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Off-Grid Solar Systems

An off-grid solar system (off-the-grid, standalone) is the obvious alternative to one that is grid-tied. For homeowners that have access to the grid, off-grid solar systems are usually out of question. Here`s why:


To ensure access to electricity at all times, off-grid solar systems require battery storage and a backup generator (if you live off-the-grid). On top of this, a battery bank typically needs to be replaced after 10 years. Batteries are complicated, expensive and decrease overall system efficiency.



Advantages of Off-Grid Solar Systems


1. No access to the utility grid

Off-grid solar systems can be cheaper than extending power lines in certain remote areas.


Consider off-gird if you’re more than 100 yards from the grid. The costs of overhead transmission lines range from S$174,000 per km to S$11,000,000 per km.


2. Become energy self-sufficient

Living off the grid and being self-sufficient feels good. For some people, this feeling feeling is worth more than saving money. Energy self-sufficiency is also a form of security. Power failures on the utility grid do not affect off-grid solar systems.


On the flip side, batteries can only store a certain amount of energy, and during cloudy times, being connected to the grid is actually where the security is. You should install a backup generator to be prepared for these kinds of situations.


Equipment for Off-Grid Solar Systems

Typical off-grid solar systems require the following extra components:

  • Solar Charge Controller

  • Battery Bank

  • DC Disconnect (additional)

  • Off-Grid Inverter

  • Backup Generator (optional)


1. Solar Charge Controller

Solar charge controllers are also known as charge regulators or just battery regulators. The last term is probably the best to describe what this device actually does: Solar battery chargers limit the rate of current being delivered to the battery bank and protect the batteries from overcharging.


Good charge controllers are crucial for keeping the batteries healthy, which ensures the lifetime of a battery bank is maximized. If you have a battery-based inverter, chances are that the charge controller is integrated.


2. Battery Bank

Without a battery bank (or a generator) it’ll be lights out by sunset. A battery bank is essentially a group of batteries wired together.


3. DC Disconnect Switch