Energy Costs

[SLOBuds]

How would I go about estimating energy costs and benefits of propane vs. electricity fuels for residential housing?

I was originally thinking of going with all-electric in our new house. I liked that idea because we are certain to supplement electricity via on-grid solar, and we then are left with one form of technology for power supply. Our area does not have access to natural gas. We will supplement with wood stoves, mainly from the aesthetic perspective.

But a few details are making me think again.

For one, I would like to have radiant heating. I DO see electric boilers, but most of the highly-rated boilers are gas or propane. Same with domestic water heating. So I begin to wonder about availability of certain mechanicals being powered by electricity.

For another, I actually like to cook with gas rather than electricity.

Another small issue involves a backup generator. My choices there are gasoline, diesel, or propane. Gas is unstable, diesel stinks, and propane is ???

Anyway. If I had the cost differential between the fuels, that would be a start. I guess this is a question of cost per BTU? And maybe a second question on general availability of residential mechanicals for each of the fuels. Heating, refrigeration, kitchen.

Thanks,
Martin

 

[ByronBob]

Propane is sold by the gallon. A gallon has some BTU rating.

Electric is sold by the Kilowatt per hour. It also must have some BTU rating I would guess?

Can you find a common denominator between the 2 might start answering your question.

Another question for you is the generator use. Will it be an emergency type system to get you by or do you want something big enough to power the whole house if needed.

 

[btolle]

Go to Google and search on "compare cost propane electricity" (without the quotes) and you will get a list of sites with calculators to compare the costs of various types of energy.

I have no personal experience with propane generators but from the RV forums I have read that those with propane generators are not happy with the high propane consumption. Some motorhome manufacturers provide propane generators in diesel powered motorhomes to cheapen the total cost but I would never buy one.

If you are talking emergency standby for a few hours a propane generator would be OK but if talking long term use diesel would be the most economical and longest lasting choice.

BTW, the biggest problem Onan has with gasoline powered generators in motorhomes is that people don't run them enough and the carburetor gets clogged up. Onan recommends running a gasoline generator at half load for 2 hours every month.

Bill Tolle

 

[Phils]

The above posts have good suggestions for help comparing fuel prices.

I'm just offering any help or info that my situation may provide you: I've been living "off-grid" for over 25 years and have had quite a few different generators (none diesel). Most of our power comes from solar panels but, as you know, this past week hasn't provided much sunshine here in California (which is good as we REALLY need the water). So I've been having to run our 10KW propane generator for about 2 hours a day to keep the battery bank charged. Gas powered means having to carry gasoline home -- a hazard and inconvenient (not too inconvenient to prevent bringing tractor gas home tho). Diesel would be the same inconvenience but not as hazardous but as you said, stinky. Propane gets delivered. I prefer cooking with gas as you do, and since we aren't on the grid, propane powers the water heater and refrigerators too.

There's a great forum dedicated to solar power at Solar Forum The members there can answer any question you'll have about the "on-grid" system you are contemplating.

If you have other questions you think I might have an opinion or answer you are also welcome to PM me.

Phil

 

[OkeeDon]

One advantage of propane (or natural gas) powered generators over gasoline or diesel is the clean-burning nature of propane. Engines using propane last longer, and generally look almost as clean as new when disassembled. As far as excess consumption is concerned, it's generally considered that propane is about 10% less efficient than gasoline, but the difference is generally make up by the lower cost of propane, made even lower by the fact that road taxes are not charged on propane for a stationary engine. Propane stores better and longer, and it'smuch easier to get deliveries. I would choose a propane powered generator over either gasoline or diesel, although diesel would be my relatively close second choice. It's interesting that most propane delivery trucks (known as "bobtails") are now diesel powered, even though they tended to be propane powered in the past. This is primarily because of two factors -- it's easier to get service on a diesel and the resale value is higher.

SLOBuds, as for comparisons between electric and propane, with increases in propane costs over the last couple of years the difference has narrowed, but it's still generally considered that propane is cheaper than electric for heating uses (furnaces, water heaters, clothes driers, etc). Like you said, I prefer to cook with gas also, except that it's important to have at least one "super burner" of 12,000 BTU or more; I once purchased an inexpensive gas stove and couldn't boil water without a lid.

Bottom line is that it makes the most sense to me to have fuels that best fit the technology. I will have gas for water heating, clothes drying, gas log fireplaces, generator, and grills. Notice that I probably won't have gas home heating; we don't actually use furnaces as such in South Florida; most have an electric coil a-frame in the forced air system; a sophisticated system uses a heat pump for heating and air conditioning. The emphasis is on AC. The heating use is so low that the payback for a more efficient system might be a couple of lifetimes.

 

[v8dave]

Here is a site with some information about comparing fuels-- nooutage.com fuels. You may be able to get some decent comparisons using these tables.

I just placed an order for 200 to 250 gallons of "red" diesel delivered at $1.44 per gallon. Red dyed diesel is untaxed diesel and is what passes for #2 heating oil here in California, kerosene is used for #1 heating oil. The last fill-up on my propane tank was at $1.68 per gallon. If you look at the charts you'll see that I'm spending a lot less per BTU on the oil heat at those prices.

My house is propane and wood (minor) heated. Propane is also used in the house for cooking, clothes dryer and hot water. My shop is heated with an oil heater. The Diesel is for the shop heater, tractor fueling and eventually a standby Diesel generator.

If you think an oil fired heat is a possibility, here is the stove I used Toyotomi OM-22 stove. Since the oil heater is working so good and the Diesel tank is already in, I am thinking of switching my house propane water heater to this oil fired water heater. If I don't switch to oil, I'm still going to switch to an on-demand tankless water heater. These propane tankless water heaters are some likely candidates.

There is no Diesel smell around the heater, i.e., inside the shop. The unit takes in outside air for combustion and vents the combustion products back outside. I have been using less than a gallon per day to heat a 1,500 sq ft shop. I keep it at about 68 to 70 degrees inside and the outside temperature has been 32 to 40 at night and about 50 during the days.

I should note that California has stringent requirements on Diesel sold here. It is all low sulphur and burns cleaner than #2 fuel oil and Diesel in most other states. It is why I am comfortable using Diesel in the heater. If it weren't for the tractor fueling and standby generator, I'd use kerosene.

 

[SLOBuds]

Those look like great products Dave. What do you use for diesel storage, how is it delivered, and what do you use for a distribution system on the site (how do you get diesel fed into the heater, generator, and on demand heater )?

Thanks for the links.

 

[v8dave]

SLOBuds, the Diesel is stored in a 275 Gallon oval tank. It is sitting slightly above ground (about 12" to 18") just outside the back of the shop. For the heater there is a copper line through the wall--a relatively easy hook up. To run the fuel the 70' to the house for the rest of the uses, I dug a trench placed schedule 40 pvc pipe in it and then put direct burial copper pipe in the PVC. The PVC is only to protect the pipe from digging. Under the house I switched back to regular copper line.

All the fuel oil appliances I use or are considering want a low pressure head for feed--less than 5' or so. The diesel generator will at the the lowest point on the feed line and will be at about 6' below the tank level. The generator pad, wiring, etc is all there. I just haven't got a genset yet.

The Diesel, or kerosene, is delivered by a local fuel oil service. They use a medium sized tank truck with a long hose for delivery. The truck is about the same size as the local propane companies use--different tank shapes though. There are actually two local fuel oil companies here, both Chevron.

 

[SLOBuds]

Do you ever have trouble containing smell when you maintain your systems?

It just seems to me that some parts of the systems require maintenance from time to time, and that could involve the possibility of spilling some of the diesel. AND ... once that diesel spills, that odor does NOT go away!

Otherwise ... the cost per btu looks pretty good!

Best,
Martin

 

[v8dave]

It is a brand new system.

I'll probably have spills outside around the tank as I fill the tractor from the tank pump and change the filters. But, that's outside.

The water heater system will be installed under the house. Lots of head room under the house, we're on the side of a hill. So, any leaks there won't cause any trouble either.

The Diesel generator is outside on its own separate concrete slab. I suspect this will be the place for spills, but it's a don't care area anyway.

Only place there might be a problem is the heater in the shop. But, then again it is a shop and I've used kerosene for cleaning my machine tools anyway. Besides, the Diesel smell will have to compete with the drips and leaks from my old cars. [By-the-way, the heater is a sealed combustion system, using outside air. Much reduced danger from fuel vapor ignition.]

I've had Diesel power in trucks since I did an engine conversion in the late 1970s. Worked on them in the garage too. The smell does go away after awhile. Not as quickly as kerosene and gasoline, but it does go away over time.

If you are concerned about the odor use kerosene. Here in Calif the price for untaxed kerosene and Diesel are within a few cents of each other.

 

[_RaT_]

Dave, does El Dorado county have any restrictions on having a fuel tank stored on your property? Do you need to have a containment area? I am interested in the links you showed for heating both water and air, thanks, Mark

 

[SLOBuds]

(Im in central California.)

Yes I am concerned about the odor, particularly knowing how diesel smell lingers for quite a while. It would not matter for me on those components that are outside, in the garage, or otherwise away from living quarters. It would definitely not be good within the living quarters.

I did not read the operating manuals for those heaters. So I couldn't tell whether they ever needed some type of maintenance that required opening the fuel lines. If so, I know that there would be fuel spills along with the smells that go along with that.

My guess is that over time they will need to be cracked open for cleaning, or maybe there are filters that need to be changed out, etc. And ther are most likely some ways to contain the spills onto drip pans or other containment devices that could be removed from the area (along with their smells).

Well. I took my original questions and confusions and dropped them onto the lap of my architect. It turns out that she uses specialized consultants for energy planning anyway. I told her that I was suffering from brain fade relative to all of the choices and tradeoffs, and that I would like to have a preliminary session with the engineer to help us get our arms around capabilities. I want to get a basic understanding of constraints before we acually start the first high-level design activities.

Thanks a lot for your feedback. It turned out to be pretty easy finding relative energy costs on the internet. (I probably should have turned to Google first as the right search terms brought back exactly what I needed.)

Thanks again,
Martin Petersen

 

[_RaT_]

Good Luck Martin. I'm in nearly the same situation as you. We are working on our plans currently. We need to build a garage/living quarters above first as our current home, a mobile home sits where the house would be. Mark

 

[v8dave]

</font><font color="blue" class="small">( Dave, does El Dorado county have any restrictions on having a fuel tank stored on your property? Do you need to have a containment area? I am interested in the links you showed for heating both water and air, thanks, Mark )</font>

I was concerned about that too. But, El Dorado county doesn't have any restrictions except for property line set back. They [El Dorado county] wanted a map of the tank placement showing its proximity to the structures and property lines. That was all, no permits. The installers handled all the paperwork.

SLOBud, there is a filter in the OM-22 heater. But the installer said the reason they used another filter outside the wall was so the heater would never have to be opened to clean that filter. The only other maintenance is soot clean out in the fire box. The installation crew was vague on how often that was necessary. They wouldn't say it wan't necessary, but it was hardly ever needed in their experience. The OM-22 goes through some kind of a self cleaning process periodically.

 

[SLOBuds]

They probably put a shutoff valve just before the heater. If you need to service the unit, you would shut off the supply and maybe follow some type of procedure to clear the fluid. Maybe it has a low-point drain, or it is able to run all of the fluid out of the line through normal combustion.

Actually, I'm positive that you could isolate the drips somehow during maintenance. And after that, if I recall my days as installer on diesel yachts, there are cleaning solutions that do neutralize the oder as well as clean the fluid.

Either way I don't think it will be a problem for you. And it looks like a swell unit!

Good luck.
Martin

 

[SLOBuds]

Thanks Mark.

I might start a post on CBN so folks can follow my travails and offer tidbits of knowledge and wisdom!

I'm fairly confused at the moment. Mainly because of the number of options combined with the limits of the parcel combined with some of the design characteristics we are married to (eg., radiant heat). So I dropped this on my architect and said 'I give.'

The architect is specialized in alternative construction methods, but she outsources the energy work to specialists. I told her yesterday that I would like an early session with the energy person to get an idea of capabilities.

Because of our mild climate here in California, there are many technologies that are not well represented. It's just easier to slap central air/heat into a structure that looks like 1000 other structures in your tract, and has the minimal amount of insulation needed to satisfy regulations. (Or at least this is the way it is in central/southern CA.) It's not as easy to find hvac professionals that are well versed in boilers, radiant heat, geothermal, etc. Solar, of course, is another story. Plenty of those folks around.

As long as I am paying to have someone educate me on all of this, it might be nice to share that with the group as well. And I know it would help for others to kick the tires too!

Regardless of the efficiences that are associated with various mechanicals, my take at this moment is that passive design techniques and conservation methods are the best ways to reduce costs. I could build a 24x7 fully-lit gambling casino, and power it fully with huge solar arrays. Or I could probably build something smaller, with plenty of natural light, that heats and cools within a reasonalbe range all year round, and ... etc.

Happy new year,
Martin

 

[rozett]

It is often a tradeoff between the (one-time) initial building costs and the (recurrring) operating costs. Most of the more efficient heating and AC technologies cost a lot more up front. So a builder, building on spec, will opt for the lower up front costs. Since you are building for yourself, and assuming that up front costs are not an issue for you, then you have many more options open to you and the use of an energy expert is a good call.