A crucial step to a greener future – Energy storage.

With renewable energy sources growing and wind and solar power generation expanding, we must beg the question what happens when the wind doesn’t blow, or the sun doesn’t shine?

Even while the production of electricity is the single largest source of greenhouse gas emissions, accounting for 25% of all emissions and increasing daily, it is also a significant component of the solution. We can use clean electricity for more than just lighting our houses and running the grid. We'll open up a source of carbon-free energy to help run the industries like manufacturing, transportation, and buildings that are responsible for the remaining 75% of greenhouse gas emissions.

So, what is stopping us?

The challenge is less obvious and more difficult. We will need important breakthroughs in technologies that are going to allow us to supply the power grid with clean energy even during windless days, cloudy weather and nighttime. The sun and wind are incredible energy sources, and although we have ways to store this energy for a couple of hours, we don’t have reliable ways to store renewable energy for days, weeks or months, as we will have to prepare for inevitable seasonal changes (unusual cloud cover for multiple weeks or many windless days) that might be brought on by climate change.

Here are some key areas of innovation:

1. HYDRO

Pumped hydro, which moves water upward to a reservoir using electric motors, is currently the most popular type of energy storage. When water is let out of the reservoir, it flows downhill and uses hydroelectric turbines to produce energy. The problem with this strategy is that it only functions in regions with both high and low elevations, and that energy is lost to elevate the water to another level. A new company by the name of Quidnet Energy is attempting a different strategy that is less expensive and can be constructed in flat places. The Quidnet technology generates enormous pressure by pumping water into subterranean wells using renewable energy. When that energy is required, the pressure is let go, forcing water through a turbine and up a well to produce power.

2. BATTERIES

One of the storage technologies that is expanding the fastest is lithium-ion batteries, like those seen in electric vehicles, mobile phones, and laptops. However, they perform best when used for short-term storage. A business called Form Energy is developing a brand-new category of batteries that would offer long-duration storage at a lower price than lithium ion batteries.

3. THERMAL STORAGE

Technologies for thermal-powered storage have the potential to provide the grid with a versatile and dependable power backup. Melted salt is one of the best places to store heat, an equivalent to a heat pump. In molten salt, renewable energy is stored as heat. When operating in discharge mode, the device functions as a heat engine, turning heat into electricity.

4. ZERO-CARBON FUELS

Other intriguing possible storage options include the usage of zero-carbon fuels generated by solar and wind energy that can be converted back into electricity or utilized to decarbonize other industries.

Yet because the world needs to strike a balance between the need to reduce carbon emissions and economic expansion, we need also think about what solutions would be most cost-effective. According to a recent study by MIT researchers, combining renewable energy with other clean energy sources, such as nuclear power and carbon capture and storage (CCS), could reduce the cost of carbon-free electricity by up to 62 percent. With the production of around 10% of the world's electricity, nuclear power is already a source of carbon-free electricity. In addition, it would be a very dependable source of clean energy to go along with renewables. Yet, the development of nuclear power has been hindered by high costs and safety worries. With advancements in nuclear power, a new generation of nuclear energy might be produced that would be safer, produce less waste, and be more affordable.

Carbon capture, utilization, and storage (CCUS) separates and permanently stores CO2 pollution from an energy plant's exhaust to keep it out of the atmosphere and is another way we can obtain zero-carbon electricity. This technology is particularly crucial in regions with poor prospects for renewable energy sources or where retiring and replacing aging power units would be prohibitively expensive.

SOURCE: Gates, Bill. “A Critical Step to Reduce Climate Change.” Gatesnotes.com, 14 May 2019, https://www.gatesnotes.com/A-critical-step-to-reduce-climate-change.