Intro to Generators and Solar Panels

Whether you’re concerned about power outages or just need some juice for camping or tailgating, the first question is what you want to power. If you just want to be able to charge your phone and other small devices, you can probably get away with a USB battery and maybe even a handheld solar panel. But if you want to be able to power bigger stuff, like refrigerators, air conditioners, or electric stoves, you’ll definitely need something bigger.

The second question is how you want to install it; you can get standalone portable generators that you can just plug devices into directly. These are cheap and portable, and can be great if you just need to run your fridge or air conditioner for a few hours every day, or keep your battery packs charged.

But if you really want to pretend like a power outage never even happened, then you can also get a big generator and wire it directly into your house using a transfer switch. This is a device that switches over your house’s circuits to connect to a generator instead of the grid. You can either get individual switches for particular circuits (e.g. heating/cooling system, refrigerator, lights, etc.), or you can get one for your entire house. If your generator is big enough, you can basically just run everything like normal! But the rest of us will still need to be careful not to run too many appliances at once (such as an air conditioner, dryer, and microwave). This style of generator installation can be especially useful if the appliances you want to run are hardwired into your house without a wall plug, such as sump pumps and many heating/cooling systems.

However, whole-house generator systems are expensive (on the order of thousands of dollars) and uncommon, so I’m not going to focus on those in this article. I’d really only consider one of those if you live in an area that gets lots of power outages, and you have plenty of money to spend. Otherwise, just get a small or medium-sized portable generator; it’s fine for an emergency backup system. If you really need heating or cooling and you can’t plug your existing system into one, just get a portable heater or air conditioner that you can use with the generator as a backup, or install a smaller transfer switch for just that circuit.

Similar to whole-house generators, you can also get whole-house solar installations, generally with panels installed on the roof. Most home solar systems in the US don’t have batteries though, and are still connected to the grid, just like normal houses. If you use more power than you generate, you pull power from the grid, and if you generate more than you use, you can actually end up putting power back into the grid (and sometimes even get credit or payment for it, depending on whether your power company provides net metering). However, if the grid power goes out, you may lose all power (even from your own system) because many residential solar systems will automatically turn off the solar panels to prevent islanding.

Yes, that’s right, if your power goes out, your solar panels could be useless. “Islanding” is when your system continues to feed power into the grid when it’s down, and is dangerous because it can shock utility workers who thought the lines were dead. To prevent this, many solar systems simply shut off if no grid power is provided. If you want to get around this, you’ll need to install an anti-islanding inverter that can keep your solar system running while the grid is down by ensuring the grid is disconnected. And then, of course, you would probably also want to install a battery system as well so that you can continue using electricity when the sun isn’t shining. At that point, your home is able to run entirely “off-the-grid”, and indeed, many off-grid homes have exactly such a “solar panel and battery” setup. Though like with whole-house generators, I would only consider these if you get lots of power outages and have lots of extra money. If you just like the idea of solar for environmental reasons, you can install rooftop solar without the battery in order to get all the environmental benefits (but without the backup power option).

Portable generators

So with that said, the main thing we’re going to talk about in this section is portable generators. I don’t actually have a ton of experience with these myself, but here are some general notes and tips on generators I’ve picked up from research:

• Do NOT use generators inside, or even near open windows/doors! Like most other gas-burning devices, they produce harmful fumes that can be deadly in large amounts.
• There are various types of generators that all use different types of fuel:
  • Gasoline: can be nice if you are already storing gasoline for your vehicle, but you have to rotate it regularly as it will break down over time (about a year). You can extend its life by adding fuel stabilizer.
  • Diesel: basically the same as gasoline.
  • Propane/LPG: nice if you’re already storing propane for use with stoves, portable heaters, etc. Plus it doesn’t degrade over time! (though the tanks might). More info on these here.
  • Natural gas: can be useful if you expect to still have a natural gas supply during an emergency, but since you can’t easily store it in tanks, you’re out of luck if the gas lines are out (like in the 2021 Texas freeze, or after an earthquake)
    • Note that you can convert a propane generator to use natural gas (and vice versa), but that’s probably the last thing you’ll want to do during an emergency. So if you have the money, I would consider keeping both a natural gas generator and a non-natural-gas generator. That way, if the gas lines are working, then you can run the generator as much as you want, and if the gas lines are out, you still have a backup. But if you can only afford one, I would go with propane, gasoline, or diesel.
• You can also get “dual fuel” ones that support both gasoline and propane; these can be a good option if you want flexibility.
• For the ultimate in flexibility, you can even get “tri-fuel” generators that support gasoline, propane, and natural gas, though these are generally not common and are usually more expensive. In fact, most natural gas generators are expensive, non-portable models to begin with.
• Remember that generators have special operating instructions to keep them operating reliably, and require periodic maintenance. You may also need to stock engine oil and replacement filters.
• Get the smallest/lowest capacity generator you need.  Smaller = quieter, more portable, and uses less fuel. Figure out which devices/appliances you need to run and how much power they use.
  • Remember that you don’t need to run all devices at the same time. For example, instead of getting a 4000-watt generator to power both your 2000-watt fridge and your 2000-watt air conditioner at the same time, consider getting a-2000 watt generator and only using one appliance at a time.
• Get one with an “inverter”; they change speed to match the electrical load, making them more efficient and quieter.
  • In particular, you probably want a “pure sine wave” inverter, as not all devices will work well (or at all) with square or modified square wave inverters. This is especially true for devices like refrigerators and A/C units.
• If you don’t want (or can’t get) one that wires directly into your house, get one with a “console”, i.e. a built-in extension cord/power strip that allows you to run power into your house (since the generator should be outside). They are designed to support the generator’s max load and are very durable so they’re less likely to get damaged when you run them through doors/windows. If you use your own extension cord, you run the risk of it catching on fire!

Solar panels and batteries

If you know what you’re doing, there’s a whole wide world of DIY solar systems you can rig up yourself. But for this article, we’re going to focus on the simple option, which are consumer-ready solar panel and battery pack combos that are easy to set up and use, even if you don’t have any experience. These are often referred to as solar generators. Here’s an example: (not a referral)

These are as simple as can be: you just plug your devices into the battery pack, and they work. Just like if you plugged into into the wall or a USB port. You can use the battery pack on its own if you want, and just charge it up via wall power, a generator, a car charger, etc. Or you can buy solar panels and charge them that way!

Battery packs like these are great for charging phones and laptops, as well as running fans, LED lights, CPAP machines, and other small devices.

A quick note: if you use battery packs like this to charge phones or other small electronics, it’s more efficient to use the USB ports directly rather than plugging your phone charger into one of the 120V wall plugs. You can probably squeeze out a whole extra phone charge or two!

However, if you need to run bigger appliances, like refrigerators, AC units, electric stoves, etc., then you start needing very large and very expensive models, and the costs can quickly balloon into the thousands. At that point, you might be better off with a regular generator instead. But what you choose really depends on a lot of factors, so let’s start comparing!

Pros and Cons

Let’s talk about a medium-scale system for now, i.e. something that can perhaps handle a small refrigerator or air conditioner. Here are the main pros and cons for each.

Generators:

• + Cheap power generation (a 2000-watt one is about $500 on Amazon)
• + Cheap energy storage (gas, propane, etc. are relatively cheap)
• + Fairly compact
• + Can work any time and in any weather (assuming shelter from rain, etc.)
• – Can run out of fuel
• – Need to rotate fuel every 6-12 months (if using gasoline or diesel)
• – Require regular maintenance
• – Noisy
• – Produce harmful fumes

Solar:

• – Expensive up-front cost for power generation (a 100W panel is about $200-$300 on Amazon)
• – Expensive up-front cost for energy storage (a 2000-watt battery is about $2000 on Amazon)
• – Takes a lot of space if you need to set out a lot of solar panels
• – Can only work during the day, and only optimally in sunny weather
• + Can work indefinitely without needing to buy fuel, can be cheaper in long term
• + Don’t need to rotate fuel
• + Easy to use, little or no maintenance required
• + Silent
• + Doesn’t produce fumes, can even be used indoors

Conclusion

So then which should you choose? Well, if up-front cost is a big concern, generators are going to win by a lot. Especially if you need a lot of power! But if you’re planning on using your system often, solar energy is actually free after you buy all the panels and batteries, so it can pay for itself eventually. On the other side of the coin, if you’re only going to be using your system for occasional emergencies, it’s likely that you won’t want to deal with regular maintenance tasks (such as running a generator regularly, changing oil, rotating fuel, replacing fuel filters, etc.). And of course, if you really want to plan for a very long-term outage (e.g. weeks or months at a time), you also might want to go with solar so that you can’t run out of fuel.

If you really want it spelled out for you, here are some rules of thumb:

• Short-term, low energy needs (e.g. just charging phones/laptops for a few days):
  • Get a USB battery or small battery pack
• Long-term, low energy needs (e.g. van life, thru-hiking):
  • Get a USB battery or small battery pack, plus a small folding solar panel
• Short-term, high energy needs (e.g. running appliances during a blackout):
  • Get a generator
• Long-term, high energy needs (e.g. living off the grid):
  • Get a solar system and large battery, possibly integrated into your house
• You just want to reduce your power bill
  • Consider installing a solar system in your house without a battery. You won’t have power during a blackout, but the system will be much cheaper.
  • You can save even more money if your electric company uses net metering.

Also remember that everyone’s situation is different, and you can even mix-and-match systems as appropriate. For example, maybe you just want to run a generator outside occasionally and charge up a battery pack, then bring in the battery pack at night to charge your phone and run a small lighting system. The sky is the limit!

Next post:

How to Pick a Solar Generator System