If you’re off-grid, this means that you have no connection to public grids providing electricity, with solar energy providing all your electrical energy needs. It’s important to remember being off-grid can also mean no access to gas, water and sewage public utilities.
Producing electricity can be quite costly
Unlike a system that operates at full capacity all the time (the grid can take any excess energy and someone else uses it), with an off-grid solar PV system producing electricity, you’re almost never going to reach close to 100% utilisation.
Excess and overdraw on electricity can be expensive
Since you don’t have an inertie system to sell excess energy, nor can you depend on public utility electricity to cover for times when you’re drawing more than your solar PV system can produce, you need some expensive countermeasures to ensure there’s minimal energy waste.
Storing energy can be expensive
Some systems you’ll need to have connected to your solar PV system are batteries and controllers for the batteries in order to store energy. Not only are these extra systems expensive and maintenance-heavy, some of that energy gets lost as it is stored.
Batteries are inherently inefficient
When energy is stored in a battery, a certain amount is lost. When energy is drawn from a battery, a certain amount lost again. On average, the loss is 20% of the total charge so for every 100 watt-hours, 20 are lost irretrievably. With age, capacity also deteriorates.
Batteries lose charge without use
If you don’t use your batteries and just let them sit there doing nothing, they’ll be losing around 5% of their stored capacity every month. Worse still, if you see that they have dirty, oily or corroded tops, you lose 5% almost every week.
Sometimes they won’t even charge properly
The internal crystals of a battery can sometimes crystallise, meaning that they are less able to hold a charge. One solution is to ensure that you frequently charge and discharge your batteries frequently. This should hopefully prevent unwanted crystallisation and improve battery life.
Battery acid is pretty nasty
Don’t touch it. But even if you don’t touch it, the gases it produces are poisonous. It’s easy to forget about it in sealed batteries that we use every day, but sealed batteries are less efficient, therefore more expensive in the long term. Consider putting them in an underground chamber.
Still not convinced batteries are dangerous?
We haven’t even mentioned the point of batteries – storing electrical energy in huge quantities and then releasing it again on demand. The amounts of current that they can output makes electrical shocks look like a tickle. It can even melt metal.
Basically, batteries are like babies. With razor sharp teeth.
Push them too hard and they’ll wear out quickly or get damaged. But give them the same care and attention (and room) as a pet and they’ll be just fine.