Virtual power plant (VPP) projects using home batteries have been launched or extended in Texas, Vermont and California.
VPPs to provide power to ERCOT, Texas grid for first time
Two VPPs using Tesla’s Powerwall home battery product will provide power to the Texas grid, operated by ERCOT, the first time VPP technology has been used on its network.
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They are the first pilot projects in an Aggregate Distributed Energy Resource (ADER) pilot project that the Public Utility Commission of Texas (PUCT) directed ERCOT to begin developing last year.
ADERs can use consumer-owned distributed resources like home batteries, backup generators and controllable electric vehicle (EV) chargers.
A total of eight ADERs have been formed totalling 7.2MW as part of the pilot project – 100kW to 1MW each – and the two using Tesla Powerwalls are the first to have completed testing and are now qualified to participate.
“As generation and distribution technology continues to improve, we expect to see more Texans
taking advantage of these small energy resources in the future,” said ERCOT President and CEO
Pablo Vegas. “This pilot project is an opportunity for us, the electric industry, and participants to
learn how to harness these resources to support reliability in the ERCOT market.”
The PUCT said that the ERCOT, Texas network has around 2.3GW of smaller energy resources such as backup generators, solar panels and battery storage systems, of which 300MW was added in 2023.
The ADER/VPP coordinates the operation of the devices to collectively reduce demand or feed power to the grid in response to instruction from ERCOT.
Vermont lifts cap on home battery programmes
The Vermont Public Utility Commission has lifted caps on how many people can participate in two home battery storage incentive schemes from utility Green Mountain Power (GMP), paving the way for more subsidised deployments.
The Commission lifted the cap in response to a request from GMP in April, following the third devastating storm in the space of three months, in light of growing customer demand, extreme weather and the widespread benefits of home battery storage.
The two programmes are the Powerwall and Bring Your Own Device (BYOD) schemes which were previously capped at 500 customers or about 5MW of energy storage a year. Both subsidise the cost of the battery to the consumer and also involve some level of grid participation.
The Powerwall programme allows customers to lease the EV giant’s residential battery product for US$55 a month while BYOD participants can get up to US$10,500 in incentives for a home battery product of their choice.
The exact amount of the latter is determined by how much storage energy they agreed to share during peak demand periods. Microinverter company Enphase Energy’s home battery product was approved for the scheme last year.
To date, about 2,900 GMP customers have more than 4,800 batteries in their homes, which could mean a total energy storage capacity of around 24MWh based on an average size of 5MWh.
SDG&E launches multi-technology VPP
California utility SDG&E has announced a new VPP pilot programme using a variety of technologies including storage, and revealed it has used the pilot projects three times this month.
It deployed its VPP pilot three times to support the grid during peak demand periods in August, and with performance meeting expectations it is considering expanding the programme to other areas. It used the VPP assets to reduce energy demand and put electricity back on the grid during peak hours
SDG&E added that its VPP pilot is different from most other VPPs which it said typically use one brand or type of device, such as battery storage. The utility said its project uses multiple brands and types of device including smart thermostats, well water controllers, as well as batteries.
The pilot is taking place in the remote Shelter Valley community in eastern San Diego County, including single-family homes with rooftop solar as well as two batteries installed at the Shelter Valley Community Center (pictured above).
