Storing diverted solar generated power

[jimbro]

I have completed and tested a circuit which diverts excess power from a solar panel array into a load within the house rather than exporting the power. I would like to use the diverted power to store the energy as heat in a fan assisted "storage heater" , there is no hot water tank, but I am concerned about this due to the normal requirements of storage heaters to be on a radial circuit with individual supplies and a 16 A breaker. Please comment on the following proposal:-

As the solar array has a maximum output of about 3.5 kW and the house has a typical standing load of about 300 W, I anticipate only having maximum of about 3kW to divert.

Since storage heaters seem to come in 2.55 kW and then 3.4 kW ratings I would use a 2.5kW heater.

The voltage in the house is typically 245 V and so the 2.55 kW heater would take 10.4 A allowing the heater to be fed from the 13 A ring main controlled by the power diverter circuit. I have tested this system out with a 1 kW panel heater and it works well gradually collecting heat as the clouds come and go over the solar array and the load changes in the house.

Please comment on this proposal before I invest in a storage heater.

 

[Worcester]

Is your circuit EMI compliant? mmmm..

You could have save yourself a lot of trouble by buying an off the shelf product, Immersun, iboost, Gem....

Generally these products all support a resistive load like a storage heater, at the same time they need to be dumb units without comprehensive digital type controls and relying on simple bi-metalic type thermostats.

Being fan assisted you may have interesting challenges with the fan as it is presented with a non-uniform sine wave. The products that use pwm seem to cope with simple fans. I an also not sure how your fan will cope with the varying voltages as it is an inductive load as opposed to a resistive load, you may find it stalls and burns out.

If you have used the openenergymonitor device (instead of re-inventing the wheel - or did you do that?) there is a lot of support on their forum on load types.

AS a professional forum, you can hopefully understand that we cannot give advice on how to connect up a home grown pices of electrical equipment to the mains supply, and can only advise strongly against it.

p.s. your voltage is supposed to be typically 230V +10% - 6%