Guide to Generator Use
By definition, all generators produce electrical power; however, the amount of electrical power they produce and the fuel consumed to produce that power vary considerably. The vast majority of home generators still use fossil fuels but recent years have seen a rise in the use of renewable energy sources, especially solar power and wind power.
For most people, the limiting factor on a generator purchase is cost since installing enough solar panels to power your whole house is extremely expensive. However, it’s important to figure in the return on that investment. Operating those solar panels costs almost nothing and the electrical power they generate is free. That makes it possible for the panels to eventually pay for themselves.
Since generators are used for multiple purposes, ultimately that purpose has to be what drives your purchase. Some generators work best in certain circumstances, while others are better suited for a totally different set of circumstances.
Individuals who are building a cabin in the mountains or those spending a weekend camping might find themselves needing short-term power. In such cases, it makes more sense to use a portable generator that burns fossil fuels, as it takes time and effort to erect a solar or wind powered generator. In these cases, inverter generators are more fuel efficient, more than making up for their higher cost.
Short-Term Emergency Power
A short-term emergency might be caused by a hurricane or storm blowing down power lines which leaves communities without power. Whole house generators have been designed with this scenario in mind as they kick on automatically with little to no disruption to normal activities.
For those who can’t afford a whole house generator, portable generators will accomplish the same thing, albeit at a lower power level. Rather than being able to run the whole house, a portable generator provides power for only the most critical of systems. How much can be used depends on the power output of the generator.
Long-Term Emergency Power
While a whole house generator will provide the necessary power to make it through a storm, a long-term situation would require constant supplies of fuel which may not be possible in a long-term emergency situation. On top of that, the constant use of fuel in a whole house or portable generator would get expensive quickly.
For long-term emergency power, wind and solar generators are better. These systems are totally self-contained and require no fuel beyond what nature provides. As such, these generator systems provide electrical power through a major disaster, even one which shuts down the power grid permanently.
Off Grid Living
Living off the grid is becoming more and more popular. People choose this lifestyle either for financial reasons to save on their monthly electric bill or for the simple reasons of wanting to live independently. In these instances, wind and solar generators are the logical choice.
Typically, people making the transition to off grid living do so gradually, adding more solar panels or more wind turbines as their budget permits. Each addition allows them to produce more of their own electricity, reducing their dependence on the grid and their monthly energy costs. From there, money saved on energy bills can then be invested into further increasing their systems capabilities.
A combination of solar and wind power is the best as it helps ensure consistent power at all times, regardless of what the weather situation is. Of course, a battery backup system helps to ensure constant power, even when neither system is capable of generating power.
Selecting the Type of Generator
We can divide generators into five different categories, each of which is designed to be ideal for certain circumstances.
Portable generators provide a reasonable amount of power for either an emergency or use in a remote location. A typical portable generator will produce from 4.5 to 6.5 kilowatt-hour (KwH) which is enough to power a room air conditioner. They work well for construction sites and camping. However, typical portable generator will consume about 1/2 gallon of fuel per hour making them somewhat fuel inefficient.
Inverter generators are a modified version of the portable generator. They produce power at 12 volts DC, rather than 120 volts AC and then use an inverter to boost the power to the higher voltage. This makes them much more energy efficient than portable generators are. A typical inverter generator will run on about two gallons of fuel per 24 hours of use. The limiting factors on these particular units are usually their size and cost.
Whole House Generators
Whole house generators are the portable generator’s big brother. They’re designed to be permanently installed and connected to the home’s electrical system, just before the breaker panel. An automatic switch starts the generator and disconnects the house from the grid in the event of a power outage. The same switch will shut down the generator and reconnect the house when power is restored.
These generators are available in a variety of sizes, with some topping 55 KwH. This allows you to select one that will provide all the power your home needs. The only problem with these units is they consume a lot of fuel, thus making them very expensive to operate.
Solar generators consist of a bank of solar panels, connected together and run through a voltage inverter. This can either be connected to a battery backup system or run directly into the home’s electrical system. The solar panels convert sunlight to electrical power, typically with an 18 to 20 volt output, hence the need for the voltage inverter.
Since solar generators need sunlight to operate, they don’t produce any power at night. Overcast days reduce their power output which is why they have a higher voltage output than is needed to charge the batteries; when their output is lowered, they’re still able to provide enough power.
Wind generators convert the kinetic power of the wind into electrical power. Like solar generators, they produce a higher voltage than is necessary to charge a 12 volt battery. That way, they can provide some power in lower wind situations. Typically, a wind generator needs 10 miles per hour of wind to work efficiently.
Because of the wind requirement, wind generators can’t be used everywhere. Some areas don’t have enough wind to make them cost effective. But in areas where there is sufficient wind, a wind generator is a very efficient means of producing power.
One problem with wind generators is that they can be noisy. For this reason, some municipalities do not allow them. Vertical axis wind generators, which are much rarer, produce much less noise.
Determining Generator Size
There are two ways of looking at what sized generator you would need for your home. One is to calculate your total power consumption and find a generator that will supply that amount of power. This means buying a whole house generator and having it permanently installed in your home. Since most people can’t afford a whole home option, they buy some sort of portable generator.
When buying a portable generator, you still have to know how much power you need before making a purchase. That means defining what your critical systems are and how much power they’ll consume. For most people, the critical systems include their refrigerator, communications, and some basic lighting; in hotter climates, a one room air conditioner should be included. Other additions might include a computer and any medical equipment that a family member needs.
Most of equipment is rated in amps of power draw, rather than watts of power consumption. Although generators are rated in watts, the conversion from one to the other is actually rather simple.
– To convert watts to amps, divide the watts by the voltage (120)
– To convert amps to watts, multiply the amps by the voltage (120)
With that, you can calculate the amount of electrical power you need your generator to produce in order to meet your needs in an emergency situation