10
HOW YOUR WATER HEATER WORKS
ABOUT YOUR SOLAHART POWERSTORE
The Solahart PowerStore Grid Interactive water heater is a premium electric water heater designed to work in
partnership with an external control device, the Energy Management Unit, in order to take advantage of special
tariffs and rebates available from your electricity retailer and when installed with solar PV, use excess solar
PV power production.
The amount of hot water stored in the Solahart PowerStore Grid Interactive water heater will be monitored
using communication through the connected Energy Management Unit and heating times optimised to use
electricity when utility grid supply is higher than customer demand. Hot water monitoring will also ensure
sufficient heating is provided to ensure there is always a minimum amount of hot water stored to meet standard
domestic needs during periods when customer demand for utility grid supply is high.
In addition, when installed with solar PV and an external Power Meter, the PowerStore Grid Interactive water
heater is able to modify its power consumption to be similar to the excess solar PV generation, when the water
it contains requires heating. Water is then heated at the expense of the surrendered solar feed-in tariff, rather
than purchasing energy from the utility grid to perform the heating.
The Solahart PowerStore Grid Interactive water heater also has the ability to tell the Energy Management Unit
and Power Meter the amount of hot water available at any time, enabling it to be used as a key component in
a sophisticated home energy management system (HEMS) provided by a third party service provider. This
would allow the water heater to use utility grid sourced power for additional water heating or to achieve safety
and compliance requirements (when required) at the most economical electricity tariff available.
SYSTEM OPERATION
The Solahart PowerStore Grid Interactive water heater operates as a staged power input water heater at times
when utility grid supply is higher than demand or when there is excess solar PV power production. When
excess power is detected and water heating is required, the water heater
’s controller module and the Energy
Management Unit or Power Meter react enabling the water heater to operate at an equivalent power
consumption.
A combination of the unique triple blade multi-stage heating unit design and electronic control enables staged
input from 515 W to full power in ~500 W steps for the lower heating unit. This power control system allows
the water heater to operate whenever smaller or larger amounts of excess solar PV power production or excess
utility grid supply are detected and water heating is required.
The Solahart PowerStore Grid Interactive water heater has inbuilt protection against running low on hot water
and will also maintain a fixed minimum water temperature as a safety and compliance requirement. During
periods when there is no excess utility grid supply or excess power from solar PV generation and heating of
the water is required, electricity from the utility grid will be used to ensure the availability of hot water, by using
the top heating unit.
The water is heated to a temperature up to 70°C under normal operation from utility grid supplied electricity.
On occasion if there is an excess of utility grid supplied electricity available, the Energy Management Unit may
command the water heater to heat the water to a maximum of 80°C to make use of this excess electricity.
Note:
If the water heater is installed without either the Energy Management Unit or Power Meter or connection
to a home energy management system (HEMS), it will operate as a conventional twin element electric water
heater. The water will be heated to 70°C. It w
on’t be able to be part of an intelligent water heating system or
take advantage of excess solar PV power production.
