I’ve been working in solar in Arizona for over 10 years. I have a board certification in photovoltaic technical sales from the North American Board of Certified Energy Practitioners. I have some thoughts about Joy Seitz’s piece, How SRP’s new solar rate proposal could crush solar in Arizona, as it relates to the need for battery adoption in Arizona.
Seitz’s piece about proposed rate structures from Salt River Project and the viability of battery storage did not vibe with my experience as a solar energy professional in Arizona. Utilities in Arizona have been under-compensating solar homeowners for the power they export to the grid for many years now, and it has only gotten worse. Solar power is often exported to the utility when home energy use is low, and solar power production is high, such as midday when sun is at full zenith.
In the evening, solar energy production drops off at the same time that the utilities begin charging their highest prices for on-peak energy (4 to 8 p.m.). Battery systems help to save customers more money because they can store their extra solar energy from earlier in the day, and use that stored solar energy when utility prices are at their highest.
Storing some kWh of energy in a battery can save a solar customer 400% to 1,000% as much as they would save by simply exporting the same amount of kWh energy to the grid for a credit against their bills.
Furthermore, a solar customer that uses their stored solar energy during peak hours will benefit by saving more than just the base cost per kWh that they avoided from their utility, because that customer also avoids the taxes and cost adjusters the utility charges on top of the base energy cost for power that customers pull from the grid.
It is true that batteries degrade over time, but for the most part, that is offset by the rising utility energy cost over time. Most batteries are warrantied to degrade by no more than about 30% in 10 years, or about 3% average per year over that decade.
If a battery degrades by 3% in one year, and the utility on peak energy cost increases by 3% in that same year, the solar customer saves approximately the same amount as they had saved over the previous 12 months by using their battery system to power their home during on peak hours. This is because they are using stored solar energy instead of buying grid power, and they avoid the cost increases associated with that grid power they did not buy.
I appreciate Seitz’s advocacy toward making sure that new proposed SRP rates are structured fairly for all current and future solar customers. However, I believe that batteries are 100% necessary for our state, utilities, businesses and homeowners to fully realize the sustainability, grid stability and savings goals we all hope to achieve.
Solar is only one part of a two-part solution to the problem of rising energy costs and grid instability that we need to address. The combination of solar and battery storage is far more powerful and valuable to utilities, businesses and homeowners than either standalone solar or standalone battery systems alone.
Please send your comments to AzOpinions@iniusa.org. We are committed to publishing a wide variety of reader opinions, as long as they meet our Civility Guidelines.
Share with others
