Batteries as America’s Energy Bank


Storage has been in solar news a lot lately. In a post originally published on Mosaic, Bill Ehrlich examines the question facing the industry today: How do we build a safe that can store all the valuable energy we generate from the sun?


This post was originally written by Bill Ehrlich and published on Mosaic.

What do you do with a trillion dollars when you don’t have a safe to store it in? That is essentially the question facing the renewable energy industry right now. How do we build a safe that can store all of this valuable energy? Every day the earth is bathed in enough sunlight to provide more than enough power for our planet. However, without the ability to inexpensively store that energy on-site, the value of the energy is greatly diminished. Energy storage is the next “big thing” in the renewable energy world and is going to change the game not just technologically but from a policy standpoint as well.


A battery by any other name would smell as sweet

The word “battery” comes from early in the history of electrochemical devices when Benjamin Franklin described a series of Leyden jars like a “battery of cannon.” No matter the etymology, the name stuck, almost a little too well. The phrase “energy storage” and the word battery are sometimes treated as synonymous. The battery is not necessarily the singular solution nor the only method of storing energy. Energy can be stored as kinetic energy in a flywheel, as potential energy in a water tower, as heat energy in steam, or as chemical energy in our dear batteries (this is by no means an exhaustive list of possibilities). Despite these other possibilities it appears that the rechargeable battery is rather ideal for many of our current electrical applications.

If I said different, I’d be Li-ion

Given the advances in current battery technology, it looks like Lithium Ion will be the weapon of choice moving forward. Many improvements in Li-ion technology have been driven by the need to power increasingly thinner phones, computers, and other consumer electronics for longer. Anyone who has a smartphone is already using a rechargeable lithium ion battery every day. Lithium ion batteries are also common in power tools that are widely available to consumers as well as standard in the construction industry. In mobile applications that need more power such as electric vehicles, the batteries are not so much BIGGER as much as there are just more of them.

The Electric Kool-Lead Acid Test

The lead-acid battery has been the battery of choice for the past 100 years and still holds the majority of the market share in off-grid renewable energy applications. Lead-acid batteries normally offer the best value for a highly-cycled application, but one of the issues with lead-acid batteries is the maintenance. There are maintenance free lead-acid batteries, but those are utilized more for backup applications than everyday use. Lithium ion batteries are starting to move into this space most notably through a partnership between Tesla Motors and SolarCity. SolarCity is beginning to offer total independence to some of its customers with existing solar installations utilizing the Tesla battery pack for this stationary home application (worth noting is Tesla Motors and SolarCity are both partially owned by Elon Musk). So if you have solar modules on your roof and batteries for back up in the garage, why stay connected to the utility?

Rate Your Utility on a Scale of $.01/kWh to $.10/kWh

Right now utilities make the case that solar customers are still benefitting from the reliability of the grid and that the intermittent electricity generated by solar modules is not worth standard retail rates. This is the utilities “big issue” with the clean energy coming on the grid and they make a reasonable point. What the utilities don’t do is provide an answer as to how they’re going to stay in business once people do not need their service. Essentially, energy back-up shifts the balance of power (quite literally) to the individual or business who can then choose whether or not they would like to be connected to the grid. From here things escalate quickly into virtual utilities and the power utilities becoming like the telecom giants but let’s not mind that for now. Once energy back-up comes standard with every renewable energy application, the value of the energy produced by alternative sources will be worth just as much, if not more, than the standard electricity generated by the utilities.