The evolution of our micro grid – upgrading our solar setup to suit our needs

Six years ago, we had this vision of making the most of Australia’s most abundant energy source which is sunshine by living 100% of solar energy. Fast forward to present time, we made this vision a reality and went even further. By the time of writing this article, we’ve been living off solar energy for almost four years and even manage to charge our electric car off our micro grid. So how did we get here?

Start small and evolve 

Before buying anything, we borrowed an electricity consumption meter to measure how much electricity our appliances and devices use.This gave us a rough idea on how big the solar system needed to be. Our initial solar system consisted of six solar panels which each generated 310W, one 4kW inverter and 24 lead-acid batteries. In total, the system generated 1.86kW. To make things easy, we bought an off-grid all in one kit from an Australian company. (To my knowledge, this company does not exist any more.)  

This “little starter kit” cost us around A$15k and it served us well for more than four years (if we include one year of building our tiny house). It was the first thing we ordered because we built our tiny house in the middle of a paddock and needed power for our tools. If we were to do it all over again and with the knowledge we have now, we would buy lithium ion batteries but back then they were still very expensive and not readily available. 

After about three years of living with this setup, we added three additional panels to our system. Each of these panels is able to generate 330W. This brought the total number of solar panels to nine and the total of solar energy generation to 2.8kW. We decided to add those panels after one particularly overcast and grey winter where there were days on which we struggled to generate enough energy to charge our batteries. After adding those additional panels, energy generation and charging our batteries got much faster and we didn’t need to worry so much anymore.

Throwing an electric car into the mix

A short time later, we bought an electric car and were determined to charge it off our micro grid. So we upgraded our solar system again. This time we added six more panels, each able to generate 330W. Our micro grid now consisted of 15 solar panels which combined generated 4.8kW. The upgrades didn’t stop there though. 

Initially, we (mostly Paul) were charging the car manually. This means that Paul had to constantly adjust the AMP rate the car was charging at to match the amount of energy the system was generating to make sure not to overwork the batteries. Needless to say that this method was not very efficient and we wanted to automate the system. This is when we came across the Zappi from My Energy. I talk about the Zappi in more detail in another blog post. In order to make the Zappi work with our solar powered off-grid micro grid, we had to change inverters. So we sold our old 4kW inverter and swapped it for a 5kW PV inverter to cope with the load and a battery inverter. Again, for the full story, click here

The system works a treat now! 

Charging the house and car has never been easier. Thanks to the Zappi, the whole system is now fully automated and we don’t worry about our batteries at all anymore. 

To sum it up, our current system consists of 

• 15 solar panels (6x310W, 9x330W)
• 24 lead-acid batteries
• 2 inverters, a 5kW PV inverter and a battery inverter

Keep in mind  that every solar setup is different and depends on a number of factors like household size, usage, types of appliances, etc. There’s no one fits all solution but there is always a solution! The beauty of a solar system is that it’s adjustable. Just look at our example. Over the years, we added nine more panels to our setup as our need for solar power increased.

There is nothing wrong with starting small and then amending your micro grid to suit your needs.