Solar energy storage is now a reality and it is commonly accepted that photovoltaic (PV) panels will play a key role in providing clean and affordable energy for our planet. However, solar energy does not come without its challenges, not the least of which is the intermittency of the resource. In order to overcome this issue, various forms of energy storage have been proposed and implemented, including pumped-hydro, compressed air, and chemical energy storage, to name just a few. In this report, we will examine one particular solution that has been the subject of much recent attention – solar energy storage via methane production. The following will provide an overview of this technology, including an explanation of how it works and the benefits that it offers compared to other storage methods.
A Brief History Of Solar Energy Storage Via Methane Production
Methane production from solar energy has been the subject of much interest and research for many years, with some even proposing it as a potential source of renewable energy. However, it wasn’t until 2009 that experiments began to confirm the enormous potential of this approach to storing energy. That year, researchers at the National Renewable Energy Laboratory in Colorado successfully demonstrated the viability of this concept and provided a model for how it could be implemented on a mass scale.
The interest in solar energy storage via methane production has since increased significantly, with various research groups across the globe launching pioneering experiments to take the technology to the next level. As these experiments prove, methane production from solar energy is a viable approach to storing renewable energy, and with recent advances in technology, it is now possible to manufacture the equipment needed to make this dream a reality.
How Does It Work?
Methane production from solar energy works on the same basic principle as other types of chemical energy storage. The difference is that instead of storing hydrogen gas, which can be difficult and dangerous to transport and handle, we instead store the chemical energy within a hydrocarbon such as methane. The following diagram provides a simple illustration of how this process works.
When sunlight enters the Earth’s atmosphere and strikes a water molecule, it releases heat which causes that water molecule to split into its two components – oxygen and hydrogen gas. The hydrogen gas can be used by our vehicles or cooked into fuel cell vehicles to power our transportation needs, while the oxygen in the air is harmless and can be safely stored.
Methane production from solar energy works on a similar principle but instead of splitting water, methane-producing bacteria within the soil use the Sun’s energy to split carbon dioxide (CO2) into carbon monoxide (CO) and methane (CH4). CO is the precursor to all forms of carbon and is also a mild greenhouse gas, while CH4 is a more potent greenhouse gas, the main source of which comes from livestock. Since methane is a more potent greenhouse gas, it is preferable to store it rather than CO for energy purposes.
The following video from the National Renewable Energy Laboratory in Colorado provides a clear overview of how solar energy is used to drive a turbine which in turn drives a generator that produces electricity:
The Benefits Of Solar Energy Storage Via Methane Production
Since methane can be stored safely and effectively in vast quantities, it has many advantages compared to other energy storage methods. First, due to its non-toxicity and high volatility, there are few, if any, dangers associated with methane storage. This is in contrast to many other forms of energy storage, such as pumped-hydro or compressed air storage, where there are health and safety concerns surrounding the storage and transport of hydrogen gas. Second, because methane production doesn’t require any moving parts and can be completely automated, the system has low maintenance requirements, meaning it requires very little human intervention to work efficiently. This not only makes the system more affordable, but also increases its available for use since it doesn’t need to be shut down for technical repairs as often as other energy storage approaches do.
One of the main issues with solar energy storage via hydrogen production is that it is difficult to ensure complete safety and security of this type of storage, meaning it requires careful consideration of the location where it will be stored and the people who will have the access to it. Another issue is that the equipment needed to produce hydrogen from solar energy is expensive and not necessarily practical for small-scale applications, which is why many look to methane production as a safer and more affordable option.
While many might see solar energy storage via methane production as a stop-gap measure, meaning it will only serve as a short-term energy solution to address the issue of resource intermittency, others see this as a viable long-term solution to our energy needs due to its abundance and the ease of use and maintenance it offers. We can’t predict the future of solar energy with absolute certainty, but it’s safe to say that as our renewable energy sources get more cost-effective and easy to use, the number of applications for this technology will continue to increase, providing more options for power generation and distribution.