Capacitor in place of batteries?

[inetdog]

PF capacitors are very small in value, and high voltage which means they are completely useless for any low voltage DC filtering and storage.

All you need is a DC to DC transformer to match the voltage levels properly.
Of course if you have invented a low loss passive bi-directional DC-to-DC convertor, you would not be fooling around with using it in a PV system.

[Sunking]

PF capacitors are very small in value, and high voltage which means they are completely useless for any low voltage DC filtering and storage. Besides a string Grid Tied Inverter does not use batteries and operates at a DC voltage of 300 to 500 volts. What did you do get a Hybrid inverter or a plug-n-play

[Mike90250]

2 different critters here.

As an engineer, you should realize, that the moment you pull power from a capacitor, it's voltage starts to drop. An inverter will only tolerate a small amount of drop, before it thinks the batteries are dead, and will shut off. Batteries supply a lot of power, and only in the later part of discharge, does their voltage sag appreciably. That's why caps alone, won't work. Even multi-Farad caps, the power/voltage curve just crashes, you can only get a couple % of their power out.

plain Grid-Tie installs, don't use batteries at all.

[inetdog]

Hi All, I live on a lifestyle block in Waikato, New Zealand and are on a big push at the moment to reduce my household expenses. I am an Engineer by trade and would rather give something a go for myself than pay someone else to do it. I have recently put together my own 3kw solar system. I wired up 3kw's of 24v panels to 48v to reduce the amount & size of cable used. I have a 5kw grid tie inverter which has an input voltage range of 28v dc to 52v dc and an open circuit voltage of about 80-90v dc, but overlooked the need for a solar regulator/controller. My question is, can I use a large capacitor in place of 48v batteries as I do not want and cannot afford to spend anymore on storage or batteries, I just want to trick the controller to think that batteries are connected. I have sourced a couple of very large capacitors that were removed in good working order from the power factor correction board in the factory I work. I fully understand how quickly capacitors charge & discharge. All I wish to do is power my grid tie inverter. Any help would be much appreciated. Cheers

Grid tie inverters do not need or use batteries. They are designed to take any and all power coming from the panels and transfer it to the power grid, either for local use or for selling back to POCO, depending on the amount of load you are feeding at the same time.

Batteries are used for an off-grid inverter or for a hybrid inverter. Either of those types require more energy storage than a capacitor could provide. The batteries are needed because the solar panels will be providing a constant output over a short time while your loads may vary. The grid performs the same function of energy storage for a grid tied inverter that batteries do for an off-grid inverter.

[muttonpig]

Hi All, I live on a lifestyle block in Waikato, New Zealand and are on a big push at the moment to reduce my household expenses. I am an Engineer by trade and would rather give something a go for myself than pay someone else to do it. I have recently put together my own 3kw solar system. I wired up 3kw's of 24v panels to 48v to reduce the amount & size of cable used. I have a 5kw grid tie inverter which has an input voltage range of 28v dc to 52v dc and an open circuit voltage of about 80-90v dc, but overlooked the need for a solar regulator/controller. My question is, can I use a large capacitor in place of 48v batteries as I do not want and cannot afford to spend anymore on storage or batteries, I just want to trick the controller to think that batteries are connected. I have sourced a couple of very large capacitors that were removed in good working order from the power factor correction board in the factory I work. I fully understand how quickly capacitors charge & discharge. All I wish to do is power my grid tie inverter. Any help would be much appreciated. Cheers