Geothermal Heat Pump part 3: How much did it save?

This is the third of three posts about my new geothermal heat pump system.

Part 1 discusses what was installed

Part 2 discusses how the system performed

This is part 3, where I talk money.  How much did the geothermal system save over the previous system?

Capital cost

I won't give a detailed capital cost except to say that after taking into account the green energy tax credits and the small Duke Energy rebate, the installation cost of my system was approximately the same cost as an equivalent air-source heat pump installation with the same features.  So by my reckoning I'm not out extra for the geo system, and all operating savings will be true savings.

It isn't quite that simple though.  I had to put out the whole cost of the installation when it was completed, and then wait to get the tax credits back.  Luckily my timing was good, my system was finished in November and I got my tax refund in February so it was a relatively short, though lean, period.  Also I don't get all the tax benefits right away.  The federal 30% tax credit all came to me in February.  But the state tax credit, which is $8,400, will come back over two years because the total amount of credits claimed in one year can't exceed 50% of the state tax liability.  So I will get most of it this year and the rest will roll to next year.

I'm sure someone more financially sophisticated than me can work out the time value of waiting to get the tax credits back, but I'll be ignoring that.

Many installers will offer 18 month no-payment no-interest financing that would seem to make the waiting "free" but in reality it isn't really no-interest.  The financing company charges the contractor a fixed fee for the financing, which he passes onto you.  My installer looked into it, we compared costs, and I decided not to do that, using a home equity line to pay for the system instead because the total interest would be less than the flat finance fee of the "no-interest" option.

Operating cost -- the data

Operating cost is where the rubber meets the road.   I won't show all my work because it would beexceedingly dull but suffice to say that I have kept significant data to figure this out.  I have tracked all my propane deliveries and what they cost, and all my per month power usage for the last two years.

You can't just compare the bills from winter to winter though, you also have to take into account how cold the winters were.  This is measured using degree days, which are explained very well here (scroll down to "Degree Days for beginners").  To figure out your degree days you need to have a fairly detailed temperature record that goes back far enough.

I do have a weather station that uploads to weather underground and have all that data, but it doesn't go back far enough to do a full comparison of the last two winters.  However I compared its data to a nearby airport and found that cumulatively over the time that I have records for, my weather station and the airport are within 3%  of each other, which is definitely close enough.

The airport has data going back as far as I need so I used it along with the excellent site degreedays.net to calculate the heating degree days for both this past winter and the previous one, and to make a fair comparison between winters, I figured my cost per heating degree day (HDD) for this past winter, with the geo system, compared to the previous winter, with the propane system.

For my purposes, I defined winter as Nov 3rd to March 12th, because I had exact electric meter readings for those days and that period includes all the cold weather we experienced this winter. .  According to degreesdays.net, using the Raleigh Executive Jetport temperature data, there were 3018 heating degree days for that winter period.

Figuring the cost is definitely not an exact science!  I don't have an easy way of telling how much of my electric bill is for the heat pump, so I approximated it by assuming that the increase in kwh usage, per degree day, from winter 2014 to winter 2015 was the cost of heating with geo, since that's the only major change from year to year.

To figure the cost per degree day of heating with propane, I just assumed all my propane usage was heating.  This works because I hardly use any propane during the warm months, even though it also heats my hot water and we cook with it.  But that usage is pretty negligible, and since I got the desuperator option with my geo system, including the hot water in the calculations is actually more accurate. I also have a gas fireplace but it's used so seldom that it hardly factors.

The results

So enough background, what's the bottom line?

I calculated that, with my previous system, I used on average 0.25 gallons of propane per heating degree day (HDD) during the winters leading up to the geo installation.

I also calculated that the geo system used 1.51 kwh per HDD during the winter of 2014-2015.

How does that translate to dollars, you ask? Good question.  It's easy to figure the geo system cost because the cost per kwh is known: it's 9.635 cents per kwh during the winter. Multiplying that by the 3018 heating degree days for the winter that just passed,  my electric heating cost for the winter that just completed works out to $439.

But my total cost was a bit more than that because I also used 60 gallons of propane this winter, primarily for hot water and for that short shot of backup heat on an 8 degree day.  I know this because, fortunately for the geek in me, my propane tank was topped off just before the geo system was turned on so I can read off my usage using its percent full meter.  I know it's not perfectly accurate, but it will do. The one delivery that I got before the geo system was turned on cost me $1.91 a gallon, so I can say that the propane I used this winter cost me $115, so added to the electrical cost of $439, my total heating and hot water cost for the winter that just passed was $554.

Now for what propane would have cost.  For the winter period that just passed, using 3018 heating degree days and propane usage of 0.25 gal per HDD, I project I would have used 755 gallons of propane over the past winter, instead of the 60 that I actually used, for a savings of 695 gallons.

So to compute my savings I need compare the cost of the gallons of propane I saved, which is 695 gallons, to the cost of the extra electricity I used, which is $439.  My savings would be:

(695 * $price per gallon) - $439

This is where it gets complicated because propane pricing is all over the map. I didn't buy propane at all this past winter so quite frankly I don't know what it would have cost me to fill up 2-3 more times like I used to, as the price usually fluctuates throughout the winter.  But I can make assumptions.

I actually had a pretty sweet deal on propane. Since I own my tank and shop around every fall, I was paying about 80 cents a gallon less than the market price as tracked by the U.S. energy information agency.  So I can make some assumptions on propane cost based on that site and what I was paying before but  they are only approximations, though I think they are pretty good.

The table below summarizes my computed savings assuming either paying my bargain price for propane, or the market value.

Here is the bottom line, summarized in a table:

Assumed Avg Propane price	Hypothetical spending for propane heat and hot water if no geothermal system installed	Actual heat and hot water spending with new geothermal system	Savings for winter 2014-2015
$1.95/gal	$1,473	$554 (actual amount discussed above)	$918 (62%)
$2.75/gal	$2,076	$604 (because the 60 gallons of propane I used would have cost more as well)	$1,472 (71%)

My actual savings were somewhere in between those two numbers, likely much closer to the lower one.  But I include the market price savings as a reference for anyone interested who can't get a good propane price, perhaps because you rent a tank so can't shop around.

But the bottom line story is even better

When I was heating with propane, I set my thermostat at 68 degrees in the house.  With the geo system, I set it at 70 degrees.  Since I have no idea how to account for that difference, I'll simply say that I saved over 60% on my heating cost, while being more comfortable.   I'd say the geo system is definitely a success!

Geothermal Heat Pump, part 2: first winter performance

It's now been one full winter since my geothermal heat pump system was installed so I can evaluate its performance.  For the details on what was installed see part 1.

This was a good winter to test it in, as you know if you live around here.  We had some pretty cold stretches.  Let's see how the system did. Note, I won't be talking about operating cost in this post.  That will be part 3 because it's not a simple topic and this post is long enough already.

Noise

As part of  the crawlspace encapsulation that was done as part of this install, the fiberglass insulation was removed from under the living floors.  The geo equipment was all placed in the crawlspace under the master suite, which is where the previous equipment was.  The geo equipment is quieter than the equipment it replaced, but without insulation in the floors more of the noise came through, so the noise in the house is a wash.

Well it is now.  At first it was very noisy, with a loud pulsing sound that sounded like there was a washing machine running.  I had the contractor back out to troubleshoot and he discovered that the noise was due to the desuperator pump.  One of the desuperator lines was resting on a PVC drain line from the master bath, so when the desuperator pump ran the noise and vibration was transmitted right up into the bedroom through the tub in the master bath!  Once that was fixed the noise level was equivalent to the old system.

However in the future I may have insulation put back under the master suite floor to quiet it more.  By nature the geo system is quieter, but removing the underfloor fiberglass insulation as a result of crawlspace encapsulation has cancelled that out.

Outside noise is non-existent.  In the previous system the compressor was outside in an assembly with a big cooling fan and whenever it kicked in, relaxing outside was interrupted.  Now the outside is perfectly quiet at all times, which is how we like it in the country!

Comfort

Well comfort is the real bottom line, right?  The job of the system is to keep the house at a comfortable temperature and humidity after all.  And on this score the new system is an A+!

With the previous system my master bedroom was always too cold because the thermostat was on a living room wall opposite a south facing wall of windows.  So in the winter the sun would shine on the thermostate and heat it up, so the system would shut off before the master bedroom was warmed up.

In the summer the previous system couldn't keep the main room where the thermostat is cool enough so the system ran all day and froze out the master bedroom.

At first I wanted to solve this with a dual-zone system but my installer talked me out of that.  He pointed out that a dual zone system is suited for a house with roughly equal zones, but in my house the master bedroom zone is only about 20% of the house so a dual zone system would be inefficient (the rest of the house is pretty much one big open space so no other zone definitions were practical).  Instead he suggested changing the thermostat to one with multiple remote sensors.  I placed the sensors around the house, out of the direct sun, and the thermostat uses the average of them to control the system.

This worked much better than I expected!  My house now maintains a consistent, comfortable temperature throughout.  The temperature in any one room has not varied by more than 2 degrees in the most extreme cold, and usually not at all.

Cold weather heat pump performance

So was my contractor right when he said I wouldn't need backup heat with my geothermal system?  Bottom line, yes.  We had a bitter winter this year with one of the coldest Februaries on record and the geothermal heat pump maintained the 70 degree set point all the way down to about 10-12 degrees F outside.  There was one morning that got down to 8 degrees F and then the system could only maintain 68 degrees against the 70 degree setpoint.  I ran 30 minutes of backup propane heat to boost the house up, switched back to the geo system, and it maintained the house at 70 for the rest of the day.

It's worth noting that during that 8 degree morning the air coming out of the vents while the heat pump was running felt just as warm as usual, so it was still generating the full amount of heat.  It's just that, when it got that cold outside, that amount of heat became not quite enough.

So I could have lived without the backup heat and just been slightly uncomfortable on one exceptionally cold (for NC) morning.  But that wasn't the only reason I had the backup heat installed, as I discussed in part 1.

Power outage protection

I had the propane backup heat installed so I could run it on a cheap generator to keep my house warm during ice storm power outages.  I was anticipating more and longer power outages since Duke Energy took over Progress Energy.  However I was pleasantly surprised.  We had one power outage that lasted about five hours during windstorm, but through two significant ice events our power never flickered, even while many areas of the state had lengthy power outages.  Over half the customers in my county were out for over a day, but I never was.  So, so far, I haven't had to run the backup heat on the generator as I expected.  This means that at this point, the propane backup heat is only providing peace of mind, and has only been run for 30 minutes since the system was installed this past fall.

The next installment will analyze the operating cost savings of the system.

Geothermal Heat Pump part 1: The new system

Just in time for winter 2014-2015 I had my HVAC system replaced.

Previous system 

I had a dual-fuel heat pump, which is a regular heat pump with an outdoor thermostat that turns off the heat pump and switches to gas heat when the outside air temperature gets below 40 degrees. The system was a Bryant 5 ton, 10 SEER,  7.0 HSPF system.  However I discovered during maintenance that the the outdoor thermostat had never worked correctly, so for all practical purposes I had been heating almost exclusively with propane.  This resulted in some monster propane bills because propane pricing is high, and volatile.  

I also discovered during maintenance that my system was on the verge of failure. It was 15 years old and with most of the equipment in a vented crawlspace, 15 years of condensation and rust had taken its toll.  After several months of deliberation and getting quotes, I decided to replace it with a dual-fuel geothermal system.

What about backup heat?

However unlike the previous dual-fuel system, the new one would switch manually to backup heat, meaning that the backup propane heater would only come on when I manually switched over to it, not automatically at a set temperature.  This way I could control the system and know exactly how effective the geothermal heat pump is at generating heat on its own.

My contractor did not think I needed the backup propane heat at all, and neither did most people with experience in this area that I talked to.  They told me that since a geothermal heat pump draws its heat from the ground, which maintains a steady 60 degrees year round, it would always be able to produce heat year round no matter how cold the air gets, without needing a backup heat source.  This is in contrast to standard heat pumps, which can't draw heat from subfreezing air so they need a backup heat source for when it gets too cold outside. Standard heat pumps also require a defrost cycle, during which backup heat runs, and geothermal systems do not.

But I had another motivation for wanting backup heat: power outages.  Out in the country where I live power outages can last a long time.  I figured if I lost power during an ice or snow storm, the backup propane furnace could be easily run from a consumer grade generator, as you really only have to power the blower.  A gas furnace runs off a standard 110v 15 amp circuit.  A heat pump really can't be run off a normal, relatively inexpensive generator, not only because of the level of current it needs, but because they are sophisticated machines that aren't very tolerant of the kind of "dirty" power produced by a consumer grade generator.  

In 13 years at our place, our power had surprisingly  proven to be pretty reliable with Progress Energy.  But then Duke Power bought Progress Energy in 2012 and almost immediately service got worse.   Shortly after Duke's acquisition of Progress closed, a routine summer NC thunderstorm that might have resulted in a 2-3 hour outage with Progress caused a 2-day outage with Duke.  It seemed clear that with the new power company, I would need to be more prepared for power outages than before.

So I had the propane backup heat installed even though the experts said I didn't "need" it.

The installation: ground field

The installation of the new system was a lot harder than anyone expected, because of the ground field.  The ground field is the network of underground pipes that draw heat from the ground (or in the summer, discharge heat to the ground).

Caved-in geo trench

The original plan was to install these pipes in trenches in my pasture.  This would require seven trenches, each about 150 feet long and six feet deep.   However the digging of the first trench revealed a problem:  Because of the composition and moisture content of my soil, the trenches that were dug were unsafe to work in... several cave-ins occurred almost immediately as the digging was underway, fortunately with no one inside.  The trenches were not going to be a safe method of installation. This required a plan B.

Horizontal drill

Plan B was to use horizontal drilling to install the geo lines.  This is actually a superior, though more expensive method.  Fortunately for me the contractor and subcontractor kept to the originally agreed price, so I got a better method for the same price.  However the horizontal drilling equipment was finicky and subject to multiple breakdowns, and the availability of the right expert personnel to run it.

The bottom line is that the geo field that was supposed to take about 10 days to two weeks to install, took over two months.  But the end result was superior.  The lines were deeper down (8 feet instead of 6) and there was less surface disturbance in my pasture (though it was still significant).

One other advantage of the damp, unstable soil, is that it conducts heat better than dry soil.    So with deeper lines than planned, and wetter soil, I got a better performing geo field than expected.

The installation: equipment

ClimateMaster Tranquility
Geothermal Heat Pump

Trane Clean Air Effects
whole house filter

I definitely went whole hog with this system.  In for a penny in for a pound, I guess. It's a Climatemaster Tranquility 5 ton system, with a Trane Clean Air Effects central filter, backup propane furnace, and desuperator.

Condenser and backup furnace

The desuperator is a feature of geothermal systems that uses waste heat to heat hot water.  The desuperator doesn't provide all my hot water needs, but it preheats water before it goes into the hot water tank, so that the actual hot water heater (propane powered in my case) has much less work to do.

The total system cost was, well, high.  However because it's a geothermal systems it qualifies for green energy tax credits that, in the end, make it cost about the same as standard heat pump system.

The installation: encapsulation

As part of this installation I also had my crawlspace encapsulated and conditioned.  This means that my crawlspace was sealed, insulated, and is heated and cooled like the rest of the house.  This is becoming the new standard in the humid southeast as we are starting to realize that vented crawlspaces in humid climates are a really bad idea.

This is your condenser in a vented crawlspace

The problem with the previous foundation standard is that during the hot summers, the foundation vents draw in warm, humid air which then condenses on anything in the crawlspace that is cooler and drier.  This includes all the HVAC ductwork and all the HVAC equipment that's under there, which in my case includes the condenser and the backup furnace. The amount of mold and mildew this caused was terrible, not to mention shortening the life of the equipment because of rust.  You can see to the left the condition my condenser was in when it was removed.

Showing a crawlspace pier,
this shows how thoroughly
the plastic is applied to seal
the crawlspace

The vented crawlspace had another problem:  critters.  Raccoons had figured out how to remove the foundation vents from my crawlspace and had moved in along with possums and who knows what else, with extremely unpleasant results.  The crawlspace was NOT someplace you wanted to go, and the odors from the crawlspace were getting into the house because the critters had damaged the flexible HVAC ducts under there, resulting in them drawing foul crawlspace air directly into the house.

Showing a side wall of the
encapsulated crawlspace
with R-10 insulation board
the plastic runs up the wall behind
the insulation board to ensure
sealing

In the encapsulated crawlspace, all openings are sealed just like they are in the living areas of the house, which keeps critters and humid air out. The entire floor is covered with 20 mil plastic that goes up the walls and piers to ensure a good seal. Also all the exterior crawlspace walls are covered with R-10 insulation boards. The existing fiberglass insulation under the floor is also removed because it's no longer needed and was in pretty bad shape because of mildew, condensation, and critter damage.

 The space is also conditioned just like the rest of the house, by opening a couple of HVAC vents into the space.  This keeps the humidity down in the space.  The crawlspace essentially becomes an extension of the living space.





The credits

HVAC Contractor: Anthony Maynor
Geo field subcontractor: Lothridge Geo
Crawlspace encapsuation:  Triangle Reconstruction

They did excellent work, handled everything, kept to the original estimate despite unexpectedly bad soil conditions and I would recommend them.

How far can you go in a small plane for your money?

The $100 hamburger is a cliche of hobby aviation.  The idea being that you fly somewhere for a meal, and when including the cost of the flight the meal costs $100.  Well that trope is pretty old and flying costs have escalated.

I've often had people ask me how much it costs to fly someplace.  There isn't a standard answer and it's hard to calculate because of various factors described, as I will now summarize.

My Piper Warrior

Background: I fly a Piper PA28-161 Warrior.  This plane type is available for rent at the Wings of Carolina Flying Club, based at the Raleigh Executive Jetport north of Sanford, NC.  The rental rate is wet, meaning everything including fuel is included, so the plane rental is the all-in cost of the flight.  The price of the rental fluctuates with fuel costs but as of this writing it is just under $105 per hour.


For your $105 per hour you get a four-seat airplane that cruises at 110 knots, or 127 miles per hour.  This is airspeed, your ground speed is affected by the winds.  For example, if you are flying against a 10 mph headwind, your speed over the ground will be 117 miles per hour.  You'll also fly slower while climbing to your cruising altitude.

Coming up with a cost by computing raw distance vs speed vs rental rate isn't sufficient because rental rates are from engine start to engine stop so you also have to account for preflight, taxiing, maneuvering in the local terminal area, etc.  Your rental time is read off a Hobbs meter that starts and stops with engine start and stop, so is usually called "Hobbs Time"

I've tried playing around with flight planning tools to make an approximation but the results don't account for all these factors so the numbers are off.  The only way to know is actual experience.

So I did some historical research in my logbook, and combined it with current airplane costs to come up for some costs for various destinations I've been to.  Hopefully this will help answer two questions, one being "how much does it cost to fly to x?" and  the other being "where can you fly for $y?"

The results are in the following table, sorted by ascending distance:

Destination	Round Trip Hobbes Time from Sanford, NC (hours)	Round trip rental plane cost (at $105/hour)	Notes
Asheboro, NC	1.2	$126.00	Nice aviation museum on the field
Person County, NC	1.3	$136.50	Nearby steakhouse will pick you up on the field
Goldsboro, NC	1.7	$178.50	Good place for Eastern NC BBQ
Lexington, NC	1.7	$178.50	Good place for Western NC BBQ
South Boston, VA	1.8	$189.00
Southport, NC	2.7	$283.50
Washington, NC	2.7	$283.50
New Bern, NC	2.7	$283.50
Blacksburg, VA	3.0	$315.00	Go Hokies! The stadium and coliseum are an easy walk from the airport.
Ocracoke, NC	3.4	$357.00	Nearby restaurant will pick you up on the field. This would be over an 11 hour round trip by car + ferry
Charleston, SC	4	$420.00
Tangier Island, VA	5.2	$546.00	Difficult to reach any other way but airplane!
Murphy, NC	5.5	$577.50	With stop in Asheville. This is as far west as you can go in NC
Cincinnati, OH (Lunken Field)	6.9	$724.50	Nice restaurant on the field. About as far as you can comfortably go without a fuel stop.
Seneca Falls, NY	9.8	$1,029.00	The Finger Lakes area of New York. Fuel stops in both directions.
Plattsburgh, NY	13.8	$1,449.00	Includes fuel stops in both directions. This airport is very near Burlington VT so the cost to there would probably be virtually the same.
Oshkosh, WI	16	$1,680.00	Includes fuel stops and spectacular flight up the Chicago lakeshore. Famous annual air show held here

You may think that some of these costs are high, and they can get high as flying is not a cheap hobby. But many if not most of these flights, especially to dinner destinations, are made with another pilot sharing the flying time and the expenses, so one person's cost for the flights is half the amount shown.  On trips to Oshkosh, sometimes three pilots go and share flying and expenses.

Another note is the big jump in time and therefore cost between Cincy and farther destinations, even though the distance is not necessarily proportionally more.  This is because once you get farther than Cincy, you have to make a fuel stop in a Warrior.  A fuel stop means extra maneuvering to land,  taxiing in and out, and taking off again and climbing out again.  This adds to the flight time.

To illustrate the cost of a fuel stop, look at the flight to Plattsburgh, NY.  I've also done this flight in a Mooney M20J, which can make the trip non-stop and also flies faster: 145 knots, which is 167mph.  This flight took 9.6 hours round trip, with no fuel stop.  However the Mooney is also more expensive to rent: $165/hr. So that flight would cost $1,584 today, or only $135 more in a much more expensive and better equipped plane that gets you there faster.  This is because of the shorter flight time, which is because of both a faster plane and the avoided overhead of a fuel stop.

There are some famous flying destinations that I have been that are not listed here.  Especially the First Flight Memorial airport at Kitty Hawk, and Asheville.  This is because to keep this list precise, I only listed flights that were directly out and back with no additional stops and no local flying at the destination.  Also some of the places I've been were not in a Warrior, so the flight times would different.  I guess that gives me an excuse to fly...I need to take the Warrior directly out and back to these places, to get numbers to update this post with!

Propane heat is for suckers... and yes that includes me

This winter saw not only the Polar Vortex, but also a propane price shock.  Propane is widely used in rural areas where natural gas is not available.

To get an idea of how much of a price shock we had in propane, here is a graph of weekly residential propane prices, from 1990 to the present day as of this writing.

This graph is a screenshot from the US Department of Energy's Energy Information Administration website. You can go there to see current information at any given time.  Note that data is only tracked during the heating season, which is Oct-March, so summer prices are not shown here.   

As you can see propane prices were nice and stable through the 1990s and then went on a gradual, steady climb from about 2004 until 2008, then bounced around a little, and then shot up this year.  Even though this graph shows prices peaking just above $4 a gallon, many people in this area were playing upwards of $5 for propane in February, which is crazy because we should not be having shortages... a propane pipeline runs through this area and there is a major terminal in Apex. 

OK, but how does this affect me?

My house has a heat pump with a propane furnace as backup.  Basically when the temperature gets below 40 degrees, it turns into a propane furnace.  This design is supposed to be the best of both words, avoiding the "feels cold" problem of heat pumps but still getting heat pump efficiency when it's not terribly cold out. However I built my house in 1999.  Looking at the graph above, that's when propane was bouncing around $1 a gallon and my heat pump was designed in that price environment.  With propane going up much higher recently, those design optimizations are no longer so optimal. 

Bottom line I recently got a propane bill for $850. That was for enough gas to last for 34 days, from Jan 17 to Feb 21.   Talking to others who use propane heat that's not an usual experience and is actually a bit on the low side.  Because I own my propane tank instead of renting from a propane company, I'm able to shop around for the best deal in the summer and fall, so the peak price I paid was $3 a gallon.  That's still high but at least it's not the $5 that some others around me who didn't have a choice were paying, either because they did not sign a contract in the summer, or can't shop around because their propane tank is owned by their gas company.

So it's obviously now expensive to use propane but how does it really compare to other heat sources I could be using?  How much more am I really paying than I would with a heat pump, for example?

Propane cost vs. other heat sources

The Energy Information Administration comes to the rescue with excellent data again.  They publish an excellent spreadsheet for comparing the cost of different heating methods.  You plug in your local costs and appliance efficiency ratings and it compares the cost of using different heating methods.  I did this for our local area and it was eye opening.

The table below comes from my work on this spreadsheet.  It shows what the price per gallon for propane would have to be to be competitive with different methods of heating your home.  I defined "competitive" as "within 10%".  The electricity rate I used is Duke Energy's standard residential rate of 9.6701 cents per kwh, set September 2013 and still in effect as of this writing.  

Heating Method	Propane is competitive at	Comments
Electric heat pump	$0.98	Assumes Heat Pump HSPF of 9.0 and use of electric strip heaters in NC climate (effective HSPF 7.8 when accounting for use of strip heaters)
Electric baseboard heater	$2.22	Assumes 100% efficiency
Natural Gas	$0.82	Uses PSNC rate of $0.85 per therm and assumes furnace AFUE of 82%
Wood Stove	$1.13	Assumes wood purchase price of $200/cord per http://ncfirewood.co/firewood-prices/ and wood stove efficency of 63%
Kerosene	$3.10	Assumes Kerosene is $4.27/gal in an 80% efficient room heater

Details on the numbers

Some notes on the efficiency ratings. I used the default values provided by the EIA, which they say are the minimum acceptable values, so if you have decent equipment your efficiency ratings are probably higher.  For the efficiency of electric heat pumps, there is an adjustment for climate to account for the time that the electric strip heaters have to kick in to help.  So in NC, for example, the EIA says a heat pump with an HSPF of 9.0 is treated like 7.8, which is the number I used in the calculations above.

So, what does this tell us?

Looking at the above table in conjunction with the price chart above, it's obvious that propane is hardly ever an economical heat source.  It really only consistently beats Kerosene room heaters.

The price for wood heat assumes you have to buy the wood.  If you're cutting it off your own property or someone is giving you wood, like letting you have it  for free if you haul it off, it's obviously an even better deal, though that's quite high maintenance.

Natural gas is the cheapest mainstream heat source, but in rural areas that's not relevant because there are no gas lines.

The primary mainstream alternative for rural areas in NC is the electric heat pump, which propane has to be under $1 a gallon to be competitive with.  That hasn't happened in years and likely never will again in the foreseeable future.  So as a strictly financial proposition, it never makes sense to heat with propane instead of a heat pump.

There is however an emotional component.  Because electric heat pumps blow air that is warm but below body temperature, a lot of people complain that they feel cold and assert that they'll pay more to heat with propane and be comfortable.  That's understandable, but 2-3 times more?  That gets harder to swallow, but if you do it with eyes open more power to you.

But on the other hand, even that may not be necessary to be comfortable. Look at the relative cost for electric baseboard heat.  This is usually considered the most expensive mainstream way to heat, but it's cheaper than propane when propane exceeds $2.22 a gallon, which it has in fact done for most of the last few heating seasons.

This is relevant because most heat pumps are designed to work at temperatures down to about 40 degrees, and they have electric strip heaters that kick in when it gets too cold for them to keep up.  Electric strip heaters work pretty much like baseboard heat and in my opinion would be similar in cost to run.  Most heat pump owners complain about high bills when the electric strip heaters come on, but in fact even the electric strip heaters in a heat pump are cheaper than propane has been in the last few heating seasons.

What this means in my opinion is that the smart thing to do if spec'ing a house today, or replacing  your HVAC system, would be to just get an electric heat pump.  If the air out of it feels cold then put it in emergency mode and run it off the electric strip heaters.  It'll be expensive, but still cheaper than propane in today's market!

The War on Christmas has been going on longer than we suspected!

Conservative commentators getting worked up over a so-called War on Christmas has become a cherished holiday tradition these days.  They are particularly upset about people wishing each other "Happy Holidays" or "Seasons Greetings" instead of "Merry Christmas."

Well as it turns out I belong to one of the millions of Facebook groups dedicated to local nostalgia, this one in particular being "You know you grew up in Cary, NC when..."  I think there is one of these for every burg or city in the nation.  Anyway, this year one member  has taken to posting scans of old holiday ads from the Cary News. They are great to see and great nostalgia.

 Here are a few samples, all from the early to mid 1960s:

Too bad we didn't have FOX News around then to tell us how awful these seasonal ads were because they didn't all specifically say "Merry Christmas"!

Maybe this is evidence that the War on Christmas started as a small guerrilla action and has taken 50 years to reach the full grown insurgency that we are told is going on now?  Or maybe right-wingers just didn't get their panties in a bunch as much back then.  Or maybe we just didn't have a provocateur class that profited so much from stirring up culture wars.  Anyway these ads are all perfectly charming and nice.

And btw it's also perfectly charming and nice for someone to wish you Happy Holidays or Seasons Greetings today as well.

Why the Big 12 will get a conference championship game without expanding

There are few interesting tidbits in this article: http://www.cbssports.com/collegefootball/blog/dennis-dodd/21620974/acc/big-12-alliance-makes-sense-to-stiff-arm-conference-realigment

I'll concentrate on one here.  Apparently the B12 may soon propose allowing conferences to hold a championship game with only 10 teams, and not even requiring divisions.

In 2004 the ACC tried to get this through because it only had 11 teams, and it didn't go anywhere. Now I think it will pass easily.  The difference is that with the size of today's leagues, divisions no longer work.

Look at the ACC because I know it best.  Two 7 team divisions.  One protected cross-division rival.  8 conference games.   See the illustration above.  Do the math.  It will be TEN YEARS between times an ACC team plays a non-protected cross-division rival.  The SEC will be in the same boat, and the B1G will also have 14 teams soon.   This is not looking like a conference.   More like a federation.

The solution to this is to dispense with divisions and go to one big "division" in which the teams rotate games every year. So instead of having to play the same seven teams every year (your division mates plus your protected crossover rival) and only having 1  game to rotate between the remaining 6 teams on the other side, you now only have to play one team (your main rival) every year and can rotate the remaining 7 games among the other 12 teams.  Or with more than one protected rival, you only have 2-3 teams you play every year and have 5-6 games to rotate among your other 10-11 conference mates.  Either way the math shows that you only go 2-3 years between games with other teams, instead of a whole freaking decade.

The basic point is this:  these 14 team leagues (and bigger in the future) have made divisions obsolete if you want your league to look anything like a real conference where teams play each other with reasonable frequency.   And because of this, I think the proposal to eliminate the need for divisions and 12 teams for a championship game will come up and pass.