Energy Storage Needs to Think Bigger Than Batteries to Beat Fossil Fuels

Batteries won't be the answer for running renewable energy 24/7.

Travis Hoium
Travis Hoium
Oct 11, 2015 at 11:05AM
Energy, Materials, and Utilities

Energy storage systems like the Tesla Powerpack are great, but they only solve the small problems of renewable energy. Image by the author. 

Wind and solar energy have been gaining ground on fossil fuel competitors like coal and natural gas for a few years now, and in 2014 more new renewable energy capacity was built than all fossil fuel plants combined. But the renewable energy industry is starting to run into some headwinds that could last for years if it doesn't innovate fast enough.

In locations where renewable energy makes financial sense, like sunny southern California or the windy Texas plains, renewable energy has brought on so much supply that the grid can't handle it. The fear is that when the sun goes down or the wind stops blowing it will put a huge stress on the grid, the kind of stress that will be costly to overcome.

Too many renewable energy developers are thinking about small solutions, like battery backup or energy management, as solutions for a large problem the industry faces. If renewable energy wants to be the dominant player in energy, it needs to think bigger than it does today.

Massive solar plants like this one need more than batteries to supply energy at night. Image: SunPower.

Energy storage on a massive scale
Batteries are a great energy storage medium for seconds, minutes, or even a few hours of storage, and those are necessary technologies for keeping the grid running. But for wind or solar energy to play a major role in the grid, the industry needs to find a way to save energy for days, weeks, and months at a time. Maybe hydrogen is the answer to this problem? 

There are options out there, like a wind-to-hydrogen project that I thought could show a path forward for turning renewable energy into a usable fuel and an energy we could use year-round. And the answer to the problem might be easier than we think. 

I recently talked to Graham Cooley, CEO of ITM Power, which is building the renewable energy to hydrogen systems in Europe. He said that a concept called power to gas energy storage is already being used to feed excess wind energy into the natural gas grid to be consumed later. It's energy storage in hydrogen, but using today's infrastructure.

Using the natural gas grid to help renewable energy
It may seem like a crazy idea to pump hydrogen into the natural gas grid, but it's actually been done for over a century. According to a report by the National Renewable Energy Laboratory (NREL) called Blending Hydrogen into Natural Gas Pipeline Networks: A Review of Key Issues, manufactured gas made from coal in the mid-1800s was used to power the gaslight era's street lamps, commercial buildings, and houses. Even today, areas like Honolulu, Hawaii deliver natural gas with "significant hydrogen blends".

Of course, there are limits on how much hydrogen you can put in the gas grid right now. But according to NREL's report, concentrations of 5% to 15% could easily be handled by today's natural gas infrastructure in the U.S. It could then even be used by hydrogen fueling stations to fuel hydrogen vehicles with clean energy.

A big benefit to renewable energy
For renewable energy developers, having a better way to store energy could be a windfall. Recently in Texas, there was so much wind being produced that wind farms actually bid negative prices to feed the grid with electricity. You read that right, wind producers paid utilities to take their energy.  

In places like Southern California and Nevada there's a worry that an overabundance of solar panels could create what's called a duck curve, a lull in demand for non-solar power in the afternoon only to be met by a huge spike in demand when people get home from work. Storing some of that energy in the form of hydrogen could solve some of that problem.

The future of energy storage
Power to gas energy storage could be a solution for renewable energy to create greater value for our energy infrastructure as a whole, but long-term I think the real answer is creating a hydrogen network that can store energy and create electricity when it's needed. Like storing natural gas for use in power plants today, renewable hydrogen could be created and stored for months and used when it's demanded by the market.

That's the best way to a future truly driven by renewable energy. It may seem like a pipe dream today, but don't overlook the potential for hydrogen to play a key role in unlocking the value of renewable energy in the future.