AC•THOR in off-grid operation

Optimizing off-grid PV systems with the AC•THOR

A British customer enhances his energy independence by optimizing his off-grid PV system with the AC•THOR.

Facts about the project

Project location
PV power and orientation
Heat storage size
Type of building
Used my-PV product
System control type
Additional PV applications
Referenzprojekt my-PV AC•THOR im netzfernen System

How did you find my-PV?

Stephen C.'s quest to maximize the efficiency of his single-family house's rooftop PV system on the South Coast of the UK was driven by a very specific goal. What sets his PV system apart is its ability to operate entirely off-grid, which means that nothing is fed into the grid. This is not an uncommon situation in the UK, where feed-in tariffs are notably low or even non-existing, leading many residential PV system owners to opt out of off-grid connection.

In his pursuit, the English customer discovered my-PV through our compatibility partner, Victron, while seeking a battery inverter. Stephen C. procured the AC•THOR through one of my-PV's authorized suppliers in UK, Wind&Sun. The decision went in favor of my-PV due to its off-grid capabilities, empowered by the unique frequency shift feature. Stephen C., from the South Coast of the UK, couldn't find this particular attribute in competing products.

Personal customer opinion and resumee

“I am satisfied with the AC•THOR, as I have finally optimized my PV system at home and can now get even more out of my off-grid PV installation,” sums up the British customer Stephen C.

Obstacles/specialties during the installation?

From the purchase to the installation, the entire process went quite smoothly.

The customer managed the installation by himself, and the only difficulty he encountered was during the commissioning phase when connecting the AC•THOR with the web interface. With the help of the assembly instructions, he was able to overcome this challenge quickly.

Short explanation of the system - what should be mentioned? Special Scenario?

The customer's primary goal was to enhance their energy independence by optimizing their off-grid PV system and expanding it for additional applications, including hot water generation.

While the house remains connected to the public grid, the PV system doesn't export surplus power to the grid. Instead, excess energy is stored in a battery storage system, effectively creating a micro-grid. When the battery storage reaches full capacity, it adjusts its frequency within a range between 50 to 60 Hz, based on user-defined settings. This frequency shift signals the PV inverter to shut down. The AC•THOR can detect this frequency change within the micro-grid and prevent the PV inverter from shutting down by quickly redirecting the excess power to the heating application after the battery storage is charged.

First, the battery is charged with the photovoltaic yield, and then the additional photovoltaic energy is directed to the heating application, specifically into the hot water. This way, even in off-grid applications, photovoltaic heat can be utilized, and operating costs can be saved.

Persons in the household - hot water demand etc.?

A household consisting of two adults and two children resides in the house. The hot water demand in the house is indeed quite significant, especially when compared to the relatively small hot water storage tank.

Is hot water backup with mains power used?

The family does not use battery power to heat water, but instead relies on backup systems powered by wood and gas. There is no heat pump installed in the house.

The maximum temperature setting in the tank is set at 60°C.

Is the combination with Victron and my-PV intended to be grid-independent?

my-PV is compatible with Victron for use in both grid-connected and off-grid operations. This makes it particularly special – when connected to the grid, surplus PV energy is regulated based on the meter value at the household connection, as it is normally the case regarding my-PV solutions.

What sets Victron apart is that in the event of a power outage, the AC•THOR automatically switches to frequency control and, in this case, utilizes PV surplus based on the battery's charge level. The customer from the United Kingdom has taken advantage of this feature and is very satisfied with it.

Referenzprojekt my-PV AC•THOR im netzfernen System
Referenzprojekt my-PV AC•THOR im netzfernen System
Referenzprojekt my-PV AC•THOR im netzfernen System
Referenzprojekt my-PV AC•THOR im netzfernen System
Referenzprojekt my-PV AC•THOR im netzfernen System
AC-THOR Seitenansicht


in use

Simple & efficient: AC•THOR controls electrical heat sources depending on the availability of PV energy and heat demand. And that for both hot water, as well as for space heating.

More infos about AC•THOR

Weitere Referenzprojekte

my-PV Referenzprojekt AC•THOR Belgien

AC•THOR: Electricity meets relaxation

A Belgian homeowner heats up his outdoor-jacuzzi in an environmentally friendly way with the AC•THOR.

Referenzprojekt my-PV AC•THOR in Neuenkirchen

Photovoltaic heat during the gas crisis

In a semi-detached house in Münsterland, the AC•THOR from my-PV supports a condensing boiler with the power of the sun.

230906_Referenz AC ELWA 2_Gasselik_Drohnenbilder (1) my-PV

AC ELWA 2 in an architect's house

The new solar-electric heating element in a renovated single-family home in Upper Austria.