Monday, August 22, 2016

Climate change and air conditioning

Perhaps the least surprising news about economic "development" and climate change is that soon after a family in China (or similar) gets a TV, thoughts turn to the one device that helps them cope with their increasingly hot and miserable lives—air conditioning.  And it doesn't take long for people to view their artificially cooled lives as a necessity ranking right up there with a roof that keeps out the rain.

While it IS possible to build very comfortable structures that don't require tons of cooling, the easiest and most reliable way is to plunk down the money for that humming compressor that spits out cool air.  Those who try it tend to really like it,  Suddenly, miserable places are transformed into the Sun Belt.

The problem is that air conditioning is a notorious energy hog.  And when the electricity to run these things come from burning coal, massive cooling leads to hotter climates.  Of course, it doesn't have to be that way.  Cooling loads tend to be highest whenever the sun shines brightest.  Bingo.  Solar-powered cooling is physically possible so in theory, this should become one of the next big marketing opportunities.  We will see if that happens because right now, the boom in air conditioning is being supplied with technologies that assume electricity from a reliable power grid.

As the mercury soars, fear grows over ‘air-con effect’

Energy experts warn more reliance on air conditioning, particularly in China, will accelerate climate change

John Vidal, 15 August 2016

Most of the world will have air conditioning in their homes, workplaces and cars within 20 years, requiring thousands of power stations to be built and potentially accelerating climate change, energy experts say.

As temperatures shatter records worldwide in 2016 and Britain anticipates its second heatwave of the summer, demand for the technology is exploding.

“Globally, 2016 is poised to be another record-breaking year for temperatures. This means more air conditioning. Much more. It is becoming an air-conditioned world,” says Lucas Davis, an energy economist at the University of California in Berkeley.

“The growth in air conditioning has been staggering. China is the sweet spot. The number of households that have it has doubled in five years. Every year, 60 million more units are being sold there, eight times as many as are sold annually in the United States.”

As large developing countries such as India, Mexico, Indonesia and Brazil grow richer, staying cool may come to be seen as a necessity and not a luxury, leading to severe energy shortages and major environmental stress, says Davis.

“Air conditioning is wonderful. As people are coming out of poverty, they buy a TV, then a fridge, then a car and air conditioning. There are a lot of hot places where people are getting richer. As average temperatures increase, the reach of air conditioning will be extended, even to the relatively cool areas of the world where saturation is currently low,” he says.

But Davis, who expects nearly all households in warm countries to have air conditioning within 20 to 30 years, warns that the extra energy needed will be dramatic and could have huge consequences for global warming. “We are talking about hundreds of new power stations having to be built in China alone over the next 20 or 30 years,” he says.

His research is backed by the US government’s Lawrence Berkeley National Laboratory, where researchers have calculated that 700 million air-conditioning units are likely to be installed worldwide by 2030 and 1.6 billion by 2050. Sales in Indonesia, Brazil and India have been growing 15% a year, it says.

Technologists say it’s not just warm countries switching from fans to air conditioning. “Offices, businesses, hospitals, shops and homes in Britain are all using air conditioning as buildings fill with computers, televisions and other heat-generating machines,” says a spokeswoman for the Institute of Refrigeration. In addition, she says, better insulation in new buildings traps heat and it is too noisy in cities to have windows open: “The way we live now increases the need for air conditioning.”

Cooling systems may already account for about 10% of total electricity consumption in the UK , says the UK Building Research Establishment. It estimates that 65% of UK office space and 30% of UK retail space was air conditioned in 2012.

The UN’s climate change body, the IPCC, has projected that global air-conditioning energy demand will grow 33-fold from 300 terawatt-hours (TWh) in 2000 to more than 10,000TWh in 2100, with most of the growth coming in developing economies.

“10,000TWh is roughly half the total electricity generated worldwide in 2010,” says Martin Freer, director of Birmingham university’s Energy Institute. In a recent report, which he co-authored, Freer says: “Worldwide energy demand for space cooling will overtake space heating by 2060, and outstrip it by 60% at the end of the century, as cooling demand in the developing countries of the global south grows faster than heating demand in the developed northern economies.”

But in a world already warming because of fossil fuel emissions from oil, gas and coal, demand for air conditioning and refrigeration is seen as one of the greatest accelerants of climate change.

“If nothing is done, within 15 years cooling will require an additional 139 GW – more than the generating capacity of Canada – and raise greenhouse gas emissions by over 1.5 billion tonnes of CO2 per year, three times the current energy emissions of Britain,” says Freer.

Concern is also mounting over a class of chemicals widely used in refrigerants and air-conditioning units. Hydrofluorocarbons, which have largely replaced CFCs, which were found to damage the ozone layer, are potent greenhouse gases. Although they are far less significant today than CO2 for global warming, if the numbers of refrigeration and air-conditioning units explode as expected, they could add to the problem.

“The data is poor, but one estimate suggests that refrigeration and air conditioning cause 10% of global CO2 emissions – three times more than is attributed to aviation and shipping combined, through energy consumption and leaks of HFC refrigerants that are themselves highly potent greenhouse gases,” says Freer.

“As climate change increases outdoor temperatures, air conditioning will more often be used to maintain comfortable indoor conditions. Climate change is expected to stimulate installation of air conditioning in some buildings that would otherwise not need air conditioning.”

Policymakers from across the world met recently in Vienna to agree to phase out HFCs but some countries are nervous about the extra cost of changing to alternative refrigerants. Researchers in India have estimated it could cost the country tens of billions of dollars. more

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