What’s better for the planet, housing or solar?
Jun 22, 2016

What’s better for the planet, housing or solar?

San Francisco and Santa Monica recently made national headlines by passing legislation requiring solar on all new construction 10 floors or less. Current state law already requires buildings to be “solar ready” by designating zones for future solar, and the state building code calls for new buildings to be Net Zero Energy by 2020.

San Francisco is the largest city to require Solar on new buildings, but it’s not the first. Our own Culver City, where Promise Energy is headquartered, actually passed the first mandatory solar law back in 2008. In 2013, Lancaster in the south and Sebastopol in the north also passed similar solar requirements, and now the big cities are getting in on the action. Santa Monica has actually been working on their solar ordinance longer, and it’s both more aggressive and scheduled to go into effect sooner than San Francisco’s.

But if the goal is to reduce carbon emissions, the question is – which would have the greater impact – requiring solar on new buildings, or simply allowing more buildings in the first place?

We have an enormous housing crisis in California, and studies have shown time and again that urban living has a lower carbon footprint than living in the suburbs and having long commutes. The website Vox points this out, and notes a UCLA study showing that while people in LA use about as much electricity as SF or NY, our GHG emissions are higher due to “widespread use of automobiles.”

Both Santa Monica and San Francisco are notoriously “green”, notoriously expensive, and also notorious for fighting new development. But if cities want to get serious about fighting climate change, then reducing zoning restrictions and increasing density could actually have a bigger impact than requiring solar.

How much bigger?

San Francisco Department of Environment estimated that 200 projects currently under construction would reduce emissions by 26,000 tons per year. And the UCLA study shows people outside urban areas produce 8 to 10 tons more CO2 each year:

So providing housing for 10,000 people in San Francisco would reduce emissions by 80,000 tons per year or more – 3x as many as requiring solar on new buildings.

Put another way, if San Francisco expanded its housing stock by 3000 units a year, that could be equivalent to the reductions from requiring solar on all new buildings.

But new buildings that burn fossil fuels exacerbate climate change just like gas guzzling cars. Even in Los Angeles, greenhouse gas emissions from buildings are higher than from transportation. 39% and 33% of emissions respectively.

So we need both density and sustainability to fight climate change.

If foggy San Francisco can get to 100% renewable energy, then sunny Southern California should be able too as well. And with the CA Energy Commission requiring Net Zero Energy for most buildings by 2020, you can expect to see more cities following suit.

Now if we could only make sure these new solar-powered buildings are affordable as well, then we’d really be getting somewhere!

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