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New Breakthroughs in Solar's Biggest Problem: Energy Storage

The greatest challenge that solar power faces is energy storage. Solar arrays can only generate power while the sun is out, so they can only be used as a sole source of electricity if they can produce and store enough excess power to cover the times when the sun is hidden.

Traditional batteries have not been up to the task, but recent innovations in energy storage are rapidly resolving the issue. Research is still ongoing, but many of the newest developments have the potential to turn solar power into the dominant source of energy. You think it’s impossible? The IRENA already confirmed in their 2014 report that it is equally, or in many cases, more cost-effective to use alternative energy for power production rather than fossil fuels.

Fractal Circuitry

Nature itself has provided the inspiration for one of the most promising ways to store energy. A team at RMIT University has come up with a new storage method that manages to be about 3000 percent more efficient than traditional batteries. It also has the potential to help with energy capture and storage in a variety of smaller contexts, such as cell phones, watches, and even electric cars. That widespread potential will most likely be enough to ensure that this technology gets all of the support that it needs to mature into a powerful tool.

The new method relies on the combination of a supercapacitor and a powerful new electrode. The supercapacitor works as the gateway to the new system. It can absorb and discharge energy very quickly, but it can’t store very much energy at once. Previously, that meant that they were almost useless for storing solar power. The new electrode fixes that problem. It uses a large set of repeating circuits to hold energy and carry it through the system. The new electrode is a much more efficient form way to store energy than traditional batters, both in terms of cost and space. Combining the two systems creates a system that can hold a huge amount of energy and transmit that energy with high speed and efficiency.

New Batteries

While most research into storing solar power focuses on finding alternatives to batteries, there are some contexts where they remain useful. Most power plants are reluctant to use batteries because they are relatively expensive and take up a lot of space compared to the amount of energy that they store. That prevents them from being viable for large facilities in most cases. On the other hand, those problems aren’t important for private homes. They don’t need to store a huge amount of energy at once, and batteries that are big enough to meet their needs are reasonably affordable. In many cases, the simplicity of using an array of batteries is more valuable than the increased efficiency of other methods.

The new Tesla Powerwall 2 is proof that batteries are strong option for storing domestic solar power. It can store more energy in less space than previous models, so it’s fairly easy to fit it into an existing home. It also includes an inverter, which is necessary to run most appliances on solar power. It doesn’t have quite as much power as most of the alternatives, but it’s more convenient than they are, which encourages adoption on a small scale.

Non-Electric Storage

The easiest way to store solar power is to keep it in a form other than electricity. That’s almost impossible for the average homeowner, but large power plants have been using the method for years.

Pumped storage is the oldest and most popular method. Solar energy is collected and sent out to homes as normal, but the excess is used to pump water up a tower into a storage reservoir. When the plant needs to release more energy, some of the water is allowed to flow down again to spin a turbine. This creates a temporary hydroelectric plant. A similar method uses the excess energy to heat salt, which can be used to create steam to spin the turbine.

These methods are already reliable and reasonably efficient, but they also take expensive infrastructure. That rules them out for most homes, and even for many local governments, but large organizations can build them now to meet the power needs for entire regions.

Solving the Storage Problem

All of these methods can help to make green energy available to more people, but none of them are going to be a solution on their own. They all work best in different situations, and engineers can usually get the best results by matching the storage method to the situation. The best hope for green energy is to use a mixture of these techniques and many others to maximize their efficiency.

Anand Srinivasan's picture

Thank Anand for the Post!

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Discussions

Bob Meinetz's picture
Bob Meinetz on Apr 25, 2017 3:26 pm GMT

Anand, the current generation of traditional lithium-ion batteries is 80-90% efficient. You say new battery technology based on “fractal circuitry” increases battery efficiency by “about 3000%”, do you?

Based on a median value of 85%, that would mean your new technology was 25,500% efficient. Since the maximum efficiency of anything is 100%, either fractal circuitry has disproven the First Law of Thermodynamics, or you are at least 99.6% wrong.

Phrased another way: your comment, like most of those sourced from renewables activism, is about 99.6% stupidity.

Hops Gegangen's picture
Hops Gegangen on Apr 25, 2017 9:17 pm GMT

So he should have said “capacity” … overall, the article shows the potential for break through technologies in the storage area.

Nathan Wilson's picture
Nathan Wilson on Apr 26, 2017 4:08 am GMT

Most power plants are reluctant to use batteries because they are relatively expensive and take up a lot of space …. those problems aren’t important for private homes.

Actually moving unaffordable batteries from the power plant to the home does not suddenly make them affordable. There may be some markets where subsidies and cost-shifting can help to hide the high cost. But it turns out the places with the highest solar penetrations are the first ones to realize that rate reform is needed to stop the cost-shifting.

In places like Nevada and Hawaii, solar PV installers are hoping that batteries can save their failing businesses, but it is only a matter of time before advocates for low income electricity users force government regulators to end the cost-shifting for those systems too.

Utilities around the world have already found a viable solution to the variable output of solar PV systems, and that is to modify their fossil fuel power plants for faster ramping (in the US, we have fast ramping fossil gas plants, and Germany has fast ramping coal plants). This is much cheaper than adding storage (even after batteries become so cheap that most new cars are electric).

So even though solar panel are perceived as green, they simply fit best in a fossil fuel dominated grid.

Darius Bentvels's picture
Darius Bentvels on Apr 26, 2017 1:12 pm GMT

In Germany most house owner who order a rooftop PV-solar installation, also order a battery pack enough to cover their evening & night consumption…

Darius Bentvels's picture
Darius Bentvels on Apr 26, 2017 1:29 pm GMT

Thanks. We need breakthroughs!
So electric bikes & cars can greatly enhance their range.

May be cars towards >1,000miles before recharging…
Which would remove important part of their disadvantage.

Bob Meinetz's picture
Bob Meinetz on Apr 26, 2017 11:56 pm GMT

And when it’s cloudy what do house owner in Germany do, Bas?

Nathan Wilson's picture
Nathan Wilson on Apr 27, 2017 2:35 am GMT

That does not prove the batteries are cost effective for the system. Home batteries basically emulate net-metering, which simply shifts cost to other grid users.

Jarmo Mikkonen's picture
Jarmo Mikkonen on Apr 27, 2017 4:36 am GMT

https://www.pv-magazine.com/2016/02/22/germanys-solarstorage-subsidy-ext...

Actually, it about 1 in 2 new PV systems that also get a subsidized battery pack. The subsidy system ran out of money but now the German government has doled out 30 million euros for it.

A cost effective solution??

Darius Bentvels's picture
Darius Bentvels on Apr 27, 2017 5:38 pm GMT

Nathan,
Your idea ends with the point that customers (households) are obliged to take all their electricity from the utility. So the customer is there to serve the (P&L of) the utility. Just as in Spain nowadays.

Still think that it should be the other way around,

Nathan Wilson's picture
Nathan Wilson on Apr 28, 2017 1:29 am GMT

Of course I agree that the utility should serve the customer. But there is simply no question that customers who buy all of their electricity from a utility (including sustainable electricity) are buying a less expensive product (per kWh) than customers who buy backup service for their home generation. Economies of scale are real, especially at the residential scale.

Therefore it is only fair that backup customers should pay a higher rate (per kWh) than other customers. The opposite is happening in places like California, where backup customers get the same rates (or lower!) than other customers, claiming that they should get the save preferred rate for conserving energy. This is not a scalable billing practice.

Darius Bentvels's picture
Darius Bentvels on Apr 28, 2017 6:56 am GMT

Agree that back-up customers should pay more if they cause higher costs.
Here a friend’s rooftop delivered 3 times more to the utility than he consumed. He switched to another utility as his utility payed only 3cnt/KWh for the extra delivered electricity.

Considering the falling prices for batteries, what is / will be the share of customers who went / will go off-grid buying a battery and an automatic starting small emergency generator (in case of a week without sun, or a fault in the solar installation)?

In most of USA that may soon become a cheaper solution. Will utilities in states like Arizona in 2050 only have a rudimentary grid and generation capacity?

With the high latitude (52°) in NL, that won’t happen soon here as solar production in the winter is so much lower.
My friend had the idea to install a wind turbine on his old farm (no longer in use), so he could go off-grid, but couldn’t pass the NIMBY obstacle.

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