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Extremely hot places like Phoenix, Arizona, live and die by air conditioning.  As both population and temperatures rise in Sacramento over the coming decades, the region will face a greater demand for cooling both day and night, as Sacramento is one of many cities also experiencing a trend of rising nighttime temperatures.

How can the city hit the A/C sustainably?

More than 90 percent of U.S. cities are already facing increased cooling demands, according to a 2018 Climate Central . With more demand for cooling comes more demand for electricity.

It appears to be an endless cycle: Greenhouse gases from fossil-fuel-based energy create hotter temperatures, which makes people use more energy to keep cool, which creates more greenhouse gases and hotter temperatures. Repeat.

California’s shift to renewable energy aims to help interrupt this cycle. Senate Bill 100 mandates the state supply 100 percent of its electricity with renewable energy by 2045. And this year, the state’s solar power mandate takes effect for new home construction. Those additional sources will be particularly important as hydropower — which is both renewable and the region’s main source of electricity — is expected to decline along with the Sierra snowpack.

Electrified

One of the key ways Sacramento aims to decarbonize the city is to take that renewable energy and electrify homes, buildings and vehicles.

“Going electric is one way to tackle reducing carbon from the built environment,” said Julia Burrows, senior policy advisor to Sacramento’s Mayor Darrell Steinberg. She added that the use of fossil fuels to heat and cool buildings accounts for higher rates of asthma, as well as excess greenhouse gas emissions.

Electrifying the built environment can include heating and cooling, as well as using all-electric appliances like refrigerators, dishwashers and laundry machines. Not to mention cars.

A Honda Fit electric vehicle is charged by renewable energy sources inside the garage of the Honda Smart Home at �°������ϲ���Ļ��Ϣ Davis West Village. (Jason Spyres)

The time-of-use mismatch

Theresa Pistochini is a mechanical engineer at the . A leader in climate-appropriate cooling technologies, the center’s key mission is to accelerate efficient cooling, heating and energy distribution systems.

“The big hurdle is not whether or not we can generate enough electricity to meet heating and cooling demands,” Pistochini said. “It’s can we do it at the right time?”

During the day, sunny California produces a surplus of solar energy, for example. But it is not always available at night, when energy demand is higher. One way utilities manage the mismatch is to raise rates during nighttime “peak load” hours — kind of like an Uber or Lyft driver raising rates during rush hour.

Short of quitting your day job, what can consumers do? A growing number of technological solutions can help people take better advantage of off-peak hours. Pistochini offers some examples:

• Grid-connected thermostats that “tell” you when it’s most cost-effective to cool your home.
• Smart appliances that can, for example, let you program your dishwasher to run at 10 a.m. rather than 6 p.m. during peak demand.
• Cities and municipalities that promote car-charging stations at work can also help alleviate the grid at night.

Kathleen Ave, climate program manager in Energy Research & Development at the Sacramento Municipal Utility District, said the utility is pursuing distributed energy resources as a resilience measure, while also trying to address peak demand issues. She said most utilities do not incorporate climate projections into their load forecasting. SMUD is in the beginning stages of exploring how to do that moving forward.

Preparing for 2100 Now and a Phoenix-Like Future in Sacramento

Earlier in the Becoming Arizona series, we noted the in creating cooler, healthier communities. We also mentioned how the built environment — that troublemaker that created urban heat islands that suck in and retain heat in its pavement and concrete walls — can also be a solution. Cool roofs, cool walls, cool pavements, more vegetation on more plantable surfaces can all help cool a warming city.

“There are three main ways to reduce temperature,” said Stephen Wheeler, a professor of urban design and planning in the . “There’s vegetation, surface materials such as pavement and rooftops, and built form.”

Rethinking built form, which is simply the arrangement of physical buildings on the landscape and roads, can help cool communities and reduce greenhouse gas emissions. For instance, taller buildings can use awnings, courtyards and their own height to create ground-level shade and comfort for residents.