Energy storage is a topic of great interest throughout our electric-fuel world. Charged batteries are integral to the way we communicate, travel, and function at home and at work. Even as batteries are becoming more efficient, they remain an expensive, high-maintenance power storage solution. Fortunately, most homeowners in PNM territory do not to need to purchase and maintain a battery storage system to complement their solar array. As part of the utility’s basic connection service, PNM banks solar energy for their customers on an ongoing basis.
PNM’s net metering policy allows homeowners with solar arrays under 10kW AC (~41 solar panels) to bank solar energy for later use. For example: Your family leaves home for work and school on the morning of a bright, breezy day in April. While your house is empty, very little energy is consumed, but your solar panel system has its best production day of the year. When your family arrives home in time for dinner, your solar array is most likely still producing enough energy to cover your evening power needs. The energy your solar array produced during the day over and above what is used in your home that day is banked for you by PNM.
For many New Mexican families, this scenario repeats most days in April and often during 3 to 4 other months of the year. At the end of every month, PNM compares how much solar energy your array produced with the total amount of energy used in your home. In mild temperature months, the energy produced will exceed the energy used. PNM will bank that surplus energy to be used as temperatures heat up in months like July, when air conditioning is needed and when hours of high usage may change due to summer schedules. The excess energy produced in the spring can be used to offset potential high summer electricity bills.
The really great news is that PNM performs this service for their solar customers as part of their grid services. All PNM customers pay an $8/month connection fee, and when you go solar, that connection fee becomes the most affordable “battery” in the nation. In contrast, buying an energy storage system for your residential system would cost most homeowners $20,000 – $30,000. PNM is also one of the most reliable utilities in the country, making a home battery system an unnecessary expense for most families.