A propane-powered generator on display at an outdoor event
As charging woes become more prevalent, marketers should prepare for the growing propane-powered generator market

The excitement around electrification is interesting. Take a quick look through the latest equipment rental publications and you’ll see ads for electric-powered trucks, tools and even heavy, earth-moving machinery. Recently, Caterpillar Inc. announced that they are coming out with a line of battery-powered machinery. Joe Creed, Energy & Transportation Group president for Caterpillar, was quoted saying, “We’re focused on helping our customers achieve the optimal product and jobsite energy life cycle, allowing them to maximize value and minimize their total cost of operation.”

After reading this, I asked myself, “Where will the minimization of cost come from? From not buying diesel fuel for the tractor? Does a battery-powered 320 excavator cost less than a diesel-powered one? Is anything new ever cheaper?”

I can hear the electric tractor customers now: “Wait … how do I charge up my shiny new Caterpillar excavator in the middle of the construction site? The grid should be able to do it. But this is a 10-acre dirt field — there is no grid. A-ha! We will use our towable diesel generator and recharge the excavator each night.”


Hold on a second there, electric tractor customer. To save money, you are going to burn diesel fuel in a generator rather than the tractor? Does that save carbon emissions? Well, that doesn’t really add up to me either. My response to this scenario is that there is no bigger hypocrisy than to charge a battery off a diesel engine — period, end of story.

You see it already on social media. There’s a remote vehicle charging station located in “Nowhereville USA.” The cellphone video operator shows the electric cars charging up and then pans around the corner to show a dirty diesel engine chugging away in the name of cleaner cars. It gets millions of views and is shared around the world in minutes flat. It is truly counterproductive — a classic “cart-before-the-horse” situation.

We want zero-emission products to use, but the infrastructure isn’t available or ready. Well, what if we use solar panels to charge these machines? That would be the best way to cut our carbon emissions, right? To put this in perspective, the Tesla Model 3 — the Tesla car with the smallest electrical need — uses around a 50-kWh battery. That will require about 12 x 400-watt solar panels to charge it up. Of course, you need to be in a place on the globe that has good solar hours available, as well as cooperative weather (i.e., no clouds). As of the writing of this article, specifications were not available online for Caterpillar’s 320-size electric excavator, but I was able to find a Caterpillar dealer in Norway who had made the conversion from diesel engine to battery/electric motor on a 320-size excavator. That machine featured a 150-kWh battery and later upgraded the machine to a 300-kWh battery system.

In Missouri, where I live, we get about five solar hours per day. If my 4,800 combined watts of solar panels get perfect sun for those five hours, that is still only 24 kWh. Even by charging the smaller 150-kWh battery pack Caterpillar used, you are looking at adding 70-plus solar panels to charge the electric tractor. But that is during the daytime. Your fancy new electric tractor is most likely being used in the daytime, so now you need a battery to store the power you harvested. The expense of this is getting out of hand.

I recently saw a 90-kWh battery system — construction site capable and towable — sell for over $70,000. Not to mention that 90 kWh isn’t nearly large enough for our 320 Caterpillar excavator. Plus, setting aside all the environmental concerns about the panels themselves, where are all those solar panels going to sit on the construction site? It takes an area of about 12 feet by 125 feet for solar panels to generate that much solar power. This is a massive undertaking for five hours of charging, by the way. And that’s only the 150-kWh version!

This isn’t about picking on Caterpillar. They are just responding to what the market is asking for. I worked for the Caterpillar dealer here in St. Louis, Missouri, and appreciate the innovation the company brings to the industry. I also love solar — just not on a mobile or temporary application. I’ve been there and done that with mobile solar.

I will say that my failures in solar led me to a much better solution. Mobile solar is not cheap and it is not portable. If we are going to power these electric machines that have significant power requirements, mobile solar isn’t the answer. Hopefully there is some technology breakthrough soon, but we need energy solutions now.

Let’s run down the available energy sources. It’s not diesel. Gasoline? No. Hydrogen? Not ready for this application. Natural gas could do it, but the infrastructure must be in place to use it and you need to have enough of it to power some large engines. Windmills? I’m stretching here, but still no. When my customers call, they need something tomorrow, not weeks or months from now.

When I left my last corporate job and decided to pursue this search for what the alternative to mobile diesel generators could be, I went through each of these available energy sources and weighed the pros and cons.

I’ve been a generator rental guy for a long time, and most of that time was spent using diesel as the energy source. I discovered propane early in my search, and it was the dark horse — at least to me at the time. I knew of it but didn’t know about it.

It’s very different to know about propane and to know it so well that you can slash through the — at times — thorny vines of the regulations that protect the propane industry. The fact was, as a recovering “diesel-holic” searching for my next energy fix, propane had the makings of a great resource for the mobile generator market. It’s clean. There would be no more dealing with exhaust aftertreatment, like on my Tier 4 diesel generator sets. It’s readily available. I can call no less than three different propane marketers in my town and get tanks, expertise and propane gas, of course.

The downside was that mobile propane-fueled generators weren’t really a thing. I had no clue about regulations behind mounting propane tanks in an enclosure with an engine to produce electricity and tow it down the road, so I walked into the business of a local propane marketer (who will remain nameless). I showed the guys there the crudely drawn machine concept I had in mind. The guy looked at the drawing, looked at me, and said, “If you think I will ever sell you a drop of propane for this, you are crazy.”

Not a good start. Once I was able to navigate the regulations and produce a compliant product, this same guy was happy to sell me propane. That allowed me to continue to develop the product. I tell you this story not because the rude propane dude was wrong; but because your industry is going to see many new, innovative ideas coming your way.

Was “Rude Dude” right to question my intentions? Probably. I don’t blame him, but it sure would have been nice if he would have directed me to the Missouri Propane Gas Association. Once I found them, resources became available, and that allowed me to get where I am today.

These days I’m humbled by the propane industry. I’m asked to speak all the time about mobile propane-powered generators. The support we receive today is amazing. The Propane Education & Research Council has helped us in so many ways, and I’m just thankful that I can make a call or even send a text and get my questions answered. I’m certainly not the smartest guy in the mobile generator market, so I suspect there will be more innovators behind me — because when it comes to electrification, propane is positioned to be the alternative energy source that we need to power these batteries. All I ask is that you help them. It will help you, too, but don’t discount what people are trying to do while we go through the change from diesel dependence to propane freedom.

As I mentioned before, I get to speak to a lot of propane folks, and I must take this opportunity to say that, while I believe the propane industry stands to benefit from the shift to battery power, the needs of the mobile generator market are different than traditional propane customers. First off, we need your best service, not your cheapest price. Yep, I said it. You don’t need to be the cheapest because I need you to do things differently than you are used to.

Deliveries could be more frequent. I may need you to set a lot of tanks. Currently just in St. Louis, Missouri, we have 13 tanks set and connected to propane-fueled generators powering mostly construction sites.

These tanks range from 250 gallons to 500 gallons, and customers on average keep these tanks for six months. Your remote monitoring capabilities for fuel level on these tanks is amazing, so we also need you to offer that. Occasionally, we will need smaller fuel drops. We don’t mind paying for that service because the diesel folks do it today, and we already pay delivery charges to them.

The mobile propane generator market is here. We are doing this, and we need the industry to be ready. The window is just starting to open, so it’s not too late. The electrification of everything is exciting for propane. I just hope that you are excited about propane power generation, because none of it will happen without you!

Chuck Justus is president of Evergreen Mobile Power based in St. Louis, Missouri. He is also the founder of Green2Go Rental Power, which serves customers in the Midwest. He is a 25-year-long servant to the rental power industry, specializing in electric power for construction sites, special events and emergency response. Visit evergreenmobilepower.com or call 855-545-6928.


The Winning Combo Fueling Power Recovery