Solar Charger for my EV?

 2020-01-18 01:37 PM by
Solar Charger for my EV?

We are often asked if we supply solar chargers for EVs. EVs don’t care from where the electricity required to charge them originates, so whether the power comes from the power grid, wind, solar and so forth, it does not matter, you simply plug your EV charger into that source of power.  So yes, we do supply solar chargers for your EV, if you have solar power or plan on getting it.

Solar technology has become cheaper over the years. There are various types of solar solutions available, with a grid tied system using PV panels and microinverters being one of the most cost effective solutions out there, but this blog is not about the various options. This blog is about my own experience with this type of solar solution for my EV.

I recently decided to install a grid-tied solar system at home. A grid-tied system means that in order for it to function, it has to be connected to the power grid (ultimately Eskom). This also means then that during load shedding, the system will not produce any electricity. I can almost hear your thoughts about this making no sense at all in a country where we all experience load shedding from time to time. Hear me out. An off grid solar system is way more expensive than a grid tied system due to the cost of the storage batteries required. Grid-tied systems do not need storage batteries, but they can be included. In my view, the cost of investing in batteries compared to the amount of load shedding we actually receive does not justify that investment. Sure, we all get very annoyed when load shedding occurs, but historically, when we are load shed, it lasts for no longer than about a week, because someone in government threatens people at Eskom and a plan is made to end it, for a while. If load shedding becomes a daily occurrence lasting for weeks on end, I would then consider adding batteries to my grid tied solar system.

Simplistically, the way a grid tied system works is that the power that you would normally draw from the grid is supplied by the PV panels. Obviously, the higher the number of panels installed, the more power will be generated by them. This means that only the shortfall of power required to power your home that the panels don’t produce is provided by the grid, or in other words, the grid can be seen to top up any shortfall of power that the panels do not produce. Grid tied systems are therefore generally for those consumers who drastically want to reduce their reliance on the grid. This could be for a number of personal reasons like wanting to be green thereby not wanting to use dirty grid energy produced form coal powered power stations or simply for saving money in the long run.

I initially installed an 8 panel system, and I have found that each of my panels produces slightly shy of 2kWh of energy per day. So, with 8 panels, the system generates 16kWh per day. I drive a BMW i3 94Ah (ie 33kWh battery) and get an average energy consumption of 14kW/100km. Let’s for simplicity sake increase the i3 consumption to 15kWh/100kms and reduce the output of 8 panels to 15kWh per day. This means that an 8 panel system is sufficient to drive my i3 100kms per day. I only drive 50km per day, so the excess power is used to help power my home and the shortfall from the grid.

I have been so impressed with how the system has performed, that I increased the number of panels to 12. These panels produce approximately 24kWh per day or 700 kWh per month. At R2,00 per kW/h for grid prices, this equates to around a reduction of R1400 per month in grid electricity costs. Another way of looking at it is that the energy produced with 12 panels would be sufficient to drive my i3 for 180kms per day or 65,700 kms per year. At the end of the day, I think it’s a no-brainer to go solar.  I welcome any questions or comments.