Residential Solar – Living Off The Grid
Living off the grid with solar power is indeed a brave step to take, as all or most of your electricity is from the sun only and none from a power utility such as a hydroelectric dam or a natural gas-fired plant.
If you want to be living off the grid, you have two choices. Either you employ an additional diesel generator to cover non-sunny periods or you have a sufficiently sized battery package and solar array to store various days of electricity. In each case, the cost for the solar system is significant and we would need to know the loads you have in your household in order to be able to size the system adequately.
Without a diesel generator as a backup option it may then occur to you that you may have some instants during the year especially in winter, where you may not have sufficient electricity to run all your loads. The cost for a completely autonomous system would likely begin with $25,000 up to $50,000 with a diesel generator as a rough dimension. This highly depends on your usage and flexibility in demand.
In order for you to be living off the grid, there is a process which will have to be undertaken:
1. We work out your power requirements
2. Sizing the battery bank appropriately
3. Sizing the solar array appropriately
4. Wire Sizing
In order for us to design an off-grid system for you, it is very essential that we understand your power requirements. We will require a background of your previous electricity bills, how much you are consuming and what you are paying for this consumption and we would also need to know what time of they day most of your electricity is consumed in. Sizing the battery bank is a critical process which can only be done properly if your power consumption data is well understood. Battery sizing will take into account your demand per day, along with the number of days in which there is no sunlight available. You can learn more about battery sizing here.
Firstly there is the sun sending it’s rays to the modules, in which electrical energy is created. The component which is involved in the next step of the process is a charge controller. This is a new component which is only required for an off-grid system only. It is this charge controller that controls the charging of the batteries, which is actually very similar to how mobile phone charger charges the battery of the mobile phone. The batteries are then involved next, and they are the most important components of the system. The electrical energy created from the modules have to be stored in these batteries when the sun isn’t shining. However if the sun is out, then the DC energy stored in the batteries will then pass through the inverter, which converts the energy into AC. This suitable AC power is then passed through to the service box in the house which distributes the electricity within the household.
As mentioned above, you can employ an optional generator, which is mostly a diesel generator. That generator can cover your house’s electrical needs when there are periods with no sun, as opposed to storing the energy in the batteries. The choice is completely up to you, if you’d like to be living off the grid.
It also needs to be mentioned that there are two types of an off-grid solar system: AC-coupled system and DC-coupled system. You can learn more about the comparison between them here.