so now let’s have a look at the chapter on generate it’s always a nice topic to talk about there’s a lot of things we can explain about it we’re going to try to keep it as focused and brief as possible so first to get a couple of things out of the way what we are talking about is a generator set so generator set is the combination of a internal combustion engine with an electrical generator and what we are using for the electrical generator is an alternator so this is what we are referring to as a generator now i’d like to discuss four different topics i want to first look at the the lingo so the the technical jargon that you often come across we’re talking about generators when we’re looking into this topic so that we can make sure that we speak the same language then i want to look separately at the standard so the conventional type of generators and in a different section we’ll look at the inverter generator types and then the last section i want to look at the different kind of few options you have and what the pros and the cons are so first let’s get some theory out of the way and look at the the technical jargon so the kind of terminology that we often come across when we’re talking about and looking into the topic of generators so the most obvious one is regarding the operating voltage of the generator so the voltage is the the electrical pressure if you will it’s indicating voltage on volts sometimes it’s indicated in in kilovolts and kv so one kilo volt equals 1000 volts then there’s quite a few other terms so we’ve got the single phase dual phase three phase we’ve got amperage kilowatts kva watts and frequency so let me cut this up into three different sections so we’ll look at defaults and amps separately at the power ratings and at the frequency i’m going to try to keep it as simple as possible i just want to clarify them all individually so let’s start by looking at the voltage in the amperage so the first thing to realize is that the output voltage of your generator fluctuates over time it depends which kind of type model and quality of generator you have but it can fluctuate as much as five to ten percent up or down now your generator is able to modify the output voltage and it does this by controlling the internal magnetic field inside of the generator so inside of the alternator but it’s important to realize that the the real reason behind why your voltage is fluctuating and why the generator needs to adjust the magnetic field strength is is basically because of you because if you are changing the loads on a generator if you are reducing the amount of power that you’re taking from it or all of a sudden you’re taking more power you’re you’re asking more power from the generator then the result is that the voltage starts to fluctuate and therefore the generator tries to mitigate this by adjusting the field strength of the magnetic field inside now you might have seen this kind of a graph before whereby on the horizontal axis we’ve got the time and on the vertical axis we’ve got the output voltage of your generator in this kind of a graph you can clearly see how the current of ac alternates right so it’s it’s high then it’s neutral then it’s negative that’s neutral then it’s positive so it’s just important to point out that these the height of these waves they determine the output voltage of your generator and if you would compare this to a dc power source or a direct current then the voltage of a dc source is just stable doesn’t it shouldn’t fluctuate over time now these are all just words and numbers and graphs but i think i can do a much better job at explaining to you the differences between voltage amperage and power by drawing a very simple but effective analogy between these electrical terms and something way more tangible out of real life so i introduced to you my dear friend john who has at his disposal a tank filled with water slightly elevated above ground level he’s wired he’s connected a hose to this water tank and he’s now watering at the guard with this system now john is getting a little bit of pressure out of his hose because he elevated the water tank above ground level now you can compare the pressure in the hose to the equivalent of electrical pressure and this is what we refer to as voltage so just compare the pressure in the hose with electrical pressure called voltage now if we would keep the situation as is but we would change only one thing we would increase the diameter of the hose quite substantially i’m sure you can understand that there’s now more water flowing out of the system right so you can imagine that the amount of water flowing out of the hose is in some way similar to the amount of current so the amount of amperage in an electrical circuit now let’s change the system back to its original condition again so we reduce the diameter of the hose but now instead what we would change is we would raise the tank quite a bit further of the ground so it would give the the system much longer legs now you can imagine that as a result you’ve got much more pressure available at the end of the hose so much more water is coming out but now imagine that if you would also increase the diameter of the hose even more water is coming out so a very large quantity of water is flowing out of the hose at this point so i’m just explaining in this simple way because i think this makes it very easy to understand that the amount of the useful power that you’re getting out of the system is the equivalent of the pressure times the flow and then so the electrical equivalent is that the power that you’re getting out of your electrical system is the voltage multiplied by the amperage so well done for sticking with me so far if you keep this thing imprinted in your brain so power equals voltage times amperage you’re way out of the rest because this very basic principle but you’ll see it coming back a lot of times and now often throughout whatever i’m explaining i’ll often refer to this principle so now all right let them shut up for a second i just want to explain to you that the content of this video is copied from the complete course of off-grid energy systems if this information is enough for you great if you want to learn more and if you want to get access to the complete course then check the information in the description below all right you go out again how do we get voltage and amperage out of the way let’s look at the next sub-topic in this chapter which is regarding power rating so how is power being identified and what kind of terminology are we using to describe power so the story of power rating starts at this very foundation because one unit of energy is described with the unit of you now it’s very unlikely that you’ll come across this terminology what is more likely that you’ll see is something described as the amount of energy flowing so if if every second one joule of energy would be consumed or produced this is then described as one watt so i’m explaining this because it’s important to realize that the unit of what actually refers to an energy flow it’s not a quantity of energy but it is a quantity of energy over time an energy an amount of energy flowing through your system now the next point is quite simple because you might often come across a value of kilowatt not watts so 1000 watts equals 1 kilowatt that gets a bit more tricky a bit more confusing when manufacturers or specification sheets are describing the term of volt amps vas instead of watts now under perfect ideal situations 1 watt is equal to 1 v8 to 1 volt amps but in more realistic more average scenarios you can assume that one watt equals around 0.75 va now the exact ratio between the watts and the volt amps is determined by a factor which is referred to as the power factor and the power factor is a value between 0 and 1.

Now for now i’m not going to dive too deep in this topic for now but it’s just important to realize that the power factor is determined by whichever kind of appliance you’re connecting to your power source so whatever you’re connecting to the power source determines the power factor it is not the power source itself so it is not your generator that determines what kind of a power factor is applicable to your situation i’ll explain you more about the power factor later on for now just remember these two things 1000 watts equals one kilowatt and on the ideal situations one watt equals one volt amp so we’re making good progress we’re almost done with the boring technical stuff you understand now the difference between volts amps and how to indicate the power rating let’s look at the last topic regarding frequency so you know by now that your generator produces alternating current so the voltage fluctuates in a very stable way over time the height of the graph indicates the actual voltage of your system so now what controls how fast that graph fluctuates right why is not going very slow why isn’t it very going very fast so this is being controlled quite simply by the speed of your engine so the faster your engine runs the higher the frequency is the slower your engine runs the slower the frequency is now whenever you buy a generator you don’t have to control this the manufacturer has already fine-tuned this and depending on the way you live what kind of a system you’re using it is set that the frequency is either a 50 or 60 hertz so 50 or 60 times per second this wave is going up and down as a result of the speed of your engine okay well done you finished the theoretical part it was just important that you understand the fundamentals so you and i speak the same language so now let’s start by looking actually into the different types of generators so let’s start by looking at the standard conventional type of generator first now there’s four topics that i’d like to discuss first we’ll look at the the fuel consumption and what influences the fuel consumption or look at a different kind of outlets different kind of connections that you might want or that you might want to consider for your generator we’ll look at the capacity so what kind of a generator size should you or would you want to choose and at last we’ll look at the different kind of features i want to point out a few features that you might want to consider for your generator so let’s start by looking at the fuel consumption of your generator first now let me just clarify one thing since i do not know what type or size of generator you have or will buy i’m not able to tell you the absolute amount of fuel per amount of time that you’re running your generator but what i will be able to indicate is the average values that you can expect for the amount of fuel that you could consume per amount of energy produced if that makes sense so what i can tell you is the amount of fuel in gallons by the amount of energy produced in kilowatts or the same the amount of liters of fuel per the amount of energy produced in kilowatts so here are some average values for you if you are running your generator under 100 percent load so under its maximum rated capacity then you’ll be consuming approximately 0.17 gallons per kilowatt or .64 liters per kilowatt but now here’s a tricky bit if you have substantially oversized your generator and instead of running your generator at nearly full or full capacity you’re running it at say 50 capacity well now your fuel consumption would be 0.

23 gallons per kilowatt or .87 liters per kilowatt now i’m explaining this to you because here’s a thing that a lot of people don’t realize if you are running your generator at a fairly low load so at 50 of its load it’s definitely true that you’re consuming less fuel per minute per hour per day that’s absolutely true but at the same time you’re also getting a very poor fuel efficiency out of your generator so yes it’s true at 50 percent of its load you’re consuming less fuel but the amount of energy that you’re getting out of one unit of fuel is also substantially less so in this example you’re getting 35 percent less fuel efficiency if you’re running your generator at 50 versus 100 load so let me further explain this to you with a simple calculation so i assume that you have some kind of appliance that consumes 4 kilowatt can be a stove top an air conditioning a heater whatever you have an appliance that consumes four kilowatt and we are going to power up your device with a generator and we have two different scenarios in the first scenario we oversize your generator and a second series scenario we match the capacity of your generator to your load so in the first setup we oversize your generator so we pick a an 8 kilowatt generator to power up your 4 kilowatt load so as a result this generator is now operating at its 50 capacity and let’s say you’re running this load straight out for 10 hours continuous then the fuel consumption of this generator during the 10 hours will be 9.2 gallons so that’s pretty straightforward right now let’s assume that you take a generator which is a perfect match with your load so your load is four kilowatt and you choose a generator which is also four kilowatt so now this generator will run at 100 of its capacity therefore it will be consuming approximately 0.17 gallons or 0.64 liters per kilowatt and therefore if you run this load 10 hours straight the end result is that with this generator set up you’ll be consuming 6.

8 gallons over the 10 hour time frame so now it becomes clear that in the first scenario you’re spending substantially more fuel on powering up the same load you’re spending more than two gallons or more than eight liters more compared to the second scenario which means that in the second scenario you’re spending less on your fuel consumption and you’re spending less on the initial purchase of your generator which is pretty good right so that’s enough about fuel consumption now let’s look at the second topic regarding the outlets of conventional standard generators now this topic is not rocket science just make sure that you match your kind of loads that you intend to power up with your generator with the right type so choose for single phase split phase three phase just match your loads with the right type of generator but there’s one thing which is often overlooked which is regarding the dc the diode current capacity of your generator so most standard or advanced generators have the ability of you connecting a battery straight to your generator but i just want to say that often people get a bit disappointed because they think they can charge a large battery bank but just double check because most standard generator can charge with around 8 amps so at a 12 volt operating voltage that’s you know just 100 watts of charging capacity which is you know enough to charge very small appliances or to charge a conventional starter battery but if you have a big house battery bank a deep cycle battery bank you you won’t be able to charge it properly with this kind of setup which brings us to the next point regarding the capacity of the generator there’s just a few simple items here that i want to explain so the first and obvious one is the nominal or rated power of the generator so this value refers to the amount of power that you can withdraw from the generator under normal operating conditions without any problems occurring so you can continually draw this amount of power from the generator without it overheating or breaking down but there’s a substantial difference with the second one which is the peak power or the max power output of the generator so just make sure that you understand the difference between the two because the maximum amount of peak power of a generator that rating you can only do it for a certain amount for a short amount of time and this is also indicated by the manufacturer so yes you can draw this amount of power from the generator but only for a short amount of time sometimes it’s 10 seconds sometimes a minute sometimes 10 minutes but you cannot continue to withdraw this amount of power from the generator without something to overheat or something to trip so the units used to describe the nominal rated or max power of a generator are normally the watts or the default amps or a multitude of that as we saw before the kilowatts or the kvas so here we bump again into that issue of the power factor right because the difference between the kilowatts and the kvas is determined by the power factor of your loads so as promised before let me explain to you a little bit more about the power factor what it is and how you use the right power factor for determining which kind of generator is correct for your setup so let me explain this with a simple example so imagine that you would want to power up your fridge with a generator and you already know what the power consumption of your fridge is you’ve looked in the specification sheet or in the the sticker on the back of the fridge but it only gives you this value in watts or in kilowatts and now you’re looking at a specific generator online or in the store and this generator only gives you the rated capacity the max and the nominal capacity in kva so if you want to convert the rating and kva towards the rating in kilowatt you multiply the kva rating times the power factor and remember the power factor is a value between zero and one so as mentioned before the exact power factor depends on your situation depends which kind of load which kind of appliance you intend to connect to your generator but values which you can expect for the power factor are for example for led lights they have a power factor of close to one so that’s pretty good but any kind of appliance which has an electric motor inside has a potentially low power factor so a fridge for example has the works with a compressor and inside of the compressor there’s an electric motor so fridges can go as low as 0.5.6 but if you have the more advanced more newer kind of fridges then they often have electronics installed that kind of compensate for the bad power factor so they might go as high as 0.8 or 0.9 so by now you understand what power factors are how they relate to the calculation of the final capacity of your generator and we have looked at the different kind of outlets and the fuel consumption of your generator so now let’s look at the last point and i just want to point out a few specific features which you might want to consider for your choice of generator so the first one is a very simple but in my opinion an essential feature to have which is the fuel valve and believe it or not there are generators out there that don’t have a fuel valve so the fuel valve just allows you to troubleshoot your system much easier and it allows you for draining your your fuel system so if you’re not using it for a while you can turn off the fuel valve you can run your generator empty and this prevents a lot of problems later on so at least make sure that you have a fuel valve it doesn’t matter which model exactly sometimes it’s a very simple you know metal or plastic valve sometimes it looks a bit more fancy with a big disc that you can turn but in essence it’s just a basic fuel valve and the second one is for you to consider an electric start you know and whenever you’re looking at the difference in prices yes you’ll pay whatever 10 20 more for your generator but i also strongly recommend that you get this one because it’s such a great convenience to have this electric start option it does add a little bit of complexity to your system because now you have a battery that you might have to replace after a couple of years etc but it creates so much value at the same time too for example if you’re troubleshooting your system it’s pretty easy to just crank the engine for a couple of seconds straight and this might make it much easier to i know if you have a fuel lock or if you want to test your spark etc so it’s a great feature to have so allow yourself some comfort and consider going for the electric start option so i think this is enough you need to know about the conventional normal generator now let’s look at the third section within the generated chapter which is about the inverter generators so as the name already suggests the basic functionality of an inverted generator is made out of two components a conventional normal generator combined with an inverter that just fused together into one housing and this is what we refer to as an inverter generator so we’re going to look at this information in three different sections we’ll look at what actually happens inside of the generator and we’ll look separately at the pros and the cons of inverter generators so what happens inside of the inverter generator is that the electrical generator part of the generator produces alternating current then this alternating current is being crushed back into a simple dc power source or a simple direct current and then this direct current is then turned through the inverter back into alternating current again so this seems a bit weird right you’ve got ac you turn it back into dc and i’m back into ac again why well this is because the ac created in the first step is can be somewhat irregular so if you take this irregular ac power from the first step and then mush it back into like crush it back into direct current which is pretty easy to to manage and then you build it back up to an ac source then your final ac wave is very stable and very controlled and this is the reason why manufacturers and suppliers of inverted generators will claim that the output of their inverted generator is much more stable it’s much cleaner and is much more controlled compared to the output of a conventional regular generator which in most cases is absolutely true so now that you know what happens inside of an inverted generator let’s look at the pros what are the benefits of an inverted generator so the first clear advantage is that inverted generators on average produce really high quality stable power output and the second clear advantage of inverted generators is that since the third step so the generation of ac power by the inverter is decoupled from the first step whereby the electrical generator creates the first ac power you are now able to actually run the engine at a much lower engine speed but at the same time still providing the correct frequency and power output that’s being created by the inverter and this is a great benefit because you’re not able to do that with a conventional generator a normal conventional generator needs to run at the same engine speed all of the time in order to maintain that frequency that we discussed before right so if in your situation you sometimes might require less power from generator and as a result the generator will just reduce its engine speed while maintaining the proper frequency now a result of this is that you have substantially less noise output from the generator now this is a great benefit of inverted generators but just realize that if you’re running your inverted generator at its maximum capacity the engine speed is also maximum so you might very well be producing the same amount of noise level with an inverter generator that’s running at 100 capacity compared to a conventional normal generator the real advantage of an inverter generator kicks in when you’re starting to run it at lower capacity whereby the engine speed reduces your fuel efficiency remains somewhat the same but your noise levels just drop drastically now these are the advantages of inverter generators but of course if you want you can also point out the disadvantages so the first one is quite obvious inverted generators are substantially more expensive compared to the traditional conventional generators and you could also argue that since there are more components inside of the inverter generator right because now it’s not only a generator but there’s also an inverter built into one unit you could say that with more components you increase the chance of components to break down so you could argue that reliability might be a bit lower or that is more difficult to repair it once it does break down and this then links to the the kiss method right keeping it stupid simple so but this is more of an opinion base i’ll let you figure out what you think about this point i think this is enough we need to discuss regarding inverted generators let’s look at the last topic in the generator chapter and we’ll look at the different kind of fuel options that you might want to consider for your setup for the few options we’ll look at three different kinds of fuel so gasoline diesel and bottled gas or lpg and i’ll give you the values for the north american market so i use the unit of dollars per gallon now you can clearly see here that gasoline is just a little bit cheaper than diesel and a lot cheaper than lpg so if you just look at the the fuel price then i would say that gasoline is the winner here but now if you look at the energy density then the situation shifts a little bit in this graph the energy density is expressed as the amount of kilowatt hours per volume per gallon of fuel and you can see here clearly maybe not surprisingly that diesel has the highest energy density per volume per gallon so by means of energy density diesel is the clear winner so let’s draw one more comparison so we we compared it based on the price you pay for the fuel we compare it on the energy density of the fuel now for the last one let’s look at the the fuel efficiency so if you take this fuel and you burn it in an internal combustion engine what is the amount of energy that you can recuperate out of the liquid fuel and here we can see that diesel is winning again so diesel’s got the highest fuel efficiency compared to gasoline lpg and lpgs get the lowest one and then if you combine these three values together so the price that you pay for the fuel the energy density of the fuel and overall efficiency of burning this fuel in an internal combustion engine then you get one value which is the energy price expressed in dollars per kilowatt hour and not surprisingly you can see that diesel is the winner here but it’s pretty close to gasoline and the reason for that is that at least in north america the prices of gasoline are a bit lower than that of diesel now this was just a technical and financial comparison between the three different kind of fuels but let’s also mention a couple of externalities that you might want to consider when you’re trying to choose which kind of fuels best for your setup now the first one we could identify is the fire hazard because there’s a clear difference between the group of lpg and gasoline versus diesel diesel is just pretty hard to set on fire so that’s something to consider but at the same time the second one is the availability because in many parts of the world it might be easier to get one of the fuels over the other one so certain countries is much easier to get gasoline certain countries are actually easier to get diesel so this is also something to consider and the third one regarding fuel rotation is quite interesting that really depends on your situation so i don’t know if you’re in a cottage in a house a boat or an rv and whether or not you should be concerned about your fuel getting old because i don’t know how often you use your fuel but a certain situation for example if your main engine runs on diesel or gasoline you might also want to consider for for the overall ease of operating all your systems to choose the same kind of fuel source for your generator as you’re using for your main engine and the last one i want to mention is regarding noise levels because diesel engines they work with self-combustion so they don’t have spark plugs that ignite the fuel and therefore diesel engines they are typically way more noisy compared to gasoline engines so if this is an important factor for you you might want to stick with gasoline generators so these are just a few of the externalities that i want to mention regarding the different fuel options that you might want to consider so you’ve got a bit of an idea what you can expect if you go for one fuel source over the other one and this brings us to the conclusion of the chapter on generators so thanks for sticking me all the way to the end and i’m sure you learned quite a bit by now

Read More: Battery Inverter-Chargers explained: Wiring Diagram & Generator Sizing