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Jan 26, 2012: If you really have nothing better to do, you can check out my powerpoint presentation on "Water Wisdom for Landscape Designers" to the Assn. of Northwest Landscape Designers winter seminar by clicking here: http://www.slideshare.net/oldmahon/water-wisdom-for-landscape-designers.

January 26, 2012: So how much does it cost to run a home’s landscape lighting system? Well, that depends on the home and the system size. Before I set out on my mind numbing math calculations, I’ll need to set up the parameters. The system we’ll be looking at is a modest – moderate home lighting system of 15 halogen luminaires. They will be a combination of 10 path lites and 5 spotlights. Let’s say the total wattages of all the lamps in the luminaires is 300 watts. Watts are a unit of electrical energy. We pay for our electricity in Kilowatt hours (1000 Kwh). Our system comes on when it gets dark and it knows this because we have a photoreceptor cell hooked to the transformer that measures when it gets dark. The transformer is what is hooked into our home electrical lines and steps down the 120 volt current to low voltage (12volts) to run our lights. We set the clock on the transformer to turn off at midnight, because, unless we’re using it for security lighting, we’ll be in bed by then (or at least I will) and cannot further enjoy the lighting.

The lights are scheduled to come on every day of the year. They’ll be on longer in winter and shorter in summer so, on average about 5 hours a day. . . .HEY!!! GET BACK HERE! SIT DOWN! Yea, I know this is boring, but stick it out. Trust me, you’ll be a better person for it. . . . .

5 hours/day x 365 days/year = 1,825 hours of lighting

1 hour on = 300 watts of power used

1825 hours of lighting x 300 watts = 547.5 Kwh (Kilowatt hours)

Total electrical cost to run the system for a year = 547.5 X .11/Kwh *= $60.23/year or $5.02/month

*(I got the $/Kwh by taking my monthly electric bill statement and dividing it by the Kwh used for the month)

Total cost to maintain the system (replace bulbs every 2 years)based on a 10 year cycle:
by owner ~ $45/yr (Electric + bulbs =~$8.77/month)
by contractor ~$90/yr (Electric + bulbs + labor =~$13.77/month)

WAIT A MINUTE!! Sit tight we’re almost done!

Now, what if I used low voltage LED lights? How much less would that be? The lower wattages of LED bulbs will equate to about 120 watts instead of 300. The other variable will be the cost of maintenance because we shouldn’t have to replace our bulbs for perhaps 10 years. All the rest of the equation is the same. I know you’re getting antsy and you have stuck with me this long (but I had to threaten you to do so), so I’ll skip the detailed calculations and reveal that the monthly cost of electricity ($2/month) + bulbs (based on a 10 year life @ $45/bulb + Labor= 7.25 month) = $7.63/month Now let’s say that the cost of installing that LED system was $1000 more. With the energy savings of LED we can pay for that in 13.5 years . . . .just about the time we’ll have to replace the LED bulbs. The savings and hence the difference between them cost-wise is in the added frequency of bulbs and labor to change out and the increased electrical cost. You had to sit through that and the conclusion to that isn’t all that dramatic . . . .BUT (and notice that’s a big “but” I’ve spelled there) that is contingent on electrical rates staying the same and the chances of that happening are worse than the chances of this article winning a Pulitzer.

For my money, I’d go with LED. In fact, in my own system I have both a run of LED lights and a run of halogen. In 8 years time I’ll tell you how they’ve fared.

GETTING LIT: PART I - A COMPARISON OF SOLAR, HALOGEN and LED LANDSCAPE LIGHTING
January 22, 2012: Landscape lighting (low voltage) has been gaining in popularity. I have installed several systems, including one at my home, and find it gives a whole new dimension to appreciating your landscape. It extends your time outdoors in the summer and, in the depths of winter, the shining lights shatter the darkness and cold and give a glimmer of hope that spring will someday come. The luminaires sing out to me “You’ll make it! Don’t move to Arizona yet!”

But this is not about the benefits nor techniques of landscape lighting. It’s about the advantages and disadvantages of the three major types of “lamps” (that’s professional code for light bulbs) that are used in landscape “luminaires” (you non-lighting laymen would call that a lamp) Those three major types are solar, halogen and LED, short for light emitting diode.

SOLAR: Solar lights operate from a small photovoltaic cell that when hit by sunlight produces energy to charge a small battery. The battery, in turn, operates a small LED or incandescent light. The advantages are no power cost, no buried wires or transformers, easy to install – all attributes that have made them very popular with the homeowner DIY (do-it-yourself) market.

For something so sustainable I hate to be negative, but I would never recommend to a client solar lighting unless they like the “glowstick” look of the lighting. Most of the solar lighting products on the market are of extremely cheap quality. Unless they’re put in full sun for 8 hours a day their light output and duration are very poor. In the Pacific Northwest don’t expect to get much out of solar lights for the 7 months or so of the rainy season. The quality of the fixtures are even worse. The cheap plastic or aluminum used breaks with ease. I’ve busted at least a dozen of them by tripping over them while doing landscaping work. A far greater percentage of low voltage luminaires pass my klutz test than do solar luminaires.

If one has a sunny location, uses high quality (higher cost) lamps and luminaires, and doesn’t need high (or even decent) light output or color quality, then solar may indeed be viable.

For the remainder of this discussion I’ll focus on low voltage (12 volt) lighting and the pros and cons of halogen lamps vs LED lamps.

HALOGEN: Halogen lights have been around for a long time. They are a form of incandescent bulb, like what Thomas Edison invented. The only difference is that halogen bulbs have halogen gas sealed inside and that allows the incandescent filament to glow at higher temperatures and for longer periods of time (about 2000 hours).

The benefits of halogen are that they are cheaper luminaires and lamps than LED. The luminaires (fixtures) are at least half the cost of LED and the lamps (bulbs) cost $5 as opposed to $40 or more for an LED lamp. I recently priced out both a halogen and an LED option for a small 10 luminaire lighting system for a client. The halogen priced out at $1800 and the LED at $2800.

Halogen lights also have a higher light output than LED’s . For example when installing a spotlight where you can use either LED or halogen as the lamp in it, a typical halogen 35 watt lamp used puts out 2100 lumens (lumen = unit of light amount – “brightness”), while a typical 4.5 watt LED bulb is about 350 lumens. In short, halogen makes a lot better reading lights (or brighter spotlights) than comparable LED’s.

On the other hand, halogen are higher wattage bulbs which mean they use more electricity. The bulbs last 2000 hours and typically have to be replaced every 1-2 years. Performance of halogen lights is critically dependent on getting just the right amount of voltage to each light, 10.5 – 12 Volts. That means careful layout and sizing of the wires running to the lights and the ability of the installer to understand and calculate voltage drop. A little too little or a little too much voltage at a light means they burn out very quickly. Don’t try this at home unless you understand voltage drop.

Synopsis: PROS – reasonable initial cost, excellent light output and color ranges. CONS – Higher energy usage, higher maintenance cost in replacing bulbs.

LED: LED is a much newer technology. One might say it’s just getting out of it’s pioneer days as a landscape lighting technology. LED lamps work by electricity flowing through a semiconducting diode. What is that you ask? . . . I don’t know, but instead of a filament glowing red hot, like in an incandescent bulb, there are a bunch of electrons that get all excited and moving around and they throw off a luminescence. Granted that’s not the best technical explanation, but dagnabbit! I don’t make these things I just install them out in the landscape.

LED’s produce little to no heat and use much lower wattages which means electrical savings and a lot more landscape lights per transformer used. The lamp ratings on LED’s are from 20,000 – 50,000 hours of life. There is really no way to be sure of the upper hour rating because LED’s haven’t been long enough out in the landscape to verify it. Still, it’s a lot longer than halogen.

LED’s can operate on a larger voltage range than halogen. If you only get 8 volts to a 12 volt LED, it doesn’t burn out as a halogen would.Iit just doesn’t shine very brightly. Wire runs and sizes are still important for consistency of light quality, but not as critical to whether it actually works or not.
As LED’s become more accepted, their price will come down. That’s part of the impetus behind the 2007 federal light bulb efficiency law (or “light bulb socialism” as some folks like to call it) that started into effect this year. The standards require manufacturers to phase out the production of low efficiency incandescent bulbs (you can get high efficiency incandescent instead) and linear fluorescents to encourage production of LED’s and CFL’s (compact fluorescents, those squirrelly looking bulbs). Similar or stricter legislation is in place in the European Union, China, Russia, Canada, Brazil to name just a few countries. The legislation was very controversial and the Republicans successfully blocked funding for its enforcement. . . And it’s about time somebody stood up for our incandescent rights! No dagnabbit government’s going to tell me how to stop wasting my energy dollars. If they want my low efficiency incandescent bulb, why then let them come to my home and pry it from my cold dead hands!! . . . Oops, I guess I’m getting off topic.

LED’s see a reduction both in color quality and intensity sometimes within a couple of years. “Warmer color” light (think reddish-yellow color) relies on lamp coatings that degrade over timeand cause the lamp to shift to “cooler colors” (think bluish-white). Warmer colors are usually more desirable in landscape lighting.

Synopsis: PROS – Longer lamp life, lower energy usage, more lights can be run from a single transformer, more flexibility in wire runs and sizing. CONS – Higher initial cost, lower lumen output, less flexibility in luminaires and lamp colors

In the soon-to-come Part II. I’ll look at an energy cost comparison of LED to halogen.

Dec. 31, 2011: As of August of this year, the use of greywater is now legal and approved (by permit) for residential irrigation use. Let’s first take a look at what greywater is, how it can be used and how pragmatic it is to do so.

Greywater (or gray water) is all the water that has been used in your house, EXCEPT the toilet. Toilet water is blackwater, which requires extensive pre-treatment and is not approved for residential irrigation use. Greywater is the water used in your kitchen and bathroom sinks, showers, bathtubs and laundry room (provided you don’t wash diapers in it). It is collected and diverted from your sanitary pipes before it mixes with blackwater . It comprises about 50-80% of household water usage. The “average” household uses 127,000 gallons of water a year in total domestic use (not irrigation).That water nows goes down the sewer or into the septic tank and there are further costs associated with that to dispose of it. Wouldn’t it be great if we could use that water beneficially to irrigate our landscape? Wouldn’t it? Well maybe, we’ll see. All that glitters, may not be grey.

Oregon greywater code stipulates that greywater can only be used for “beneficial purposes”. That means you just can’t dump it outside your house. It’s got to be directed to a useful purpose, like irrigating plants. The code has 3 different permitting levels:
Type I – For residences that generate less than 300 GPD (gallons per day). The water cannot be stored more than 24 hours and can only be applied through sub-surface (below the ground) irrigation.
Type II – For any structure that generates less than 1200 GPD. The water can be store longer than 24 hours but must treated by chemical or biological means to reduce suspended solids and organic matter. It can be applied by drip irrigation on the surface of the soil.
Type III – Anything that doesn’t fall within type I or II permits. This greywater must receive type II treatment and a chemical disinfectant. It can be applied through a sprinkler system.

There is a lot more to the codes than this and I would highly recommend you go to the Oregon DEQ website if you have further interest. http://www.deq.state.or.us/wq/reuse/graywater.htm#Intro

So let’s look at the advantages and disadvantages of greywater. (IMHP – In my humble perspective)

ADVANTAGES:
1.Reduction of some of your freshwater irrigation needs
2.Less strain on sewer or septic systems. Particularly septic systems benefit from less water that has to be handled
3.You feel good by doing something concrete to reduce your water footprint.

DISADVANTAGES:
1.The irrigation water cost you save for the “average” landscape is not huge. The average greywater generation of an average household (and keeping in mind that finding the truly average of anything that’s not a math equation is like finding the Holy Grail) is probably about 100 GPD. At current Portland water rates ($3.09/784 gals) that’s a cost savings of .39/day or about $46.80 over an irrigation season.

Now if you compare that with the cost of installing a greywater system . . . here’s where it’s tricky. Since greywater irrigation is so new and largely untested, few if any contractors have installed these to come up with an average cost. I haven’t. From researching some current on the market residential greywater systems, I estimate about $1500 installed (and I’m probably underbidding) and that would be for a drip system that might cover 50-100 plants. So the payback time on that investment would be 32 years. (Granted that there are other investment returns of environmental and community benefit . . . but I don’t know how to figure those out).

2.To me the biggest disadvantage with the type 1 greywater systems is the inability to store. If you need to irrigate your plants you need to take a shower (preferably a long one) or do your laundry. Frequency and amounts of water are totally dependent on the inside water use. That makes for alot of variability which some plants can take and some plants can’t. From a pragmatic standpoint, greywater irrigation of lawns is out. Irrigating vegetable gardens isn’t that feasible. Fruit trees seem to be the best use for type 1 greywater use.

3.Greywater irrigation systems take a lot of maintenance. Because of suspended solids and fatty residues in the water (kitchen sink water is the worst culprit), filtration systems, pumps, distribution lines and emitters get clogged easily. Often you won’t know when a system is malfunctioning until you see plants dying. The more complicated the greywater system (ie type II or III) the more maintenance and the more components that can malfunction.

4.You can only use your greywater system when plants need irrigation. That means when there’s not enough rainfall. That means in the Pacific NW that it can’t be used for 6-7 months of the year. You have to have a diverter valve that diverts the greywater back to it’s original disposal route.

5.It takes unconventional irrigation components. Greywater piping should be purple pipe. We don’t want to confuse it with white PVC potable water pipe. Conventional drip irrigation clogs easily, so often, the delivery system must be modified so this happens less. For type III irrigation sprinkler use, you must use large impact heads and special dirty water valves. It just takes a whole lot more customizing of the installation.

Note: The greywater technology for commercial irrigation systems (parks, golf courses, etc.) has been around for years and is well established and works, but often these systems use treated effluent from sewage plants. The greywater is treated offsite which makes it quite a bit different from residential, onsite treatment.

6.More complicated systems, like type III, must have disinfection monitoring 3 times a week.

7. Greywater cannot contact any edible portion of a vegetable. That means for vegetable gardening no root crops can be watered by greywater.

In summation and in my humble perspective (as a contractor who has not installed a greywater system and has no hands-on experience), my feelings towards greywater are . . . well , a little gray. But that’s OK, because it matches my life philosophy very well – no blacks or whites, only shades of gray. I think in limited particular situations, it can be a pragmatic and sustainable choice and, in some situations, it is not. I think I’ll try it first in my home lab before installing and warranting a system for a client.

Two years ago I had to replace my septic tank sump pump, which I did myself. I can’t imagine a more unpleasant task and it is my most fervent desire that I am dead or in a retirement home before I need to replace it again. If greywater irrigation will help me meet that goal, I’m willing to try it. I’ll let you know next year, hopefully, how it worked out.

Happy New Year!