It was a pleasant surprise to see USA TODAY recently gave hundreds of words to the topic of energy storage. It’s not a glamorous topic yet the impact and importance of energy storage in our lives is quickly increasing.
The USA TODAY article linked above focuses heavily on the evolution and future of batteries. Anyone with a portable electronic device like a phone, music player or computer has probably noticed that each successive upgrade offers better battery life.
The article makes the points that storing our excess energy to use later unlocks the potential of renewable energy sources like wind and solar power that aren’t always available. Storing that energy when it’s available could reduce our energy costs and give us greater energy security… if not energy independence. For example, you could store energy from solar panels on the roof of your home to use at night when those panels don’t provide power.
There are also examples for making a better use of our power grid. Many utilities charge more for peak load power – power provided when demand is at its highest. An example of peak load power would be a hot afternoon when most buildings have their normal power consumption plus the power demands of an air conditioner running all the time. With better energy storage solutions we could store power from the power grid at off-peak hours when the rates are lower.
In response to the USA TODAY article, we offer three comments:
1. Batteries Aren’t the Only Way to Store Energy
Energy storage is one of the most exciting emerging technologies because people are figuring out how to use all sorts of methods for storing energy. You may remember from physics class that an object can store energy as a result of its position. For example, when you draw back a bow to shoot an arrow, you’ve loaded the bow with potential energy. Or, if you raise a heavy object, it now has potential energy because gravity will pull it down. Inventors are coming up with alternatives to store our excess energy.
The Tennessee Valley Authority’s Raccoon Mountain Pumped-Storage Plant is an example of a utility-scale way to store energy. The image below shows the reservoir created when the TVA uses excess energy to pump water from the Tennessee River to the top of a hill where it’s stored until the energy is needed.
The Chattanooga Times Free Press has written about the replacement of equipment at the Raccoon Mountain facility. The article includes a very helpful diagram by Laura McNutt that we’ve included below. It shows the tunnels and equipment necessary to make the facility possible.
According to the Chattanooga Times Free Press, the Raccoon Mountain facility can generate 1,652 megawatts per day. The EIA estimates the energy consumption of an average US home at 31.3 kilowatts per day. By our calculations, the stored water at the Raccoon Mountain facility can power approximately 52,723 homes for each day it produces power. That’s a lot of energy!
If you’re like us, when you read about a project like Raccoon Mountain, you’re wondering how much water you’d have to pump up to a tank on your roof to store enough potential energy to power your house. Energy storage solutions on a small or micro scale are making it possible to store energy in our homes.
2. Efficiency is the Key Compliment to Energy Storage
It’s not enough just to figure out how to store enough energy to match our current energy consumption. We should also reduce our energy consumption by making our buildings more efficient with better design, better air conditioning and better insulation. If we’re careful about reducing our consumption and increasing efficiency, we can achieve net-zero buildings – buildings that produce as much energy as they consume.
3. Capital Markets & Competition are Driving Development
The presentations and panel discussions on emerging energy storage solutions were among the most exciting at the Savannah International Clean Energy Conference. Venture capitalists, government representatives and others talked about relatively safe ways to store energy through solutions like compressed air. There are a tremendous number of companies working on various solutions to our energy storage needs. Competition among those companies and innovation in related fields like renewable energy sources haves made the market very dynamic. The upside is that there’s more than one answer to our energy storage needs so we expect many of the companies in the market to be very successful.
Energy storage is a critical part of our daily lives. When your car won’t start or your phone dies, it’s often because you don’t have enough stored energy. The potential for safely storing energy at our homes will have a huge impact on our economy, energy security and other related challenges we’ve been talking about since the 1960’s. We’re optimistic that significantly better energy storage will be one of the most important developments of this decade.
First photo by deanj used under creative commons license. Second photo of Raccoon Mountain Pumped-Storage Plant from the Tennessee Valley Authority. Third image by Laura McNutt of the Chattanooga Times Free Press. You can find more of her work on the newspaper’s website.