Preparing Dutch houses for the green energy transition
If we’re ever going to reach a more sustainable future, one of the big hurdles we have to face is altering how cities work — and this means thinking deeply about houses. While small on an individual level, together, the untold millions of these properties combined makes a huge impact on the planet.
An example? Well, heat generation alone in residential buildings in the Netherlands consumes an estimated 24% of all final energy costs.
This hasn’t gone unnoticed. In the Netherlands there’s been a huge push away from fossil fuels in the housing sector, with a ban on installing new boilers arriving in 2026. Instead, owners will have to use the more sustainable heat pumps to manage the temperature of their homes.
Undoubtedly, this is a positive. A step in the right direction for the planet — but little in life is that simple. Supplying and managing energy is a constant juggling act, and moving to an entirely new method of dealing with it in households alters the way in which homes and the grid are stressed.
Before we can progress into a sustainable future, it’s this balance that needs to be sorted. But, thankfully, this is precisely what Joel Alpízar-Castillo — a PhD candidate in multi-energy systems and smart grids at TU Delft — looked to tackle with his research and open source model.
This offers a way of understanding what the best potential setup for various emerging energy systems might be, both for Dutch houses and the grid as a whole. We sat down with Alpízar-Castillo to get more insight into this story.
How new renewable tech puts pressure on the grid
When it comes to replacing boilers and other sources of energy in the home, heat pumps and photovoltaic-thermal (PVT) systems are some of the most promising.
Heat pumps, for example, have high coefficients of performance, while PVT systems can both give off electric and thermal outputs. The problem though is that adopting these technologies can unbalance how houses use energy and power — and when that’s multiplied over a large number of dwellings it can become a big issue.
For example, heat pumps often consume more electricity than the current standard of gas boilers, which use very minimal amounts. While PVT systems (much like regular solar panels) often experience a mismatch between times of high generation and demand, meaning surplus electrical energy is fed back into the system.
For the grid, this is a problem.
“The pace of the energy transition adoption, as of now, is not sustainable from an electric infrastructure perspective at the residential level,” Alpízar-Castillo explains.
He goes on to say that although large consumers such as commercial or industrial clients can support the grid, this is tougher to achieve on a household scale. Because these big bodies use so much power, they can agree to demand response, store and generate their own electricity, or even provide ancillary services, such as frequency regulation or voltage support.
As households are more varied and not controllable by a single figure, this can lead to the aforementioned unbalance, meaning times with a surplus or deficit are unpredictable.
As heat pumps and PVT systems proliferate, there’d need to be huge investment to overhaul energy infrastructure, something that’s time consuming and expensive, which can slow down the transition to this greener type of technology.
“A house alone cannot influence the grid, but many houses working together can,” says Alpízar-Castillo. This is why he researched and developed the modelling framework.
“We aimed to determine if it is possible to use residential energy storage assets to better utilize the existing electric networks,” he says, “minimizing the need for reinforcements.”
That’s Alpízar-Castillo’s goal: making the path to a more sustainable energy system easier.
Effectively, whether a combination of different green energy systems can be used to support Dutch houses in their transition away from fossil fuels, all while ensuring as little impact on grid infrastructure as possible.
And, if such a thing was possible, how could it be achieved?
Genesis of the idea
Alpízar-Castillo tells us that he and the team were inspired to take this journey because much of the previous research in this field only looked at electrical assets or thermal components, not a combination of both.
This, they believed, was an important step in organising energy, as Alpízar-Castillo says, “heating comprises the major energy consumption in residential buildings.”
When it comes to the focus on Dutch houses in particular, this was for ease rather than anything else. “We are targeting the residential sector and have the Green Village as a partner for consumption data; thus, we focused on the local case,” Alpízar-Castillo explains.
This doesn’t mean results are geo-locked though, far from it.
“Our results can be extrapolated to pretty much any other context with similar conditions (eg., Germany, Belgium, Denmark...), as long as the parameters are adjusted, but the model itself would only require minor, if any, changes.”
With this goal in mind, the next step was actually undertaking the research. This, of course, was easier said than done.
Tackling the research
When beginning to understand if a modelling framework could be created for a single house that would impact the grid, Alpízar-Castillo bumped into a few issues along the way.
Arguably, the biggest challenge was access to data.
“As we required electricity and gas consumption to establish the base point, accessing this kind of information always requires a careful approach, as there are not many sources for this information and it is highly confidential due to privacy concerns,” he says.
It was also a struggle getting data on the electrical networks, because the operators are understandably cautious about sharing this.
Getting around this involved generating representative datasets for consumers. “This way,” Alpízar-Castillo says, “real personal data would not be in danger of being accessed, while we could show and share our input data to other researchers.”
And when it comes to the grid? Alpízar-Castillo and the team “worked with data from the Go-E project that provides anonymized distribution networks.”
The other issue he and the team bumped into was, as this was focusing on multi-carrier systems, there were an array of siloed research areas. For example, electricity and heat are two different types of energy that are rarely considered together.
“We had to nurture these collaborations,” Alpízar-Castillo says, explaining how they overcame the challenge, in order that “the models and results satisfy both the electrical and the thermal engineering communities.”
Once those issues were faced, the team were able to continue with their work — and arrive at some fascinating results.
Outcomes
“The research showed that, from a technical perspective, it is possible to coordinate multiple residential systems to support the electrical infrastructure.”
Following close assessment of thermal performance, electrical performance, and equivalent carbon dioxide (CO2) emissions, the research discovered that the most favourable combination for houses was a heat pump combined with a PVT system and a battery.
If this setup and model is followed, then the transition away from fossil fuels into a way that supports the grid can happen faster and more efficiently.
But there’s a problem.
“From an economic perspective, it’s not yet so attractive,” Alpízar-Castillo says. Because the current residential energy market doesn’t incentivise consumers to support the grid
In fact, the dynamic tariffs currently in play for things like solar panels could actually have a negative impact. “This would lead to many people consuming during low-priced periods, congesting the local grid.”
Effectively, reducing prices by availability alone can have the reverse of the desired impact, putting the grid under pressure when energy becomes too cheap for consumers to ignore.
The solution to solving this is giving users an incentive and clear instructions on how to manage the energy, encouraging them to adopt heat pumps, PVT systems, and a battery.
This will require “effective communication between policymakers, system operators and prosumers,” he explains. Effectively, there needs to be benefits and cohesion in order for this transition to work.
The future and next steps
The next is taking these findings away from the lab and into the real world — and this is something Alpízar-Castillo and the team are building.
“We have determined the theoretical background, and are currently deploying prototypes in two living labs, the Green Village in Delft, and at a HET energy cooperative in Hilversum.”
Alongside this, the team is trying to actively involve themselves with general stakeholders, such as homeowners and policymakers in order to convince governments to balance the congestion in energy infrastructure that’s on the horizon with this green transition.
The fact of the matter is that the transition to greener household energy won’t just happen. Open source and open access models like those from Alpízar-Castillo and the team are helpful, but consumers and companies need to be taken on that journey too.