Friday 17 April 2009

home recycling - something everyone could do!

Random facts on how much home recycling could contribute -

image from http://www.flickr.com/photos/simonandhayley

Every ton of recycled paper saves 17 12-metre Douglas Fir trees.

image from http://www.flickr.com/photos/cobalt/

Up to 90% of recycled glass can be reused to make new glass items, such as bottles and jars.

Every glass bottle recycled saves enough energy for a 100 watt light bulb to be lit for 4 hours.

image from http://www.flickr.com/photos/sblackley/

Recycling one aluminum can saves enough energy to run your TV for 3 hours.

43 recycled bottles can make 1 m2 of carpet.

Recycling a 1-gallon (3.79L) plastic milk jug will save enough energy to keep a 100-watt bulb burning for 11 hours.

Tips on recycling various home waste materials -

paper & cardboard
- newspapers should be saved in its own bin, as this material goes directly back into newsprint recycling. Recycling a 1.2m stack of newspapers saves the equivalent of one 12-metre fir tree.
- magazines, glossy printed flyers or newspaper inserts, phone books, envelopes, computer paper, old letters, and paper packaging can be saved together in one bin.
- Staples in paper are acceptable, but remove rubber bands or plastic wrap.
- Do not include the following in your paper recycling: carbon paper, stickers, cardboard, laminated paper, laminated cardboard.
- plastic-lined paper drink cartons are recyclable. Most recycling centers now accept these items; ask locally.
- Discard fast food wrappers made from plastic, dirty or food-stained paper tissues or napkins.
- corrugated cardboard is a highly valued recyclable. Most curbside collectors ask you to bale the cardboard together and tie it with string. Check to see if there are size and weight limits to how much you are allowed to bale together. The most important thing to remember is to keep it dry. Plastic or waxy coated, and wet or greasy cardboard, such as pizza boxes, cannot be recycled because it clogs sorting machines.

plastics
- plastic goods are assigned different numbers to grade them for recycling:
#1 (PET) and #2 (HDPE) for containers, #4 (LDPE) for bags, #7 for mixed plastics that are not recyclable.
- plastic bottles are usually made of #1 PET plastic, a valuable recyclable material. Among many other items, this plastic can be "spun' into fleece fabric. Tops should be removed before recycling, and put in with your general plastic items.
- because it is difficult to clean PET plastic without releasing harmful chemicals, bottles made of PET should not be reused.
- plastic grocery bags - most grocery bags are made of high density polyethylene, a Type 2 recyclable plastic. Most grocery stores have bins outside so customers can drop off used plastic bags for recycling.
- polystyrene (#6) (cups, food trays, egg cartons, etc) is not biodegradable. Try reduce your use of this material.
- polypropylene (#5) is one of the least recyclable plastics. Considered one of the safest plastics, #5 plastic is used for packaging items such as yogurt, cottage cheese, margarine and vitamins, and is contained in food wraps and bottle tops. It is one of the least expensive plastics to make. However, the process of recycling plastic #5 is less efficient than other plastics, and the end result has little market value.
• Choose products packaged with plastic #2 (HDPE). Many companies, especially those selling organic food, have switched to plastic #2, a better (but more expensive) alternative.
• Find out if your community has an All Plastics Recycling program which accepts plastic #5.
• Set aside your plastic #5 containers for reuse.

glass
- glass is recycled according to color: clear, green and brown. If possible separated them this way.
- paper labels can be left on the glass.
- store lightbulbs, sheet glass, mirrors and pyrex separately from bottles, since they have a different composition.
- compact flourescent lightbulbs (CFLs) may be recycled at your local Ryness store.
aluminum, steel & copper
- food cans should be rinsed and have lids and labels removed. It helps if they are flattened, although many new cans are difficult to flatten; they should still be recycled.
- aluminum cans are very valuable as recyclable items. Do not crush aerosol cans.
- aluminum foil and foil packaging are also important to recycle; they are reprocessed into aluminum mechanical components, such as engine parts.
- paint cans, aerosol cans are recyclable, but are considered hazardous waste and need to be kept separate from other metals. It is important to leave labels on these cans, as recyclers need to know the former contents. Try to return the lids along with empty paint cans.
- copper is one of the most recycled and recyclable of metals. In fact, copper is 100% recyclable, as are all its alloys, such as bronze and brass. The recycling of copper requires only 15% of the total energy otherwise consumed in mining, milling, smelting and refining.

computers, printers and hardwares
- Pass it on. The simplest solution to recycling your old computer. Ask at a local school or put a notice on a community bulletin board offering your computer free for the taking. Many people without a computer will still find use with the word processor and basic programs.

rechargeable batteries
- Some high street electronics retailers collect (free of charge!), all old mobile batteries and used rechargeable batteries (as in electronic/electrical appliances) for recycling.
- In most boroughs you can take car batteries to a local Reuse and Recycling Centre. In some parts of London they can be collected as part of the kerbside collection.
- If you can’t recycle batteries, consider doing the following before you buy:
• Use mains electricity where possible
• Use rechargeable batteries and a battery charger. The energy needed to make batteries is 50 times greater than the energy they give out.
• Send batteries back to manufacturers, where such a scheme is available, or set up a scheme with your local supplier if possible

clothes & textile
- Many recycling banks are operated by charities, such as Oxfam and Scope and they empty the textile banks and sort the clothes and textiles. Wearable clothes and shoes are then distributed through their network of charity shops or sent overseas to those in need.
Those clothes and textiles that cannot be worn or used again can be sold for other uses such as for padding and stuffing in loudspeaker cones and furniture. Some are made into wiping cloths for industrial use and some woollen yarns and fibres can be reprocessed and made into fibre for new garments.
- Soiled/stained clothing or carpets cannot be recycled.
- Shoes can also be recycled. Some boroughs have recycling banks just for shoes - tie shoes up to keep them in pairs.
- As well as recycling unwanted clothing, don't forget to recycle other textiles such as towels, sheets, bedding and blankets, and even soft furnishings, like cushion covers.

Information from some of the following websites.
Some further readings -

recycle for london -
http://recycleforlondon.com

save the hussles at home and let tesco work for you (UK) -
http://www.mrw.co.uk/page.cfm/action=Archive/ArchiveID=10/EntryID=5277

how to set up a home recycling system (USA) -
http://www.wikihow.com/Set-Up-a-Home-Recycling-System

check with your local councils to see what could be recycled & how (UK) -
http://www.uk-energy-saving.com/local_recycling.html

Friday 16 January 2009

revolution of AC/DC electricity to contribute for energy efficiency

eco home, from sharp

家電產品朝直流電發展 狄高
2009年1月6日 信報財經新聞

目前大部分家庭電器都使用 220V 交流電(AC),如電燈、冷氣機或雪櫃等。但我們日常使用的中、小型電器卻大多數使用直流電;例如電腦、LCD 電視、電話或影音器材等,都是使用火牛(即變壓器)把交流電轉換成直流電(DC)運作。有沒有想過既然很多電器都使用直流電,我們可以把全屋電制變成直流電接口,所有電器便毋須再用火牛,直接插到電制上使用便可以了。

效果更加環保

事實上,日本已有電器生產商朝這個方向發展,研製直流供電系統,直接向全家電器提供直流電。使用了直流供電系統後,電器便毋須再使用火牛,這既可簡化電器的設計,也可以提高電力轉換效率,更加省電環保。
我們使用直流電的電器規格並不統一,因此每件電器都要使用自己的火牛,才可變壓。例如室內無線電話多使用 3.6v 電壓、電腦使用 12v 及 5v,有些家電為配合筆芯電的 1.5v 電壓,因而使用 3v 或 9v,沒有統一標準。直流供電系統出現後,小電器的電壓多會跟隨電腦常用 12v 和 5v,跟電腦規格看齊。

適用於數據中心

當所有電器都使用 12v 和 5v 後,加上全屋使用直流供電,電器便毋須再使用內置變壓器或外置火牛了,可以直接接駁到直流電源上使用。直流供電系統將最先應用在數據中心,這可以令每台伺服器簡化,毋須再使用火牛,令每個機櫃可以安裝更多的伺服器,也減少了火牛發熱的問題。
此外,在目前數據中心的設備中,為確保電力不會中斷,數據中心必須使用 UPS 後備電源。UPS 可以在斷電時繼續提供 220V 交流電,令伺服器繼續運作。若整個數據中心改用直流供電,UPS 便只須提供 12v 直流電便可,設計上可簡單得多。
多年來,我們一直使用高電壓的交流電,是因為在輸電網上,高電壓可以減少電力損耗,但當電力進入家中後,由於現在大部分電子器材都使用低電壓直流電,如果能夠在室內預先把交流電轉成低電壓直流電,避免每件電器自行轉壓,轉換效率可以更高,因此直流供電系統將是一套極具潛力的環保電力系統。

AC/DC: Not just a rock band anymore . Junko Yoshida
02.10.2008 EETimes.com
http://www.eetimes.com/showArticle.jhtml?articleID=210605193

MAKUHARI, Japan — Sharp Corp. and TDK Corp. have revived the apparently never-ending DC vs. AC debate.

You'll recall that it started back when Thomas Edison promoted direct current power generation while Nikola Tesla invented a relatively simple AC induction motor and advocated a alternating current distribution system.

At the Ceatec Japan show here, Sharp showed what the company calls its "DC Eco House," a concept illustrating carbon-neutral living.

Sharp created a miniature house equipped with crystalline solar modules on its roof, generating power in DC, which can be directly distributed throughout the house to power up "the next-generation" refrigerator, air conditioner, LCD TVs and power LED lights, all featuring a DC input.

Similarly, TDK promoted a partly DC-powered "eco home," anticipating a combination of clean energies, such as solar and wind power, and conventional commercial electricity.

The TDK mock-up showed a flow of energy from multiple energy sources not only to the home but throughout the home, with Home Energy Management System installed inside the home.

Both companies are advocating foregoing multiple conversions of DC-to-AC and AC-to-DC. They believe such a step will prevent energy losses by up to "several percent."

They are asking: Isn't it about time for DC power delivery systems to replace, or at least augment, the current AC distribution system " at home?

Some active discussions are already taking place in the United States to promote the use of DC power in facilities such as datacenters.

What's new at Ceatec, a Japanese consumer electronics show, is that the similar debate now includes power to the home.

DC power delivery systems for home?

A Sharp spokeswoman stressed that the company is not being naive. "We understand that proposing a DC infrastructure is a bold move. It affects power companies' business, it asks for alterations in power transmission cables, and it demands big changes in every home appliance now equipped with an AC input," she said.
But Sharp thinks it's time to start exploring enabling technologies capable of supplying constant and stable DC electricity power.

She said, "Today, the power generated by solar cells needs to be converted into AC, before it's sent to the grid. The power, transmitted from the grid back to home, needs to be converted to DC again, at every home appliance. We're introducing a lot of inefficiencies in our energy use."

Historical fact

It is a historical fact that Tesla won the argument as seen in today's utilities, which are designed to generate, transmit, and deliver electricity in the form of alternating current.

But the Japanese companies believe that fundamental premises for the original debate have become obsolete.

For its part, Edison, unable to improve his DC system, lost the battle, because in the 19th century, DC power generation was limited to a relatively low voltage potential and DC power could not be transmitted beyond a mile. Today, high-voltage direct current is a viable method of transmitting power over long distances.

But more importantly, they say, what if future homes do come with solar panels and they start generating their own power?

Further, they pointed out that many consumer electronics devices and appliances today already operate " internally " on DC power.

An official at TDK's booth noted, "Unlike old picture-tube TVs or washing machines of 20 years ago, a growing number of consumer devices today use DC, including PCs, LCD TV and portable devices like cell phones." This is because DC can be precisely regulated for sensitive components.

Neither Sharp nor TDK gave out exact figures -- how much power is actually being wasted in the process of AC-DC conversions, except for saying "several percent." They said that each device and appliance is different.

While the proposal for DC power delivery systems may sound like pie-in-the-sky, both Sharp and TDK believe they can influence the debate, because they have technologies relevant to an eventual transition.

Sharp, armed with crystalline solar cells and LCD technologies, demonstrated a prototype of solar-powered LCD TV.

Calling it "off-the-grid TV," the Japanese company illustrated in its prototype how it's possible for a 52-inch LCD TV, consuming 220 kWh (kilowatt hour) per year (assuming a consumer watches TV 4.5 hours a day), can be powered by crystalline solar modules " measuring roughly 1 meter x 1.6 meters -- capable of generating 220 Wh.

Similarly, TDK displayed the company's dye-sensitized solar cell technology, which can now be applied to flexible cells. TDK also showed: DC-to-DC power modules, essential for stable power supply; a two-way AC-to-DC converter, capable of converting surplus power back into AC, which is in development; and a Lithium ion battery for storing energy, also still in development.

*****

Further reading -
Bringing Back DC Electricity from ecogeek
A Current in Every Ceiling from greentech media

Sunday 9 November 2008

anthony wong's visit to germany on renewable energy 黃耀明 德國再生能源之旅

anthony wong's visit to germany on renewable energy 黃耀明 德國再生能源之旅



today's green lime -
airports going green

Friday 31 October 2008

Tree Power 樹木發電締造真正綠色能源

by 狄高, extracted from the Hongkong Economic Journal 31.10.1008

tree power
image from http://web.mit.edu/newsoffice/2008/trees-2-enlarged.html

tree power
image from http://web.mit.edu/newsoffice/2008/trees-1-enlarged.html

風力發電、太陽能發電、乙醇是新一代再生能源,嘗試以清潔能源取代石油、煤碳的高污染能源,我們努力尋找一種可以持續發展又環保的能源,這是我們對地球的責任。最新的研究發明是利用活生生的樹木來發電,如果成功的話,這就是真真正正的「綠色能源」。

研究樹木發電原不是為了解決現有的能源問題,而是為了監察山火計劃的一部分,這是美國林務署的一個研究計劃,方法是每一英畝區域範圍內的四棵樹上裝置無線感測器,探測環境溫度以檢定是否有山火的潛在風險,藉以提供更佳的火災預警。警報器更會透過無線網絡傳送訊息,一旦有警報,當局可以作出即時反應,問題是感應器需要電力推動才能運作,但在深山卻不能提供一個完善的電力網,如果利用太陽能發電,其地面面積過大又不符合環保原則,因此想出利用樹木來發電的新奇點子。

麻省理工學院的科學家找出樹木與地面存在電壓差的現象,在排除了諸如電磁輻射等可能性後,他們證實了一個十九世紀以來的理論:不同的酸鹼值(pH)值會產生電壓差。樹木內部與所栽植的土壤間的 pH 值不平衡,因此產生了電壓。研究人員指出每一刻度的 pH 值差異,會產生五十九毫伏的電壓。研究人員已成立了一間科技公司 Voltree Power,成功將數毫伏的樹電力提升到一伏特,足夠慢慢充飽一顆電池,並以無線電將感測器的數據傳送到網絡系統上。目前已經有一塊十英畝大小的「樹電」無線感測網絡在美國林務署的指示建成,準備在2009年春天進行現場測試。

透過這種技術,林業署人員便可以監測森林的實際情況,而電池則可以透過這些「電樹」來充電功能。樹木與其栽植土壤之間的電壓差,是由樹木本身的新陳代謝來維持,因此無論是白天晚上、春夏秋冬四季或是晴天下雨,都不受影響,這是大自然的自我調節機制,因此電池便在一個穩定的環境下充電,既安全亦環保。

現階段這種充電技術只能提供輕微電力能量,但從這技術方向發展,可以把森林發電發展成為一個「樹林發電廠」的構想,這樣絕對是一個極大的經濟誘因,有望帶來豐厚的利潤,於是促使我們種植更多樹木,而不是去砍伐樹木,這樣又多了一項環保貢獻。不過,樹林發電廠必須經過詳細的評估和規劃,因為投資者必定以利潤為先,尋找那些樹木是最具成本效益來發電,然後一窩峰地鎖定種植這種經濟效益高的樹木,這樣便會影響生態的平衡發展,造成另一個環境破壞的問題,最後變成好心做壞事。

*****

further reading -
Preventing forest fires with tree power
Sensor system runs on electricity generated by trees

by Elizabeth A. Thomson, MIT News Office 23.09.2008

Wednesday 10 September 2008

green feeds . 10.09.2008

Sahara forest

Could it become a reality? Charlie Paton, Michael Pawlyn and Bill Watts propose to combine two innovative technologies, Concentrated Solar Power & Seawater Greenhouses, to produce renewable energy, water and food in one of the hottest places on earth. Read more about it here.

*****************

Cooper Union Student Eco initiative

Designers across the world: any opinion on the current trend of green design? See below or read more here -

[Please cut the questions bellow and paste them into a reply email to cooper.eco@gmail.com]

The U.S. Green Building Council defines 'green buildings' as structures that work “to significantly reduce or eliminate the negative impact of buildings on the environment and on the building occupants, green building design and construction practices address: sustainable site planning, safeguarding water and water efficiency, energy efficiency, conservation of materials and resources, and indoor environmental quality.”


1. Please describe your initial reaction to the term 'Green Design'.


2. What are your personal ideas of ‘green’ or ecologically minded design?


3. Are you at all skeptical about the aims of “green development” or the designation ‘green’?


4. Do you think there are ways in which ecologically minded design can impact fields other than construction? If so, how?


5. Do you think there should be a set of binding rules for new developments (regarding their environmental impact)? If so, what should they be?


6. Will green practices in the United States be enough to solve ecological problems, or is the help of other nations also required?