One of our many concurrent projects that turned into a very delayed one. We needed to trench a gas line extension to install a propane tank for our appliance conversion. Running our home all electric was drowning us in power bills, we were frequently $400 or more without HVAC. Our overall goal: replace our electric dryer, water heater, range and heat pump with propane fueled counterparts. As of this post, we have replaced all but the heat pump. Another post in the making 🙂

While researching this project, we needed to weigh a number of issues, such as tank size and permitting. In our County, you can place up to a 500 gallon tank without a minor use permit, so that was a fairly easy decision. We also wanted at least one year worth of gas for the entire property once we convert everything. We contacted every lease company we were referred to, but no one was interested in servicing the size we wanted, only tanks that were 180-300 gallons. This would mean we wouldn’t be able to ride out the commodity fluctuations of the winter market, which can be 100% or higher that the lows of summer pricing.

So what did we do? After months of online search permutations, we found a company local to Southern California that happens to have an annex location in our town; with 500 gallon tanks in stock! We had to buy one, which was not something we really wanted to do; but in our climate, the tank should remain serviceable for 25 years or longer. Once we saved the funds to get the tank installed and filled, we pulled the trigger and finished this project.

Line has been trenched, installed, tracer wire placed, and pressure tested for inspection. An airline inspection consists of pressurizing the entire pipe system, and monitoring it for a drop. If the pressure drops, there is a leak. If not, you don’t. It is a simple way to test a complex system. Once we had the sign off, it was time to bury the line and schedule the tank delivery and installation.

Trench before filling. We had a number of irrigation and drain lines in the area we needed to dig.

Trench before filling, after inspection. 5 gallon tank hooked up to get appliances going. We ran the dryer and range for a bit off a small tank with frequent change outs while we budget for the real tank. We were using about 9 gallons a month at this point.

Trench is finally filled in! Time to get the yard back in order… We wanted to maximize the BTU availability while minimizing install costs. One inch poly pipe and risers for our length of run net us over 700,000 BTU at the inlet to the house. This is more than enough volume to run everything we have and want, plus a pool heater, and backup generator. WHAT?!?! The regulator we are using can supply 1,200,000 BTU, which should meet our demands nicely. For reference, our entire fuel load is currently 300,000 BTU which includes our tankless water heater, range, dryer, and 5 burner BBQ.

Trench is filled in, and sprinkler lines and drainage are back in place.

We needed to get permission from our neighbor to get the tank craned over the fence, otherwise we would have had a huge issue on our hands. Once permission was received, we scheduled the delivery and installation.

Even with a short reach, we were at the limit of the installer’s crane setup.

Almost home!

Tank is placed and hooked up. Time to get it filled, and we are in business for at least 12 months. The downside with a propane tank is that they can only be filled to 80% capacity for safety purposes. That means our 500 gallon tank only holds 400. This is why a 250 gallon tank wouldn’t work well for us, with only 200 gallons available. You might be asking yourself (probably not), how much energy is available? After some research and calculations, our tank when filled has the equivalent of 11,174 kilowatt hours (38,128,200 btus or 15,251 cubic feet) stored.

We are a few feet shy of the overall hose length the delivery trucks have. Luckily it is a straight shot across the yard to the tank for the driver.

After a month of checking the gauge, I broke down and ordered a WiFi based tank monitoring solution. You can easily see that there is zero temperature correction for the daily use calculation, but it does read the percentage accurately; which is the important thing I was looking for. Our house full tilt with dryer, tankless water heater, range, and BBQ has been averaging one gallon a day. Not shabby, and a massive $200+ reduction in electric use per month.

“Why didn’t you just go solar?” I can hear you asking from there. This project for the tank and 400 gallon fill clocked in at $3500 with tax, not including incidentals for the line installation. A comparable solar install for just the use of these appliances would be $20,000+. If we do the math, this project amortizes to full payoff in less than 18 months, including the offset for fuel use. Solar would payoff in 8 years and 3 months, longer if we installed to cover our entire usage. ( At $200 a month. At $244 a month, our actual savings, it would payoff in 6 years and 11 months at 0% interest; see below.)

From a continuity of services approach, we can run more appliances with less generator while maintaining our full standard of living for an extended time. We can also fuel a whole house generator in the future, which we have plumbed for already. We have our eyes on a 22KW, 4 pole 1800 RPM unit with automatic transfer switch… one day!

Edit to add: year over year proof is in the pudding

The primary factors in reducing our use by 642 KwH, or a staggering 36.5% were: switching from electric dryer and water heating to propane. In reality, we added a second full size refrigerator after the January 2019 billing cycle, yet we are still down in actual use. This will drop by another 25-30% when we replace our heat pump with a furnace. Our YoY savings on electricity was $244 gross, or $184 net after paying for $60 of propane.

The above reduction included 18 hours additional heating via our heat pump; which just goes to show how much electricity we are saving!

Here is a calculator showing how large of a PV system we would need for this kind of generation: about 4.5Kw.

Here is an actual bid for that system on my old property: $20,251. At $244 a month in payment, this would be a 6 year, 11 month break even payoff with zero interest calculated.