# Category Archives: money

“(Annual returns of +10%, -5%, +22% and -3% will always result in a four year return of +23.7% no matter what order they came in.) … starting out risky and ending safe has exactly the same expected result as starting safe and ending risky.

… then why would it make sense as generic advice to those saving for retirement? Well, of course, it doesn’t.”

http://badmoneyadvice.com/2009/01/great-life-cycle-of-risk-aversion.html

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## Drive to the library? Yeah right.

Careful towns of the world out there… before you spend lots of money on new or revamped libraries. Unless you are in a city, or near a walkable and vibrant town center, they are a tough sell, even with cheap \$3.50/gasoline. And how long will that last?

Here’s the math for me in suburban MA:
- Distance to library: 5.2 miles. 10.4 miles round trip
- Our minivan — let’s say I get 20.8 MPG to make the math simple.

So that’s:

10.4 miles * 1/20.8 MPG * \$3.50 \$/gallon = \$1.75 per trip assuming there is no overlap with other errands, which is likely given the route.

And that’s just the cost of the gas of course. If you use the ~\$0.50/mi that the US government uses for taxes for business mileage (accounting for the full cost of ownership) then that’s 10.4 miles * \$0.50/mi = \$5.20 per trip.

And then add in the cost of the time. Let’s say 20 minutes of driving.

It’s a tough sell. Not just the library. All of suburbia. It’s ultimately kinda in serious doo-doo, ain’t it? James Howard Kunstler is probably on to something.

Counter-points and followups:

1) I say all the above as someone who has LOVED libraries in the past. But I guess the difference was: 1) that was pre-interweb and 2) that was libraries I walked to or rode my bike to (the Amherst Jones Library, and the UMass/Amherst Dubois library)

2) I am fond of the idea of the library being a “town center” that is more about ideas and people than being about media (paper or digital). Related concepts are Sudbury Schools, the Transition Town movement (tool sharing, etc), Cohousing.

3) The article linked below talks about “Library as Platform” which to me is basically acknowledging that there are increasing numbers of private services we use which “out do” libraries in terms of connecting us with media. Amazon. Google Books. Goodreads. “The Library” *could* do all of that. But how?
LINK

4) PS. And what about all those duplicate public school libraries! What a shame! What if all the schools in town were clustered around the town’s libraries and they all shared! I know, I know… one can’t turn back the clock on sprawling suburban development. It’s just sorta a shame.

5) Speaking of poorly designed public resources… I’ll talk about the placement and design of playgrounds sometime soon. Ugh. Almost always another huge missed opportunity. But there are some good ones!

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## We can heat our house with a hair dryer. Is that inexpensive?

The house we are building here in lovely Massachusetts, USA… almost a Passive House, but not quite certifiable… well, we can heat it with a hair dryer (1500 W of heat). And two on a very cold day (6F design temperature). Does this mean our heating bills will be low? Pretty low, I imagine, yes. But not zero.

Let’s do some math… And first let’s simplify things… the HDD (heating degree days) for Stow, MA is somewhere around 7200 (base 68F) meaning that if you multiply the days of the year we need heat times the temperature differential between the inside and outside temperature on these days, you’ll get 7200. It’s a little more exact than this (think “area under the curve” from calculus — using hour by hour measurements), but that’s the basic idea.

So let’s simplify it even more. Let’s call every winter day exactly 32F outside vs 68F inside and assume our 1500 W can keep up with that (which from my back-of-the-envelope calculations seems about right…) So that’s a delta of 36F. Now how many days is that? 7200 F*days / 36 F = 200 days = 6.66 months. Let’s go crazy and call it 7 months.

OK, so let’s say one really did run a hair dryer for 7 months, 24 hours a day. What would that cost to run 1500 W (1.5kW) that whole time? Well, we pay \$0.20/KWh. So using the factor-label method to keep track of our units… making sure numerators and denominators cancel out, that’s:

7 months * 30 days/month * 24 h / day * 1.5 KW * \$0.20 / KWh = \$1,512.00 per year

In other words, kinda a lot!!!!

But that’s why people don’t typically use electric heat, it’s expensive. (It’s also not a great idea because fossil-fuel power plants are roughly 33% efficient in converting the fuel to electricity… I imagine that’s exactly why it’s expensive! So… it’s better to use it in direct form at your house…) That’s where the heat pump comes in. If we factor in the 2.7 COP (coefficient of performance) of our Mitsubishi “Mr Slim” air-source heat pumps that’s:

\$ 1512 / 2.7 = \$560

OK, now we’re talking! This also happens to be almost exactly the number you would get if you calculated the cost of delivering 1500W of heat via propane or natural gas. That would be fine and dandy too. So the 2.7 COP mainly serves to green up the electricity use, getting back to parity with using propane directly. 2.7 * 0.33 = 0.8991 (probably about the efficiency of a Rinnai propane direct-vent heater)

Now, the reality is that I hope most of this heat comes from active solar heating. But more on that later!

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## Where is my electric car?

I’m waiting for an electric car I can buy. I don’t think any of the ones in the works fit the bill… so sorry Prius plug in hybrid, Chevy Volt, Nissan Leaf, Mini E, Tesla S, etc, etc… my problems?

1) They are too small! That’s a problem because of a) carpooling… I need to be able to haul at LEAST 5 kids to and from school. We’re talking mini-van or SUV I guess. b) safety. Check the numbers at IIHS.org/HLDI.org. A prius is still about twice as dangerous in terms of injury and death rates as our Saab 9-5. I want to save the planet, but I’m not will to risk my family. This is no joke… as I’m sure you know… the chances of dying in a car crash are in the neighborhood of 1/8000 a year or 1/5244 in 2 years

2) They are too quiet! I am hoping this gets resolved somehow, but I am just not willing to risk killing a pedestrian because they didn’t hear my car coming. Apparently folks will be figuring out what to do about this at some point, but until then, I am seriously considering sitting on the sidelines.

OK, so what other problems did I forget? There are other (non?) issues, … There are probably answers to these…

1) Effective MPG hurts a bit (maybe only a bit?) because there is no waste heat to heat the car in the winter. And it’s cold here.

2) Cradle-to-cradle environmental impact / full-life-cycle of the cars: Are the batteries a concern or not? I heard that there are some crazy rare earth metals that are needed for them that is decimating china, etc. NYTIMES My guess here is that it pulls down the green-ness a bit, but maybe overall still worth it vs internal combustion engines.

3) Is this is a solution for everybody? Can the electric-grid handle it? My answer here is that it seems like if people install several kW solar arrays on their roofs, they might do quite well for covering their commuter miles at least.

4) We are already a 1-car family. So it’s a little odd to buy a second car. Would we then sell our other one? But then what about long trips that are outside the range of an electric car? Rent?

5) Bang for the buck. Is buying a brand new car to cut our fossil fuel use in half a good use of money vs other ways of “saving the planet”? (we already average 26MPG in our Saab 9-5… closer to 30+ on the highway or local carpool if I hypermile…)

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## economic solar heating

“I really think the problem is that the use of solar energy is
being discussed by scientists and we have a passion for being
a technological society. As such, we almost frown a little when
someone finds a very simple economic way of using solar heat.
That is much too simple for us. And so we have to find something
very exotic, so that we can earn the name of scientist or engineer.”

Walter A Meisen, circa 1972, at the solar energy roundtable in NY

MORE…

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## Solar Panels and Payback

It’s instant! First month!

Here is some simple math. Our PV array is going to cost \$36,000 I believe to install I have heard. It will generate 7200 KWh of electricity every year until the thing dies. Oh, and first some assumptions:

1. Let’s say it lasts 30 years, which I think is reasonable.
2. Let’s ignore the loan that is helping finance it, because if one assumes inflation of 4% a year, then over the 30 years lifetime of a 5.25% loan (1.25% after factoring in inflation), one has really only paid slightly more than \$36k in 2009 dollars.
3. Let’s also ignore subsidies and tax credits, etc. Some of which we will get, but some not because Stow, MA’s municipal electric company has not yet decided to take part in the state program that would give their customers access to some funds for PVs.
4. And let’s also ignore the fact that there is NO NET METERING yet in Stow (that’s OK, we’ll only use electricity when the sun is shining).

OK, so here’s the math:

\$36000 / (30 years * 7200 KWh/year) = \$0.16/KWh

WOW!!!! That’s less than I pay now for very dirty electricity (we buy offsets via MTC Wind Fund) but there is no direct way to select a Green supplier in Stow, MA.

Anyway, point being… this is a great deal even if you don’t care about global warming or energy security, etc.

From a practical standpoint what it means is that if one adds up the increase in our mortgage and our electricity bill each month, it will be less than our electricity bill had we installed no photovoltaic array.

That you are using no fossil fuels is icing on the cake!

Go sun!

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## Green Decking — recycled milk jugs

OK, so everyone knows about trex and thinks it’s great. Which OK, it’s maybe a little easier than standard decking in that it doesn’t need to be restained. But it does have some percentage of wood in it, and my understanding from reading (and visiting a relatives house) is it *DOES* certainly get mildew on it here in the lovely HOT AND HUMID summers in the northeastern US. What a pain in the rear! I want zero maintenance AND a “green” deck! Is it possible? I think so!

But wait, back up. So in addition to it (Trex, and it’s relatives in the “composite” category) not being NO MAINTENANCE, it’s also not particularly recyclable is my understanding (since it’s a mix of wood and plastic). OK, perhaps this will be different in 10/15/25 years when you decide (or the next owner) to huck it. But who knows?

So, what to do? I’ve heard good things about ipe/ironwood. As long as you can get sustainably harvested wood, you might be in good shape, since it apparently lasts a long long time.

But how about HDPE? Recyled Milk Jugs. YES! It gets an “A” in this GREEN DECKING REPORT

COST OF OWNERSHIP COMPARISON which seems not-totally-unreasonable based on my own experiences with a cedar deck for 5 years

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