Remember when solar power was snickered at? Now, huge companies like Google, Tesla, even BP are betting on solar. If you’re not quite ready to replace your primary power with solar electricity, why not use solar electricity to replace your back-up power?
Do you really need a gas or diesel powered generator anymore? Would a solar generator make more sense? What solar generator options are out there? Those are the questions we’ll look at today.
How Does a Solar Generator Work?
Solar electricity generators are made up of photovoltaic (PV) panels, batteries, a charge regulator, and an inverter. The PV panels convert sunlight into electricity and sends it off to the charge regulator.
The charge regulator pumps the electricity into the batteries and stops it when they are fully charged. The inverter takes the DC (direct current) electricity from the batteries and converts it into AC (alternating current) electricity.
That’s the kind of electricity that you need for your home. It’s a pretty simple system with no moving parts. Because of how it works, a solar generator has certain benefits.
What are the Benefits of a Solar Generator?
Here are the benefits of solar generators:
- No moving parts. That makes for silent operation. It also makes for a lower maintenance system. Parts that don’t move don’t wear out so fast.
- There’s also the green benefit that they don’t burn gas and they don’t give off toxic exhaust.
- Finally, once the solar generator is up to full speed, it will run day and night without any input from you. During the day, the electricity charges the batteries and excess powers your equipment. At night, the batteries power your equipment. As long as there’s enough daylight every day, it just goes on and on.
How Does a Gas Generator Work?
A gas generator converts the chemical energy of gasoline into mechanical energy and then into electrical energy.
It does this using an engine and an alternator. The gas combusts in the engine, turning the crankshaft just like in a car. Instead of turning the wheels of a car, though, it turns the rotor in the alternator.
The rotor is a coil of copper wire. The copper wire spins past stationary magnets. As copper wire passes over magnets, the magnets induce a slight electrical charge in the wire. Do this very fast and you generate a significant amount of electricity. It’s a fairly complex system with lots of moving parts.
What are the Benefits of a Gas Generator?
So, what are the benefits of gas generators:
- Gas generators can be really compact and still put out a large amount of electricity.
- They’re easy to operate and get going. Just fill with gas, pull the cord or press the starter button and you’ve got power. As long as you can keep putting gas in it, it’ll keep running and putting out a lot of power.
- Most home-use generators can be loaded by one or two people in the back of a truck, with plenty of room for other things.
- Finally, because they are mass-produced and pretty simple to build, they are also a lot less expensive than a solar generator of the same ability.
So Which One Do I Need?
There are so many different situations where you might need a generator. It’s impossible to cover them all. What we can do is take a look at a couple different scenarios.
Each scenario will be best served by either the solar or the gas generator. Compare your situation to these two scenarios, think about how each generator works and its benefits and drawbacks.
Do that and you’ll make the best choice you can for your situation.
Scenario One – Backup Power for Power Outages
You live in town. You’re thinking about being prepared for the next big hurricane or blizzard. You want to make sure that if the power goes out, you can run the most necessary things in your house, like a heater and some lights. What do you need?
You need something that can be stored easily and set up quick. You need something that doesn’t take up too much space while doing its job. Maybe you’ve got a small yard or just a balcony.
You need something that can put out a few thousand Watts at 2 Amps or more. You need it to work right now and for as long as you need it to. Hopefully, that’s no more than a day or two. When the grid power comes back, you need to be able to pack it up and get it out of the way.
In this scenario, the gas generator is likely your best bet. A gas generator that would do the job is about the same size as a large luggage bag or maybe a footlocker. If you know the storm is coming, you can get a jerry can or two of gas to have on hand.
All it takes to set it up is to put it near enough to your home to run an extension cord, but far enough that the exhaust fumes don’t come into the house. The gas generator will instantly provide enough power to run your most necessary things, and maybe a few nice-to-haves as well.
Once the storm is done and the power is back up, you simply turn it off, let it cool down, drain the gas that’s left, and put it back into storage. Sure, they need a little maintenance every now and again, but nothing more than a lawn mower needs.
Scenario Two – Camping with the Family
You’ve got a small travel trailer, maybe even just a tent. You and the family go camping for maybe a week or two every summer. You don’t really need any electrical devices, but it’d sure be nice to have a little TV for the rainy days, and have a little more light at night.
Maybe you need to keep a phone charged just in case there’s an emergency back in the urban world. You need maybe a few hundred watts at under 2 Amps. All you want to do is enjoy this great planet and hear yourself think, or not think. Whichever.
In this scenario, the solar generator makes the most sense. Once you get to your campsite, you’ll spend a little longer setting it up than a gas generator. But once it’s set up, you can forget about it. It’ll spend the rest of the day gathering sunlight and making electricity for you.
It’ll definitely give you the power you need for those twilight hours and it’ll do it with complete silence. Now you can listen to the call of the loons, breathe the fresh air, and have enough light for some fun shadow puppet time with the kids.
The next time you even think about the generator is when you’re packing it up to put in the SUV and head home. No fuel to drain, no jerry cans to lug, no gas smell in the car for the next 3 weeks. Sounds good, doesn’t it?
What Size Generator Do I Need?
Now that you know what kind of generator you want, you need to figure out what size of generator you need. To figure that out you’ll need to understand a bit about generator ratings.
Gas or solar generators are rated in different ways. You need to know the peak Amperage either can handle. For gas generators, you need to know their Wattage (W) rating. Often, the Watts will be in the thousands so it’s expressed as Kilowatts (kW).
For solar generators, you need to know their Amp hour (Ah) rating, because the electricity generally comes out of a battery. That’s nice, but what do those things mean?
Understanding the Terminology
Here’s a quick overview of amps, amp-hours and watts.
- An Amp (A), or Ampere, is the unit of measure for electrical current. The electrical current is the rate of flow – how much can flow at once. To calculate the peak Amps you’ll need, find out the Amp rating of all the devices you’d want to run, add them up, and then look for an Amp rating that could run them all at once. The calculation looks like this: Item 1 Amps + Item 2 Amps + Item 3 Amps … = Total Amps
- An Amp hour is how much electricity can flow from the battery at a usable voltage, typically for a 20 hour period. You’ll often see it expressed as something like 100Ah. Divide that 100Ah by 20 hours. You’re left with 5A. The calculation looks like this: 100Ah ÷ 20h = 5A for 20 hours
- A Watt (W) is the unit of measure for the amount of work 1 Volt (V) of electricity at 1 Amp (A) can do per second. Here’s the calculation: 1 Volt x 1 Amp = 1 Watt
When considering Watts, be careful! Usually the Wattage rating that you first see is how many running Watts the generator can handle. Some electrical devices have a starting Watt rating that’s much higher than its running Wattage. For example, a dishwasher may run at 1200W but require 3000W to start up. Make sure your gas generator can handle bursts like that.
There are lots of online calculators to help you size a gas generator. This generator size calculator from Briggs and Stratton is pretty good. But let’s get back to solar generators.
What Kinds of Solar Generators Are There?
We’ve mostly referred to the kind of solar generators that you can lug in the family vehicle. But a solar generator could be something as small as a solar-powered battery pack for your phone, to a couch-size unit for your home, up to a trailer-size model to run industrial equipment.
Knowing that, you can see how the solar generator is moving from being a niche eco-product to a serious contender to gas generators.
Even if you think a gas generator is the right thing for your needs, take some time to look at what’s out there for solar generators. More companies are making newer types almost daily.
As the public desire to cut back on carbon fuels increases, expect to see these generators take on more forms, become less expensive to buy and get more efficient.
Let’s take a look at a few that are available now.
Goal Zero has put a lot of thought into designing their solar generators. The base unit is compact, intuitive to use, and can be charged off of your regular home electricity. That means you can charge it completely at home in about 5 hours.
When you next want to use it, it should have close to a full charge. Expect it to take a fair bit longer charging solely off the panels. But once charged, the panels should keep you topped up nicely.
The Yeti Solar Generator kit will cover things like charging a phone or laptop and maybe running a few LED lights quite nicely. High current items like electric motors and hair dryers probably aren’t a good idea with this unit.
The Wagan EL2546 Solar eCube 1500 has more power than the Goal Zero but not quite enough to carry your home through an emergency.
It could be used to make camping very comfortable, or give you just enough to keep radios and phones well charged for an extended power outage. If you need to run a single heavy draw item, like a fridge or a small microwave, you could do it if that was the only thing attached to it.
The beauty of the Wagan is how compact and self-contained it is. Panels, battery, inverter, and cables all stow neatly in it. It looks like a large cooler.
The Wagan hits a sweet spot between capability and price. Like the Goal Zero, it can be charged off house power or the solar panels. It’s design allows for you to add on to it. That gives you so many more options.
The base unit could be your go-to generator for camping. Keep a few extra batteries at home, and you can hook those up to it to get you easily through small emergencies. Add extra panels for even faster charging when the power is down.
If you’re bent on having green backup power for your home, this is a good way to go. At 3500W and 225Ah it will run any number of devices collectively using under 3500W and 11A for a maximum of 20 hours.
Let’s ballpark this. You could run your furnace’s blower, a radio, a sump pump, and a computer long enough to get you through most power outages.
With the VSP you can run AC and DC appliances directly off it. This unit does come with the solar PV panels, but you can also charge it off your house electricity if you need it to be ready quickly.
Perhaps the best part is that it comes with a built-in transfer switch. You can have it connected to your house, charging up. You could also have critical appliances connected to it. The appliance would run off the house power coming through the VSP, but if the house power failed it would automatically start powering the appliance from the VSP’s batteries. Very handy.
To top it off, you could boost your car with it!
We’ve covered a lot today. Now you know the subtle differences between solar and gas generators. You also know some solid basics about electricity to help you figure out what size would best fit your needs. Finally, you’ve got a look at some solid small, medium, and large solar generators. With all this and a little planning, you’ll always be charged up and ready to go!
Image Credits: VSP-225AH Generator, via VSP Products Inc., Goal Zero Yeti 400 Kit, via Goal Zero, Wagan EL2546 Solar e Cube 1500, via Wagan, Power Outage in Town, via Flickr, Generac Portable Gas Generator, Camping by Barriere Lake, British Columbia, via Wikipedia, Trailer Sized Solar Generator, via JoyToTheWorld2012.