Arizona is the stage for a very important debate at the heart of the solar industry right now, and it could have a big effect on some of the industry’s largest players. Arizona Public Service (APS), the regulated monopoly utility for Arizona, is proposing major changes to the way solar customers are paid for the energy they provide, essentially hoping to upend the net metering that’s led to a residential solar boom.
Net metering is the process of selling extra electricity that solar panels create back to the utility and getting “paid” the same rate you pay for electricity. A customer only pays for the net energy used so, if a customer uses 1,000 kW-hours per month and generates 700 kW-hours of solar power her net bill will be for 300 kW-hours of electricity, no matter when the power is produced or generated.
Utilities, particularly in the southwestern U.S., have started to fight this system, arguing that it doesn’t properly compensate them for grid services supplied to customers and will eventually push grid costs onto those customers without solar. But is that true, and how will this impact investors? Let’s take a look at what we know right now.
Monopoly vs. non-monopolies
Solar power is coming to the grid, no matter what utilities want, and that creates a conflict for monopoly utilities. The cushy business of supplying power at a set return on equity doesn’t require much innovation or adaptation and it’s highly profitable, especially if you can constantly grow your assets. That’s why solar power is so scary. Instead of relying on utility investment in grid and power generation assets, solar allows a customer to own the power-generating assets at home, taking away a potential revenue source.
That’s part of the prism people need to understand when looking at net metering and how utilities around the world view solar. It’s different in regulated markets, where utilities have more incentive to innovate.
Does solar really cost everyone else?
In the abstract, the concept of pushing costs from solar owners to non-solar owners makes sense. Think of an example of a grid with two customers, both using 1,000 kW-hours of electricity per month and regulated rates requiring $200 in revenue for the utility ($0.10 per kW-hr). Without solar the bill for both customers would be $100.
If one of these customers installed solar power that generates 700 kW-hours per month, then the $200 in revenue would be split among the additional 1,300 kW-hours, resulting in a 15.4 cent per kW-hour rate and a $153.85 bill for the non-solar owner. This is the argument APS and other utilities are making against net metering.
Reality, however, is far more complex than this simple example. The biggest reason is that solar panels generate the most power when wholesale power rates are the highest, so solar actually lowers the average cost per kW-hour the utility pays for power by reducing peak demand, at least until solar adoption is too high.
Some will also point to evidence that solar can have an adverse impact on grid prices based on Germany, where solar adoption is the highest in the world and at times can generate 40% of the country’s electricity. Germany’s electricity costs have risen about 4% annually since 2000 and 4.8% over the past two years, largely because of the adoption of solar. This compares to about a 2% increase in electricity costs annually in the U.S.
