The oldest wind farm in the United States is in Palm Springs, California. As a kid, I remember seeing it as my family drove along the I-10, surrounded by miles and miles of wind turbines. Even today, their stark white towers and pointed blades seem unnatural against the desert sands — but the strangest thing about them is their size.
These wind turbines are huge. They stand 65 feet tall, with 15-foot blades. They look too large to exist in the mostly empty desert, even from a distance.
Here's how they work: wind naturally flows between the mountains in Palm Springs, allowing wind speeds in the area to reach upwards of 80 miles per hour. That energy is harvested by the wind turbines, which generate enough power for approximately 300,000 homes.
The Challenges Of Storing Renewable Power
Not all cities are graced with the topography of Palm Springs. In fact, even in areas where renewable energy sources are plentiful, one of the biggest obstacles facing energy companies and research laboratories today is where to cheaply and reliably store all of that power. After all, just as the wind doesn’t blow 24/7, the sun doesn’t shine all day. What do we do during the off hours?
Energy storage and renewable power generation are deeply connected issues. On one hand, wind and solar energy are powerful ways to combat our reliance on fossil fuels, and they’ve gained widespread acceptance in recent years (particularly solar — thanks, Elon Musk).
On the other hand, energy storage can be expensive and inefficient due to materials and manufacturing costs. But energy wizards (also known as scientists and engineers) are working on ways to make energy storage both safe and cost-effective for residential and commercial applications — and some of their solutions sound like they were ripped from the pages of a sci-fi book.
Here are the ways we may be storing our power within the next decade:
1. Flow Batteries
Flow batteries are large-scale, rechargeable batteries. They’re composed of two tanks that contain electrolytes. No, not Gatorade electrolytes — we’re talking about chemicals dissolved in liquids, creating a substance that produces electricity once it’s pumped through the flow battery’s core.
The capacity of flow batteries depends on the volume of electrolytes, which means that bigger tanks equal greater energy storage. And while this could mean that house-sized flow batteries may be needed to power a city, the biggest issue with flow batteries is not their size, but their cost.
Most flow battery designs use metal ions, such as vanadium. But metals are tricky because they’re corrosive, and supply is limited. American Vanadium, an energy storage company, recently developed the first domestic vanadium mine in order to keep the price of the metal down.
Other flow battery designs use more sustainable, nontoxic materials, such as the water-based system developed by Harvard scientists and engineers. Michael J. Aziz, the project’s principal investigator, told the Harvard Gazette that the materials “placed in water solution mean that it’s safe — it can’t catch on fire — and that’s huge when you’re storing large amounts of electrical energy anywhere near people.”
Metal-based liquids and water-based solutions for flow batteries have their own set of pros and cons. Water limits the energy density of the battery, and it makes the battery more vulnerable to temperature fluctuations. But in general, flow batteries charge quickly, last for thousands of cycles, and are safer on larger scales because they separate their chemical components.
2. Lithium-Based Batteries
Lithium is the gold standard in renewable energy storage: it creates long-lasting, high energy density batteries with the potential to power large-scale utility grids. Lithium-ion batteries are commonly used in electronics, like your phone and laptop, and they already power electric vehicles like the Tesla Roadster and Nissan Leaf.
However, putting them into bigger applications requires greater energy density than what current models allow. Additionally, cost and safety issues need to be solved before lithium-ion technology can truly power an entire city.
There are various types of lithium battery technology in development, all of which are attempts to make the tech more sustainable and cost-effective. But why bother with all this extra research when we can literally pull solutions out of thin air?
Lithium-air batteries are promising because they use oxygen pulled from the air, a process that translates into energy storage capacities up to ten times more than lithium-ion. In fact, lithium-air batteries have an energy density comparable to that of gasoline — which makes them a realistic option for widespread usage of electric vehicles in the near future.
3. Sodium-Ion Batteries
Sure, lithium-ion batteries are great, but sodium-ion batteries are the cool new kid on the block. These rechargeable metallic batteries use sodium ions to carry an electric charge. They perform better than their lithium-ion counterparts, and they make use of an abundant natural resource: sodium makes up over 2.6 percent of the Earth’s crust. That abundance makes sodium-ion a strong contender in applications like electric vehicle battery research.
Even though cost is the major obstacle holding this technology back from widespread adoption, the Pacific Northwest National Laboratory (PNNL) seeks to fix that issue. PNNL’s research lowers the battery’s problematic operating temperature by using a sodium alloy, as opposed to pure sodium — a switch that can potentially extend the battery’s lifespan to useful levels. The lab’s research is only in the test phases right now, but our fingers are crossed that their research continues to yield great results.
Anything with “ultra” in the name sounds exciting, and UltraBatteries are no exception. An UltraBattery is a mega-hybrid energy storage system that combines ultracapacitor technology with lead-acid battery technology. What does that mean? To illustrate, let’s take a trip to New Mexico.
PNM is the leading electric utility company in New Mexico. They have embarked on a project, called PNM Prosperity, to demonstrate how an energy storage system can seamlessly integrate with a utility grid. In fact, PNM Prosperity is the first solar energy storage facility in the United States to fully integrate into a utility’s power grid.
To accomplish this goal, PNM installed one of the largest combinations of photovoltaic energy and solar panel battery storage in the nation. Their UltraBattery system helps manage energy output fluctuations, which means it smoothes variable power into a consistent, predictable signal.
We know that wind and solar are intermittent energy sources. It isn’t always windy, and it isn’t always sunny. PNM’s UltraBattery deals with this issue by immediately releasing or absorbing extra energy, allowing power to be accessible even during peak times. In short, PNM Prosperity proves how great renewable energy can be on a large scale when it works with an energy storage system — and that proof makes it more likely that other utility companies will follow suit.
Energy Storage Systems Of The Future
Even though wind and solar energy have been getting tons of press in recent years, renewable energy storage is an important piece of the conversation. Without a cost-efficient energy storage method that works on a large scale, we’re missing out on efficiently using all of the energy we’re harvesting from wind farms and solar panels — and that loss is an issue if we want to power the cities of the future.
Whenever I drive through Palm Springs today, I look at the endless miles of wind turbines and feel hopeful. Sure, it might be a while until everyone is driving electric vehicles and everyone’s home is powered by the sun — but in the meantime, those wind turbine blades keep spinning. And that constant push — of energy, research, and innovation — is what will take us toward a greener future.