Arizona Republic; Ryan Randazzo; Oct 15, 2017; photo: Arizona Republic
A Prescott Valley housing development will include 2,900 homes with solar and battery backup systems, Mandalay Homes has announced.
The Jasper development will break ground this year and have models available by September, according to Geoff Ferrell, Mandalay Homes chief technology officer.
The development will be built in phases, including single-family homes, age-restricted areas and rental-style income properties, he said, and all will include rooftop solar and a residential battery system standard. Prices at a nearby Mandalay project run about $336,000 for a three-bedroom, two-bath 2,100-square-foot home.
Sonnen, a Germany company, will supply the batteries and solar, Ferrell said.
Batteries can store energy for ‘on-peak’ use
The batteries will allow customers to store the power from their solar panels made early in the day and use it during “on-peak” hours between 3-8 p.m., when energy prices are higher in the Arizona Public Service Co. territory.
The batteries also will be able to take advantage of lower overnight electricity prices to charge up, Ferrell said.
“What we are trying to do is optimize this for the home to be of maximum benefit to the utility and fiscally to the potential homeowner,” Ferrell said. “We want to make sure installing these in homes standard is not a burden and that the benefit the homeowner will get in terms of a lower month energy bill is a premium.”
Batteries have seen limited use so far in Arizona, although APS has a pilot project testing their use with solar and other technologies that better match a home’s power use with the supply on the grid.
Batteries are widely thought to be the next big development to help spur increased use of rooftop solar because they can make better use of the power that comes from solar.
Solar creates a ‘duck curve’ problem
Solar creates a problem known as the “duck curve” where demand on the power grid rises sharply like a duck’s neck in the late afternoon at the same time solar panels cease production.
MORE: What is the power demand of your home?
The more solar installed on the grid, the sharper the duck curve, and the more need for technology to better align power production and demand.
“This can really start to change the duck-curve issues on the grid that are such a problem today,” Ferrell said. “From 3-8 p.m., what (the utility) needs is for customers to turn things off. That’s what the battery does. It is a repository for that energy all day long, and the homes are so efficient we can tell them to turn off from the grid at 3 p.m. every day and rely on the battery.”
Batteries could work in unison with APS
The batteries will have a capacity of either 8 or 10 kilowatt-hours, he said.
An average-sized air-conditioner can draw 3-4 kilowatts of power, so the battery could supply that appliance for about two hours of use. Because air conditioners cycle on and off, how long the battery could fully power a home would depend how hot it was outside and the thermostat setting, as well as other appliances.
Additionally, Sonnen batteries can link together and could provide additional services for APS by working in unison, he said.
“We would like that partnership and would like to work with them to utilize these batteries to a higher purpose,” he said.
Mandalay has built a conceptual home with the battery system at its Dells community in Prescott.
APS’ program for customers with solar, batteries
APS recently won approval from state regulators to change its rate plans. Among those changes was the creation of a new rate called Saver Choice Tech that will benefit customers with solar and batteries.
The rate rate charges a “demand fee” based on the highest one-hour use of energy during peak hours in the month, but charges less for the total volume of energy used, said Jessica Hobbick, manager of regulatory affairs for APS.
Battery systems will help customers mitigate the demand fee, which was designed to encourage customers to reduce energy use during peak hours, she said.
She said the purpose was to design something that was mutually beneficial to customers and the utility, and to encourage solar installations that better align with the power grid.
Arizona Eco Development, a land-holding company, is developing the Jasper community, which will have an entrance at Santa Fe Loop and Glassford Hill Road.
Mandalay also is planning a similar project in Wickenburg, Ferrell said.
Reach the reporter at 602-444-4331 or ryan.randazzo@arizonare