"Getting off the Grid" - Solar systems
There’s no doubt, to be totally self-sufficient and independent from the National grid would be amazing!
However, when dealing with solar power, there are a few things you should know.
Off the grid is a term that gets thrown around easily but entails more than a flick of the switch. It is a little more intricate than that. Especially when you are investigating the most viable alternative: Solar.
Understanding Solar panels
Firstly, your peak energy requirements (Hot water and mealtimes) normally occur early in the morning and late during the day or evening. Your solar panels on the other hand will be producing their peak power around mid-day.
Secondly the daily power production from your solar panels is dependent on sunshine hours. They can fluctuate from one day to the other. A rainy overcast day will drop your power production substantially. In wintertime sunlight hours decrease.
As a result, you will need to store the energy on site. This means you will require batteries.
In this short blog entry, we pick apart the 3 main options available when looking at a Solar energy system:
If you are convinced you want to be self-sufficient or your location limits the access to the National Grid, then a pure Off-grid solar solution is for you.
An Off-grid system will consist of Solar panels, Solar charge controller, Off-grid inverter, DC disconnect switch, back up.
Lead Acid batteries are suitable when the system is not used frequently.
Solar Charge Controller.
A solar charge controller is a battery regulator that protects the battery from overcharging. It limits the rate of current being delivered to the battery. A top-quality controller will ensure the health and life span of your batteries. The solar charge controller can be included in the Inverter.
Off grid inverter.
DC Disconnect Switch.
Safety AC and DC disconnect switches are mandatory for all solar installations. However, for an Off-grid system an additional DC disconnect switch is required. It is placed between the battery bank and the inverter. This allows the current to be switched off between the two components. This is important for protection and during troubleshooting. It also allows safe access during maintenance work.
You should consider back up. A lack of sunshine during a few days or a problem with the system could leave you stranded with no electricity at all. The backup can be a connection to the grid (if nearby). If you do not have access to the grid, you should consider a generator or perhaps an additional UPS system.
Grid tied solar system
At present Grid tied solar systems have the best economical return. That is if your utility supplier at your location allows net metering.
Grid tied systems are made up of solar panels, inverter, and a power metre.
If you can match your solar panels to your usage, you could technically no longer have an electricity bill to pay.
As previously stated, an inverter will transform the DC power into AC. However, you will require an inverter able to match the grid’s frequency.
Keep some candles.
The downside of a Grid-tied solar system is that it doesn’t protect you from power outages (load shedding). To do that you would have to look at a Hybrid Solar system. . In order for your system to be operational, the grid needs to operational too.
Hybrid solar system
The easiest way to describe a Hybrid system is to see it as a Grid tied system with an extra battery back up built in. This allows you to overcome load shedding.