California’s Energy Supply and Demand

It’s May, and that means it’s the start of Wind Power Season in California. California has worked for years to build a sustainable energy system with solar and wind, and now consumers can start reaping the rewards in terms of air quality, and in terms of lower energy costs. For the year to date, California has curtailed about one-quarter million MegaWatt Hours (MWh) of solar and wind power. If that sounds like a lot, it is and it isn’t. It’s 250 Million kWh of clean energy that could’ve gone into homes like yours if you knew it was there and how to use it. With 11 million homes though, that’s only about 22 kWh per household, or about a day’s worth of electricity for each household. That number will grow each year now, until demand shifts and batteries soak up the good, clean energy.

As California transitions to time of use rates, clean energy costs less and less. Residential customers will transition to time of use rates in 2019, but many can start saving today. Prior to this year, time of use rates offered discounts during the overnight and weekend hours, but these rates have become altered by California’s abundant solar power. California has about 15 gigawatts of solar on both sides of the meter. Now there is a demand spike in the morning, and a larger spike in the afternoon. The size of this spike varies with the seasons. Rates are higher when demand spikes, although current time of use rates only charge more in the afternoon. Electric vehicle owners have even more options with utility rates.

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As the interior of California heats up, it creates a natural phenomena that generates wind power. Cold air along the coast is dense and drawn inland towards less dense hot air.  The state’s wind farms are located in areas optimal for wind power generation and power transmission in this natural system of air movement. Wind power is strongest during this warm season during the afternoon, overnight, and early morning hours. By contrast, wind power tends to die down during the daytime hours, as the heat builds to start the cycle all over again. It’s quite predictable, though weather and electric power demand can lead to electric price fluctuations.

The Wind Number shows you when your power supply is cleaner and costs less. It’s defined as the ratio of power coming from wind over power from fossil fuels, times 100. A Wind Number of 100 means that equal amounts of your power are coming from wind and fossil fuels, which is pretty clean. The Wind Number takes into account both solar and wind, because when it’s sunny, solar power production reduces fossil fuel consumption. Since solar power is cranking when wind power is dropping off in California on most days, the two renewable energy resources balance each other well, but not perfectly. There is that morning peak in demand, and a much larger afternoon peak in demand. This is the time when natural gas peaker plants are cranking up to meet that demand, and when California’s energy supply is dirtiest and most costly.

How Can I Control When I Use Power?

There are a surprising number of ways to change your home’s load for the better. The easiest is to replace your lighting with LED light bulbs. Using the delay button on your dishwasher or clothes washer is another easy thing to do. Own a pool? Try running the pool pump during the early morning hours, or just after the morning peak. If you have air conditioning, you might try raising the temperature a degree or two when that last natural gas peaker plant is cranking up. That’s when energy is dirtiest (usually around 9 pm in the Summer), and you probably won’t even feel a difference in your comfort. Switching your hot water heater, dryer, or cooktop to gas eliminates their electric power demand, and it’s more efficient. If you do have an electric hot water heater, it can be controlled to heat the water off-peak. As we automate with the Internet of Things in our homes, you’ll be able to hit auto and run your appliances, charge your car, or take other measures to increase your clean energy consumption relative to your fossil fuel consumption. That’s the definition of the Wind Number, and if you contact us, we’ll be happy to tell you more ways to save. Clean Energy Costs Less!