a second application for the technology which SHE has been exploring. Mr McElroy and Mr Rooney say that the company is in talks with Arizona State University to build a manufacturing prototype for their creation on the college’s campus.

The connection is significant given the university’s status as a global leader in renewables research. Arizona, as an arid state, knows all about the over-production of solar-generated electricity while SHE’s machine requires compressed air. The meeting of minds would see compressed air generated from electricity not being taken up by the grid. So one renewable energy generates another.

Now SHE is engaged in a funding phase with the goal of building a full-size operational machine with the college. “That’ll serve as the exemplar for global licensing,” Mr Rooney says.

Were the university connection to come to fruition, the two friends say, the resultant mould could be used to construct multiple units, and the move to profitability could begin, with applications from supplementary power generation, with factories using their own waste compressed air to fuel their own manufacturing processes.

Not that SHE envisages being involved in going global in a physical sense. “We don’t ever want to be involved in manufacture, only in licensing,” Mr Rooney says.

It should be noted that not everyone associated with the technology has been positive about it. One academic, who wished to remain anonymous and who previously ran a feasibility study on the prototype — which concluded that the machine was capable of 96 per cent transfer efficiency — told The Times that in their opinion the proposed machine could not be considered viable economically due to its expending more energy to create compressed air than it generates via water flow.

The same researcher did acknowledge that such reservations could “perhaps” be successfully resolved should a running machine have effective access to a supply of waste compressed air, something which was not on the agenda at the time of their initial consultation four years ago.

Amir Esmaeily, research fellow with the school of physics at Trinity College, who was commissioned to write an examination of the SHE machine’s working processes in November 2014, disagrees and declared the prototype “very viable”.

“There are hundreds of millions of euros worth of compressed air wasted each year by industry, air that’s just released into the atmosphere. If you could harness 2 per cent, just 2 per cent of that wasted air, nothing more, that could be worth €20 million per year in regenerated power,” Dr Esmaeily said.

Mr McElroy dismisses the negative comment as being opinion offered on an old version of the project. “That was before we built the prototype, a small-scale version of the machine, roughly six metres in height, has been built above ground at SHE’s base in north Dublin,” he says. “Nobody thought we could do it, and we have done it.”

Arizona university “enthusiastically” has confirmed to The Times that it is in negotiations with SHE with regard to “demonstrating their Powerstar compressed air hydro technology”, but added the caveat “that it will require outside contractors for anything larger than a laboratory demo”.

“The concept behind using waste compressed air is intriguing and a nice first application for the technology, but I have learnt that even when things look simple on paper, the devil is still in the detail. So we look forward to working through that application when we identify a site and a funding source,” says Ellen Stechel, professor of practice at the university’s school of molecular sciences and SHE’s chief point of contact with the college.

In the meantime, Mr Rooney and Mr McElroy are set to continue “focusing on getting our patents in” and seeing what happens next.

“We don’t know how much of the company we’ll own in six months, a year, nor would any prudent investor,” Mr Rooney says. “We’ve been staring at this in excitement for five years. We’re only talking about it now. You have to keep your feet on the ground.”