SOLAR GENERATORS: Build-It-Yourself Plans Beat Ready-Made

UPDATED 22Aug2018: Have you heard about solar generators? I’ve been teaching people to build their own from parts since 2016, and folks love the energy independence these things provide. Solar generators are an up-and-coming portable energy technology that lets you make modest amounts of electricity without connection to the utility grid and without burning any fuel or making any noise.  They generate power from the sun to charge a battery, with a built-in inverter transforming that power to a usable form for plug-in appliances. Solar generators need no fuel and they just keep on working without oil changes or tuneups. Think of them like small, portable, self-contained versions of the kind of photovoltaic system off-grid people might put in their homes. It’s a great idea if you want to get into solar power, but there’s a problem.

These days a lot of companies are selling ready-made solar generators that sound great on paper, but don’t perform well in real life. I know because I’ve checked out the situation closely.  This article shines a light on the most common deficiencies hidden by some of the companies that sell-ready-made solar generators, and it explains some of the typical design limitations and false claims you’ll find in plain language. I’ll also tell you about the build-it-yourself solar generator I designed that delivers much more value for the money. I have no reason to recommend the specific components  you’ll read about here. They’re simply the best I know of for this kind of project

Problem#1: Ready-made solar generators often deliver way too little power

solar generator inverter

This is the Go Power GP3000HD modified sine wave inverter. It’ll supply 3000 watts of power – substantially more than ready-made solar generators

Some of the most heavily publicized solar generator models I’ve seen claim 1800 watts of output. That sounds impressive, but there are two problems with the claim. First, 1800 watts is not that much power. One measly toaster oven uses 1500 watts; a water well pump needs more than 2000 watts on start-up; even a simple coffee maker needs almost the full 1800 watt output.

The second problem is that an 1800 watt rating says nothing about how long a factory-built solar generator can deliver that much power. Most can’t sustain their rated maximum output for more than 30 minutes. What good is an 1800 watt solar generator when it won’t cook more than a couple of pans of bacon or make a pot or two of coffee before dying? There are ways to do better, but you need to understand how. The output of a solar generator is a function of the size of inverter it’s equipped with. 2000 to 3000 watt inverters work well for build-it-yourself solar generators. The Go Power GP3000HD inverter shown here is one I recommend for DIY projects.

Problem#2: Many ready-made solar generators recharge way too slowly.

This 100 watt PV panel with adjustable Windy Nation adjustable panel mount provides much faster recharge times than any ready-made solar generator.

The claim to fame of solar generators is that they need no fuel, make no fumes and create no noise. This is completely true. Trouble is, when it comes to ready-made units it’s only a half truth. What the sneaky sales pitches never explain is how long it takes to recharge the internal batteries in the solar generator so you can use it again. For example, if you make a pot of coffee and fry a pan of eggs, many solar generators will be dead until it recharges again. The crazy thing is, it will take 9 or 10 hours in full sun to make that recharge happen. Many ready-made, factory-built solar generators take at least 15 times as long to recharge as they do to deplete. The problem is the solar panels that come with ready-made units are way too small. Although it’s less convenient to have a large solar panel, the bigger the panel the faster the recharge time. The trick is to make your panel easy to disconnect from the solar generator unit when you want to move it. The Windy Nation adjustable panel mounting system shown here is one of the items I recommend for my build-it-yourself solar generator design.

Problem#3: Ready-made solar generators cost much more than their components.

One of the slippery tricks of solar generator marketers is to talk about them as a black box, revealing nothing about what goes on inside. But the fact is, there’s nothing technologically new or innovative about a “solar generator”. It’s a marketing term. Solar generators are nothing more than a combination of four components the world has had for a long time. These include a photovoltaic panel to make power from the sun, a battery to store that power, a charge controller and an inverter to change DC to AC power. The thing that interests me about building my own solar generator is that you can mix and match the best quality components from reputable manufacturers and keep spare parts on hand. The cost for high quality components is roughly 60% to 70% of what you’d spend buying a ready-made unit.

Problem#4: Most ready-made solar generators can’t be repaired

This Renogy Rover 20 amp MPPT charge controller does an excellent job making the most from the current generated by a PV panel. The charging pattern also extends battery life.

While it’s true that manufactured solar generators include the four main parts I mentioned, they’re combined in a way that stops you from fixing them. One part breaks and you’re toast. Not only do you not have power, but you’re out a pile of money.  The really valuable part of building your own solar generator from parts is that you know the system inside out. It probably won’t break if you use good components, but it if does go down you’re the best one to fix it. Building something is always the best way to be an expert on fixing things.

Lack of expandability is also  related to the lack of repairability. When you buy an ordinary, ready-made solar generator you can’t upgrade the inverter, you can’t add a bigger battery, nor can you increase the photovoltaic surface area or install a better inverter. The Renogy Rover charge controller shown here is an excellent option for a build-it-yourself project. The design even increases battery life by modulating the charge current.

solar generator coverBuilding a solar generator isn’t the kind of project everyone can tackle, but if you’re handy, it’s a great way to get better energy performance and security at a better price than ready-made units. It’s also a great way to get small-scale experience with solar energy to see if you’d like to equip your home with a large system.

PORTABLE SOLAR GENERATOR is my detailed guide for making it all happen. It includes detailed plans and shopping lists, 5 instructional online videos, a reasonable price and money-back guarantee. This is the most complete set of plans and instructions in the world for building your own solar generator. Examine it risk-free for 90 days and see for yourself. If this guide doesn’t deliver full value, just let me know. I’ll refund your money and you get to keep the guide.

Click here to learn more.


The diagrams, instructional videos and written instructions in Steve Maxwell’s Build Your Own Solar Generator course were very helpful for understanding and constructing by own generator.  I’ve tested the unit, charged the battery and had a”eureka” moment when it produced 110 volt power from the sun.  Hopefully hurricane season on the east coast will not press it into service, but if so, it’s ready to go.  

Bill Vye – Bedford, Nova Scotia, Canada

Click here to download the BUILD YOUR OWN SOLAR GENERATOR video course risk-free.


Posted on June 15th, 2018