“For every complex problem, there is an answer that is clear, simple and wrong.” This aphorism frequently comes to mind when I reflect on climate solutions.
Problems don’t come more complex or urgent than climate change, and sadly there is no shortage of solutions that seem appealing and straightforward, but are, at best, distractions. In the worst cases, some of these solutions can be more harmful than doing nothing at all.
Hydrotreated vegetable oil (HVO) is one such solution. HVO is being aggressively promoted as a convenient, low-carbon “drop-in” substitute for diesel, heating oil and jet kerosene, requiring no modifications to engines or boilers. Its apparent simplicity makes it an attractive quick fix.
Proponents claim HVO is a sustainable alternative to fossil fuels because it is manufactured from waste, like used cooking oil (UCO) and palm oil mill effluent (POME), a byproduct of palm oil processing. Using these waste products ostensibly sidesteps the well-known pitfalls of crop-based biofuels: land use change, deforestation, biodiversity loss and rising food prices.
If only we had enough genuine waste oil in the world to make even a small dent in our vast oil demand. The numbers simply don’t add up. Take a typical fast food restaurant, which might produce 50 litres of waste cooking oil weekly. This would produce enough HVO to fuel a typical diesel car to drive perhaps 600 kilometres. Useful, yes – possibly enough for the restaurant’s delivery driver, but nowhere nearly sufficient to meet more than a small fraction of Ireland’s diesel demand. There are simply not enough chip shops in the world.
So, where does our imported HVO actually come from? According to data from Ireland’s National Oil Reserve Agency (Nora), about half of the transport biofuel entering our market in 2024 came from UCO and POME, which are mostly imported from Malaysia, Indonesia and China, regions plagued by deforestation as a result of expanding palm oil production.
Suspicion is mounting internationally about rampant fraud in these supply chains. Given lax auditing and strong financial incentives, it’s disturbingly easy and attractive to pass off virgin palm oil as a waste product.
The implications for the climate are dire. Many studies have shown how biodiesel from virgin vegetable oils cause similar greenhouse gas emissions as diesel, and in some cases, are much worse. According to one study, emissions from palm oil biodiesel are three times greater than those from fossil diesel, because of its association with tropical rainforest deforestation. Substituting fossil fuels with palm oil-derived HVO isn’t just unhelpful, it’s blatantly harmful and irresponsible.
I first raised this issue in my column two years ago, calling HVO a “life raft for the liquid fuels industry”. In many ways, the situation has deteriorated since then. “HVO-ready boilers” are widely marketed as an easy solution to decarbonising home heating and, anecdotally, I have heard that plumbers are discouraging homeowners interested in installing heat pumps, in favour of these oil boilers. The new programme for government also commits to supporting HVO in road freight and to consider its use in older homes.
Support for HVO has followed from strong advocacy and lobbying from Ireland’s fuel industry and affiliated groups. A group misleadingly named the Alliance for Zero Carbon Heating (TAZCH) – actually a Coalition of trade organisations representing boiler manufacturers and fuel distributors, including Fuels for Ireland – is lobbying heavily for mandates to blend 20 per cent HVO into home heating oil. Their own research acknowledges this blended fuel would not offer significant climate benefits compared to electrification via heat pumps, and that HVO costs roughly 80 per cent more than regular heating oil.
Alarmingly, HVO may also be taking off as a fuel for data centres, allowing them to claim sustainability.
On the other hand, there is growing awareness of the problems with importing such dubious biofuels.
Nora has flagged some of the risks in a letter to the Government this January, and it has taken steps to reduce additional incentives for POME and tighten import rules in the Renewable Transport Fuel Policy. It also commits to working at the EU level to tighten supply chain integrity.
However, these are small regulatory steps, mainly covering transport, and incentives as well as loopholes remain. For example, HVO is still treated as a zero carbon fuel in our carbon budget and greenhouse gas accounting. Incremental measures won’t solve the underlying issue. The core problem isn’t simply inadequate regulation or unreliable supply chains; it’s the fundamental unsuitability of liquid biofuels as a large-scale decarbonisation strategy. The vast majority of applications targeted for HVO use should instead be electrified or reduced through energy efficiency measures.
Electrification and energy demand reduction involve complex, sometimes disruptive changes and upfront investment. While these transitions pay dividends through lower costs, healthier homes, cleaner air and genuine climate progress, inertia remains at many levels.
An electricity grid that isn’t yet fully ready, alongside lingering fears about heat pumps, electric vehicles and renewable infrastructure, creates a tempting but false allure for simplistic solutions like HVO.
Prof Hannah Daly is professor of sustainable energy at University College Cork
