Know how to get energy secure with renewable energy storageMarch 10, 2017
Renewable energy is the trend of the day.
From the roof of government buildings. To residential properties. To vast stretches of land. Solar PV materials exist everywhere.
Thus, it does not come as a surprise that India has surpassed its initial target of 1 GW.
Well, why it should not be that way. Solar power generation has a number of merits.
It is available all round the year. Does not gets used up. Moreover, its production does not cost a penny.
These reasons are good enough to overlook the shortcomings of solar power generation.
Not being available in the night. And reduced supply in seasons of monsoons and extreme winter. These 2 reasons make up the pitfalls of going solar.
Why renewable energy storage matters?
Although the power from renewables is perennial. But its stream of supply is inconsistent.
The radiation from the Sun varies as per the seasons. Monsoons and chilling winters have less solar supply vis-a-vis summers.
To optimize the benefits from alternative energy sources. There is a need to store them and then use as per respective requirements.
It is like the local grid or the dams. Both store power which then disperses as per the need.
World Energy Outlook’s (WEO) electrification database figures from 2016. As much as 1.2 billion people do not have access to electricity. That is 16% of the entire global population.
Out of the ones who do not receive electricity. More than 95% belong to the developing nations of Asia and Africa. Within these, more than 80% are in rural regions.
Moreover, out of the ones who do receive power. They suffer from a poor quality supply.
Since most of these places are far flung from the grid. The soon to get over fossil fuel generated power does not fulfill the need. Thus, diesel generated power back-up remains the second option. But the supply of gasoline/ diesel for its operation adds a huge price toll. The expulsion of toxic fumes is an another drawback.
Thus, there is an imminent need for alternative perennial power for these regions. Energy from renewable sources fits the bill perfect in that scenario. Plus, an additional storage system ensures that their stream of supply remains unaltered.
A battery energy storage system ensures 24 x 7 power all round the year. Hence, it is a significant factor for getting an energy independent status.
What constitutes renewable energy storage?
There are various energy storage technologies, each serving various purposes.
The common ones include:
1. Rechargeable batteries
These ones work as accumulators. They gather and store energy through a reversible electrochemical reaction. Various permutations and combinations of electrode and electrolytes result in varied rechargeable batteries.
The common rechargeable batteries include:
- Nickel cadmium (NiCd)
- Nickel metal hydride (NiMH)
- Lithium-ion (Li-ion)
- Lithium ion polymer (Li-ion polymer)
Tesla energy storage systems are the Li-ion ones. This form of storage is ideal for retail applications.
2. Compressed air energy storage
This technology compresses excess energy to compress air. The compressed air is then stored in a reservoir. Then, at the time of electricity crisis. The compressed air then powers respective applications.
From running clocks to locomotives. Compressed air energy storage finds a wide range of industrial uses.
3. Thermal storage
This storage method involves a varied media. That includes:
- water or ice-slush tanks
- masses of native earth or molten salts
- deep aquifers
- shallow pits filled with gravel and water
Solana generating station in Arizona and Andasol Solar power station in Spain. Both use molten salt beds to store power.
4. Superconducting magnetic coils
This storage method supplies energy back up in an instant. It is also capable of providing a high output for short periods of time.
This storage method has a superconducting coil. The coil charges when it stores the energy generated from renewable sources. Stored energy releases to the network as per supply requirements. Thereby discharging the coil.
Limitations of power storage system:
With such features and advantages. It feels strange that the energy storage system is not popular.
The world of renewable energy storage is not all hunky-dory today. Be it due to the initial stages of development. Or because of the absence of large-scale adoption. There exist a few limitations, such as:
1. High price
Price is a major factor because of which the battery storage systems are not popular. For obvious reasons. The Storage systems for industrial uses cost a lot.
Even the rechargeable battery systems for home use are expensive.
300 MWh of their batteries by October 2016
. While the global Solar installations reached 76 GW in 2016.
Thus, in comparison to the number of solar panels installed. The figures of battery storage are minuscule. Do take into consideration that the product comes from the undisputed industry leader.
This analogy presents the wide gap in the renewable energy industry. The solar PV installations and the respective battery add-ons have a huge mismatch.
The prominent battery storage product by Tesla is a lithium-ion one.
As of writing this article. An estimated cost of Powerwall 2 is USD 7000. Although Tesla does not provide an Indian counterpart e-commerce store. But as per math. The conversion would cost somewhere around INR 5,00,000.
This is exorbitant for an average residential household. Thus, the high price is a strong deterrent for less adoption of renewable energy storage.
2. Carbon emissions
This will bring disappointments to someone emotional about their carbon footprints. Rechargeable battery add-ons for storing renewable energy has its share of carbon emissions.
This is counter intuitive to the green intentions of involving solar solutions.
But the disadvantages of a battery backup is not a new concept. Traditional non-rechargeable batteries score higher on the environmental damages. In comparison to them, lithium ones are much benign.
The lithium-ion ones are recyclable. The industry leaders foresee next-gen businesses in recycling them on a large scale.
Moreover, the demerits of environmental damages due to fossil-fueled power are many.
Thus, in comparison to the green benefits of renewable energy. The woes of their storage are few.
3. Energy losses
Solar storage batteries store the excess energy. Thus, lead to energy conservation. That is why it comes as a surprise to know that the storage leads to power losses.
The battery itself requires some energy to brace up for its storage functions. So, it consumes some power while it functions. Thus, losses happen while the storage unit charges and discharges.
This may pinch consumers of locations where local utility charges are high. As these losses imply a loss of money.
The Einstein theory of mass and energy applies to stationary objects. For moving ones, E may not equal to mc^2.
This may provide solace to anyone mulling over the renewable energy storage losses.
Renewable energy storage options are an add-on to the solar power generation process.
They store the energy from the renewable sources. Thus, prove beneficial in times of low supply of energy production. In the context of energy from the Sun. This means having a stored supply of energy in offseasons. That includes the periods of heavy rainfall. Or the seasons when the fog and smog are at peak.
Apart from seasonal disparities. A solar power energy storage system is of immense help for off-grid locations.
About a billion people on Earth do not have an access to a perennial supply of electricity. A huge percentage of these people belong to the developing nations. For obvious reasons. These people are in the rural pockets.
For them, renewable energy storage options are the need of the hour. Although these options may seem exorbitant today. But once economies of scale come into play. The price of the storage options will come down.
The more we embrace these options. The sooner we achieve the goal of holistic development.