This is an age-old question that has been asked as soon as people discovered they could devise machinery to perform work: How can I stop from having to use straw, wood or cow patties to keep this dad-gum machine running?
We have invented materials to assist with friction and reduce weight. We have redesigned machinery to run on different fuels, depending on which one is cheaper. We have re-tooled machines that would typically run on fossil fuels, such as your weed whacker, lawn mower, snow blower, or even your car, to run on electricity. If only someone could figure out perpetual motion so that we did not have to keep adding energy to keep things running.
To tie this all together, energy storage is another piece to the energy efficiency puzzle. Energy storage, when in reference to the electrical grid, is considered by some to be the Holy Grail. Meaning if we could find a way to efficiently store energy and release it when it is needed, we would be able to decrease the need for new generation while maintaining load growth. Essentially focusing our energy delivery to the locations that require it.
To illustrate how we are currently generating and consuming energy, I would encourage you to visualize using a fire hose to fill a shot glass. While it’s an overly simple comparison, the point is that we are not using 100 percent of all the energy we generate. We estimate the need for the energy and ramp up to supply that estimated need. If the imbalance from the power generated to the power being consumed could be saved, we could curtail future generation and save our natural resources. Reading those words almost makes it seem like nirvana.
What is out there?
There are many forms of energy storage available. We have pumped storage in the form of water reservoirs, batteries, fly wheels, geothermal, compressed air, even weighted train cars on tracks. The energy community “jury” is still out on which one of these storage techniques is the right selection, though we have seen pilot installations of each one.
With advancements in chemistry and technology, we are entering a time where it is starting to make sense to deploy storage on our systems. This, along with certain companies such as Solar City and Tesla jumping into the battery space, it appears that batteries are taking the lead. One development that will be interesting to watch is Tesla’s recent announcement of a $5 billion battery plant. According to a recent article by the San Francisco Gate, the factory will have the capacity to double lithium-ion battery production worldwide, and prices are expected to drop by nearly 30 percent, making battery storage even more appealing, at least financially.
How does this affect the current grid operation?
In the Northeast, we are seeing energy storage used to perform frequency regulation. We are seeing states like California install batteries for peak load shaving and renewable energy storage. But, like a computer uninterruptible power supply (UPS), we have a limited discharge, so long-term storage discharge systems still elude us. But for now, we can apply available storage techniques to smooth out the rough edges. A list of applications that come to mind:
- Frequency regulation
- Storm restoration
- Emergency communications
- Large facility back-up
- Renewable integration to smooth outputs
- Peak load shaving
- Residential storage
What does it all mean?
Battery storage is not new. There have been medium-voltage industrial facilities with large UPS systems built over the years using large battery storage techniques. The challenge is that these systems have historically been very expensive and it has been unrealistic to integrate them into the mainstream electric distribution system. Yet we are seeing storage becoming more prevalent, using improved manufacturing methods, advances in chemical and material engineering, and a public request to become more sustainable.
While a national renewable energy policy is great for everyone, utilities will continue to keep our lights on for years to come. I don’t know if we’ll ever see an electricity grid where large swaths of customers are self-sufficient 24/7. What I can say is that our energy system of the future is closer than we think, and I am excited to be part of the solution.