Solving Energy Storage, One Appliance At A Time
Renewable energy, especially solar, continues to grow at an exponential pace (solar is the leading source of new power added to the grid in the past year). Yet to fully transition to low carbon energy, we will need a reliable way to store power when these sources are not adequate.
The conventional wisdom for solving this is to build power storage systems that are big enough to power an entire house or an entire neighborhood. This is a valid approach, but it takes time, and more importantly people are reluctant to invest in large scale facilities when the cost of component technologies is declining year over year. Why build a large battery complex today when it will cost half as much to build in a few years?
One solution to this is to embed power storage and management into nearly every appliance. Imagine, for example, that you buy a decorative lamp that has a small battery pack embedded in the base. LED lights consume very little electricity, just a few watts, so a small lithium ion battery back hidden in the base is sufficient to power the light overnight. The incremental cost of the batteries is small, and as an added bonus you now have lights that have built in backup power in case the power goes out. Add circuitry so the lamp can switch to battery while the grid is functioning, and you have the basis for a power management system where the grid can ask appliances to run on battery power when asked to do so.
As a mental exercise, imagine that some 10 years in the future, nearly all consumer appliances are sold with integrated power storage and power management. Instead of relying on the grid as a primary power source, they rely on it as a backup. Your TV for example, would learn that you watch, on average 2.5 hours per day, and would trickle charge throughout the day in anticipation of this. The TV would fall back to grid power when the battery is depleted, not unlike a serial hybrid vehicle, and would recharge when the grid would like it to. Each appliance would individually not store that much power, but multiplied across millions of households, the numbers add up. A TV, for example, might be configured to store around up to a few hundred Watt-hours depending on its power draw when active and the desired all battery runtime. Multiply that across a million households, and that adds up to several hundred megawatt hours of power storage.
You can think of millions of battery equipped appliances as a giant network of batteries that, when needed, can reduce grid demand by using local battery power. In addition to that they draw power from the grid at a constant predictable rate, and if remotely controllable, could be told to charge mostly at times when there is excess power on the grid. The grid itself would become more reliable because most devices connected to it would have integrated backup power. A power outage might disable a few appliances that draw a lot of power (a toaster oven for example), but most would keep on ticking during a power outage.
To give you an idea of how much energy can be stored this way, let’s use TVs in California as an example. California’s population is currently about 40 million people. Let’s assume that there is one television for every two people. As this program is phased in, most of these TVs will have been replaced by ten years from now, for an installed base of 20 million sets, each of which can store 100 to 500 Watt-hours of electricity. That’s 2 billion to 10 billion Watt-hours (2 to 10 Gigawatt hours) of combined storage capacity, comparable to the amount of energy a nuclear power plant generates over the course of several hours. Extend this to many other types of appliances and the combined storage capacity becomes quite large.
What’s especially interesting with this approach is its the sort of thing that can be phased into existing energy efficiency standards, and in such a way that consumers benefit from the transition. The costs of building this would be shared widely, and if needed could be offset with rebates from utilities since they benefit from the build out of grid integrated storage. While grid level infrastructure will still need to be built for power storage, this approach would reduce the need for it.
It’s not a silver bullet, and no single technology will solve every problem, but its a potentially powerful approach to use in the transition to a low carbon energy system.
