May 2007


Uncategorized22 May 2007 07:06 pm

An article in today’s New York Times highlights a little-known company that is considered one of the greatest success stories in corporate environmental performance. At Interface, a major carpet tile company:

Use of fossil fuels is down 45 percent (and net greenhouse gas production, by weight, is down 60 percent), he said, while sales are up 49 percent. Globally, the company’s carpet-making uses one-third the water it used to. The company’s worldwide contribution to landfills has been cut by 80 percent.

Unfortunately, we can’t buy their carpet here in South Africa. So why do I mention them? Because the story of their transformation is a vivid tale of the power of enlightened consumers anywhere in the world.

What Ray Anderson calls his “conversion experience” occurred in the summer of 1994, when he was asked to give the sales force at Interface, the carpet tile company he founded, some talking points about the company’s approach to the environment.

He looked into the issue and concluded, “I was running a company that was plundering the earth.”

But later in the article, we learn that this epiphany didn’t really begin with his sales staff.

It was questions from customers that prompted the sales force to ask for his environmental views in the first place.

Ray Anderson is now considered a hero for environmental progress. He’s a member of the advisory board of the Harvard Center for Health and the Global Environment. I won’t begrudge him that status. But out there somewhere are the anonymous heroes who began the whole process simply by asking their carpet salesperson about the environmental impact of carpet tiles.

It doesn’t cost a cent. Ask the person trying to sell you appliances or office equipment which machine uses the least electricity. Phone the 0800 customer service line on one of those bottles under the sink and ask about the environmental impact of the chemicals inside. You may not get a good answer, but that’s OK. When people are embarrassed because they can’t answer customers’ questions, they start asking questions themselves. Be an anonymous hero.

Global Warming &Pool &Water Use/Greywater15 May 2007 01:33 pm

Pool full of Coal

Winter is a tough time to hold down electricity consumption. Days are shorter so lights burn longer. The cold air begs for hot tea, hot meals, hot water, and hot electric heaters. (See this post on heaters.) Even solar-heated water needs an electric boost in the winter. But there is one easy place to save electricity as the days get colder: the swimming pool.

One of the best things anyone can do to make a greener house is to fill in the pool. Swimming pools waste water, use huge amounts of electricity, and require toxic chemicals. But my kids would kill me if I filled in the pool, and there are ways to mitigate the environmental cost of a pool.

The first priority is to get a pool cover that keeps out dirt and ultraviolet and prevents evaporation. If it’s a bubble cover, it will keep your pool warmer, too. In Namibia the law insists on pool covers to prevent evaporation. A cover will save thousands of litres a year.

Ultraviolet breaks down chlorine, which is why you have to add cyanuric acid to stabilize the chlorine. Put on a pool cover and you can save on both stabilizer and chlorine. Most important, with less dirt and more effective chlorine, you should be able to reduce your pool pump’s running time.

In most homes with a pool, the pump is the second or third largest consumer of electricity, after the geyser. If I followed HTH’s standard recommendation to run my pool pump 12 hours a day in the summer, and if I hadn’t resisted a sales pitch a couple of years ago to trade in my 750 watt pump for a new 1 100 watt model, I would be using 13 kilowatt hours a day to filter pool water, more than half my current total daily consumption.

Ignore HTH’s 12-hour guideline, and rather follow the suggestions of the California Swimming Pool Industry Energy Conservation Task Force:

Reduce filter operating times to no less than 4 to 5 hours per day during the summer and 2 to 3 hours per day during the winter period. This will reduce annual electrical consumption by 40 to 50 percent. Normal and heavier swimming use may require as much as eight or more hours filtration per day. Should water clarity or chemical imbalance indicate inadequate filtration, immediately operate the filter until acceptable water clarity has again been established. If additional filtration is still indicated, increase filter operating time in one-half hour increments until the water remains clear and properly balanced chemically.

I run my pool six or seven hours a day during the summer. Since cold water inhibits the growth of nasties, yesterday I reset the pump timer to three hours for the winter. Eskom struggles to keep up with peak winter demand in the morning between 6 and 10 a.m. and in the early evenings between 6 and 9 p.m., so make sure the timer is not set to run the pump during those hours.

All of this inspired me to do some calculations. A cubic metre of coal can produce roughly 3 000 kWh of electricity. My pool holds roughly 30 cubic metres. So if I kept a 1.1 kw pump running 12 hours a day year-round, as many South Africans do, the coal burned over 18 years to keep that pump going could fill the pool to the brim. Better a green pool than a black one.

Global Warming &Heating and Cooling07 May 2007 02:56 pm

Rinnai 323 Gas heater

My Rinnai

I saw frost for the first time in 2007 today. My wife has started to grumble about the cold. And the stores are full of heaters for sale, all of them claiming to be energy efficient. It’s time to review which heating options will warm your home without heating up the planet too much.

First, the worst: electric underfloor heating and open fireplaces. Talk to any underfloor heating salesperson, and they will tell you that underfloor heating is incredibly efficient. Talk to any homeowner who has had it installed, and they will tell you that their toes are very warm on the tiles (don’t these people own slippers?) and that their electricity bill shot up the day they turned on the underfloor heating.

The issue is not so much whether underfloor heating is efficient or not. It’s a form of central heating, and most South African suburban houses are not built for central heating. They have big, draughty, single-glazed windows, and uninsulated walls and ceilings. When I moved into my house, each room had a brick with big holes in it to let in outside air, for heaven’s sake. To centrally heat such a house with coal-derived electricity is an environmental abomination.

Open fireplaces have lots of charm, but two big drawbacks. The first is that most of their heat goes up the chimney, and in doing so, draws cold air into the house through any leaky door or window it can find. Nature abhors a vacuum. The second drawback is that, whether burning wood or coal, they emit lots of pollution up the chimney.

According to The Consumer’s Guide to Effective Environmental Choices, by Michael Brower and Warren Leon:

On a per-household basis, the most polluting option is wood heat. The main reason is the very high emissions of particulate matter from uncontrolled fireplaces and wood stoves. Particulates are given a heavy weight in our air pollution index because of strong evidence that they cause serious health problems.

I hate to diss wood heat, because it is carbon neutral, presuming that a new tree is growing in the place of the one you are burning. A good compromise is a modern, super-efficient wood stove, such as the ones sold by Franco-Belge or Morso. The best wood stoves produce one-twelfth the emissions of a typical fireplace.

Electric heat in all forms is relatively efficient, but that isn’t a great help because generating the electricity from coal is very inefficient, and releases far too much pollution and carbon dioxide. If you are heating a relatively small space for a couple of hours in the morning and few hours in the evening, however, it is an affordable, environmentally tolerable option.

Research at the University of Pretoria found that the quickest, most efficient electric heater for warming a space is a fan-assisted heater with a thermostat. Fin radiator heaters—often called oil heaters because of the liquid circulating inside them—and other heaters without fans are slower to heat a room and let much of that heat drift to the ceiling.

Radiant bar heaters, which glow red, do not heat a space, but can efficiently heat any person who stays close to them. If you are staying put, reading or working, they may be your best option, particularly if you buy one with a low wattage setting. (1000 W or less) Leaving one of these heaters on when no one is in the room, however, is a complete waste. An electric blanket is another good option for anyone who isn’t moving.

If you are lucky enough to live in a Johannesburg suburb with piped gas, this is an excellent option, particularly now that South Africa is importing natural gas from Mozambique. Gas is the cleanest-burning fossil fuel and releases the least carbon dioxide, too. Bottled propane gas also burns cleanly, but its global-warming credentials are tainted by the fact that in South Africa much of it is produced from coal. Gas is also more efficient than coal-derived electricity because the heat from burning the gas goes straight into your house, bypassing the inefficiencies of generating electricity.

Burning gas in an open fireplace takes us right back to where we started, however, with heat escaping out of the chimney. My favourite gas heaters are the pricey, but super efficient ones made by Rinnai. My Rinnai has given me three years of faultless service. I keep large, 48 kg bottles of LPG outside my house, piped to a wall outlet where I connect the Rinnai. It produces heat in seconds and uses very little gas. (To find a local dealer, phone the distributor Jay MacDonald and Sons, 021 696 7930.) The only problem is that my children fight over who gets to sit closest to it when they turn it on in the mornings.

I’ll take a risk and produce an unscientific ranking of heaters from best to worst:

1. Gas heater with piped natural gas
2. Gas heater with LPG
3. Modern, efficient stove burning wood
4. Modern, efficient stove burning anthracite
5. Electric bar heater for warming people who are staying in one place
6. Electric fan heater with thermostat
7. Other Electric heaters
8. Gas fireplace
9. Wood fireplace
10. Anthracite fireplace
11. Electric underfloor