THE volunteer coal power lobby in the Philippines posed a question last week that, despite its weak attempt at sarcasm, actually deserves some closer examination. "How many archipelagos," our carbonaceous friend asked, "will be needed by [sic] the Philippines' energy transition?"

Making the assertion, "The question is not facetious," (although it totally was), our modern-day Ned Ludd continued, "It is serious and must be addressed by Sen. Sherwin Gatchalian and the Senate if they intend to mandate the country's transition to renewables."

For the record, I would love to have Sen. Gatchalian give his views on the various criticisms of renewable energy that have been raised, as he strikes me as someone who has done his homework on the subject matter. But as far as his being made the bogeyman by those frantically trying to preserve the unsustainable status quo, that is unfair. The country's transition to renewables was mandated more than a decade ago, with the enactment of Republic Act 9513, the "Renewable Energy Act of 2008". Given the anti-environment advocacy's preference for outdated information, however, it is perhaps not surprising that particular development has been overlooked.

To make the case there is simply not enough available land in the Philippines to support renewable energy, eye-catching assertions from two opinion pieces - one from 2018, and one from last month - were cited, although, as usual, neither of those two original articles provided any credible evidence for their claims. According to these critics, one megawatt (MW) of solar photovoltaic (solar PV) power requires approximately 2.5 acres, or slightly more than one hectare of land, while nearly 50 acres, or about 20.2 hectares, is required for one megawatt of wind power.

To drive home the fear that renewable energy will gobble up all the land on the planet, the two writers resorted to hyperbole. One wrote, "Now, considering the growth of world energy consumption, which amounts to 2000 terawatt-hours per year, that adds up to 350,000 two-MW wind turbines. Just to meet yearly additional energy needs with wind power would thus require an area the size of the British Isles every year or half of Russia in 50 years."

The second article took a similarly alarmist path, stating, "To replace the total energy (not just electricity) use of the UK with the best available mix of wind, solar and hydroelectricity would require the entire land mass of the country. To do it for Singapore would require the area of 60 Singapores."

To find some reliable figures on the potential footprint of wind and solar power, we turned instead to sources that demonstrate a bit more technical rigor, in particular the University of Michigan Center for Sustainable Systems and the Solar Energy Industries Association, and then checked their information against that of US Department of Energy and the International Energy Agency.

Although there are variations depending on the specific technology used and the location where it is deployed, the consensus rules-of-thumb for planning wind or solar power installations are that one MW of wind power (i.e., in the familiar form of the large horizontal turbine) requires approximately 0.043 hectares of land, or about 430 square meters. A wind farm of about 20 MW capacity, or 10 two-MW turbines, would occupy about 34.4 hectares of land in order to provide sufficient spacing of the turbines, but 99 percent of that land is still usable for other purposes, such as agriculture. In the US, most wind installations are located on private farmland, which provides the landowners with an annual average lease income of about $3,000 per MW while still leaving most of their property available for crops or grazing of livestock.

For utility-scale, ground-mounted solar PV installations, the land use is obviously higher. One MW of capacity would occupy, on average, about 2.43 hectares of land, and unlike wind power, the land cannot be used for other purposes. To put in perspective, enough solar PV power to meet the entire Philippines' electricity demand of 13,104 MW (the peak demand on Monday, July 12) would require about 31,843 hectares, or about 318.43 square kilometers of land - an area about the size of Cebu City, about 0.11 percent of the total land area of the country. If the electricity demand was met by land-based wind power instead, only about 0.08 percent of the country's land would be needed, and again, most of that space could still also be used for farming or other purposes.

Even taking into account growth in electricity demand, land area would be needed for energy storage given the intermittent nature of wind and solar, and space would be occupied by the necessary expansion of the electricity transmission and distribution grids, one archipelago is an entire order of magnitude more space than the Philippines needs to satisfy its energy demand with renewable sources. Keep in mind, this is in an unrealistic hypothetical scenario in which the country would make the highly inefficient choice to use all solar or all wind power; that obviously is not and will not be the case, and therefore, the amount of land required will be even less.

Furthermore, continuous technical developments in both wind and solar power are increasing efficiencies so more energy can be obtained from the same volume of space. Other simple, sensible strategies to make RE even less intrusive can easily be implemented as well, such as substituting many small distributed, "swarm" type solar installations for single large ones, or moving wind power offshore, both of which require precisely zero additional land area.

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Twitter: @benkritz