by Nick B.
Green is in. Green is sexy.
Put solar here, put solar there–plenty of people say this. The solar industry experienced ten consecutive quarters of 1 gigawatt-plus of photovoltaic installations. To put that in perspective, 1 gigawatt of energy is 60% of what the Hoover Dam produces, what 484 wind turbines produce, and what 1.6 millions horses could produce (horsepower), or in more lay terms: a LOT.
Solar Installation numbers courtesy of Greentech Media.
Unfortunately, many people don’t understand that solar is, and should be thought of as, one source of renewable energy generation among plenty. We need numerous energy sources, and we as energy users expect to be able to flip the lights on, turn on the TV, and turn on the hot water whenever we want (or 99.99% of the time).
While solar functions as a way to reduce greenhouse gas (GHG) emissions, solar alone is not reliable enough to be the only source of energy for generating electricity. For one thing, the sun goes down at night, and energy production from solar panels goes down to zero at that point. Also, without adequate energy storage capabilities, solar energy cannot be kept for future usage, and storage technology hasn’t yet been adopted at a high enough rate.
The long-term solution is to have a nice mix of technologies for cleaner energy generation–solar, wind, biomass, geothermal, and water. However, as the transition is being made, people still need reliable energy sources so that flipping on the lights is a sure thing. But don’t just think of people at home turning on lights. Think of grocery stores, hospitals, malls, post offices, etc. Regulators across the country make it clear to energy providers that they must maintain a very high level of reliability and only allow what is basically 24 hours of power outage throughout the year. If today all fossil fuel generation were shut down, there would be chaos since the renewable energy infrastructure still needs to be put online. As seen below…quite literally.
The short-term answer seems to be natural gas–a fossil fuel that is shown to burn less bad (“cleaner”) than coal. The easiest way to explain the challenges of making renewable energy solutions our primary energy sources is the need for “ramping up.” For example, at the snap of a finger, natural gas can be flipped on to provide power. There are still opportunities for improvement to do this with renewables.
Take a look at California’s energy usage throughout a typical day. It looks like and is known as a “duck curve.” Simply put, the duck shape shows how people are mainly using energy at home after they return home from work (cooking dinner, watching TV, turning on the heat/air, etc.). As you can see, energy usage increases significantly during these hours and requires very fast ramping. Looks like a duck, quacks like a duck.
In case you can’t see the duck…try again.
Think about all the things you like to do after you get home from work or school. You are using energy–flipping on lights, charging your phone, cooking dinner, watching TV, turning on the air conditioner, and so on. You and everyone else are doing that, making the duck quack.
Now, solving the duck curve doesn’t meaning killing the duck; it just means we need to flatten out that curve. Flattening the curve lessens the chance of a power outage and ruffling all of your feathers when you can’t go on Facebook, make pizza, and watch cute cat videos because you can’t charge your stuff. Adding more renewable energy sources will effectively level out the ramping energy usage in the evening because it will already be available (via storage and other resources that keep working after sundown and aren’t fossil fuels!). If that works out, the duck will look more docile and less quacky because the line of energy usage will be flatter.
Recap: Green is good, solar will help us get there, but we need to add other stuff (wind, biomass, water, storage) to the mix to get there.