Spain: A Comeback for Wood and Pellet Heating

World events are shaping remote, rural villages

I recently took a trip to Spain with my wife to walk the Camino Primitivo, a Christian pilgrim route connecting small towns in the far northwest corner of the country. I wasn’t looking for wood or pellet stoves—but there were so many that I couldn’t help but start paying attention, given my day job. In one town, Tineo, nearly every store and restaurant had a pellet stove, and they all looked brand new.

As I started talking to people and doing a bit of reading, an interesting story emerged. The invasion of Ukraine sent shockwaves through European energy markets that are still reverberating today. Then came the bombing of Iran and closure of the Straits of Hormuz. The result: Spain is now offering more incentives for homes and businesses to switch to pellet stoves and boilers.

Along the Camino, pellet stoves showed up everywhere, each in its own context. In one hotel lobby, a stove had a large handwritten note: “Do not touch.” In a general store, one was surrounded by a small safety fence. In an upscale eatery, the pellet stove was part of a carefully curated retro aesthetic. They clearly add a sense of coziness—but like everywhere else, the real driver is economics.

We saw several Italian models, but the most common seemed to be made in Galicia in Northwest Spain by Ecoforest. One popular model, the Bolonia, is strikingly slim—designed to fit even in a hallway. Ecoforest also makes heat pumps, and with smart thermostat software, the two types of heaters can switch back and forth depending on outdoor temperatures and heating needs.

In Spain, incentives are often targeted at towns with fewer than 5,000 residents, part of a broader effort to combat rural depopulation and support areas without access to natural gas networks. These programs align with European Union funding frameworks aimed at sparsely populated and economically disadvantaged regions, with some funding coming directly from the EU.

Incentives are handled regionally, not nationally, and usually involve documentation from both a qualified installer and a local permit.  When an existing stove is simply swapped out for a new one, there is less paperwork to access incentives, but DIY installs are rare whether incentives are involved or not. Professional installation is required and stoves must be registered with the local authority.  The trail we walked went through two regions - Galicia and Asturias - and both have generous subsidies but Galicia's  are even more generous leading to a greater use of pellet heating.  In some provinces, subsidies are more if you are reducing reliance on coal or oil, and less for electricity. In others, household income may have more of an impact, and residing in a rural area or small town almost always increases the amount. Both equipment cost and installation are covered with total costs usually coming to 3,000 - 5,000 Euros ($3,500 0 $5,800 US). and the incentive usually between 30 - 50%.

Cordwood heating

Cordwood heating is still more common than pellet heating, though it receives few if any incentives. A few things stood out to me. Firewood lengths were often surprisingly short—frequently just 8–10 inches, and rarely more than 14–16 inches. Wood was almost always stored under a roof, and much of it looked like it had been seasoning for several years.

That suggested a mature, long-standing wood heating culture where the importance of properly dried wood is well understood. Interestingly, the shorter log lengths didn’t seem tied to stove size. Many older rural stoves are sized more like U.S. stoves and bear little resemblance to the more modern, sleek, vertically oriented European models.

One rural restaurant along the trail—also offering a few guest rooms—used a wood-fired cookstove that piped hot water upstairs. While I was there, the good-natured cook was cursing the stove, which had just started leaking. It was a reminder that these hot water systems can lead, and also they ca be fixed by the owner. 

Spain, like the rest of Europe, has at least a 3,000-year head start on wood heating and forest harvesting. We saw countless stone homes that looked 500 years old, many with equally old chimneys still in use. That long history is also visible in the landscape: massive trees continue to be coppiced, a practice where branches are cut regularly for fuel and allowed to regrow—a system still actively used today.

Heavy deforestation began during Roman times about 2,000 years ago and peaked between 1850 and 1920, much like in the United States. But the legacy of that history feels more visible in Spain. Unlike the U.S., where large natural forests remain, many of the forests we saw appeared to be plantations, and not always managed sustainably.

As in the U.S., most wood demand is driven by construction, not firewood. Firewood use is relatively small by comparison.

National heating trends

Reliable data on how many Spanish homes use wood or pellet heating is hard to pin down, but most estimates suggest that 15–20% of homes use wood or pellets as a primary or secondary heating source. Up to 5% may rely on it as their primary fuel.

Spain is less densely populated than countries like France, Germany, or Italy, but it is also warmer, and wood and pellet heating are less established. Unlike Austria, France, Germany, and Italy, Spain has not historically provided strong incentives for pellet stoves and boilers—though that is now changing.

Global energy disruptions are shifting the equation. Locally sourced, renewable energy is becoming more attractive compared to fossil fuels that must travel long distances. This provides not only more stable prices, but a healthy diversity of local sources of electricity.

Spain’s population is about 49 million—roughly 10 million more than California—and rural depopulation is a significant issue. Energy policy is increasingly being used as a tool to support small-town economies.

Most of Spain has relatively mild winters, and about 30% of homes lack central heating. As in Italy, this makes pellet stoves a practical option for  heating the core of the house rather than whole-home systems. In the colder, mountainous northern regions—which are also more forested—winters are harsher, and in some areas up to a third of homes still use wood or pellets.

Spain produces, exports and imports wood pellets which are almost entirely used for small and large heating systems. Many pellet plants are co-located with sawmills or carpentry shops. In some regions, biomass boilers also burn olive pits, nut shells, and, to a lesser extent, sunflower husks. Most pellet production happens in rural areas, so incentives for pellet heating also function as support for local businesses.

Electric rates and pellet heating

One newer incentive for pellet stoves comes from electricity pricing. Under Spain’s tariff structure, electricity is most expensive during peak hours—typically 10am–2pm and 6pm–10pm on weekdays. Heat pumps are very popular, so this creates an opportunity: households can rely more on pellet stoves during those expensive hours and when temperatures drop below freezing.

At the same time, broader trends are shifting. Since 2022, electricity prices in Spain and much of Europe have stabilized or declined, while pellet prices have risen.

Where we were hiking, in the mountainous northwest, wind turbines were everywhere. The expansion of wind energy there—and solar in the south—has helped bring electricity prices down. As a result, Spain now has some of the lowest electricity rates in Europe.

 

Conclusion

If you enjoy hiking, I highly recommend the Camino Primitivo—or any of the caminos in Spain. You pass

through stunning countryside and small towns, stay in affordable local inns, and can even have your luggage transported each day between accommodations.

Along the way, you don’t just see beautiful landscapes—you also witness thousands of years of human history, including the evolution of how people heat their homes. And that history is still unfolding, as Spain begins to embrace a new generation of pellet heating.

Further reading

 

Spanish Energy Efficiency Grants in 2025

How Spaniards Can Get a Subsidy to Replace an Old Boiler

Subsidies to fund the energy transition

USDA Spanish Wood Pellet Market Outlook 2023

Rules for Wood Burners in Spain

Spain Sees Increase in Pellet Fuel Market

Ecoforest celebrates 30 years of innovation in sustainable HVAC equipment

 

Comment on Massachusetts's H.3211/S.2137 "An Act Limiting the Eligibility of Woody Biomass as an Alternative Energy Supply"

AGH recently submitted a comment on H.3211/S.2137 out of Massachusetts that proposes to eliminate woody biomass from the alternative energy supply definition. This would make modern pellet boilers ineligible for the Alternative Energy Portfolio Standard and subsequent incentives associated with the program. Read below for the full comment:

One main example of a
high-tech pellet boiler.

"Chairs Barrett & Roy:

The Alliance for Green Heat opposes H.3211/S.2137, known as “An Act Limiting the Eligibility of Woody Biomass as an Alternative Energy Supply.” As an organization working to make local, low-carbon heat more accessible, we support many technologies, from heat pumps to pellet stoves. No technology is perfect but, in this age, when getting off fossil fuels is paramount, it is hard to believe legislation would oppose the inclusion of the cleanest pellet heating systems in the world.

We also work with firewood banks in Massachusetts that take waste wood and provide it to low-income homes on an emergency basis. The amount of wood that is available for free from towns, cities and utilities is enormous, and it is often thrown away.

Disqualifying woody biomass fuel from being an “alternative energy supply,” deters a viable low-carbon fuel choice, which most New England states are trying to expand. Eliminating a valuable tool for households that would qualify for incentives under the Alternative Energy Portfolio Standard, through the earning and selling of Alternative Energy Credits (AECs) with their wood pellet or wood chip biomass systems, is contrary to the promotion of renewable energy goals and priorities of the state of Massachusetts. The bulk of peer reviewed scientific analysis shows clear carbon benefits for small scale biomass heating. Unfortunately, some people are confusing this with the largescale, industrial use of pellets to generate electricity.

The Alternative Energy Portfolio Standard is a program that provides homeowners and businesses an incentive to install eligible alternative energy systems that both lower GHG emissions and increase energy efficiency (Massachusetts Department of Energy Resources). This market-based program seeks helps homeowners participate in helping the state to reach its climate goals. Owners of an eligible system, including ones that produce thermal energy, receive AECs that are then put on a market to be bought by entities in Massachusetts with a compliance obligation. For woody biomass systems, eligible fuels are wood pellets, dried wood chips, and green chips. In order to participate, a homeowner needs to install an eligible system, submit a Statement of Qualification, and then wait for approval.

The process that owners of woody biomass systems must undertake in the gaining of AECs involves multiple steps ensuring sustainable sourcing of the wood pellets and chips. Each owner of a qualifying woody biomass system must purchase their pellets or chips from a verified and set list of distributors/suppliers who are evaluated for their sustainability practices. Most of the pellets and chips involved are specifically from wood waste streams, meaning no trees are being cut down to feed the woody biomass systems involved in the Alternative Energy Portfolio Standard. The consumption of this fuel is then reported quarterly to a third-party, independent verifier. There is little worry about the misuse or exploitation of local forest systems within this process.

Another example of a
high-tech pellet boiler.

The technology that H.3211/S.2137 intends to disincentivize appears to be further misunderstood. These are not like cordwood stoves or outdoor boilers. These systems are expensive, highly advanced, automatically fed, and capable of thermal storage that can replace oil boilers in your home. In a 2,000-square-foot home, an automated wood heat system emits 1.8 metric tons of CO2 annually compared to heating oil’s 5.2 metric tons of CO2 or 3.6 metric tons of CO2 with natural gas systems (Massachusetts Clean Energy Center). Because of the high upfront cost, there is not a widespread demand for them, and payments from the AECs are modest at best.

In terms of the annual cost to operate an automated wood heating system, a household can save, on average, $415 in comparison to an oil system. The saving jumps even higher when compared to electric baseboard heating ($2,771) and propane ($1,441). It is only $48 more expensive than a natural gas system on average, but with automated wood heating’s advantage of being a renewable source of energy, the slight cost difference pales in comparison to the climate impact overall (Massachusetts Clean Energy Center).

For those concerned about woody biomass’s place in the renewable energy field, it is important to remember that no renewable energy source is perfect. Each comes with its own less-than-ideal supply chain stories and impact on the environment. In the past, Massachusetts has seen undeveloped land, some 10,000 acres of the state’s forest, be cleared for solar farms (Boston Globe 2020). This is less than ideal. Still, many fertile fields which could return to forest are being used for solar farms. Large off-shore wind farms have always been plagued with concerns for marine habitat health, like the 2021 lawsuit out of Nantucket (Boston NPR 2021). Again, less than ideal. However, these technologies, despite their challenges, are constantly evolving to instill more policy guardrails and stronger research to bring them to fruition. The methods used to evaluate these renewable technologies produce the understanding that they are essential but need to be guided with scientific evidence and reflective consideration—the same method by which woody biomass should be judged.

Passing H.3211/S.2137 would diminish the most modern and cleanest biomass heating technology. If the state, counties, or towns want to address problematic wood heating technology, such as wood stoves, there are many tools to use. We urge you to vote “NO” on H.3211/S.2137 “An Act Limiting the Eligibility of Woody Biomass as an Alternative Energy Supply.”"

Pellet Boiler Also Makes Enough Electricity to Power Home

Austrian company OkoFEN has brought to market the first residential electricity producing pellet boiler, the Pellematic Smart_e. The boiler uses a pellet-condensing module from an earlier pellet boiler design, the Pellematic Smart and outfitted it with with a Microgen Stirling Engine. The engine uses a heated/cooled helium hydraulic system. The result of these two technologies is a unique boiler that is capable of outputting 14 kW (47,770 Btu/h) of thermal energy and 1 kW of electricity.

The Pellematic Smart_e can save households’ money on both heat and electricity bills. Switching from oil, propane, or electricity to pellets usually results in substantial savings. The heat is used for space heating of the living area and domestic hot water generation. Plus with the added Stirling Engine, the electricity you produce in your own house can offset part of a home’s monthly electricity bill. A full load of 24 hours can produce 24 kWh of electricity at 1kW.

At 24 kWh per day, the Pellematic Smart_e could generate enough electricity for most or all of a home’s average daily electricity needs. However, in order to create this electricity, the boiler must run at full capacity, which can create a substantial amount of excess heat. The surplus heat may be stored while the electricity is still produced but even with the heat storage capabilities, some of the heat may be lost, and the efficiency of the boiler falls. For the Pellematic Smart_e to meet the electricity needs of a house, it would have to extend far beyond the heating needs of that house.

“The issue is the large 14:1 ratio between thermal and electricity on this unit, and the (likely) narrow output curve,” explains Norbert Senf, one of the judges for the Wood Stove Design Challenge, “In a thermal electricity generating station, you get about a 2.5:1 ratio.”

Although it is perhaps not the most efficient when it comes to producing electricity, OkoFEN’s innovative boiler demonstrates the potential of this hybrid technology. The success of this product is likely to lead to further industry advancements to manufacture and distribute pellet boilers capable of producing even greater amounts of electricity.

For more information check out OkoFEN’s website here

Also, their FAQ page here