Anyone who’s seen the California ISO “Duck Curve” knows south-facing roof-top solar is not particularly good for utilities. The problem, which appears so clearly in the eloquent graph below, is that daily peak continues to grow, so utilities still have to build out new generation, transmission and distribution facilities. But, household solar reduces overall energy sales, and this is where most of the money comes from to pay for the new capacity. Some utilities are referring to this as the “death spiral.”
But the real problem may be in the way that things are done. Right now, it's every man or woman for him or herself.
Most states allow individuals to buy their own solar, and the customer’s net savings – after reducing the electric bill and paying the loan taken out to buy the PV – is small. Consumers are reaping around $20 to $30 per month in savings … or less. Given these numbers, PV owners want maximum energy for maximum savings, and hence they’re aiming their collectors south.
But, that’s not necessarily the right way to do it. In 2013, the Pecan Street Research Institute found that west-facing PV panels produced a 65 percent reduction in peak, versus south-facing panels, which only produced a 54 percent peak reduction.
What’s more, homeowners didn’t sacrifice energy production to have west-facingPV panels that would help their utility level out peaks overall. The Pecan Street researchers found that south-facing systems produced about 35 percent of a home’s daily electricity, while west-facing units produced 37 percent. More power, less peak: I say, go west.
So do two utilities in Arizona. Tucson Electric and Arizona Public Service are now trying to get more people to install west-facing PV system, and they’re even paying customers to do it. This past July, APS installed the first of 1,500 systems it will give away free to homeowners with roofs that have an east-west pitch. The utility installs, owns and maintains the collectors. They pay the home owner $30 a month -- $360 a year – to help the utility manage its peak loads by producing energy just when the utility needs it. Tucson Electric Power has a similar approach.
If you look at this approach and then add Enbala to the mix, there is a good chance that the need for the chemical battery storage will be much less. Because the collectors now help to reduce the peak, the role for a company like Enbala becomes one of firming both real and reactive power on the distribution feeder.
At Enbala, we applaud APS, TEP and other utilities making similar moves because they’re taking the right approach to solar deployment. In most places, utilities work to manage load while solar companies and homeowners install equipment to minimize bills. But, we need everyone working on the same target. In Arizona, the solar collectors, the consumers and the utility are working on the same target: a cleaner energy future. Doesn’t that make good sense?