Last nuclear plant in California may close

California’s lone nuclear power plant, Diablo Canyon, would close completely by 2025 under a plan announced by Pacific Gas and Electric. Its electricity production would be replaced by sources that do not emit greenhouse gases, The New York Times reports.

Critics of the plant, located in San Luis Obispo, have been pressing for the closure of Diablo Canyon’s two reactors for years because of their location near several underground fault lines and because they use sea water for cooling. One reactor would close in 2024 and the second in 2025 when their operating licenses expire, as long as PG&E wins approval from the State Lands Commission for continued access to the ocean for cooling when the current permit expires in 2018. The proposal also needs approval from the California Public Utilities Commission.

The move comes at a time of diminished importance for nuclear power. A majority of the country’s 99 nuclear reactors are more than 30 years old, and a combination of low natural gas prices and lower demand for electricity in general has made it harder for these older plants to compete in wholesale electricity markets.

New nuclear plants can take decades to design, permit, and build, and aside from a few new reactors in the South there isn’t much on the horizon. Still, nuclear power provides almost 60% of the country’s carbon-free electricity, The Times said, so there are efforts underway to save some operating plants.

California will require that 50% of the electricity utilities provide be from renewable sources by 2030, but PG&E says it will do better than that — 55% of the mix by 2031 — while spending $350 million to help workers affected by the shutdown. Decommissioning the plant, which opened in 1985, will cost an estimated $3.8 billion.

Design competition deadline extended to July 15

Pacific Northwest builder Hammer & Hand is taking entries for its perFORM design competition through July 15, 2016, with $6,000 going to the winning entries.

The competition, now in its third year, is open to architectural students and interns. They will be asked to design a net-zero energy, mixed-use multifamily building in a part of Seattle known as Rainier Beach. The 125-foot by 225-foot site sits next to the Rainier Beach High School track, across the street from a community center.

Despite the local flavor of the competition, Hammer & Hand’s Zack Semke says that it will accept entries from anywhere in the U.S. and Canada and that past winners have come from outside the region.

“When it comes to the climate crisis, buildings have been a problem,” Hammer & Hand’s announcement says. “According to Architecture 2030, nearly half of U.S. CO2 emissions come from buildings, mostly to heat, cool, and power them. But today we have the science, materials, and components to make buildings that can generate more energy than they consume. Buildings can be part of the solution.”

The panel of judges includes Rob Peña of the University of Washington, Mary Johnston of Johnston Architects and president of AIA Seattle, Cory Hawbecker of Holst Architecture, Gladys Ly-Au Young of Sundberg Kennedy Ly-Au Young Architects, Robert Hutchison of Hutchison Architecture, Rick Mohler of Mohler+Ghillino Architects, and Semke.

You can register at the Hammer & Hand website.

Tesla wants to buy SolarCity

Electric vehicle maker Tesla is offering to buy SolarCity, the country’s biggest residential solar installer, for roughly $2.5 billion.

Greentech Media says that Tesla has floated a share price for SolarCity stock of between $26.50 and $28.50. In after-hours trading following the announcement, SolarCity stock rose more than 15% in value while Tesla’s dropped by more than 12%. Shareholders will have to approve the deal once negotiations are complete.

Tesla CEO Elon Musk says that the plan has been in the works for years, and the two companies already are very closely tied. Musk is currently chairman of SolarCity, which is run by his cousin, Lyndon Rive, and there have been a variety of financial dealings between Musk companies and SolarCity.

“We would be the world’s only vertically integrated energy company offering end-to-end clean energy products to our customers,” Tesla says in a news release posted at its website. “This would start with the car that you drive and the energy that you use to charge it, and would extend to how everything else in your home or business is powered.”

Greentech Media’s Stephen Lacey says that the deal would allow Tesla to take advantage of lower share costs for SolarCity — so far they’re down 60% for the year — while potentially giving SolarCity better access to new customers through retail stores. Tesla hinted it would possibly redesign rooftop solar systems to make them more attractive, and the merger also would help SolarCity extend its reach internationally.

But there also are risks, Lacey adds.

“Tesla is already managing a lot,” he says. “It is simultaneously building a massive battery factory, scaling up to meet high demand for the Model 3, attempting to grow its stationary battery business, and expanding into markets all over the world. Buying SolarCity — a company also trying to build its own solar manufacturing facility in New York — adds yet more complexity. Recent experience would suggest this kind of expansion is fraught with risk.”

Nest adds time-of-use option to thermostat

Nest Labs is tweaking the software for its thermostat, adding a “Time of Savings” program to allow owners in some parts of the country to benefit from utility rate plans that base the cost of electricity on the time of day it’s used.

“It’s a shift in the residential space for how people are interacting with energy,” Praveen Subramani, Nest’s head of energy products, told The Washington Post. “So the advantage of Time of Savings is that it helps our customers manage time of use rate plans, and not worry about it. Nest can make all the magic happen in the background without making customers deal with the rates on a daily or seasonal basis.”

In a deal with SolarCity, Nest will offer the Time of Savings plan in California, New York and Arizona, giving SolarCity customers with time-of-use plans a free Nest thermostat and the software that goes with it.

Thermostats with the software will show a green gear icon and a dollar sign in the middle when electricity rates are higher — a signal to the homeowner to turn off or turn down devices that draw power. Significantly, a Nest thermostat also could make changes on its own, turning down air conditioning slightly while the higher rates were in effect, The Post said.

Time-of-use plans are likely to become more common, and customers who don’t know when higher rates kick in, or don’t pay attention, could rack up some very big charges. That’s what makes automated devices like the Nest attractive.

The California Public Utilities Commission has ordered the state’s major utilities to move residential customers to time-of-use (TOU) rates by 2019, Nest said said in a news release. When customers sign up for the Time of Savings plan, their TOU rate information is shared with their Nests, and the thermostats use the information to learn and automatically adjust.

AC temperatures wouldn’t be altered by more than a degree or two, the company said, and customers can always change the temperature at any time.