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Posts Tagged ‘Lawrence Berkeley National Laboratory’

Lawrence Berkeley solar study

The Lawrence Berkeley National Laboratory this week released a comprehensive study on the cost of going solar in the United States. No surprise that the cost of installing a photovoltaic solar system has fallen 30 percent over the past decade, but there are some interesting developments. For instance, California may be the biggest solar state but it’s not the cheapest. As I write in The New York Times on Friday:

The cost of going solar fell last year, resuming a decade-long decline after several years of flat prices, according to a new study from Lawrence Berkeley National Laboratory.

The report found that the installed cost of residential and commercial photovoltaic systems in the United States dropped 30 percent overall between 1998 and 2008. But prices had become relatively stagnant between 2005 and 2007, as demand spiked and solar module makers ramped up production.

The global economic meltdown, however, along with a resulting oversupply of modules, led the cost of installing a solar system last year to fall from $7.80 in a watt to $7.50 a watt — though the actual cost to homeowners actually increased slightly as state incentives for installing solar arrays fell faster than module prices.

In states like California, the per-watt rebate declines as more solar systems are installed.

Among other findings: the researchers, who reviewed data from the installations of 52,356 solar systems, discovered that it is 10 percent less expensive to install a solar array on a new home than to retrofit an existing home.

And although California is by far the largest solar market in the United States with 81 percent of all installed photovoltaic systems, it isn’t the cheapest place to install small-scale solar.

That distinction goes to Arizona, where the installed cost of solar systems smaller than 10 kilowatts was $7.30 per watt compared to $8.20 per watt in California.

You can read the rest of the story here.

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Green Wombat often highlights high tech when it comes to tackling global warming and energy independence. But a new study from the University of California’s Lawrence Berkeley National Laboratory shows that simply installing white roofs on homes and commercial buildings – to reflect the sun’s rays rather than absorb them – can reduce air-conditioning costs by 20% and could save $1 billion a year in energy outlays in the United States.

Switch to cool sidewalks and roads and the savings rise to $2 billion annually, according to the study by scientists Hashem Akbari and Surabi Menon and California Energy Commissioner Art Rosenfeld to be published in the journal Climate Change.

The scientists calculated that a global white roofs and roads effort would offset 44 billion metric tons of greenhouse gas emissions, or more than a year’s worth of carbon, and help stablize future C02 emission increases.

“The 44 Gt CO2-equivalent offset potential for cool roofs and cool pavements would counteract
the effect of the growth in CO2-equivalent emission rates for 11 years,” according to the authors.

Such emission reductions, of course, can be securitized into tradable carbon credits, which the study estimates would be worth $1.1 trillion. Regulated carbon market exist in places like Europe but securities based on cool roofs have not yet been created.

A global cool roofs agreement could avoid the pitfalls of Kyoto-style accords, the scientists note.  “Installing cool roofs and cool pavements in cities worldwide does not need delicate negotiations between nations in terms of curbing each country’s CO2 emission rates.”

It’s one of those low-tech, commonsense solutions to both energy use and global warming – one used for thousands of years in the regions like the Mediterranean; those picturesque villages overlooking the sea are white-washed for a reason.

In California, commercial buildings with flat roofs have been required to cool it since 2005. But one of the biggest hurdles in the U.S. to doing the white thing may be homeowner associations that dictate everything from the color of your mailbox to where you place your rubbish bin. The vast majority of homes in California either have standard black shingle roofs or Spanish-style red tiles. A proposal to paint those roofs white will likely incite architectural outrage.

But there’s another, albeit much more expensive solution, to hot roofs: Cover them with solar panels.

photo: California Energy Commission

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