Business is booming for Astatine boss Tom Marren. Over a two-year span, the Dublin native expects his company’s revenues to increase tenfold, buoyed by a big new partnership with Aviva.
He has come prepared for our interview with a PowerPoint presentation, and after spending the first 20 minutes trying to figure out where we know each other from, I ask him where the name for his company comes from.
“Astatine. It is the rarest, naturally occurring element in the world,” Marren says, his engineering background shining through. “When we started the business, the marketing people hated it.”
Sometimes, people don’t know how to pronounce the name of the business, he laughs.
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“Remember when Google first came out? You probably don’t,” he laughs. “Well, when Google came out we all asked what a Google was! But now, it is a brand. It’s the same with Astatine.”
Wishful thinking, perhaps, but time will tell.
Astatine is an “energy infrastructure solutions” company, they don’t just specialise in a single portion of the energy cycle.
“Rather than a client going out and getting a solar guy, getting a battery guy, getting a heat pump guy, getting a truck guy, you name it,” says Marren; that Astatine “just do everything”.
He says it gives them a significant advantage in price competitiveness, as the company handles everything from securing the planning permission for renewable energy infrastructure projects down to the delivery and operation of these assets.
Astatine has been involved in funding renewable energy projects for several years, aiming to drive the adoption of carbon-efficient energy sources. “And this is where the joint venture with Aviva is coming in,” he says.
One year ago, the company sought a funding partner that could provide the backing necessary to scale its operations significantly. After bouncing the idea off several big investors, they tied the knot with Aviva Investors, the global asset management business of Aviva plc.
What’s the platform going to be called? That’s still in the works, but Marren isn’t stressed. “To be honest, I don’t know yet, but we’ll figure that out.”

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Astatine will be the minority partner in the deal, and handle the delivery of renewable projects in Ireland, the UK and other parts of Europe. It is targeting some of the highest-use sectors, such as data centres, the dairy industry, cement manufacturers and pharmaceuticals.
“We are really keen on the food and beverages sector – that’s huge in Ireland. Dairy is also a huge sector for us,” Marren says.
A recent project with dairy co-operative Arrabawn is “very typical of the projects” that will be funded under the partnership with Aviva. Astatine built a 5.6 megawatt solar farm beside the co-ops processing plant in Nenagh, Co Tipperary. The 12,815 panel project is reducing its draw on the grid by 15 per cent with no upfront capital investment from the co-operative.
“We own that site. We will sell the power back to Arrabawn over a number of years and then we will hand it back,” he says, “It is a no-brainer. The whole site will be paid for, and they will have [the asset] as well as the ongoing energy reductions.”
Astatine also sees significant room for growth in helping data centres to reduce their reliance on the grid and on carbon-emitting energy sources.
“Data centres need to deliver large [amounts of energy] and the great thing about Ireland, we’re unbelievably positioned to deliver huge amounts of renewable energy.”
He says the west of Ireland has a unique opportunity to harbour carbon-efficient data centres: “We can deliver 85 per cent green power into a data centre competitively, because we have got one of the most competitive renewable resources in Europe on the west coast of Ireland because of our wind speeds,” he says.
Marren believes that the next few years in Ireland will be critical for the development of carbon-efficient infrastructure. “I’m always on about urgency,” he says, which is one of the company’s core values. “We need to be more competitive in Europe.”
In driving adoption of renewable energy and energy efficient practices, Marren says the most important thing is to make the choice economical for businesses.
Astatine is trialling the use of electric trucks for a big Irish company at a cost reduction of 10 to 15 per cent, with carbon reductions of about 90 per cent. It’s a “win-win” from both a climate and financial perspective, which he believes is key.
He runs through a long list of projects the group has delivered, including for Jameson owner Pernod Ricard, farmer-owned dairy co-operative Dale Farm, and French utilities company Engie – each time listing impressive figures for carbon emission and cost savings.
“But it is economical, and this is where we need to be,” he emphasises. “Everyone has this mindset that reducing carbon emissions costs money, but it is actually the opposite – these are extremely good paybacks.
“Energy efficiency is an area that Europe needs to focus on, and Ireland needs to focus on,” Marren says. “Everyone wants to build something new, but really, efficiency is number one.”
He says the market is strong in Ireland for carbon reduction projects, which has fuelled the company’s rapid growth since it was founded in 2020. Last year, the company posted €22 million in revenues.
“This year it will probably be €70 million, and next year we are expecting about €200 million,” Marren says.
“I’ve done pretty well at staying out of the picture for the last while,” says Marren of its low-media profile at the company offices in the Guinness Enterprise Centre.
What drove the growth? “Part of it is experience. We understood that we needed to build a good team. Part of it was having a certain reputation with clients anyway from previous businesses.”
Astatine is built on the lessons that Marren has learned from founding seven other businesses. He holds an engineering degree from Trinity College Dublin and an MBA from UCD.
After a short stint working with Mitsubishi after college, he set up Marren Engineering, which focused on air conditioning work and became a big contractor in that field.
After a holiday to Australia, he set up Cogent Engineering, which sold heat and electricity. A “mini utility company”, it was acquired in 2007 by the largest utility company in Australia, Origin, for more than €27 million, he says.
He went on to found CES Energy, which operated internationally, including doing work in the Middle East, on projects such as the King Abdullah Port. He sold the business to UK-based Centrica plc, which is also the owner of Bord Gáis Energy.
“This isn’t my first start-up, but it will be my last,” he laughs.
When it came to setting up Astatine, he “knew the market was there”, but timing was his enemy.
The business began operating in 2020, just before the pandemic. “Covid was a distraction to say the least – more than a distraction really – it cost us a lot of money. But ultimately, we knew that the market was there. We just had to keep our heads down and drive on.”
The “we” is critical, he says, crediting much of the business’s growth to his co-founder and current chief operating officer Pat Nolan, whom he first met at a previous business when Marren hired him as an intern.
“I brought him over to a big meeting in London, an important meeting, so he bought a new suit for the occasion. There we were, sitting in a meeting with 18 people, with people from Spain, the UK and the US as they introduced themselves.”
When it came to Pat’s turn, a proud lilywhite, he announced he was from “south Kildare”, reasoning that north Kildare is “just Dublin”. The two went on to form a close-knit team, and Astatine is an effort of “70 hours of work a week” by the duo for many years.
Before the business took off, its first Christmas party comprised just two people, its founders, going to a pub together. After a few pints, they stumbled through the door of Pat’s house and vowed to his partner that “some day we would have 150 employees at our Christmas party”.
“This year we will.”
CV:
Name: Tom Marren
Job: Astatine chief executive
Age: 57
Lives: Splits his time between Dublin and Dingle
Family: Married to Liadain with seven children
Hobbies: Keeps hens and bees in Dingle, and plays golf, albeit less often than he would like
Something we might expect: He supports the move to renewable energy
Something that might surprise: Going to the Antarctic in November. “I’ve always wanted to go. It’s one of the last unspoilt areas in the world”



















