permaculture

[Saor Stetler <saor@ycbtal.net>]

U.S. Led Global Wind Power Surge in 2005
March 1, 2006
Reporting by Roddy Scheer

To the surprise of those who still view Americans as laggards in terms 
of alternative energy development, more new wind power generation 
facilities were installed in the United States in 2005 than anywhere 
else in the world. According to the Global Wind Energy Council (GWEC), 
an international trade group which helps promote wind power globally, 
the U.S. installed 2,400 megawatts--equivalent to the energy produced by 
five large coal-fired power plants in a year--during 2005 alone. The 
second-place finisher, Germany, installed 1,810 megawatts of wind power 
last year, but leads the world in overall wind capacity, with more than 
18,000 megawatts of installed wind power now online. Even after its 
banner year in 2005, though, the U.S. still only has about half as much 
total installed wind power capacity as Germany.

© NREL

The fast-growing American wind power industry is grateful to Congress 
for extending the wind energy production tax credit which helps keep 
costs down on the installation of new facilities. Surges in wind energy 
development in the U.S. have gone hand-in-hand with the institution of 
the credit, which Congress let expire twice during the 1990s, sending 
many small wind producers into bankruptcy.

While wind power sales have become a billion-dollar global industry for 
companies like General Electric, still only about one percent of 
Americans' total energy consumption comes from it. Christopher Flavin of 
the Worldwatch Institute postulates that wind turbines installed on just 
0.6 percent of the land area of the contiguous U.S.--mainly on the windy 
Great Plains--could meet more than 20 percent of current American power 
needs.

GWEC reports that on a global scale, 2005 saw the installation of almost 
12,000 megawatts of wind power overall, representing more than a 40 
percent increase from the 8,000 wind megawatts added in 2004. Worldwide, 
total wind power capacity now stands at almost 60,000 megawatts, an 
increase of 25 percent from the previous year.

Sources: 
http://planetark.com/dailynewsstory.cfm/newsid/35244/newsDate/22-Feb-2006/story.htm 
and www.gwec.net <http://www.gwec.net>


   Rainwater Harvesting and Purification System

1500 gallon cistern fed from 2 gable downspouts In January 1996 we 
installed a rainwater catchment system to capture Oregon's abundant 
rainfall. Portland receives between 3 and 4 feet of rainfall annually. 
During a gentle rain a typical Oregon downspout sheds several gallons 
per minute. Our twelve hundred square foot roof captures on average 3600 
cubic feet (27,000 gallons) of water per year.

In 1998 we received approval from the city of Portland to use this water 
for all household use. This system, which cost less than $1,500, 
consists of the following components:

   * A 1500 gallon plastic cistern, approximate cost: $500. Purchased
     from Northwest Irrigation, Tangent, Oregon, 541-928-0114. Contact
     local agriculture/farm stores for best prices.
   * A 1/2 horsepower shallow-well pump to pressurize the water to
     between 20 and 30 psi (pressure is adjustable), approximate cost:
     $250. I utilized a Jaccuzzi brand pump.
   * Plastic (outdoor PVC and indoor CPVC) piping to connect to the
     household cold water system.
   * Two particulate filters in series, rated at 20 and 5 micron
     particle size, approximate cost: $20 each; replaceable filter
     cartridges cost $3-5 each.
   * An ultraviolet light sterilizer capable of sterilizing water at 10
     gallons per minute. This appliance was recently approved for use
     in Oregon. I used the PURA (1-800-292-PURA, Valencia, California)
     model UV20-1, cost approximately $350. Uses about 40 watts.
     Fluorescent ultraviolet light rated at 9600 hours, about one year
     of continuous use. Replacement cost of fluorescent tube: about $80.
   * Screen covering the cistern to prevent entry of mosquitoes and to
     catch any large particles that make it past the gutter screening.
   * A roof-washer which wastes the first 7.5 gallons of captured water
     which has "washed" the roof. Once the roof washer has filled, the
     rest of the water flows to the cistern. See below for details.
   * A 20 gallon water butyl rubber diaphragm pressure storage tank,
     approximate cost: $150.
   * A reduced pressure backflow prevention device. This was required
     by the city to prevent flow of rainwater into the public system.
     Cost: $120. This would not be necessary if we used rainwater
     exclusively. However, Oregon has very dry summers and our cistern
     is exhausted by July. We currently depend on city water during the
     summer. The city requires annual inspection of these devices,
     costing about $30. (See photo below.)
   * A (optional) water meter to measure rainwater output, approximate
     cost: $45.

Reduced pressure blackflow prevention deviceRainwater 
"machine"Maintenance consists of keeping gutters and cistern screen 
clean. Filters and ultra-violet lamp will need periodic replacement. The 
tank is thoroughly cleaned annually in the summer when it empties. 
Backflow prevention device requires annual inspection. Public health 
authorities recommend periodic testing of water for fecal coliform 
bacteria, as for any private water system. Several recent tests showed 
none. The inside components of our system, pictured here, take up about 
6 square feet of floor space.

At the current time we continue to use the public water supply only for 
summertime water and occasional drinking and cooking. In fact, during 
the rainy season, which lasts from about September to June, our only 
connection to the public utility is one faucet at the kitchen sink which 
uses less than one gallon per day, which got us into hot water with the 
city water bureau.

In my research on rainwater catchment systems the best single reference 
I have come across for detailed design guidelines is the Texas Water 
Development Board's Texas Guide to Rainwater Harvesting.

Roofwashers. A simple prototype is shown in the TG. It consists of a 
length of pipe for storage of the initial flush of water with a trickle 
valve (hose bib just slightly opened) and clean out valve at the bottom. 
Only when the this pipe fills is water then allowed to continue into the 
cistern. It's very simple, no moving parts. The only thing I would 
change is to have a narrow section or trap configuration at the top to 
reduce mixing of the flush water with the still arriving (clean) water. 
Yet another method to aid this is to add a lightweight (like styrofoam) 
ball that would seal the intake when the roof washer fills. This simple 
design is very inexpensive, easy to drain or clean manually, and works 
very well. The TG suggests one gallon of washer capacity for each 100 
square feet of roof. So make your roof washer pipe length long enough. 
For our model we used 20 feet of 3" ABS. We made it in the shape of a 
giant U to get this length. Remember, volume equals length times area. 
Area equals pi times radius squared (in our case 3 inches internal 
diameter, or .25 foot) and one cubic foot equals 7.5 gallons. To avoid 
long lengths of roofwasher pipe, it makes sense to use larger diameters. 
Portland's chief residential plumbing inspector commented that our use 
of ABS didn't conform to code as plastic may eventually decay in 
sunlight. Therefore, you should use copper, iron, or other 
sunlight-resistant materials to be completely correct.

Rainbarrels. A rainwater harvesting system can be as simple as a barrel 
connected to a downspout. Check the Rainbarrel Tutorial 
<http://www.geocities.com/rainsystem/howto.html> for tips on how to put 
together a system for as little as $15-20. One of our neighbors has 
connected his rainbarrel to his basement washing machine and gets 
virtually all his laundry water from this super-soft source for a 
miniscule investment.

One notable advantage of rainwater is its softness. Rainfall in the 
Portland area contains about 5 mg/liter of dissolved minerals. Compare 
this with some hard groundwater which exceeds 500 mg/liter. Portland 
city water, which has an exceptionally pure source, is rated at 18 mg/liter.

According to two officials in Alaska and Hawaii with whom I have 
communicated, there is a long established tradition of rainwater 
collection in some parts of their states. According to Sourcebook 
Harvested Rainwater 
<http://www.greenbuilder.com/Sourcebook/Rainwater.html#Resources>, in 
some areas of the Caribbean, new houses are required to have rainwater 
capture systems. Hawaii apparently is currently developing (or has 
already developed) guidelines. In Oregon, there is no regulation of 
water quality for individual residences -- this is left up to the 
homeowner. The only regulations I have come across relating to rainwater 
harvesting are from Ohio, whose Department of Health Administrative Code 
regulates private water systems 
<http://www.odh.state.oh.us/rules/final/chap28/fr28_lst.htm>. Note, in 
particular, Rules 3701-28-09 Continuous disinfection and 3701-28-13 
Construction and surface design of cisterns, hauled water storage tanks, 
and roof washers.

Two other great resources for rainwater harvesting information are 
Warwick (Coventry, United Kingdom) University's Development Technology 
Unit  Roofwater Harvesting Programme 
<http://www.eng.warwick.ac.uk/DTU/rainwaterharvesting/> and the 
roofwater harvesting listserve archives 
<http://www.mailbase.ac.uk/lists/rwh/>.

Update Summer 2002 -- A different style of roof washer. This summer we 
installed a commercially available roof washer <http://saferain.com.au> 
that uses a programmable valve to divert a rain's first flow away from 
the cistern. A purported advantage is the absence of standing water that 
can stagnate and potentially contaminate the cistern water. (This could 
happen, for example, if the trickle valve on the conventional device 
were to clog or it were left closed.) Below are two photos of the system 
with this new device. The first photo shows the roof washer mounted on a 
window frame near the cistern. Rainwater, which enters from the two 
downspouts above, can be observed from inside the dwelling. The first 
flush is diverted downwards into a holding barrel. An overflow hose from 
the top of the cistern also empties into this barrel. Post-flush water 
enters the cistern via the roof washer's side port through a screened 
cistern entry hole. The barrel overflow is directed to a swale in the 
middle of our back yard.


Update January 2004 -- An American-made roof washer and rainwater 
sculpture. I never was able to get the SafeRain roof washer to function 
properly in Oregon's often drizzly weather. Either the roof washer 
diversion valve would not properly close, thus diverting all the 
rainwater into the overflow, or it would not open after the rainfall 
event ended, retaining dirty water in the device. I attempted numerous 
times to adjust it, all to no avail. Unfortunately, for this reason, I 
can not recommend this device. The last straw came during recent 
freezing weather when the device froze with water in it, rendering it 
non-functional. Therefore, recently, I installed a newer style of 
first-flush device <http://www.flotrue.com/page/page/485471.htm>. This 
device is considerably less expensive (approximately $66 versus $140 at 
currency exchange rates 22 Jan 2004, including shipping) for North 
Americans, since it is locally made and uses standard pipe fittings. The 
first-flush valve kit consists of a hollow ball (see middle two photos 
below) which, when filled by the initial flow of water, seats itself 
onto a rubber gasket. This closes the overflow pipe and subsequent 
rainwater is then diverted to the cistern. After the rain stops the ball 
empties and the diversion valve returns to the open position. I will 
post a review of how well this device performs at the end of this rainy 
season. At this time it already seems to be functioning properly.

Water Sculpture FloTrue Smart Valve Smart-Valve in 4'' cleanout Kinetic 
Sculpture detail

At the same time I installed this roof washer I also installed a more 
elaborate piping configuration (see photo, above, left) leading from the 
downspouts to the cistern that is intended to act as a water sculpture. 
Viewable from our dining room window, it will display ten areas of 
flowing water, depending on the time in a rainwater event and the 
rainwater flow. During a typical Oregon drizzle, only the left most 
vertical pipe (see photo, above right) carries water. During a downpour 
all three pipes will be filled to capacity and additional flow will 
emerge from the 2" elbow.

Update January 2005 -- final roof washer review. Unfortunately, this 
second roof washer employs the same mechanism as the earlier, 
Australian, model to reset itself after a storm event. Both devices use 
a small, hollow, plastic ball that fills with water when rain begins. 
While the ball fills, the initial dirty rainwater is wasted. When the 
ball is full, it lowers over a drain hole, causing the remaining clean 
rainwater to be diverted into the cistern. The problem with both these 
devices is that their ball depends on a tiny pin-hole to empty their 
water when the rain stops. However, it is all too easy for this hole to 
become obstructed with small particles of sand or other debris common in 
a gutter. The ball then does not drain properly and the device does not 
reset itself. Thus, both devices required close monitoring and frequent 
manual cleaning in our system. I regret to say that I cannot recommend 
either one. My recommendation at this time is to employ a homemade Texas 
style standpipe roof washer. Its simplicity allows it to be constructed 
and maintained inexpensively.

We have now sold this house and moved to a different residence. We will 
work with the new owners who will continue using this system.

Rainwater Harvesting Discussion Forum  Click here. 
<http://groups.yahoo.com/group/rainwaterharvesting/>