How I make my solar panels last long enough to pay for themselves


Backyard solar panels

Maria Diaz/ZDNET

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ZDNET’s key takeaways

  • It will take many years for a solar panel to pay for itself.
  • Cleaning is vital, as dust can dramatically reduce power output.
  • Testing a suspect panel is pretty straightforward.

Even small solar panels are expensive, so they need to last a long time in order to make their money back. 

Take my EcoFlow 400W flexible panel. This retails for $550. 

If you take the average price for a kWh of electricity in the US (let’s say $0.19), combine that with the average amount of peak sunshine (let’s say 5 hours), and allow for losses through inefficiencies, this panel can make about 1.5 kWh a day, or just under 30 cents a day of power.

Also: Avoid these 8 solar mistakes that cut your power output in half – I learned the hard way

At that rate, it’ll take 5 years for the panel to pay for itself. And that’s before you add any batteries into the equation. This is why you need your panels to last as long as possible.

The problem is, panels live outside. In the sun, rain, mist, and sea salt. They get covered in all sorts of muck, ranging from dust and pollen to bird poo. And if they’re portable, they get handled and abused.

How to maintain solar panels

So, how do you get years of service out of something that gets such a hard life? A care and feeding plan.

1. Careful handling

Solar panels started life as something people put on the roof of buildings. Now that we have portable units, they’re much more prone to damage from rough handling.

Also: I spent two years testing wind power at home – here’s why solar is still my preferred source

  • Be careful not to bend panels — this will damage them.
  • Be sure to fold portable panels the right way. Folding a joint the wrong way can damage the wiring.
  • Don’t put panels facedown on rough surfaces.
  • Never pick up or drag panels by the wiring (sounds like a no-brainer, but I’ve seen it happen).

2. Regular cleaning is key

Even a light coating of dust can cut your panel output by 5%, while pollen, being stickier and more persistent, can cut output by as much as 15%. Combined, that’s a 20% hit, and that could add a year to the time it takes for the panels to pay for themselves. 

Throw dust and sand into the equation, and you could see their performance cut by as much as 50%. All of a sudden, your panels need to work for a decade to pay for themselves.

Also: Switch to plug-in solar? My advice after testing the DIY energy tech at home

This is why it’s important to clean your panels regularly. 

Here’s how I do it. First, gather the tools and supplies. I keep it simple:

Also: Considering plug-in solar? My expert advice after setting up the DIY energy tech at home

Now to the cleaning. Because solar panels can get hot, it’s best to leave cleaning to the morning or evening, when they’ll be cooler. While rare, it is possible for the panels to crack because of thermal shock (hot panel and cool water).

  • Use the soft brush to clean off any big chunks of dirt. Take care not to scratch the surface of the panel, because scratches can severely affect the efficiency of the panel (and once scratched, they’re scratched forever).
  • Once the big chunks are off, get the soapy water and one of the cloths, and wash the surface of the panel. Most of the dirt should lift easily, but if anything is well adhered — like bird poop — leave the water to soak in for a bit.
  • The final step is to dry the panel using a clean microfiber cloth, and if you’re a total perfectionist, use the squeegee to get a perfect finish (I never bother with this step).

3. The all-important visual inspection

While cleaning the panels, look at the panel itself, along with the wiring and connectors, for any damage. You’re looking for chips and cracks on the panel itself, abraded wires, broken connectors, or delamination.

I’ve fixed small chips and cracks by carefully painting polyurethane sealer over the crack. 

Also: How I easily built my own Wi-Fi router with a Raspberry Pi – for Starlink and solar control

As for broken wires or connectors, you need to buy replacement MC4 connectors, along with the tool for fitting the connectors. If your panels are suffering from delamination — where the panel has separated into its different layers, most often from being dropped on a corner or from a crack letting in water and causing corrosion — then I’ve never been able to fix that or found anyone to do it.

For plug-in balcony solar systems, check the mounting points for damage.

How to tell if a solar panel isn’t working

If you have a panel that you suspect isn’t working, then it’s time to do some testing.

Before I go further, you may have noticed a warning printed onto the MC4 connectors used for solar panels that says something along the lines of not disconnecting while under load. A lot of people mistakenly think this means you can only disconnect the connector at night or throw a blanket over the panel. No.

Also: Considering plug-in solar at home? How to know if it’s legal in your state – and actually worth it

In this case, “load” is referring to the stuff that the panel is connected to. So before undoing any MC4 connectors, make sure to turn off your power station or plug-in solar microinverter to eliminate the chance of electrical arcing causing damage, and possibly a small burn or electrical shock.

An MC4 connector - Note the tiny "Do not disconnect under load"

An MC4 connector – Note the tiny “Do not disconnect under load”

Adrian Kingsley-Hughes/ZDNET

A note about MC4 connectors: You might think that one MC4 connector is the same as any other. You’d be wrong. Only connect MC4 connectors of the same brand and type together. Otherwise, they might cause loose connections or even arcing, and get jammed or damaged.

There are two ways to test a suspect panel. There’s an easy way, and a more involved, high-tech way.

Start by disconnecting all your panels from the power station or microinverter, and then, one at a time, connect them, power up the system, and see if you get any power. It’s much easier to spot a defective panel when testing them individually. Also, if it’s a problem like a loose connector somewhere, remember to also check the connector going into the power station or microinverter.

Also: How I boosted my portable solar panels’ power by up to 30% – 11 expert-approved tips

The more geeky way of testing a panel involves using a multimeter. You don’t need anything fancy; any basic multimeter that can measure DC voltage and current up to 10 amps will do. Here, I’m going fancy with the Pokit Pro multimeter, and I’m testing my 200W rigid Renogy ShadowFlux panel.

Most solar panels have the open-circuit voltage and short-circuit current printed on them.

Most solar panels have the open-circuit voltage and short-circuit current printed on them.

Adrian Kingsley-Hughes/ZDNET

We’re testing two things: open-circuit voltage (called Voc) and short-circuit current (called Isc).

Testing open-circuit voltage

  1. Note that you need sunlight on the panels to do this test.
  2. Set the multimeter to DC volts (there might be multiple options; you’re looking for a setting in the 10- to 100-volt range).
  3. Touch your multimeter’s red probe to the panel’s positive (+) output and the black probe to the negative (-) output.
  4. Make a note of the reading. Compare this to the Voc rating printed on the panel. It should be within 10% of the rated Voc. If not, the panel has a problem.
Testing a solar panel's open-circuit voltage.

Testing a solar panel’s open-circuit voltage. This would be much easier with two people!

Adrian Kingsley-Hughes/ZDNET

Testing short-circuit current

  1. Set the multimeter to DC amps (consult your meter’s manual, because you’ll likely need to move one of the probes to a different port).
  2. Cover the panel or flip it upside down (you’ll likely need help for this) to prevent arcing.
  3. Touch your multimeter’s red probe to the panel’s positive (+) output and the black probe to the negative (-) output.
  4. Remove the cover or flip the panel over and check the reading. It should be pretty close to the Isc rating printed on the panel. If not, the panel has a problem.
  5. Quickly disconnect the probes to prevent sparking.

If a panel isn’t outputting the right voltage or current, there’s a problem, and if that isn’t an obvious issue with the cabling, connector, or the panel itself, then check if the panel is still under warranty, or see if you can find someone who repairs panels.

Also: This is the power backup setup I trust after years of testing – solar panels included

Hopefully, with a bit of TLC, your solar panels will give you years of service.





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2026 has shaped up to be a big year for Milwaukee, and the company shows no signs of slowing down as it expands its product line. For example, it has announced that some solid new Milwaukee hand tools and organizers will be arriving throughout the summer, but that’s not all. At the end of the day, you need somewhere to put all of this stuff, and while the Milwaukee Packout storage system is deep and varied as is, the company will expand the line in the summer months.

More methods for organizing your tools are on the way, too, with the Milwaukee Packout line set to introduce some new entries this summer. They vary in size, purpose, and price point, but they’re all compatible with the wider Packout line. That means they can connect to each other, making transportation easier. In some cases, they’ll be able to help keep tools and other items secure and organized while on the move. Additionally, all of these new Packout products are covered by Milwaukee’s Limited Lifetime Warranty.

So, what new products does Milwaukee have to offer from its Packout line this summer? Here are the drops you can look forward to throughout June and July 2026.

Milwaukee compact crate

Sometimes, a massive Packout crate isn’t a necessity, which is why the line has its share of smaller options. Yet another will be coming to the Milwaukee catalog in the form of the Milwaukee Packout compact crate, which is set for a June 2026 release and will cost $39.97. It has a 30-pound weight capacity, comes in at 8.75 inches tall, 9.5 inches wide, 15.5 inches long, and 3.75 pounds, and includes two removable dividers to create up to three sections within the crate. The dividers can also be customized by cutting them to size along the pre-made score lines.

This compact crate features a wide front opening for easy access to its contents while on the job, as well as a metal top handle to carry it around on its own. Should you want to add it to your current Packout stack, you can use the connection points at the top and bottom of the crate. Speaking of durability, Milwaukee notes that it has an impact-resistant body along with weep holes to prevent water collection. At the same time, there is some nuance regarding the waterproof nature of Milwaukee Packout products, so keep that in mind before letting this crate get soaked.

Milwaukee Packout low-profile crate

A shorter but equally mighty Milwaukee Packout container is also on its way to customers this summer. The Milwaukee Packout low-profile crate is the shortest of the new releases at just 6.625 inches tall, though it makes up for what it lacks in height with a 15-inch length and an 18.625-inch width. Even though it’s slightly heavier than the compact crate at 4.85 pounds, it wins out in weight capacity with a 50-pound limit. It will be released in June 2026 and will cost $44.97.

For added modularity, the low-profile crate includes three different divider types: eight short, two long, and one for the middle of the container. When combined, they form up to 12 individual sections for tool and accessory organization. In terms of connecting to other Packout containers, it can do so from the top and bottom. Alternatively, built-in side handles are integrated into the design to make it easier to carry the crate on its own. The crate has weep holes for water drainage and an impact-resistant body.

Milwaukee Packout XL crate

Moving on to one of the larger upcoming Milwaukee Packout releases — even if it ultimately lands somewhere in the middle of the smallest and largest Packout containers for sale — there’s the aptly-named Milwaukee Packout XL crate. This release will hit shelves in June 2026 and comes with a $69.97 price tag. The 8.03-pound crate can take on some serious tools with its 75-pound weight capacity. It measures 15 inches tall, 15.75 inches long, and 18.625 inches wide. Despite its size, it can be hung up on a wall like most other Packout containers.

While some may hang this crate in their workshop, many will use it as part of their mobile Packout stack. You can connect it to your existing setup via the top and bottom connection points. It can also be used with Milwaukee toolbox attachments to hold smaller tools and batteries with connection points on the sides. Alternatively, you can move the crate around using its built-in side handles. It’s advertised as having an impact-resistant body along with anti-water collection weep holes. Suffice to say, there’s more to this seemingly simple crate than initially meets the eye.

Milwaukee Packout Wire Pulling XL Crate

For the most part, the Milwaukee Packout line is so popular because of its versatility. While most entries can be used for just about anything, there are those that come with a specialized function. Case in point, the forthcoming Milwaukee Packout Wire Pulling XL crate, which is designed for dispensing wire. This involves inserting and locking in spools of the user’s needed material, threading the wire through the wire retention slots, and using the fold-down panel to keep the end of the wire from rolling back into the box.

Overall, this crate has the same dimensions and weight capacity as the previously covered Packout XL crate, though it is the heavier of the two at 9.85 pounds. It can accommodate up to six spools, can be stacked onto other Packout containers or hung up, and has an impact-resistant body. This is the most expensive of the new Packout releases at a hefty $119.97, and it’s set to release during July 2026. Alongside the best Milwaukee power tools for electrical work, this crate seems like a vital piece for any Milwaukee-enthusiast electrician’s kit.

New Milwaukee Packout inserts are coming, too

That’s it for the new Milwaukee Packout containers set to debut this summer, but there are more new releases yet to cover. To pair with some of these containers and improve their levels of organization and function, come two new insert sets. First is the divider for the Milwaukee Packout XL crate, which splits the container into two sections. It simply slides down the middle of the crate and fits snugly into place, while retaining its ability to connect with smaller Packout attachments. It will be released in July 2026 for $29.97.

Alongside the Packout XL crate divider is the set of Packout wire pulling inserts for the XL crate. You’ll need these if you end up buying an XL crate and later want to use it as a wire-pulling crate. These inserts allow you to convert it instead of having to buy a new designated wire pulling crate. They attach to two of the inner sides of the crate via T-25 screws and include wire puller guards as well. The Milwaukee product listing says these inserts are meant for 1/2-inch EMT conduit. This insert set also comes out in July and will cost $49.97. 





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