In 2011, California lawmakers set an ambitious target for utilities to generate 33% of the state’s electricity from renewable energy by 2020. At the time that seemed like a lofty goal. But California reached this goal two years early, hitting 34% by the end of 2018. As a result, air pollution is down in most regions of the state, and the state’s greenhouse gas emissions have fallen 14% from their peak in 2004.
Last month at an event near Fresno, former governors Arnold Schwarzenegger and Jerry Brown celebrated the state reaching 1 million solar rooftops on homes and businesses — a goal Schwarzenegger set in 2006.
Today, 6.6% of California homes have solar panels on their roofs, almost of that number were installed in the last 10 years. So what has powered (get it?) this rapid transformation of California’s energy industry? Good government policy, and falling prices. Mass production of solar panels is the biggest reason for the price decline. The average cost of a solar panel has dropped from about $1,000 to about $200. This growth is almost certain to continue to grow significantly for many years to come. Panels and inverters continue to be more powerful and less expensive, and the state's building code continues to require all new homes to be built with solar panels, or to be powered by a larger solar array somewhere else.
The solar industry has historically roughly calculated system cost on a dollar-per-watt basis. In 2001, the average residential system was capable of generating about 4 kilowatts and cost about $40,000. That’s about $10 per watt of rated generation potential. Rebates and tax credits brought the payback down to 7 to 10 years. Today, here in the Santa Rosa area, the average system size is about 7 kilowatts and costs about $25,000, or about $3.50 a watt, with paybacks in the 4-to-8 year range. And for at least the next three years the federal government is rebating a significant portion of that cost.
California has, and will, continue to benefit greatly from using solar for most of its power supply. The high returns and low risk of installing rooftop solar are better than just about any other investment one can make. For example, according to the California Energy Commission, the rule requiring solar to be included on new homes increases the cost of a mortgage by about $40 a month, but will save homeowners an average of $80 a month in energy costs. Solar equipment is reliable, with 25-year warranties. Maintenance is minimal, being little more than washing panels off once or twice a year. The financing mortgage or loan rate is probably fixed, so homeowners can be certain their energy expense is fixed, and far into the future. As a bonus at some point when the loan is paid off the power generated becomes free; while it is safe to predict electric rates will continue to rise into the foreseeable future. Buying solar is like buying an energy futures contract.
This, plus the fact that almost 2/3’s of California’s electricity comes from non-greenhouse gas emitting sources, makes our electricity among the cleanest and greenest in the county. With a solar system, a snug thermal enclosure, and high efficiency electric mechanical systems, it is totally feasible to reduce a home’s operational expense to $10 per month ( the minimum charge to remain connected to the electric grid.) This is a so called Zero Net Energy home. Being now able to have "ZNE" houses makes California’s shift to all electric houses a major greenhouse gas emission reduction measure.
A final word: The big change rapidly headed our way is not just solar power, but a whole suite of energy management items. These can include battery storage, electric vehicles, emergency generation, full electrification of building mechanical systems, and a smart grid, all controlled by an internet linked, smart home energy management system.
Hold on to your seat California. We are in for a wild, but beneficial, energy ride for the next twenty to thirty years.