I had time to make a few images of what I had in mind for the dutch bucket system. They are not done to scale, but I think they give you a better idea what I am/was thinking. Also the designs are drawn around using 5 gallon buckets for the large bucket, and 3 or 4 gallon buckets for the small bucket (that holds the plants). But the basic idea is what's important because I am not sure what you have available. You can use almost anything you can get your hands on. I can get many different size storage containers at the local Walmart fairly cheaply. You may even find local restaurants that are throwing away containers that would work for you.
Also to make it easy to draw, I made the overflow tube inside the large bucket straight, but you can use a flexible line if space is an issue. The key is the top of the overflow is above the bottom of the bucket that holds the plants. This way the
growing medium will be able to wick up the water from the reserve in the bottom bucket, when/if power goes out. Problem is (as with the dutch bucket design) if the water level in the bottom bucket is too high, it can water log the root system (power or not). Getting the best fit for this level is the key to it working well. So you will need to do some trial and error with this height, as well as the type of growing medium you are using, and even time of year.