{"id":3549,"date":"2026-10-21T23:34:44","date_gmt":"2026-10-21T15:34:44","guid":{"rendered":"http:\/\/www.skylinewanderers.com\/blog\/?p=3549"},"modified":"2026-10-21T23:34:44","modified_gmt":"2026-10-21T15:34:44","slug":"what-are-the-pros-and-cons-of-using-alternative-fuels-in-a-generator-set-4a72-4cd0fa","status":"publish","type":"post","link":"http:\/\/www.skylinewanderers.com\/blog\/2026\/10\/21\/what-are-the-pros-and-cons-of-using-alternative-fuels-in-a-generator-set-4a72-4cd0fa\/","title":{"rendered":"What are the pros and cons of using alternative fuels in a generator set?"},"content":{"rendered":"

If you\u2019ve ever stood on a job site at 2 a.m. when the grid dies, or helped a small business owner keep their refrigerated inventory from spoiling during a storm, you know how critical a reliable generator set is. For 12 years, I\u2019ve built and sold generator sets\u2014first as a technician, now as a supplier\u2014and over that time, one question comes up more than any other: \u201cShould I run my genset on an alternative fuel instead of diesel?\u201d Generator Set<\/a><\/p>\n

<\/p>\n

I get it. Diesel has been the workhorse of backup power for decades. It\u2019s easy to find, it packs a lot of energy into a small tank, and people trust it. But over the last few years, alternative fuels\u2014natural gas, propane, biodiesel, hydrogen\u2014have stopped being a niche gimmick and started feeling like a real option. Every week, a new customer stops by our lot or calls to ask about switching. Some want to cut costs, some want to lower their carbon footprint, and some just got tired of waiting for diesel deliveries during a pandemic or a hurricane. But no one has the full picture, and honestly, neither did I until I installed and serviced every type of genset fuel system you can imagine.<\/p>\n

Today, I want to break down the pros and cons of alternative fuels for generator sets, straight from the perspective of a guy who works with these machines every day. No fancy jargon, no sales pitches (well, a soft one at the end), just what I\u2019ve seen, what my customers have lived through, and what the data actually says.<\/p>\n

The Big Pros of Alternative Fuels for Gensets<\/h3>\n

Let\u2019s start with the good stuff. The benefits are real, but they don\u2019t apply to every scenario\u2014here\u2019s where they shine.<\/p>\n

Lower Long-Term Operating Costs (When It Makes Sense)<\/h4>\n

I don\u2019t mean the sticker price of fuel at the pump (though that matters too). I mean total cost over time, and that\u2019s where alternative fuels pull ahead a lot of the time. Take propane, for example. A lot of people don\u2019t realize that if you already have a gas line running to your home or business, adding a propane genset is almost plug-and-play. Our customer who runs a 24-hour grocery store in suburban Cleveland had a diesel genset that cost him $450 a month in fuel during peak winter. He switched to a propane genset tied to his existing tank, and his monthly fuel bill dropped by $180. That\u2019s a big chunk of change for a small business.<\/p>\n

Biodiesel is another one. It\u2019s made from vegetable oil and animal fat, so it\u2019s domestic for the most part\u2014no more worrying about supply chain issues when a shipping lane gets blocked. I had a landscaping company customer who used to spend $1,200 a week on diesel for their portable gensets on job sites. They switched to B20 biodiesel (20% biodiesel, 80% petroleum diesel) and saved about $210 a week. The price per gallon is slightly higher than regular diesel right now, but when you factor in federal tax credits for using alternative fuels, that gap shrinks fast. And here\u2019s a big one: biodiesel is less likely to gel in cold weather than diesel, so our Minnesota customers tell us they don\u2019t have to fight cold starts as much in January.<\/p>\n

Natural gas is the king here for large-scale backup. A hospital in Detroit we equipped uses a 500kW natural gas genset, and their fuel bill is 30% lower than it was with their old diesel unit. Because natural gas pipelines are widespread, they never have to worry about running out of fuel during a power outage\u2014something that happened twice when they were on diesel in 2019 and 2020. That peace of mind alone is worth the extra cost for a lot of critical facilities.<\/p>\n

Better for the Environment (If You Pick the Right Alternative)<\/h4>\n

Let\u2019s be honest: climate change is no longer a distant threat. My 16-year-old son\u2019s high school has mandatory recycling, and the construction industry my cousin works in is getting pressured by clients to cut emissions. Alternative fuels deliver here, but not all of them are created equal.<\/p>\n

Biodiesel cuts greenhouse gas emissions by 50 to 80% compared to petroleum diesel, according to the EPA. That\u2019s a number I\u2019ve seen in our own data\u2014customers who switch to biodiesel report a noticeable drop in black smoke coming out of their exhaust, which is great for their neighbors, their workers, and the environment. Propane and natural gas gensets also burn cleaner than diesel. The same Cleveland grocery store I mentioned earlier cut their nitrogen oxide (NOx) emissions by 25% and particulate matter by 30% when they switched to propane. The air quality around their store is better, and they qualified for a local green business tax credit, which saved them another $1,200 a year.<\/p>\n

Hydrogen is the wild card here. It emits zero tailpipe emissions when burned in a genset\u2014only water vapor. We\u2019ve installed a couple of small hydrogen gensets at rural data centers, and while they\u2019re still in the testing phase, the feedback so far is that their carbon footprint is almost negligible. The catch is that hydrogen fuel is still expensive and hard to source in most parts of the U.S., so it\u2019s not a practical choice for most customers right now.<\/p>\n

Increased Reliability and Convenience<\/h4>\n

Diesel has a weakness everyone who\u2019s ever lived through a storm knows about: supply shortages. When a hurricane hits Florida or a winter storm hits Texas, diesel pumps run dry within hours. I\u2019ve had customers in Tampa who waited three days for a diesel delivery during Hurricane Ian in 2022\u2014by that time, their backup power had already failed. Alternative fuels don\u2019t have that same problem if they\u2019re tied to a pre-existing infrastructure. If you have a natural gas line or a propane tank on-site, you don\u2019t have to chase deliveries during an outage. Our customers with on-site propane tanks never wait for fuel\u2014they just keep the tank filled during normal times, so when the grid goes down, their genset is ready to go.<\/p>\n

Another reliability win is for standby applications. Diesel gensets need regular maintenance to keep their fuel from gelling or going bad if they sit unused for long periods. A lot of small business owners only test their gensets once a month, and if they\u2019re on diesel, they have to drain the fuel and replace it every year to keep it from clogging the engine. Alternative fuels like propane and natural gas don\u2019t degrade nearly as fast. We did a test last year where we left two gensets running on different fuels for six months without use. The diesel unit had fuel that was 30% less energy-dense, and it took three tries to start when we tested it. The propane unit started on the first crank, just like it was brand new. That\u2019s a huge deal for anyone who relies on backup power that needs to work immediately\u2014no time to troubleshoot a clogged fuel line.<\/p>\n

Lower Maintenance Costs (Most of the Time)<\/h4>\n

I used to service diesel gensets 10 years ago, and I can tell you: the fuel lines, injectors, and filters on diesel units get clogged all the time. Alternative fuels burn more cleanly, so they leave less residue in the engine. A restaurant customer in Chicago that switched to biodiesel last year spent half as much on engine maintenance as they did with diesel. Their service intervals went from every 200 hours to every 400 hours, which means less downtime and less money spent on parts and labor.<\/p>\n

Propane and natural gas gensets have even fewer moving parts in the fuel system. We\u2019ve had a few customers who have run their propane gensets for 10 years with only minor tune-ups, compared to a diesel unit that needs an injector replacement every three years. That\u2019s another big plus for long-term ownership.<\/p>\n

The Not-So-Great Cons of Alternative Fuels for Gensets<\/h3>\n

Now, let\u2019s get real\u2014alternative fuels aren\u2019t perfect. If I only told you the good stuff, I\u2019d be doing you a disservice. I\u2019ve seen way too many customers buy into the hype and end up with a genset that doesn\u2019t work for their needs.<\/p>\n

Higher Upfront Costs<\/h4>\n

This is the biggest one. A basic 20kW diesel genset for a small home or business costs around $6,000, installed. The same size genset running on propane is $8,000 to $9,000, and a natural gas unit is even more\u2014around $10,000 for a comparable model. For larger units, the gap is even wider. A 500kW diesel genset is about $50,000 installed, while a natural gas unit is $70,000. Why? Because the fuel systems for alternative fuels are more complex\u2014they have to handle different pressure levels, different combustion rates, and different storage requirements.<\/p>\n

I recently had a customer who runs a small warehouse in Indianapolis come to me. They wanted to switch from diesel to natural gas because of lower fuel costs, but the upfront cost to run a natural gas line to their property was $15,000 on top of the genset. Even with the lower fuel bills, it would take them 10 years to recoup that cost. They ended up sticking with diesel for now, and they\u2019re waiting for the local gas company to expand lines to their area. Upfront cost isn\u2019t a dealbreaker if you have the capital, but it\u2019s a major barrier for small businesses and homeowners on a budget.<\/p>\n

Limited Availability and Infrastructure<\/h4>\n

I touched on this earlier, but it\u2019s worth repeating. While natural gas lines are common in most urban and suburban areas, rural areas often don\u2019t have access to natural gas pipelines. Propane is more widely available in rural areas, but you have to store it in large tanks on your property, which takes up space and requires regular refills. Biodiesel is available at most gas stations now, but not every station has it, and in remote areas, you might have to drive 50 miles to find a pump with B20 or higher.<\/p>\n

Hydrogen is the worst for availability right now. There are only a handful of hydrogen fueling stations in the entire country, so unless you\u2019re located near one, a hydrogen genset is basically a paperweight right now. We had a customer in Wyoming who bought a hydrogen genset as a \u201cfuture-proof\u201d solution, but they still can\u2019t get hydrogen delivered to their site, three years later. It\u2019s a cool technology, but it\u2019s not ready for mainstream use yet.<\/p>\n

Lower Energy Density (Which Means Less Power Per Gallon)<\/h4>\n

Diesel is one of the most energy-dense fuels we have\u2014one gallon of diesel has about 138,000 BTUs of energy. Compare that to propane, which has about 91,500 BTUs per gallon, and natural gas, which is only about 1,020 BTUs per cubic foot (so a gallon of natural gas equivalent has around 100,000 BTUs, tops). What does that mean in real terms? You need a bigger tank to get the same amount of power, or you\u2019ll run out of fuel faster.<\/p>\n

For example, a 20kW diesel genset will run for about 10 hours on a 50-gallon tank. A 20kW propane genset will only run for about 7 hours on the same size tank. If you need power for a long outage, that means you\u2019ll have to refuel your propane genset more often, which is a hassle. For a large commercial genset, that can mean needing a much bigger fuel tank, which takes up space and adds to the upfront cost. I had a grocery store in Detroit that switched to a propane genset, and they had to double the size of their outdoor tank to keep enough fuel on hand for 24-hour outages. That added $3,000 to their installation cost.<\/p>\n

Cold Weather Performance Issues<\/h4>\n

I mentioned earlier that biodiesel doesn\u2019t gel as easily as diesel, but that\u2019s not true for all alternative fuels. Propane and natural gas can have issues in very cold temperatures. When the temperature drops below 20 degrees Fahrenheit, propane can start to vaporize poorly, which means the genset might not start or might run rough. We had a customer in northern Minnesota who bought a propane genset for their cabin, and on the first night it got below 10 degrees, the genset wouldn\u2019t start. We had to add a heating element to the propane line, which cost them $500 extra and required more maintenance.<\/p>\n

Natural gas gensets have similar issues in extreme cold. The gas can condense in the lines if they\u2019re not properly insulated, which can cause pressure drops and engine stalling. That\u2019s a big problem for anyone in northern climates who relies on backup power during the winter.<\/p>\n

Emission Regulations and Certifications<\/h4>\n

Believe it or not, alternative fuels come with their own set of regulatory hoops. Most areas have strict emission standards for generator sets, and even though alternative fuels burn cleaner than diesel, you still have to make sure your unit is certified for your area. For example, some states in California require gensets to meet very low NOx emissions standards, and while natural gas gensets meet those standards, not all propane gensets do. If you buy a propane genset that\u2019s not certified for California, you can\u2019t legally use it there, no matter how cheap it is.<\/p>\n

We had a customer in Los Angeles who bought a cheap uncertified propane genset online, and when we tried to install it, we found out it didn\u2019t meet the city\u2019s emission rules. We had to take it back and upgrade to a certified model, which cost him an extra $2,000 and a week of waiting for delivery. That\u2019s a costly mistake a lot of people make when they shop around without checking local rules.<\/p>\n

So, Who Should Use Alternative Fuels for Their Generator Set?<\/h3>\n

Let\u2019s cut to the chase. Alternative fuels aren\u2019t right for everyone, but they\u2019re a great choice for certain groups:<\/p>\n