The headache of any solar PV system owner ? exporting too much of power and no way to store them ! A 4kW produces above 3.5 kW during the peak hours and personally I have seen my system clocking more than 4 kW during sunny autumn months . 90% of that production is exported until the energy demand is properly managed.
That’s e where exactly our solar immersion switch comes in. The pv heater switch monitor the PV power and manage the load to maximize the system efficiency.
Several ways exist to store the surplus power and use it later when the demand increases. Batteries offer the facility to store the power, but maintenance could be an issue. Hydrogen storage needs innovations to make it safe.
In Europe, with its cold weather, probably storing the surplus power as hot water could be the most efficient way, as we buy costly energy to heat water. Why buy energy when you have surplus power inhouse ?
The solar pv controller monitor the pv production / house consumption and divert the surplus power to the immersion heater to store the free energy as hot water for future use. The savings ? Normal house hold that use gas for heating water saves around £100 and if you use oil, the savings could be much higher, standing at around £200. That makes the system a great investment offering full return of investment in less than 2 years. If you are at the old fit rate, the switch itself is less than 3 months worth of the FIT payment.
On a normal day, the boiler hardly wakes up to heat the water and on a dull winter day, the effectively pre-heat water reducing the load on the boiler and saving on your gas bill.
The factors that are not considered here – The CO2 savings !
Now tell me – Does it not make financial sense to invest in these switches ?