by Katherine Berezowkyj
David J.C. Mackay’s recent piece in the New York Times discussed a question that surprisingly few have considered amid rising concerns about future energy supplies, “Where will the world get its energy from next ─ when, inevitably, humans stop using fossil fuels?”
The Cambridge University physics professor has broken down the debate by asking:
“How much energy does our chosen lifestyle use?”
“How much land area do we have?”
“And how much could we produce, from each source, and at what cost?”
He asks these questions because to consider using only renewable energy sources to power a country, it’s necessary to know how much power that country uses relative to its size.
Mackay says that knowing how much land area is used by power sources is valuable because “almost all renewables are harvested on land, and it is possible to quantify the potential power production from renewables in exactly the same consumption: watts per square meter.”
“Countries with power consumption per unit area of more than 1 watt per square meter, like Britain, Germany, Japan, the Netherlands, Belgium and South Korea, would have to industrialize much of their countryside to live on their own renewables. Alternatively, their options are to radically reduce consumption, use nuclear power and buy additional renewable power from other, less densely populated, countries.”
Mackay also describes what a portfolio of one-third wind, desert solar, and nuclear power would be:
If a country with the size and population of Britain — 61 million people — adopted that mix, the land area occupied by wind farms would be nearly 10 percent of the country, or roughly the size of Wales. The area occupied by desert solar power stations — in the case of Britain, they would have to be connected by long-distance power lines — would be five times the size of London. The 50 nuclear power stations required would occupy a more modest 50 square kilometers.
This is not to downplay the importance of renewables to meeting the future energy needs of the United States and other highly developed nations. AREVA fully supports a range of renewable generation and is actively engaged in developing biopower and offshore wind projects around the world. However, it is important to recognize different energy sources bring with them distinct requirements that cannot be ignored as options are discussed.
The rest of his article, “Illuminating the Future of Energy,” really breaks down these watts per square meter calculations for a look at renewable options.
For a look at his book, “Sustainable Energy—Without the Hot Air,” see www.withouthotair.com.
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