Saturday, September 21, 2013

A Tree Should Grow In Brooklyn

Dano, who drops by here on occasion has a paper, Urban forests and solar power generation: partners in urban heat island mitigation, in the International Journal of Low Carbon Technologies

The urban forest is generally decreasing in areal extent. At the same time, human population is urbanizing and urban areal extent per capita is increasing. Eighty percent of North Americans are now living in urbanized areas. Urban forests directly affect quality of life for residents of cities via the ecosystem services and psychosocial restoration they provide. The urban forest canopy is a key component of reducing the urban heat island, slowing stormwater runoff and making urban environments more efficient and livable. Municipalities in North America are reacting to concerns about urbanization and economic trends by permitting an increasing number of compact developments that may conflict with beneficial Green Infrastructure. Compact development may also present challenges to solar access for solar power generation. This paper identifies and illustrates key strategies to increase urban forest cover and decrease infrastructure conflicts by implementing given innovative design details, detailing specific zoning and code language, and providing best practices from multiple disciplines. These strategies to increase urban forest canopy cover frame a coherent set of ideas to decrease the effects of the urban heat island, increase solar power generation and improve urban quality of life in cities.
Among the interesting points is that the virtuous circle works for solar power installations in housing, if your neighbor has one, you rapidly become envious.  Anyone who has walked in a city knows that the urban forest is a major plus, better smelling (cleaner) air, huge cooling effect during a hot summer and just damn calming and nice to look at.  But all is not well, trees will shade solar installations, and so the problem becomes can we have it all and write zoning/construction codes that give it to us.

Let Eli point out one place where he and Dano disagree.  The later writes
Parking lots afford an excellent opportunity to achieve heat island reduction and canopy cover goals. A commitment must be made to allow for fewer parking stalls, as a parking surface area must be reduced and dedicated to tree roots. Progressive jurisdictions may be able to easily make these commitments, as there is growing indication that many areas in the USA may be providing too much parking for various reasons
So many years ago Eli and a buddy found about 100K for a liquid nitrogen tank at the Uni.  Went to the Dean of Engineering to pitch the thing, and the only issue
was "Not if it costs parking spots"

15 comments:

John Mashey said...

Recommended and relevant: Don Shoup's The high cost of free parking.

Anonymous said...

I'm watching with dismay as the pleasant green town I live in is being slowly transformed into a ghastly giant car park. And its not being done by some evil corporation or some short sighted administrator. Its being done by its inhabitants who grub up their front gardens to create ever more car parking. I believe a similar process is happening all over the UK.

Gingerbaker said...

Here's a radical idea:

Why not put as many trees as we want in cities and put as many solar installations as we need where they work best - which is in the American Southwest nowhere near cities?

John Mashey said...

Utility-grade solar in dserts and rooftop solar are not either-or.

The former can have installation economies, but also require building transmission lines from places where they don't already exist.

The latter cost more to install/kwh, but do not need the same $$ for transmission.

For any given location:
1)One could choose green or solar
2) neither work
3) solar works, but not green
4) green works, but not solar

Obviously only in case 1) is there a possible conflict.

Around here, many companies, schools etc cover parking lots with solar shades, which is a big win, since:
a) Cars stay cooler.
b) Asphalt stays cooler
c) Generates power

But, both towns I've lived in here have tree logos (redwood or oak), and one needs a real permit to cut down any tree of any size.

But again, look at Shoup's book.
We also have lots of bicycles, bike share (you should drive through the land of Google at lunch, including such things as Conference Bikes.

Of course, for cars, there are also things like Zipcar for people with occasional needs.

Russell Seitz said...

Let me reconcole Eli & Dano

University parking surface area can be conserved and, tree roots accomodated using the post-neolithic wonder material. gravel, and its organic , biodegradable urban heat island effect fighting, high albedo analog, oyster shells.

Available at bays and estuaries near you !

Anonymous said...

As a follow-on to Dr. Seitz's comment, there is something called grasspave. google it.

Dano said...

Thank you Eli.

Glad to see Russell weighing in. Here in the intermountain west, structural soil must be supplementally irrigated.

This requires maintenance that needs panelized concrete, which the old-guard Public Works officials frown on. The new men and women can't wait to use it, and I'm ready to use structural soil based on glass cullet, which closes the loop on recycling.

Best,

D

Dano said...

Thank you Eli.

Glad to see Russell weighing in. Here in the intermountain west, structural soil must be supplementally irrigated.

This requires maintenance that needs panelized concrete, which the old-guard Public Works officials frown on. The new men and women can't wait to use it, and I'm ready to use structural soil based on glass cullet, which closes the loop on recycling.

Best,

D

Combo said...

I'm on the same line of thinking as John: car parks with solar panels which provide shade for the said cars.

EliRabett said...

Solar panels do not transpire, the shade is better than nothing, but the cooling effect is smaller, which is why urban forests are so effective.

John Mashey said...

Nice paper, Dano, thanks.

On the argument of costing parking spots, again, I urge reading Shoup.



I don't know of any simple rule for the cases where either solar or trees work, as I think the choice depends a lot of local conditions.


Cities can make more efficient use of parking spaces they have (and possibly reduce numbers) via technologies like those of Streetline. I certainly much prefer tree-lined urban streets. The solar-covered carparks tend to be in suburban corporate areas.

Note that in fire-prone areas, planners are not very keen on big trees overhanging houses.

Mal Adapted said...

"car parks with solar panels which provide shade for the said cars."

And battery-charging, too.

James Wimberley said...

IKEA is already covering its parking lots in Spain with solar panels (Google Images for ¨IKEA Malaga¨). I would expect WalMart to follow soon in the US.

Developers have ducked the opportunity of planting shade trees in cobbled car parks for a century. I´m not clear why - is it fear of the sacrilege of leaves falling on car bodywork?

Dano said...

James: many trees attract aphids, which feed on the trees and secrete honeydew that often bothers car owners. Recently near Portland, OR, USA a contractor sprayed trees in a mall car park for aphids and killed thousands of bees as a result.

I appreciate the kind words folks

Best,

D

John said...

More on parking...

Back in the 1960's, when Clark Kerr (CK) was Chancellor of Berkeley, money was flowing out of every spigot, so University administrators didn't worry about money.

CK said that university administrators only worried about three things:

Football for the alumni,
Parking for the faculty, and
Sex for the students.