How do the sensor calculate the active aerea [m²] of the panel because the sensor measures W/m²?
In my case the module shown has 420 W (I set 8*420 in the config), but the same sice panel today has maybe 465 W.
So the estimated yield was calculated ro 14kWh for today, but the MPPT has harvested 13,14 kWh.
Max power is shown as 2472 W, measured 2445 W so very close.
Hi @Sebastian, the SolarSense doesn’t actually need to know the area of your PV panels.
A 420Wp panel will produce 420W at an irradiance of 1000W/m² (STC). Consequently, the SolarSense can estimate the instantaneous output of the PV array by dividing the Wp rating of your installation by 1000W/m² and multiplying by the instantaneous irradiance level. For instance, at 100W/m2 this will be 42W per panel. The surface area of the panel isn’t part of the equation.
In most cases the estimated yield will be slightly higher than the actual yield due to losses in the MPPT/inverter or other inefficiencies.
Now another question came to my mind:
The device is also made to check a new spot for solarpanels. Is there a way to import the recorded data via the VictronConnect app? So no GX device is needed at that new location
Can we please have VRM adjusted so it shows Watts in the dashboard view versus just irradiance? Basically like how it shows in Victron Connect would be ideal.
Hi @CZvacko since the SolarSense is quite a simple device, the datasheet and manual are combined in one document. The datasheet download includes all instructions for usage and installation.
If there is no manual, is there a description of the available MQTT values and their meanings?
I just bought it and have a few questions.:
In MQTT, I noticed the topic ‘N/xxx/meteo/20/TxPowerLevel’. This means, how strong is the received Bluetooth signal from the perspective of the Cerbo GX device? If yes, what is the worst value (or range)? It’s important for me to know this because right now it’s not in the ideal place and I don’t know how far I can still move it.
What does N/xxx/meteo/20/UnspecifiedRemnant mean?
N/xxx/meteo/20/TimeSinceLastSun is still 0, so I’m wondering if it should work.
Hi @CZvacko, the topics you mention aren’t relevant for normal operation and might change without notice. That being said:
TxPowerLevel indicates the output power of the SolarSense radio in dBm (at low battery this is reduced). It does not indicate signal strength at the GX device.
UnspecifiedRemnant indicates which version of the instantReadout record definition the SolarSense uses.
TimeSinceLastSun indicates how many minutes have passed since the SolarSense determined the sun has set.
However this is getting really off-track of the original question in this topic, so if you have further questions I would recommend creating a new topic.
@Luc Today I imported the data and most data are reading correctly, but the estimated yield is rounded to full kwh. However, “Wh” is specified in the header
@Luc Then I set it correctly, but I noticed a discrepancy with the actual MTTP power. SolarSense overestimates power in the early morning and late afternoon, and underestimates it for the rest of the day. What can be the reason?
The most likely reason is that solar charger / inverter efficiency isn’t constant. At low power levels, the efficiency is relatively low.
Furthermore, PV-panels themselves actually have irradiance dependent efficiency as well. Unfortunately this is almost never specified in the datasheets.
