Generators
Generators can provide electricity where there is no electrical grid by burning gasoline, diesel fuel or propane.
Although they can provide large amounts of power, they are noisy, polluting and expensive to run for long periods of time. Also, as with all combustion engines, the efficiency of a generator is quite low. Typically, 80% of the energy in the fuel is lost as heat.
Television Example
You use a light and a television for one evening (4 hours):
- On the Hydro-Quebec network, the energy needed would cost you $0.04
- The same energy, coming from a gasoline generator, would cost around 4 $*, so 100x more.
*) assumed: 1.70 $ per litre of gasoline, 0.6 L/h of consumption on average, television and light: 90 W on average, Hydro-Quebec: 0.08 $/kWh
Example fridge
You plug in your fridge all day (24h):
- On the Hydro-Quebec network, the necessary energy would cost you $0.10
- The same energy, coming from a gasoline generator, would cost around $24*, so 240x more.
*) assumed: 1.70 $ per litre of gasoline, 0.6 L/h of consumption on average, fridge: 50 W on average, Hydro-Quebec: 0.08 $/kWh
The huge difference in price can be explained with the idle consumption of a generator: The engine consumes around 0.5 L per hour just to keep itself running.
What are the alternatives?
For permanent installations, off-grid solar systems are an interesting option.
For small to medium loads, small portable solar power stations, also called solar generators, are a portable alternative. They have built-in batteries that can be charged directly with solar panels.
When should you avoid using a generator?
- When the electrical consumption is low (lighting, refrigerator, cell phone, laptop), the efficiency of the generator is even lower.
- When used for long periods of time (several hours a day, several weeks a year).
- When noise and pollution are particularly undesirable.
When does it make sense to use a generator?
- As a backup, e.g. for off-grid solar systems (when batteries are low, on cloudy days).
- For temporary situations requiring high power, such as on construction sites with air compressors and heavy tools.
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