The images below provide a demonstration For stand alone applications without a battery bank. More information is provided in the adjacent text to the image.
A stand alone application is when there is not a battery bank in the system. Each demonstration shows a grid-tied inverter, but an inverter is not required for operation. The grid tied inverter has the advantage of providing a way to use solar power once the heating device is done, by feeding it back to the grid for credit from the utility company (when available).
It is important to note the size of the solar array AND the environmental factors (Sun, shading, temperature, etc) determine the amount of solar power available. For more information relating solar power to heat (BTUs), see the Energy Converter link on the Resources page.
Click the image to start the animation.
Device Installation
for domestic hot water
What the animation shows:
PV panels are installed in a location with optimal Sun exposure. For demonstration purposes, a roof mount system is shown, but any configuration is acceptable.
PV power wires are run from the panels to the device. Wire gauge and conduit based on operating conditions, environment and electrical code. See your local building codes for more information.
Heated water is stored using a dedicated heating loop. A standard electric hot water heater has a hot port, cold port, thermal relief port and cleanout port. By using the hot port and cleanout port, the device can easily be installed without having to modify the electric hot water heater. If a dedicated loop cannot be used an isolation valve may be required for the device. It is also possible to use the lower element in the tank for PV direct heating, which eliminates any changes to the existing plumbing.
Wiring from device to inverter/utility meter is done to allow the device to bypass PV power to the inverter to be sold on the grid. The inverter is not required for the device to operate.
Wiring from house to the pole is shown for conceptual purposes only. Unless the residence is a new construction, the wiring to the pole would already be in place.
What the animation doesn’t show:
Combiner box and/or circuit breaker panel may be required. This would be installed as close to the panels as possible.
Inline strainer is recommended if cleanout port on electric hot water tank is used. This is to prevent sediment at the bottom of the tank from being pumped through the heating loop.
Electric hot water heater thermostat should be lower than the device temperature setting to allow the device to be the primary heat source during daylight hours.
Operating conditions:
Solar array operating conditions must be less than 200VDC open circuit voltage and greater than 60VDC maximum power point voltage.
DC circulatory pump can be directly powered by the device. If a larger pump is required an external power source is needed.
Size of the heating elements are based on the power of the solar array.
Actual power used by device is based on solar conditions at your location.
device Operation
for domestic hot water
What the animation shows:
PV direct power is used for heating water that is stored in a bulk tank. The temperature is set by the user with the device’s display interface.
Existing electric hot water tank can be used with the device without modification or alteration to the existing tank.
Inverter is not required for operation, but has the advantage of using PV power once heating is done.
PV power bypassed to inverter once the target temperature is reached. This allows power to be sold to the grid.
What the animation doesn’t show:
Efficiency of device at least 95% under all operating conditions. .
Maximum power point tracking performed by the device to keep solar system at the peak operating point.
Target temperature drops below a user defined threshold, PV power is switched back from inverter (if installed) to heating device.
device Operation
for space heating
What the animation shows:
PV direct power is used for space heating. An inline circulatory pump is operated by the device and is used to provide heat to the target application, whether it is baseboard, radiant or other hydronic based heating system.
Existing hydronic based heating system can be used with device without modification or alteration.
Inverter is not required for operation, but has the advantage of using PV power once heating is done.
PV power bypassed to inverter once the target temperature is reached. This allows power to be sold to the grid.
What the animation doesn’t show:
Inverter is optional and operates just as before with the domestic hot water application. It is not shown to provide a more focused demonstration of the device operating with the furnace.
Efficiency of device at least 95% under all operating conditions.
Maximum power point tracking performed by the device to keep solar system in peak operating point.
Target temperature drops, PV power is switched back from inverter to heating device.