1. Everything You Wanted To Know About Generators But Were Disinclined  To Ask
Dr. Ed Goldberg, CBCP
Manager, Eversource Business Continuity, Disaster Recovery and Threat Assessment;
Faculty, Capella University.
ACP Corporate Board, Education Committee Chair

3. What is a generator? You put the fuel in and the electricity
comes out. True, but a bit simplified….
A device that converts mechanical energy to electrical energy.
To make electricity, the generator rotates so that a magnetic field moves along internal wires, inducing electric current flow.
Something has to turn the generator – a crank, pedals, a hamster…..but more practically, an engine….
Something has to cause the engine to turn – and without getting into all those nasty details, yes – you put the gas in and the engine runs and turns the generator…voila!

4. Power = current X voltage
Power is delivered to “the load” by wires that form a complete circuit to/from the generator.
One side of the generator is connected to the ground which is a good conductor of electricity
That’s why you don’t touch live wires! YOU can complete the circuit between the wire and the ground!
Current “flows” through the wires like water through a hose. The “voltage” is like that water pressure
It’s the pressure that drives the current through the load and that power – pressure and flow - is what does the work.

5. What is a transfer switch?
Transfers the building (load) from street power (the grid) to the generator once it is running.
Automatic transfer switches sense the loss of power from the street to start the generator and make the transfer, and then monitor for restoration of power so it can transfer the load back to the street and turn off the generator
For portable generators, loads are connected by a cord – conventional extension cords for direct connection to appliances, lights, etc. OR special heavy duty cords that can connect to a special receptacle

6. Whole house/building transfer switches
Automatic transfer switch
Manual transfer switch
Manhattan Transfer Switch

7. Why shouldn’t I just plug it into the dryer outlet and power the house?
It’s very dangerous to do so. You would need to do what a transfer switch does, which includes….
….disconnect power from the street, though doing so means you may not know when the power on the street is back on.
….shed load because the load in the house/building may exceed the capacity of the generator, including automatic loads (water heater, A/C, heat, sump pump, water pump, etc. etc. ) that may have “surge” currents.
Do it in the right sequence…..failure to disconnect from the street causes “backfeed” which has two potentially destructive and fatal consequences.

8. Backfeed!
The power that travels long distances from the power station and eventually down your street does so at a very high voltage – thousands or tens of thousands of volts, on the highest wires on the poles, called “primaries”.
Your house runs on 120 and 240 volts, and those wires are called “secondaries”.
A “transformer” changes the voltage to your house from that higher voltage. It is mounted on a pole or, for underground utilities, on the ground nearby.
That transformer is an unintelligent but highly effective and efficient device. It is simply designed for some ratio so that the output voltage is some percentage of the input voltage.

9. Backfeed (continued)
Backfeeding involves connecting your portable generator to the house improperly and thereby energizing the wires from your house to the street.
The transformer will take that 120 or 240 volts and step it up to the primary voltage. An improperly connected generator will cause thousands or tens of thousands of volts to energize the primary wires on the pole, energizing wires on which linemen from the utility may be working. Deaths and damage have occurred as a result of backfeeding.
When the power comes back on the street and the generator is connected to “the grid”, the generator will likely be destroyed with consequential damages, too – catastrophic mechanical and electrical failure, etc.

10. Snakes on a plane? No! Transformer on a pole
Primary (from top of pole)
Normally converts 4-15kv down to 120/240v
Backfeeding the secondary with 120/240v produces 4-15kv on the primary
Secondary (to house)

11. Pad mounted transformer (where utilities are underground)

12. One (correct) way to connect a portable generator to the whole house
Electric meter
Meter socket (on house)
Transfer switch - Installed by electrician or power company; up to 200 amp service; price is determined by length of cable and generator size: ~$1,000 to $1,500 range.
Socket for generator cable
Source:
Generator Cable

13. Portable vs. Permanent
Portable units tend to be smaller capacity and cheaper, though there is overlap in size, capacity and cost;
A transfer switch is not needed for a portable unit depending on the intended use:
Prewire house with a connection to the portable generator, including a transfer switch.
Use extension cords and connect appliances, lights, etc. directly to the generator.

14. Do it yourself or turnkey?
It is a moot point if a licensed electrician is required to do all the work.
But if not…..What’s involved in the installation?
Determine size
Determine location – generator, transfer switch, status indicator(s), existing electric service, gas line and tank, if needed
Obtain permit – probably need electrician first per local rules and for connection
Order the generator
Place conduit, gas line, etc.
Pour a concrete pad (could be gravel, stone dust or other stable base material)
Set and secure the generator
Connect (electrician required)
Commission
Maintain
Can you do all of this yourself and is it worth it?
Turnkey costs more but support is seamless (usually)
Your labor vs. theirs
Their expertise (and risk ownership) vs. yours
Support, maintenance over time

15. What size is the right size generator
What size is the right size generator? (“Whole House Generator” is a misnomer)
What do you need to power?
Heat (gas, oil, heat pump)
Air conditioning
Water pump
Sump pump
Lighting
Garage door openers
Refrigerator
Freezer
Washer
Water heater (good load shed)
What do you want to power?
Everything 
Electronics (TV, computer, etc.)
Pool pump
Dishwasher
Trash compactor
Microwave
What should you avoid powering?
Resistance-principle devices….
Electric oven(s)
Electric dryer
Electric baseboards
Heat pump backup coils

16. Why not power resistance-principle appliances?
You can if necessary, but such devices are generally very large loads, so the size of the generator increases dramatically;
There are usually alternatives. For example, propane heaters, cooktops, grills, etc. are not particularly expensive. Cooking outside on the grill for a week may be inconvenient, but it could halve the size of the generator;
To power an electric oven might take 8kw. That could double the size of your generator;
To run a generator just for that load would use roughly 2 gallons of propane per hour. Cooking a turkey for, say 8 hours, would take 16 gallons at $3/gallon = $48. Cooking it on the grill for 8 hours might use 2 gallons….but in general, do you really need to cook a turkey or bake a cake during a power outage? 

17. Too big….

18. Too small….

19. Just right!

20. Other sizing considerations
The largest air cooled generators are 20kw; anything larger becomes a commercial unit that’s water cooled (like most automobile engines);
Load it lightly and it will run longer, last longer; 50% - 75% is fine, but don’t design it to run at full load all the time;
Fuel consumption – this is not a cheap way to make electricity. A 20kw unit uses upwards of 3 gallons of propane per hour at $2-$4 a gallon = $144 - $288 per day! (I turn mine off during prolonged outages when I can do so)
Size the tank appropriately. A 20kw unit using 72 gallons per day that you need to run for 7 days would need 500 gallons of propane. There are standard 80, 120, 500 and 1,000 gallon tanks, but propane tanks can only fill to 80%, so for this example, you’d need a 1,000 gallon tank filled with at least 500 gallons.

21. Determine location for permanent generator installation
Near service entrance
Near gas line
Adequate distance from any building openings (code and manufacturer’s specifications)
Adequate clearance around air intake and exhaust
Consider noise, exhaust, heat, serviceability
Above any possible flood level
Aesthetics – these aren’t ugly per se but, well, it’s a box.

22. If you choose propane, consider the tank
If propane is used, consider location of the tank and, again, how it looks.
I prefer to keep it away from the house and plumb it underground, but that’s not necessary;
Tanks are usually white, so if you are in a woodsy area, consider a camouflage cover;
Underground tanks are available, too….
80 gal.
200 gal.
500 gal.

23. Get a permit! Probably required by law
Just a good idea – it’s a review by someone who has seen many other installations
The inspector is really protecting you and your interests….consider the implications of a poor or dangerous installation with respect to your insurance carrier, resale value of the home, etc.
Helps to ensure it’s done right

24. Order the Generator
A dealer does this for you, but if you go the DIY route, there are many options:
Because generators have become popular and profitable, Home Depot and Lowe’s sell them, even have one or two on display in their stores;
One of the best websites for shopping, comparing, learning about generators is They’re reputable and competitive, but there are many others, too. The site is full of good information even if you buy elsewhere or do turnkey;
Generators are big and heavy and drop ship by motor freight from the factory which means a tractor trailer drops it at the end of your driveway; you need to specify and pay for a liftgate delivery unless you have a full sized loading dock; some retailers may deliver it to your pad, but I’m guessing that’s expensive;
A 20kw generator weighs upwards of 700 pounds in the crate; the base of the generator usually has holes into which you can put steel pipe to use as 4 handles for 4 pretty strong backs….otherwise, you’ll need a pallet jack or some other means of moving it;

25. What’s the best brand?
Obviously, this is always a religion-like question since it pertains to perception absent any hard supporting data.
The most popular brands of permanent home-size generators, in order and based on my conversations with dealers, are Generac, Kohler, Onan, GE/Briggs & Stratton (B&S brand labels and does support for GE). Some make portable units, too. I believe Honda makes only portable generators.
If you’re going turnkey, it’s best to buy the brand that a good, local dealer supports and sells. On your own, it’s best to compare by price, features, etc. Be sure to calculate total cost i.e. generator, transfer switch, freight, etc.

26. About generator dealers…
Portable generators are generally serviced by small engine repair shops – not unlike lawn mowers, etc.
Permanently installed generators are serviced, generally, by dealers who sell and service generators. Typically, repairs and maintenance must be done on site, and the repair/maintenance technician is often an electrician with generator-specific experience.
There are large and small generator sales/service dealers, including some that cover many states. There are also small electrician-based companies that do the same thing.
It can be problematic to buy from one dealer and seek service from another, though it can be done successfully. Familiarity with a brand and their service network is one reason to find a dealer and stick with her/him.

27. Generators come with engines that can run on your choice of either gasoline, propane, natural gas or diesel.
Gasoline is most common in portable generators because the generator is stored dry and fueled when needed. Gasoline begins to break down in as little as 30 days and should not be left in the generator. Stabilizer can be added to the gas to prolong its life, but it is still relatively unstable.
Most home generators run on propane or natural gas, and most accommodate either. Note that when running on natural gas, the power output of the generator will be ~15% less than on propane i.e. a 20kw generator will only put out 17kw.
Propane is stored locally in a tank; natural gas comes out of a pipe supplied by a local gas company;
Some generators can run on either gasoline or propane or natural gas fyi….unusual and more expensive.
Like any commodity in the supply chain, fuel delivery and storage need to be planned and implemented with firm commitments for performance during and after an event.
How much fuel do you need? How long should you plan to run? These have to be part of the organization’s risk analysis. For a home, it’s smart to have 7-10 days of fuel on hand. Reduce the amount needed and extend that time by turning the generator off when not needed.
Managing that supply and storage of it are critical to the fuel being useful when it’s needed.

28. Moron More on Propane
For propane, if you lease the tank you must buy from the same supplier; the propane dealer owns the tank and you can’t shop for fuel price, so that typically results in a higher price per gallon;
If you buy the tank, you can shop for best price on fuel and so the price is usually less per gallon;
A tank is full at 80% because propane needs space to evaporate and create pressure. A 500 gallon tank is full with 400 gallons, etc.
Propane does not deteriorate in any way over time.

29. More on Diesel (there’s fungus among us)
Typically used for commercial systems because it’s complicated;
Prone to form wax and collect moisture from condensation;
Prone to fungus, sediment, gum over time;
Tank requires cleaning every 10 years;
Fuel can last 5-10 years as long as….
….water is removed weekly (drains from bottom of tank)
….anti-oxidants and metal deactivators are used to reduce reactions, sediment and gum;
….fungicide/biocide used to prevent/kill fungus;
….stabilizer foam (floats, requires a hatch) used;
….fuel is circulated through a filter as it is in some but not all commercial systems
Diesel should be used up and refreshed every 1-5 years;
Samples should be tested to monitor fuel condition;

30. So far, this is all about preparedness…
So far, this is all about preparedness….what about when the generator is running?
Generators are not a cost effective alternative to commercial power – they use a lot of fuel. A 20kw generator under load uses ~2-3 gallons of propane per HOUR!!! Do the math – that’s upwards of 75 gallons a day, at $1.75-$3.50 a gallon can be $250 a day. 
Generators require maintenance. Most gas, propane and natural gas generators run at 3,600 RPM to maintain normal 60hz. 240/120VAC household power. Consider running your car at 3,600 RPM for 24 hours - try it for a couple of minutes by downshifting or driving fast (as long as it’s safe to do so). It’s screaming.
Most generators require oil changes every ~100 hours (every 4th day during a prolonged outage!)
Consider running it intermittently during an outage to save fuel, etc.
******CHECK THE OIL REGULARLY*********
– EVERY MORNING AND EVERY NIGHT IF IT’S
RUNNING CONTINUOUSLY! IT’S RUNNING AT
3,600 RPM (gasoline or gas models) AND IS
LIKELY TO USE OIL!

31. Features
Load shed – Intelligent generators and their transfer switches often have the capability to “shed load” i.e. to sense when the generator is close to capacity and then disconnect loads selectively. This is done through relays and, of course, requires some rewiring of the existing electrical panel in the house, etc.
Consider that not everything need run all the time. For example, the water in the hot water heater won’t get cold if power to the water heater is interrupted whenever someone turns on all the burners on the cooktop….because it’s not likely (nor prudent) that they’d all be on for very extended periods of time.
Similarly, not everything needs to be powered at all by the generator. We decided not to power our double ovens because, frankly, we can get by for a week without making cakes, a turkey, etc. The stovetop and gas grill are viable options for us. Same for the electric dryer – we can hang dry for a week (if we need to do laundry at all).
Self-test – most generators with automatic transfer switches are programmed to start and run without a load for 20 minutes once per week. That’s generally the shortest time where it is certain everything heats up enough to dry components that may be subject to condensation, etc.

32. Can I just rent a generator when I need it?
It’s possible but it requires planning and it isn’t a solution without cost incurred prior to the event;
There are companies that rent generators. The main issue is what the price and availability will be when a regional or broader disaster is imminent;
It’s VERY similar to the type of planning and preparation that Continuity Housing does to ensure that their clients have the lodging they need when they need it without incurring unnecessary cost.
Two main aspects to renting a generator require preparation:
Prewire the building with the power connection and a transfer switch;
Establish a commercial relationship, probably via contract, to have some sort of priority for a generator when they are likely to be in great demand and short supply. Local and regional suppliers (Kinsley Power in the northeast, for example) as well as national vendors (Rentsys and Agility, for example) offer a variety of programs with different levels of commitment. You need to evaluate your appetite for risk and determine the best path for your organization.
The entire commercial “scene” is to avoid a Catch 22 situation – companies that rent generators need some form of sustainability when the generators aren’t in demand without gouging when they are needed, ensuring adequate supply and having the infrastructure to support those generators until they are needed – hence the many different business models from which to choose.

33. Commercial Installations
Turnkey and service from a good dealer are smart choices (unless you have 24/7 expertise in house that is available, has access to parts, etc.);
Requires maintenance, including fuel management;
Where the power is used for electronics, it’s wise to condition the power with a UPS – uninterruptable power supply – that includes battery backup;
The UPS will carry the load until the generator senses loss of external power, starts, reaches speed and can pick up the load. That might be 20 or 30 seconds to a minute or two.
Data centers, for example, might have multiple generators and multiple UPS units.

34. Portable commercial units
Run on diesel because they are on a trailer and propane is hard to transport (bridge and tunnel restrictions, special permitting/licenses, etc.);
Need to be refueled periodically;
Same maintenance requirements as other units;
Building should be prewired;

35. Installed commercial units
Can run on diesel – good choice but requires management of the fuel – quality, storage, delivery
Diesel engines run at 1,800 RPM usually – ½ speed of most gas/gasoline units, so less maintenance, longer life generally;
If natural gas is available, also a great choice;
Size determines engine type, too;
Some of these are very large;
Critical applications: might want multiple units perhaps in different locations;

36. Questions?

37. Thank you….
….for helping to make your organizations and our communities resilient and prepared, and thank you for your time and interest
Not so resilient
Resilient
Dr. Ed Goldberg, CBCP
Eversource
Berlin, Connecticut