Boise & Bilbao, More Musings on Public Transit

In earlier posts, I’ve written about the extensive public transit system in Bilbao and how surprising it is to see so much investment in a metropolitan region that’s not even twice the population of Boise.  One of the big differences, as I’ve pointed out, is not in population, but in population density.  Looking only at the incorporated cities of Bilbao and Boise, we find that Bilbao is 7 times as densely populated as Boise.  That’s amazing no matter how you slice it.

Given that distinction, one might come to the conclusion that it will never make sense to invest in public transit in Boise, as our population density is not likely to double let alone increase seven-fold.

But I disagree.  To be sure, population density is an important attribute when considering such an investiment, but equally important is population distribution.  In a city like Columbus, Ohio (pop density only 12% higher than Boise), mass transit is particularly challenging because, well, there’s just isn’t any geography there. (I know, that’s not a true statement, but if you ever lived there, you’d know what I mean).  For the most part, development is free to expand in concentric circles leading to a population that is evenly distributed over a fairly large region.  That’s a nightmare for transportation planners.

But what if the city happens to have significant geographical features? Bilbao, for example, is surrounded by mountains so the entire city sits in a relatively small bowl.  The greater metropolitan area is spread out along a fairly narrow river valley and is only just now beginning to sprawl.  Are there any US cities we can look toward with a similar situation?

Leaving the obvious one aside for a moment, let’s look at Salt Lake City.  The population of the city proper is actually smaller that Boise while the greater metro is much larger weighing in at just over 1.1 M.  The population density of the city is (get this) HALF of Boise’s!  In addition, the greater metro area is sandwiched between the Wasatch mountains and the Great Salt Lake.

Add to this the national attention (and ensuing politcal clout) it received when it won the opportunity to host the 2002 winter Olympic Games and the stage is set for some serious infrastructure.  Today SLC boasts an extensive public transit system which includes light rail, commuter rail and an extensive bus system.  About a year ago, I saw a presentation by the director of the Utah Transit Authority and he described the birth of the system marked with much public opposition ranging from a citizens’ group that argued “light rail kills children” to skepticism that the system would ever have any riders and it’s simply a waste of taxpayer money.

If any of this sounds familiar, then perhaps you live in Boise, ID.  We have a relatively small population but it’s not evenly distributed, nor is it expanding in concentric circles.  We’re constrained by the geometry of the Boise Front and the desert of the Snake River Plane.

I, for one, applaud our leaders who are sticking their necks out and demonstrating the vision to bring this discussion front and center.  Like SLC, a little help from the feds could go a long way to get things going, but we need to do it right, and we need to go beyond the federal government for help.

I agree with the local business leaders who think the first fixed-route link should be between Boise State and downtown.  There the city will find a willing partner and a lot of customers.  I’ll be the first to ride the streetcar and expecxt to use it heavily.

I also think we need to stop throwing up our hands about the bus system.  Public transit is a classic Catch-22.  We don’t invest because ‘no one rides the buses’ and we don’t ride the buses because they don’t come often enough or close enough to make it work for us.  It’s long past time to roll up our sleeves and start activities that target specific routes and gear them up for high ridership.  Simply put, we need to make it more convenient than driving.  (We at Boise State are doing our part by reducing subsidies to the parking system and making it pay for itself by ratcheting up the price to park there)  State street seems like a good place to start.

And, of course, our leaders in the statehouse need to be serious about the claim that the best government is the government closest to the people.  The people of Ada and Canyon counties need to have their rights restored to them, even if it includes the right to tax themselves.

Electric Cars and the Smart Grid

In the class I’m teaching in Bilbao, I decided to show a video from the incredible TED series.  This talk is about 18 months old and I never tire of seeing it, I pick up new stuff every time.  Please don’t miss the last 60 seconds or so, it just about blew my mind.

The basic premise, using electric cars with swappable batteries instead of ones permanently attached, is one I’ve spoke and written on before.  If every current service station became a place where batteries are charged, then we’d have an extensive distributed energy storage network that, with the help of the smart grid, could allow us to utilize clean renewable energy from wind and solar while we wean ourselves from petroleum.  What’s not to like?

Renewable Energy – Taking it Old School, Part I

Last week, I took my students in the USAC class on a field trip to a wonderful little village called Lekeitia, one of literally dozens small coastal villages in the Basque Country.  We tool a bus that was part of the extensive regional bus system (BizkaiBus) from the downtown Biblao bus terminal to Lekeitio with about 10 stops along the way.  The trip as about 75 minutes through beautiful green mountains, dotted with farms and small farm towns.

The purpose for the trip was to visit the site of the Merierrota Tidal Mill, built in 1555 on the River Lea, which forms an estuary on which the town of Lekeitio was founded. Here we are on the bridge over the Lea.

"S", "P" and me

The ruins of the tidal mill were just off the main road.

A tidal mill (molino de mareas) is much like to old water wheels that were ubiquitous around Europe (and elsewhere) and for centuries, they were the only means of harnessing significant amounts of energy without using animals (including humans).  Unlike their river cousins, a tidal mill usually didn’t obstruct the run of the river. Instead, an area alongside an estuary (which is the wide, flat plane at where a river meets the ocean) is excavated and a dike is built between the excavated area and the main flow of the river.  Here’s a shot of that wall that we saw on our hike.

Dike in the estuary at Lekeitio

Actually, there were two walls, one made of earth, the other stone.  The informational placard was difficult to read.  One version was in English, but a poor translation, the other two (in Spanish and Basque) were perhaps more informative, but I had the distinct impression that the person who wrote the text was not too clear on the mill’s operation either.  It would appear that there was a fairly complex interaction between the stone wall, which had gates in it to admit or hold the water, and the three separate basins held in by the earthen walls.

Gates in the stone dike

In any event, the basic principle is fairly simple.  During rising tides, the ocean water comes up the estuary, raising the water level there.  In that case, you open the gates and admit the water into the basins you excavated.  As the tide peaks, you close the gates, thus sequestering the water.   As the tide lowers, the potential of your sequestered water to do useful work increases, reaching its maximum at low tide.  If you construct a water wheel between the basin and the extuary, you can run it during low tide and extract useful energy!

How much energy?  I’ll take a stab at that in a later post.

Renewable Energy: Old School, Part II

In a previous post, I talked about visiting the 16th century tidal basin in Lekeitio.  I was curious about how much energy it could produce, so let’s walk through a little physics, shall we?

First off, it’s important to realize that water mills of any kind, whether they’re tidal mills of Europe or modern hydro electric plants, produce energy by virtue of the fact that water is moving from a higher elevation to a lower elevation. That delta-h is the difference in levels between the reservoir behind the dam and the surface of the body of water into which it is being released.

In one of my favorite books on energy, David MacKay analyzes the amount of energy that can be extracted from a tidal mill. It always helps to start with a picture.

Sktech of the tidal pool

Note that the range of tides is determined by the location and geometry of the esutary itself (and phase of the moon).  The delta-h for the energy calculation is actually half the range of the tide, because we have to consider the average delta-h the water goes through.  As the pool empties, the surface of the sequestered water drops and the last few drops have vanishingly small delta-h.

So, the total energy available in the tidal pool is equal to the weight (mass times gravity) of the water times the height it falls.

E=mgh

(mass times gravity times height)

OK, almost there.

The mass of the water that’s sequestered is equal to the density of the seawter (1020 kg/cubic meter) times the volume of the water.  The volume of the reservoir can be estimated by taking the surface area of the pond and multiplying it by the depth (which will be the range of the tide: The pond is empty at low tide and full at high…) In the figure above, the depth of the pool is 2h. So:

E = (1020) x A x 2h x (9.81) x h

All we need now is the area of the pool and the range of the tide for the region.

When we were standing at the pond looking at it, our estimate for the area of the pond ran between 2.5 to 5 acres.  Pretty big range.  Fortunately, the information placards near the site gave us the real number: 17,300 square meters.

MacKay says the average tide for the Isle of Britain is about 4 meters. That’s consistent with our observations with the high tide marks we saw in Lekeitio that day, so let’s go with that, making our value of h = 2.

So, putting these in our equation, the amount of energy that could be expended by releasing this tidal basin at low tide is:

E = 1,384,858,080 Joules

Wow! That sounds like a lot of energy, doesn’t it?  And it’s nothing to sneeze at, to be sure, but let’s go a little deeper.  The Joule is the fundamental unit of energy for the SI system of units and it equals the amount of work done by exerting a force of 1 N through 1 m.  For those of us born in the US with a genetic predisposition for the clunkier British system of units, imagine lifting a quarter-pounder from your waist (where it will end up anyway) to the top of your head.  Not much work, but they add up.

Let’s see if we can convert it to something we can get our head around.  Electric utilities charge us for electrical energy use in kilowatt-hours.  The typical monthly electric bill in my neighborhood in Idaho is just over 1000 kWh.  And it takes 3,600,000 Joules to make up one kWh.  Converting the tidal mill energy we get:

E = 384.7 kWh

There’s a number we can get our head around.  Every time the tidal pool fills up, it stores the potential energy equivalent to just under 385 kWh.  And it does it twice a day, so that’s 770 kWh per day.  Over the period of a month, it would store and release 23,080 kWh, enough to equal the energy consumed by 23 homes in modern day Idaho (ignoring the conversion losses, of which there would be many).

Here’s another way to look at it.  We also consider energy by the RATE at which we use it, not just the total amount of work done.  Someone hauling one brick at a time can move several tons of bricks. But the advantage of an oxcart is that it can do it in one trip!

770 kWh per day translates to a power source capable of producing, on average 32 kilowatts.  By contrast, today’s modern wind turbines can produce electricity at a rage of 1,500 to 3,000 kilowatts.  But hey, that’s progress.

What kind if impact could a 32 kilowatt mill have for a town in 1555, I wonder?

Here’s one way of looking at it, again hats off to Prof MacKay in this great book.  The mill could do an amount of work equivalent to 770 kWh each day.  There are practical limits to how much of that would be truly useful, so let’s round it down and take a round number of 600 kWh.

It turns out that 1 kWh is about how much useful mechancial work you could expect a reasonably strong and healthy man to produce in a given day, in a sustainable manner (assuming you weren’t interested in working the person, literally, to death).  And that’s how they got stuff done back then, using strong backs to move millstones around and hall heavy things around.

So the day this mill was opened, they owner was able tap an energy source that was the same as having 600 strong men working for him.  And while some mainentence was required of the mill, it’s nothing like feeding, housing or paying 600 people (and their families).

In a  town that  had a population on the order of 100 to 200 people, that’s huge!  It probably goes a long way toward explaining why they kept it running for centuries.

Electric Heat and Preparations

I can’t believe it, but in just two days, we’ll be on our way to Bilbao, Spain for a month of adventure.  In the few days we’ve been back in our home since our trip Back East, I haven’t had much time to add posts about K&J’s house, perhaps I’ll have more time after we settle in.

Until then, here’s a quick post about K&J’s innovative heating system.

Central PA is a challenging place to keep warm. The winters are dreary at times (although winter sun is not all that unusual) and it can get mighty cold.  I recall a February morning when the temp was -19 F (!)  It doesn’t usually get that cold, but it dips below freezing sometime in December and doesn’t come up for more than an hour or two till March.

Combine that with a region where natural gas distribution is spotty at best and you’ve got a prescription for very high heating bills.  Here are the typical options:

Biomass:  OK, that’s just a fancy name for wood fires, but it’s the option of choice for most folks who are out of the towns and in the woods.  Trees are a plentiful and renewable resource. Most of the tree-covered hill sides in the region have been clear cut at least twice since the colonial days.  This region has a rich history in the early iron smelting days and wood (charcoal) was the only fuel for the process.  Today, wood stoves are common and are often used to supplement other heating systems.  There’s a downside, of course. I remember driving to the child care provider on cold still mornings and seeing the uniform blue haze settled in over the valleys.  Modern high-efficiency stoves help alleviate this, but it’s naive to think that this is an energy source with low environmental impact.

Propane:  There’s a delivery infrastructure that you can use to refill your local propane supply and use a force-air gas furnace, but that’s pricey.  Winter bills in excess of $1,000 would not be uncommon.

Electric/Baseboard:  This method uses a larger electric water heater (often sharing the task with the domestic hot water appliance) and uses the water to carry heat to radiators in every room.  These systems have come a long way since the clanking radiator and can be finely controlled, but electric is still a tough way to make heat.

Electric/Heat Pump:  This is what we had when we lived there.  Just a big central AC unit that can run both ways.  In the summer you extract heat from the air in the house and reject it to the outside.  In the winter, you extract heat from the outside air and move it into the house.  While the engineering principles are sound, practical limitations always get in the way.  You’re always pushing heat up hill, rejecting it to humid 95 degree air in the summer (which means the coils have to be much hotter) and trying to collect it from bone dry 10 degree F air in the winter (again, the outside coils must be colder than the air to move the heat that way.  Our own experience was that the ehat pump worked fine for about 90% of time when the outside air was between 20 and 90 degrees F.  Any colder and the supplemental duct heaters kicked in (image a 2 kW toaster in your furnace ducts).  Any hotter and, well, you just moved slower and spent more time in the basement.

Solar Heat:  In temperate and cold climates, solar heaters are engineered frames that are glazed and sealed from the outside air to prevent convective losses.  Inside, water is heated by the solar radiation that penetrates the glazing and the hot water can be used for domestic hot water and space heating.  More on this later.

Solar Thermal Panels

Variations and combinations:  This is what or friends did.  You can avoid the shortcomings of heat pumps by exchanging heat with ground water.  in this case, your always conducting heat downhill and the efficiency skyrockets.  Combine this with a couple high-efficiency wood stoves and some solar heaters and you’ve got a system that incorporates the best features of each technology but with none of the shortcomings.

More on that later.