AC ELWA 2 in the Netherlands
Saving €450 in feed-in fees with the AC ELWA 2 in the Netherlands
Durch den Einsatz der AC ELWA 2 konnte ein niederländischer Hausbesitzer seine Netzeinspeisung deutlich reduzieren.
Facts about the project
- Planner/Installer
- Location
- Photovoltaic output and orientation
- Inverter, battery storage
- Heat storage size
- Building type
- Year of construction
- my-PV product
- System control
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What was the way to my-PV?
Since 2024, energy suppliers in the Netherlands are charging PV-system owners a fee for feeding their surplus energy into the grid. In response, Dutch homeowners with PV systems seek for ways to decrease the energy fed into the grid and maximize self-consumption of their surplus PV energy.
This challenge was no different for the owner of a 50-year-old single-family house in the Dutch city of Lekkerkerk. Equipped with a robust 15 kWp PV system, the homeowner was faced with a significant PV surplus. The homeowner generated a significant energy surplus, which, due to the newly introduced feed-in fees, would now result in high additional costs. Since only two people live in the household, far more electricity was generated than was actually needed. On sunny days, a large portion of the energy went unused and was fed into the grid—a practical solution in the Netherlands before the legislative change.
The homeowner knew the advantage of storing surplus PV energy in the form of heat and was searching for a device with which he could use the surplus energy to heat water. His key requirement? A device with linear control to ensure every watt of surplus energy could be utilized for water heating. With just two people living in the house, the 15 kWp PV system generates more than enough energy for their needs. However, on sunny days, a substantial portion of this energy remained unused and was sent back to the grid.
Personal customer opinion and resumee
“I feel confident that I made the right choice – not only for the environment but also for saving money, especially considering the current situation in the Netherlands. It’s a solid investment that will certainly pay for itself over time. The system operates completely automatically, which provides a great sense of convenience. The mobile application works well with IOs and gives you the ability to remotely monitor the equipment.”
AC ELWA 2 from my-PV, a 0 - 3.5 kW linearly controlled water heating device, met his requirements. What particularly convinced him during the purchasing decision was the ability to track system data through the my-PV Cloud.
A short explanation of the system
The AC ELWA 2 was installed in a 200-liter buffer tank. Thanks to the compatibility of my-PV devices with the P1 meter, no additional device was required to monitor PV surplus. Since most Dutch households are equipped with digital meters, the AC ELWA 2 can communicate directly via the P1 interface.
As the home’s existing plumbing and heating system cannot handle a constant hot water temperature of 95°C, a configuration with two valves was implemented to separately regulate the temperatures for space heating and domestic hot water. This solution enables optimal use of PV energy for both applications.
The buffer tank is configured to store water at high temperatures (up to 95°C). The two valves ensure separate temperature control for different applications:
The first valve regulates the heating water temperature for space heating to 0–50°C, making it compatible with the existing central heating system.
The second valve mixes the hot water from the buffer tank with cold water to provide a usable temperature of approximately 60°C for domestic hot water.
This eliminates the need for additional energy sources for water heating, ensuring the PV surplus is utilized optimally.
Were there any obstacles in the installation?
The only obstacle encountered was related to the boiler rather than the device itself. Due to the boiler’s thick insulation, fastening the heating element proved challenging as the pliers couldn’t reach behind.
Installing the AC ELWA 2 was straightforward, and the availability of the menu in multiple languages (as well as in Dutch) was particularly appreciated.
In the first few days, the homeowner closely monitored the device to ensure the battery storage was prioritized for charging before surplus energy was used for heating water. He found it especially helpful that the control settings allowed him to easily adjust the target value for surplus energy utilization.
How much can a Dutch homeowner save annually?
An annual feed-in of 7,525 kWh results in a feed-in fee of €787. By switching to higher self-consumption with photovoltaic heat, the annual feed-in is expected to decrease to just 3,213 kWh, incurring a significantly lower fee of only €330. This means that simply transitioning to photovoltaic water heating can save nearly €450 in feed-in fees per year!
Additional savings are, of course, achieved through water heating using "free" energy from your own roof – an absolute win on two fronts for the Dutch homeowner.
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AC ELWA 2
To maximize the self-consumption of your current PV system, AC ELWA 2 harnesses the system's surplus photovoltaic energy to heat your water. Increasing self-sufficiency simultaneously safeguards against unpredictable or rising operating costs.
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