For installation companies · Retrofitting existing buildings
PV, battery and boilers.
Designed as one system.
SOLIS shows how existing electric hot-water boilers can be integrated into intelligent energy management. The retrofit focuses on the electrical distribution – with additional benefits for owners and residents.
Taking the offer further
Self-consumption also comes
from good timing.
A PV system supplies electricity. A battery shifts part of it to later hours. In addition, releasing existing boilers in a targeted way can store solar energy as hot water.
For installation companies, this opens up a further approach to planning: generation, thermal storage, electrical storage and load management are considered together. The customer benefit comes from the interplay.
The documented project combines seven boilers, 11 kWp of PV and a 10 kWh battery. The total investment is €18,000, of which €2,500 is for the controller, installation and configuration. These are the costs of this specific project, not a general offer.
Installation
The technology sits
in the distribution board.
One contactor and one energy meter are provided per boiler. The WAGO controller reads the measured values and releases charging individually. In the reference project, no bathrooms had to be opened and no new sensor cables had to be laid to all boilers.
The electrical power consumption is used to detect the end of charging. If the boiler stops drawing current while voltage is present, the controller marks it as charged.
The professional dimensioning of switchgear, cables and protective devices as well as the electrical installation work are the responsibility of the executing electrical contractor.
Project planning
From the existing installation to the right configuration.
Building and consumption.
Record the number of boilers, rated powers, usage profiles, distribution boards and supply lines. Include the PV system, battery and existing metering options.
Define power limits.
Group boilers into distribution groups. Define permissible group power, total power and grid import power separately. Plan metering and switching per boiler.
Tune the operation.
Set up device connections, weather and tariff data. Adapt charging modes, special charges and notifications to the actual use of the building.
Bringing existing connections
together deliberately.
In the example, hot-water boilers and communal power are electrically combined with the PV system at one connection. The tenants' separate connections remain in place.
The interfaces to the existing installation and the metering concept are therefore part of the planning. Energy metering per boiler makes consumption traceable individually.
The technical basis
- WAGO PLC with configurable CODESYS software
- MODBUS RTU at 19,200 baud
- Measured values from inverter, battery and energy meters
- Weather forecasts and quarter-hourly tariffs via APIs
- Individual boiler release and staged power limits
- Remote overview, daily and monthly values, and error notifications
Added value
The infrastructure
can do more.
In the project, an additional M-Bus module reads the apartments' heat meters monthly and sends the readings by email. This remote reading uses the existing controller but does not intervene in the heating control.
Outdoor, flow and return temperatures as well as one easily accessible boiler are also displayed. Further functions such as showing the heating status can be added.
An implemented concept
as inspiration.
I am the owner of the building and an electrical engineer trained at a higher technical college (HTL). The concept and technical design are mine; I installed and programmed the controller. The electrical installation work is carried out by a qualified electrician on site.
I want to show how the idea can be used in an existing building and exchange ideas about it with interested installation companies.
Contact the project