Pros and Cons of Solar Generators

There are many types of power-generating systems.

This article is about Solar Generators (also commonly referred to as Portable Power Stations when not sold with solar panels as a power source).

Solar generators collect energy from the sun and store it in a battery to provide electrical power to power your appliances and equipment. Gas-powered generators provide the same electrical power as batteries except that the power is from their internal combustion engines.

What are Solar Generators / Portable Power Stations?

A Solar generator is a combination of 2 things:

  1. A Portable Power Station (a battery with an inverter that produces AC current like the electrical outlet at your home) and
  2. Solar panels collect sunlight energy and store it in the Portable Power Station’s battery.

Power stations are power banks on steroids. They provide USB outlets, standard 120-volt household outlets, 12-volt car socket outlets, and 12-volt DC ports. Portable Power Stations can be charged through your home 120-volt regular outlets, but, more importantly, they can also charge from solar panels when a power outage lasts too long and their batteries are depleted.

The largest breed of Power Stations is a whole-house backup system such as Tesla’s Powerwall, sometimes coupled with solar panels. A whole-house backup system is usually a permanent installation that requires enough space for a large battery bank and a large roof surface area to install solar panels if you choose.

Energy generated from the solar panels can be either sold back to the grid or stored in the battery bank for later use in the event of a power outage or during the day when electricity prices are at their highest (also known as energy arbitrage). In some models, battery generators can remain on standby and kick in when a power outage occurs.

Portable Power Stations and Solar Generators

Battery-powered generators have been around for a long time but have recently gained the public’s attention as technology has improved. Battery-powered generators are known as Solar Generators, Portable Power Stations, Home Battery Systems, and many others, but those are the most common.

As we gradually become more reliant on backup power, I expect the prices for all battery generators to drop over the coming years.

A battery-powered generator is an integrated system with a few components. First, the batteries are charged from solar panels (through a charge controller device) or straight from the grid. Then an inverter is connected to the battery’s output to produce 120 volts through regular household outlets and other outlets such as USB.

Below are all the sources that can charge your Portable Power Station:

  • The Main Grid
  • Solar Panels
  • Wind Turbines
  • Conventional and Inverter Generators
  • Other DC power sources, such as 12v car outlets  

Remember that the size of a battery system is directly correlated with the amount of power it can provide. Portable Power Stations are best for short weekend trips or apartments (as they cannot run conventional or inverter generators). A Powerwall, on the other hand, will run your entire house in case of a power outage.

Advantages of Solar Generators

1. Solar generators are your go-to solution if you live in an apartment. Traditional gasoline and propane generators emit carbon monoxide and are, therefore, not allowed in any closed areas. Click here for my article about using a solar generator in your apartment.

2. You can charge any device on the go without worrying about gasoline or propane. You can always have your little portable power station to cover your basic needs over a weekend without needing to recharge.

3. They produce clean power with a very low THD and are, therefore, safe for all sensitive electronics.

4. You and your neighbors will be happy as they produce no noise (it has no mechanical moving parts inside).

5. You can top off your battery from many sources:

  1. Portable solar panels
  2. Any standard 120v wall outlet,
  3. Conventional and Inverter generators,
  4. A charged portable power station,
  5. Wind turbines,
  6. A 12v car outlet,
  7. Some models can be charged for free at many Electric Vehicle Charging Stations nationwide. 

6. They require zero maintenance.

7. They are safe to operate unattended and around children as they don’t emit carbon monoxide.

8. They can be as small or as big as you want. Starting with cell phone power banks all the way to full-fledged home backup.

9. Potentially free energy supply if you are using solar panels, wind turbines, or Electric Vehicle Charging Stations.

10. Low running costs due to low maintenance.

11. Environmentally friendly with zero carbon emissions.

Disadvantages of Solar Generators

1. Batteries are very sensitive to temperature and prefer to charge and discharge between 41°F and 113°F (5°C and 45°C)

2. Size: the more output power, the bigger and heavier the unit gets, and it gets very heavy very fast.

3. They are still much more expensive than conventional and inverter generators

4. They charge much slower than discharging, i.e., using a battery for an hour requires many hours to recharge it. (This is starting to change, though!)

5. You have to plan ahead where you’re getting your next refill of energy. You can’t just empty your batteries without being sure that you have a sunny day for the solar panels or access to 120v outlets.

6. Even small batteries are quite heavy. Remember the weight of that small car battery!

7. Limited storage capacity (you can have as many jerry cans of gas and tanks of propane, but you can’t haul around ten or twenty battery packs)

8. Dependence on sunlight during power outages.

9. Power output is limited by the size of your inverter, even if you have a large battery bank.

10. Batteries’ performance degrades very fast if they are fully discharged. A fully charged battery is not equal to a full gas tank.

11. Battery-powered generators usually have poor roundtrip efficiency. i.e., you get much less energy than what you put into it.

Will batteries replace generators?

Batteries and their current technology will not replace generators in the foreseeable future as they are still too heavy, overpriced, and take too long to reach a useful charge.

In a battery-based generator, the energy source is the sun or the grid. And the storage receptacle is the battery itself.

In conventional and inverter generators, gasoline and propane produce power; the energy receptacle is the gasoline jerrycan or propane tank.

You will need as many batteries as gasoline jerry cans or propane tanks to match a conventional or inverter generator power output. Batteries are costly compared to fossil fuels.

Now, even if you were to purchase a lot of batteries, you would still be limited by the inverter, limiting the power output. An inverter converts the DC power stored in the battery to a useful 120-volt AC that can power your house. Your power output is as good as your inverter’s output. So if you increase the size of your battery bank, you will have to add a bigger inverter. 

Now all those batteries (jerrycans and tanks) will need to recharge themselves, and they are limited by a certain speed of charge (you cannot fill them up like pouring gas in a jerrycan). You can buy even more batteries to offset the low charging speed, which means you will need even more solar panels (possibly more than your roof’s surface area) to charge all those batteries. Meanwhile, all those batteries are being drained by your home appliances much faster than being charged. 

Lastly, batteries don’t like to be charged or discharged too fast as they overheat, and your charge controller will stop sending energy to them until they cool down!  

What is the most powerful battery generator?

As mentioned earlier, there are many sizes of Portable Power Stations for all sorts of needs and uses. But if we were to try to match the power output of conventional and inverter generators, we would need to look at the most powerful available and tested battery generator.

Currently, the most powerful battery generator (and still somewhat portable) is the EcoFlow DELTA Pro Portable Power Station. It is too good even to describe. So go here to read all about it from its makers.

This kind of expandable battery power offered by the EcoFlow DELTA Pro Portable Power Station will run your refrigerator and your entire house. It will also cost you a hefty sum, so you must be ready to splurge some. The Delta Pro completely charges itself in less than 2 hours and has ALL the options and benefits that come with battery-powered generators.

Can a solar generator run a whole house?

No. A solar generator that can run a whole house is simply called installing solar panels on your roof (provided you have enough space) and coupling that with a large battery like Tesla’s Powerwall.

A conventional generator is usually better for large loads and high-demanding appliances (for as long as your gasoline stock can last).

A solar generator is useful for emergency situations in apartments to power a few lights, cellphones, laptops, and a TV and if big enough, a refrigerator and a space heater. Keeping in mind that it will need at least a day to recharge itself from solar panels if the power outage lasts longer than expected.

So assuming you need a backup for a power outage, a solar generator / Portable Power Station will cover your major needs at home.