Residential backup generators have become more than just a luxury in some parts of the country, especially those that receive regular bouts of severe weather that strain the infrastructure of the electricity grid. In fact, they’ve become regular items on many suggested emergency preparedness lists for your home.
But while setting up one might sound as easy as just going down to your local home improvement store, creating a permanent stand-by system is actually complex and incorporates safety features best handled by professionals. So, if you’re thinking about investing in a generator for your home, it will pay to understand what these systems are and how they work.
The Basics of the Grid-Tie Standby Generators
The average residential standby generator is placed outside the home on precast concrete slabs. And since an engine spins the generator to make electric power, the noise created by that engine is definitely a factor when choosing which system is right for your needs.
For grid-tie installations, the generator and the incoming grid wires must be tied into the transfer switch. This works by monitoring the incoming grid power. If the power fails, the generator switches off contact with the grid and starts up its engine to generate power for your home.
By disconnecting contact with the grid, the generator’s electricity will only power your house. This usually takes no more than thirty seconds. When the grid power becomes available again, the switching circuit will automatically switch over and then the generator will turn off.
Know Your Fuel Options
Residential standby generators commonly use natural gas for fuel, which means you’d need to set up a natural gas line from your gas meter right to the generator. However, if your neighborhood lacks natural gas lines, you can use liquid propane (LP). A standard residential-sized LP tank holds 500 gallons and would require piping to to the generator. If you want another option, diesel-powered generators are also available.
The amount of fuel the generator burns depends on its size and the electrical load, so you’ll also want to examine the energy efficiency of your home in conjunction with that of the generator.
Know What’s Watt
Residential backup generators are sold by wattage capacity – aka, how much power they put out – and it’s usually measured in kilowatts (kW). You’ll need to know the wattage-usage of your home, and this can depend on where you live and the time of year, as blasting your air conditioner in the summer can really add onto your electricity usage.
To find an approximate average watts used by hour in your home, find the average kilowatt/hour (kWh) usage per day on your electricity bill and divide that number by 24 hours. For additional help, generator manufacturers like Cummins, GE, Generac, and Kohler have home wattage tools on their websites to help you calculate how much you need.
It’s better to buy a backup generator that meets your power needs instead of one that delivers 3/4 of what you need just because it’s cheaper. Over-burdening a generator can negatively affect its voltage output and damage the things it’s powering, including HVAC motors and compressors. Overloads can also overheat the generator and melt its components.
Bringing the Power into the Home
Because of all the sensitive electronics in our homes, you should have Alternating Current electricity with a nice, clean sine-wave cycling at a frequency of 60 hertz. Unfortunately, noise and harmonics in the electricity (from electric motors, transforming circuits, and more – from anywhere on the grid) disrupts that sine-wave, which can damage these valuable electronics.
Thankfully, residential backup generators include power filter circuitry to remove damaging noise and harmonics. Most portable generators don’t, requiring you to purchase add-on filters.
Talk to a Professional
Installing a generator for your home is complex and must meet local and state safety regulations. This is especially true when you consider the safety requirements of different fuel systems and making safe electrical connections.
Contact the electricity professionals at Mister Sparky to learn what it would take to install a permanent standby generator in your home. You will want a safe, reliable, and affordable system so your family can be safe – and not in the dark – if you ever lose power because of a weather emergency.