Practical Guide
Generating Power During a Grid Outage
A real-world guide to generators for the home -- types, costs, maintenance, operation, and a complete setup example. Written after hands-on experience helping neighbors through a major hurricane in Houston.
Introduction
The information provided in this guide is not all-inclusive. It is a collection of my research results and experiences. If you have corrections or additions, please submit them to tjelias@yahoo.com. This guide is meant for personal home environments -- commercial applications vary greatly from what is contained here. Feel free to share this guide with others.
Safety must come first when applying any solutions regarding electricity and fuels. Read the owner's / operator's manual for the products you are using. Pay special attention to the safety warnings and maintenance sections.
Whole-home power refers to the ability to have power throughout the entire house. This does not necessarily mean you can power everything at once, but you can power most things on demand -- turning a light on, using any outlet, etc. The advantage is that refrigerators, freezers, air conditioners, gas clothes dryers, and gas water heaters will automatically be powered as needed. This is accomplished by connecting the generator to the 220-volt house power feed (or back-feeding into a 220-volt dryer outlet), feeding both 110-volt phases simultaneously and eliminating the need to run extension cords to individual appliances.
I provided advice and training to several friends and neighbors on generator setup, operation, and maintenance during the recent hurricane that hit Houston. Most of us cannot justify the purchase of a standby generator. I am writing this guide because the information is fresh in my mind and others have asked for direction going forward. I will update this guide as new information comes to me and as I receive feedback.
I do not hold any interest in the products, services, or brands mentioned in this guide.
Why Get a Generator?
Most people are fine without power for a few hours, even a day. The longer the outage, the more difficult life becomes.
- Food preservation -- Keeping refrigerated and frozen food is at the top of most people's list, especially families with children. It represents both a food supply and a significant dollar investment.
- Cooking -- Restaurants are often closed during outages. Outside grills help, but not everything can be cooked on one.
- Medications and pets -- Medications requiring refrigeration and pet breeds sensitive to heat are strong motivators.
- Creature comfort -- High temperatures and humidity wear on you. Sleep becomes difficult without air conditioning or fans.
Generator Types
There are several generator types available for personal use. The notable options are portable inverters, portable generators, portable whole-home generators, and standby generators.
Most apartments do not allow running generators. A portable power station may be a viable option in that case.
Power Bank
Portable Power Station
Portable Inverter
Portable Generator
Portable Whole-Home Generator
Standby Power Generator
Standby generators are sometimes installed on the same exterior wall as a central air compressor. The AC unit can push exhaust gases up into overhead soffit vents, causing a dangerous accumulation of CO (carbon monoxide) inside the house -- CO is heavier than air and will migrate down from the attic into living areas. Choose placement carefully.
Home Solar Panels
Operating Costs
These are general calculations. Actual load on the generator will cause variances. Most generators other than standby units are single-fuel (gasoline only). Other models are dual-fuel (gasoline or propane). Tri-fuel models are also available (gasoline, propane, or natural gas).
Calculations are based on: Gasoline $3.00/gallon • Propane $18.00/15-lb bottle exchange • Natural gas based on average internet cost.
In addition to fuel, oil changes should be factored in -- typically every 4 days (96 hours) of continuous use.
| Generator Type | Fuel | Max Runtime | Min Operating Cost |
|---|---|---|---|
| Portable Inverter | Gasoline | 12 hrs / 3 gal | $0.75/hr ($18/day) |
| Propane | 12 hrs / 15 lbs | $1.50/hr ($36/day) | |
| Portable Generator | Gasoline | 12 hrs / 5 gal | $1.25/hr ($30/day) |
| Propane | 7.2 hrs / 15 lbs | $2.50/hr ($60/day) | |
| Portable Whole-Home | Gasoline | 12 hrs / 8 gal | $2.00/hr ($48/day) |
| Propane | 12 hrs / 15 lbs | $4.00/hr ($96/day) | |
| Natural Gas | Indefinite | $1.50/hr ($36/day) | |
| Standby Generator | Natural Gas | Indefinite | $2.00/hr ($48/day) |
| Propane | Unknown | Unknown |
Generator Maintenance
Always read the documentation supplied with your specific generator for guidelines more precise than those provided here.
Pre-Use (New Generator Break-In)
A new generator motor needs to run for an initial period to allow engine parts to wear in together, which produces metallic byproducts. Most manufacturers recommend running without a load for 5 hours on the initial oil fill. After that, change the oil and the generator is ready for full duty. Strict adherence is not required, but the engine will last longer if this is followed.
While In Use
- Periodically inspect power cords for binding, wear, and hot ends -- any of these can cause issues if unattended.
- Change the oil (and filter if equipped) every 4 days (96 hours) of continuous use.
Long-Term Maintenance
- Add fuel stabilizer to stored gasoline.
- Keep the battery charged (if equipped).
- Change the oil yearly, even if the generator has not been used much.
Preparations
- Keep a few extra quarts of oil on hand -- change every 4 days of continuous running.
- Have the necessary tools and an oil drain pan available.
- Store fuel ahead of time. Gasoline and propane may be in short supply immediately before and during an event.
- Run the generator every 3 months to confirm it starts and runs normally.
Generator Placement
Choose a location that is dry and close to the power connection point. Ensure adequate ventilation to prevent CO (carbon monoxide) gases from accumulating or being directed into inhabited spaces. Keep in mind that CO is heavier than air and will settle at floor level.
For permanent standby installations: position away from air conditioning compressors and soffit vents (see the standby generator warning above). Provide a dedicated location close to the fixed fuel source and fixed electrical feed. Consider an automatic transfer switch ($700 -- $1,500 installed) or a manual transfer switch.
Operation
Do
- Practice safety at all times while handling and operating generators.
- Check cords frequently for heat -- hot cords indicate too much load.
- Change the oil per the manual. Consistent oil changes can make a generator last decades.
- Have a fire extinguisher nearby.
Don't
- Run an engine in an enclosed area -- house, garage, or closed patio. People die from CO poisoning during events because of this.
- Add fuel while the generator is running -- fuel can ignite from heat or spark. Many house fires during outages start this way.
- Overload the generator -- sustained bogging indicates too much load. On lower-capacity units avoid hair dryers, air fryers, microwave ovens, and toasters simultaneously.
- Daisy-chain too many extension cords in series.
- Use extension cords with small-gauge wire (low load capacity).
- Operate in rain or wet conditions -- water can damage electrical components and cause cracking from cold water hitting a hot engine block.
Best Practices
- Install CO (carbon monoxide) detectors near floor level on all floors -- CO is heavier than air and accumulates at ground level.
- Let the generator cool 5 -- 10 minutes before adding fuel.
- Let the generator cool 5 -- 10 minutes before changing the oil.
- Change the oil (and filter if present) every 4 days of continuous use.
- Lock the generator with a chain -- they are common theft targets during events.
- Keep extra oil on hand, as it may be hard to purchase during an extended outage.
Shutdown
- If the oil has been in use for less than 4 days, leave it in the generator for storage. Putting fresh oil in and then storing is wasteful.
- Connect the battery to a trickle charger to keep it from dying between uses. Most electric-start generators charge the battery while running.
Short-Term Storage -- Gasoline (Up to 3 Months)
This is the recommended method during storm season.
- Run the generator for 15 minutes, then stop the fuel supply and let the engine die on its own. This empties the carburetor of fuel, preventing varnish buildup. Consult the manual -- most generators have a fuel shutoff valve.
- Leave remaining fuel in the generator tank.
- Keep remaining fuel in approved gas cans.
- Adding a fuel stabilizer is never a bad idea.
Long-Term Storage
Option 1
- Drain fuel from the generator tank and repurpose it.
- Use remaining gas-can fuel for other purposes.
Option 2
- Leave fuel in the generator with stabilizer added.
- Run the generator 10 minutes every 2 -- 3 months under load, then shut off the fuel to the carburetor to let it die.
- After 2 years, follow Option 1.
Additional Information
Watts and Amps
Typical Loads
Consult owner's manuals for power requirements of specific devices. As a general rule, keep running load at no more than 60% of the generator's rated capacity to allow headroom for startup surges from inductive loads (AC units, refrigerators, freezers).
- 3 KW -- Refrigerator, freezer, portable or small window AC, a fan or two, and charging phones/tablets/laptops.
- 6 KW -- Everything in the 3 KW list, plus microwave ovens and hot plates.
- 10 KW -- 3-ton central air conditioner, microwave ovens, pool pump, gas clothes dryer.
- 20 KW -- 5-ton central AC, electric clothes dryer and washer, air fryers, toaster ovens, hair dryers, curling irons.
High-draw items to manage carefully: hair dryer, flat iron, curling iron, clothes iron, electric dryer, air conditioner, space heater, toaster, hot plate, microwave, washing machine, and pool pump. If large loads are needed, stagger them -- run only a few at a time.
Real-world example: I helped a small business run a large ice machine, 3 freezers, 2 refrigerators, 2 large TVs with satellite receivers, several fans, and multiple phones charging -- all from a 6.5 KW generator -- for days without issues. Your mileage may vary.
Fuel Sources
Fuel sourcing is often the most frustrating part of operating a generator during an event. When demand for gasoline or propane spikes, lines are long, and gas stations without power cannot sell fuel.
Gasoline -- The most common fuel. Affordable and widely available except during high-demand events. Produces the most power from a multi-fuel generator. Stock up when an event is approaching -- do not wait. Gasoline stored more than 3 months needs a fuel stabilizer. Gasoline that has gone bad develops a strange smell and will gum up the carburetor. If condensation has introduced water into a tank, add a few ounces of rubbing alcohol -- it bonds with the water and evaporates with it.
For older generators with carbon buildup, Sea Foam fuel additive is recommended. It cleans engine internals as the engine runs. Using slightly more than specified is fine -- the worst result is white exhaust smoke until the carbon clears.
Most gasoline today is an ethanol blend. Up to 15% ethanol (E15) is fine for small engines. E-85 (85% ethanol) is not appropriate for small engines and will cause engine damage.
Propane -- A convenient option if the generator supports it. 15-lb bottles can be purchased or exchanged at grocery stores, Lowe's, Home Depot, and many other locations. They can also be refilled at ACE Hardware and U-Haul locations.
Natural Gas -- The most convenient and reliable fuel source. Typically available throughout events, eliminating the need to forage for fuel. For portable generators, a ¾″ gas feed from a dryer connection or the gas meter is adequate. This line can double as a feed for a natural gas grill when the generator is not in use. Produces slightly less power and more noise than gasoline. Standby generators typically require a 1″ feed from the gas meter.
Solar -- Free but inefficient, and unavailable at night or during cloudy weather.
Fuel Stabilizers
Additives that extend the shelf life of gasoline -- up to 2 years depending on the product (read the label). Sea Foam is a great stabilizer that also provides additional cleaning benefits. Available at Walmart, Lowe's, auto parts stores, and most hardware stores. Stabilized fuel should be repurposed after 2 years. Unstabilized fuel should be repurposed after 3 months.
Oil
All generators use essentially the same type of oil. The generator manual will provide specific guidance. SAE 30 small engine oil is fine. 10W-30 (or 10W-40 in a pinch) also works. Some higher-end units recommend 5W-30. When changing, pour the drained oil into the empty oil bottle after it cools slightly. Most auto parts stores collect used oil for recycling.
Automation
Electric start is a significant convenience -- no pull cord required. Most new generators start in 1 -- 2 pulls when properly maintained, but pull-starting becomes harder as they age. Factor this into your purchase decision. All generator types can have the electric start option, and electric-start generators include a battery.
Automatic transfer switches are most practical with standby generators. They manage power switching automatically and cost approximately $700 -- $1,500 installed. For portable generators, a manual transfer switch is more appropriate but is not required -- without one, the main breaker is simply switched manually as needed.
Power Connectivity
Efficiency means more available power reaching the load. Resistance reduces power delivery and heats wires.
- Shorter power cords are more efficient.
- Thicker wire gauge is more efficient.
- Fewer connections in the cord run means more efficiency.
Recommendations: avoid chaining multiple cords together where possible; avoid power splitters, surge strips, and mini extension cords for larger loads; use heavier-gauge extension cords for high-draw devices (a refrigerator draws far more than a fan).
Trickle Charger
A trickle charger connects to the generator battery to keep it charged between uses. Quality units extend battery life. They eliminate the need to manually check and charge the battery periodically. Cost: $15 -- $80.
CO -- Carbon Monoxide Safety
CO (carbon monoxide) is produced by combustion engines burning fossil fuel. It is colorless, odorless, and extremely dangerous even in small concentrations. It is heavier than air and settles near the ground unless disturbed by fans or air movement. Never run a generator in an enclosed or partially enclosed space. Install CO detectors on every floor, positioned near floor level.
By contrast, CO₂ (carbon dioxide) is what humans and animals exhale -- harmless in normal outdoor concentrations. Do not confuse the two. The danger from generators is CO, not CO₂.
Lighting
Install LED bulbs wherever possible. They draw less than 1/10th the power of conventional incandescent bulbs. A 4-watt LED can produce as much light as a 100-watt conventional bulb, representing a 96% reduction in lighting load.
Air Conditioning
Air conditioners are a large load for generators. Higher-KW models are generally required. Older, less-efficient AC units demand more power than newer ones.
For central air compressors, a soft-start module can be installed to reduce the startup surge on the generator and lower overall operating costs.
Miscellaneous
- Close window coverings to reduce solar heat gain and lower the cooling load on the generator.
Retailers
Amazon, Lowe's, Home Depot, Costco, Walmart, Harbor Freight, and many others carry generators, accessories, oil, stabilizers, and related supplies.
Troubleshooting
If everything is set up and maintained properly, things should go fine -- except when they don't. The generator manual is the best first resource for specific malfunctions. Keep in mind that an engine needs four things to run: compression, spark, fuel, and air.
Gasoline Leaks Out
Never run a generator that is leaking fuel. A fuel fire can spread rapidly.
Possible causes:
- Cracked or broken fuel line -- replace damaged or worn parts.
- Cracked or worn gaskets or O-rings -- replace damaged or worn parts.
- Carburetor float stuck open -- consult a mechanic.
Generator Will Not Start
Unfortunately common when a generator has not been run for an extended period. This is why periodic test-runs are important.
Check startup procedures first:
- Fuel is available (tank filled, gas/propane hose connected)
- Fuel valve is open (if equipped)
- Correct fuel type selected (if equipped)
- On/Off switch in the on position (if equipped)
- Choke not engaged (for warm start)
- Disconnect any electrical load and try again
Dead battery (electric start): If the engine clicks or won't turn over, the battery may be dead or connections corroded. Clean connections, attempt a jump-start (same process as a car), or use the manual pull cord.
If the engine turns over but won't start:
- Old fuel -- may not burn. Try fresh fuel.
- Gummed carburetor -- old fuel left in the carburetor evaporates and leaves a sticky deposit. A mechanic may need to disassemble and clean it. Fuel stabilizer prevents this.
- Low oil level -- most generators shut down on low oil to protect the engine. Check and fill.
- Dirty air filter -- engines run on air; the fuel makes the air combustible. Remove, inspect, and clean or replace the filter. Do not run without a filter.
- No spark -- could be the plug, plug wire, or ignition coil. Consult YouTube or a mechanic.
- Compression issue -- rare in an otherwise healthy engine. Could be valves, piston rings, pistons, or the engine block. Last-resort diagnosis; consult a mechanic.
Motor Running Badly
Continuous surging, bogging, or backfiring indicates loose components, vacuum leaks, or a partially gummed carburetor.
- Check for loose components, especially the carburetor mounting screws and electrical modules.
- A partially gummed carburetor -- see above.
- Backfires are serious and indicate incorrect running or tuning. Backfires can damage the engine and cause fire. Consult a mechanic promptly.
Generator Stopped Running
- Check fuel level and connections.
- Check oil level.
- Disconnect the load and attempt to restart.
- If it dies when a load is reconnected, reduce the load.
Total Loss of Power
Generator is running but no power reaches the loads:
- Check all power cords and connections.
- Check breakers on the generator.
- Check breakers in the breaker box (if connected to the house).
Partial Loss of Power
Some loads or part of the house loses power. A cord may be partially connected, or a breaker may be partially tripped. Follow the same steps as total loss of power above.
My Setup
Total Investment: Under $1,800
- Generator: $1,100 (Amazon)
- Gas outlet installation: $300 (plumber)
- Electric plug installation: $300 (electrician)
- 220V / 50A power cable (generator to RV plug): $40 (Amazon)
My Action Plan
These are the general procedures I follow when using my generator. Your procedures will vary, especially if you use gasoline (see the Shutdown section above). Having an ordered plan avoids potentially serious mistakes. Consider keeping a printed copy in a convenient location.
When the Power Goes Out
- Bring the generator out of the garage and position it at the back of the garage.
- Connect the natural gas hose from the outdoor outlet to the generator.
- Start the generator and let it warm up while completing the remaining steps.
- Turn the AC units OFF at the thermostats inside.
- Turn OFF the breaker to the pool pump.
- Turn off or unplug all non-essential items in the house and garage (air compressor, etc.).
- At the breaker box, turn OFF the main power feed breaker (largest breaker at the top). Critical -- prevents back-feeding the power grid, which can injure utility workers and damage equipment.
- At the breaker box, turn OFF all breakers feeding the house.
- Connect the 220V power cord from the generator to the RV plug on the garage.
- At the breaker box, turn ON the breaker for the RV plug (normally kept off).
- At the breaker box, turn ON all house breakers one at a time.
- Turn the upstairs 3-ton AC unit ON at the thermostat.
When the Power Comes Back On
- Turn the upstairs AC OFF at the thermostat.
- At the breaker box, turn OFF the RV plug breaker.
- Disconnect the 220V power cord from the RV plug and generator (prevents back-feed).
- At the breaker box, turn OFF all breakers feeding the house.
- At the breaker box, turn ON the main power feed breaker (largest breaker at top).
- At the breaker box, turn ON all house breakers one at a time -- verify power is restored.
- Shut down the generator.
- Turn all AC units ON at the thermostats.
- Turn ON the pool pump breaker.
- Disconnect the natural gas hose from the generator and outdoor outlet.
- Coil and store the gas hose and power cord in the garage.
- After the generator cools, store it in the garage.
Version: 240807 • By TJ Elias • tjelias@yahoo.com