The Key to Sustainable Energy: Energy Storage Solutions

One of the biggest criticism on renewable energy is its inability to act as a baseload plant. With the exception of geothermal energy, renewable energy sources such as wind and solar cannot provide power 24/7 and have variable outputs, thus making the task of balancing the supply and demand a tedious one.

This is why we need additional technology to store the energy sourced from renewables. Gladly, scientists discovered energy storage technologies for RE. They have been available for some time now, but with the rise of renewables, their importance is now being emphasized

There are different kinds of technologies for energy storage. The most mature and common energy storage is the pumped hydropower where two reservoirs with different elevation are used to store excess power. Water is pumped to the reservoir with a higher elevation when there is excess hydropower supply. Stored energy is drawn when needed by releasing the stored water into the reservoir with the lower height with the help of turbines.

In the Philippines, the Kalayaan Pump Storage is one such type of storage.  Originally designed for the Bataan Nuclear Power plant, the National Power Corporation in the 1990s expanded the capacity to 600 MW to precisely act as a pump storage. In its design, however, it was not contemplated to store renewable energy. This facility provides ancillary services to the system to regulate voltage and frequency.

There are also other storage technologies available, as well.

For example, thermal storage is used by solar plants where the heat from the sun is stored in molten salts, water or other liquid.  Another storage technology is the compressed air energy storage that compresses air and stored in underground caverns. The compressed air is then drawn from their storage and a combustion turbine is used to fire the air with the help of natural gas to produce power.

At Emerging Power Inc or EPI, we use the multi-hour flywheel battery storage. We are in partnership with California-based company, Amber Kinetics for our power storage needs in our solar power plant. The flywheels serve as the reservoir of significant volume of kinetic energy with the high-speed steel rotors. The fly-wheel batteries have been around for some time, but we chose Amber Kinetics’ technology since it can store and release power for hours unlike other similar technology that works only for some minutes. The pilot model is currently installed in the Subic solar farm.


Flywheel technology by Amber Kinetics at the JSI Subic Solar farm


Recently, the World Economic Forum named battery storage as one of the Top Ten Emerging Technologies of 2016, the advances in technologies that can help improve lives and industries significantly and help protect the environment.  This list includes technologies that have been available for some time but have reached a tipping point, or where the development in such technology is significant and advantageous to many.

Battery storage solutions after all, are on the rise, too. Zinc, aluminum and sodium batteries are being employed to service small areas. For example, Fluidic Energy, a start-up company that specializes in making batteries using air and zinc has already signed a deal with the Indonesian government to help power-up some 500 remote villages using solar power in the country. The firm will provide air batteries that can store as much as 250-megawatt hours of energy. Fluidic Energy, has earlier inked an agreement with the government of Madagascar to help 100 remote villages put up a mini-grid with the aid of their zinc-air batteries.

As we push for more use of RE, we also need to find a way to store harnessed power from renewables and its integration to grids more feasible. And fortunately, various organizations including governments are now heavily involved in research work to find more power storage solutions that will pave the way for a cheaper, greener and cleaner energy consumption.


The Next King

Last year was another spectacular year for solar energy as a total of 73 gigawatts (GW) came online, breaking the record posted in 2015 of 56 GW installed capacity.

China and the United States contributed the most to the high growth of solar power last year as both almost doubled their installed solar power from 2015. China added 34.2 GW from 15 GW in 2015 and the U.S. with 13 GW from 7.3 GW. Other countries also added more power sourced from the sun such as India with 4.2 GW and UK, France and Germany with each adding at least one GW.

Naturally, more employment was generated from solar PV as it provided some 2.8 million full-time equivalent jobs. This figure accounts for one-third of the all the jobs for renewable energy (RE) sector worldwide. In the U.S., solar PV added around 73,000 jobs last year, twice the jobs generated by the coal industry in the country.

Aside from the growth in installed capacity, solar prices dropped significantly, too. The World Economic Forum notes that the price of solar power is currently lower than coal in some 30 countries. Indeed, there has been a continuous decrease in prices of solar power in the last few years as costs have dropped by 62% since 2009 according to the Bloomberg New Energy Finance (BNEF). And many predict that this trend is likely to continue.

Sohail Hasnie, Principal Energy Specialist for Central and West Asia Department of the Asian Development Bank, for one, foresees that global average price of coal would increase to $65- $100 per megawatt hour (MWh) for 2017 from its $60 per MWh. On the other hand, solar prices, he notes are now at $60-70 MWh, and likely to go lower in the next few months as solar energy in some countries were sold at low levels early this year.  Hasnie cites the case of India’s Madhya Pradesh state where solar power was sold was roughly $45 per MWh for 750 MW generated last February.  He believes that prices could drop below $25 per MWh this year in some auctions abroad.


India’s 750 MW solar plant. Photo c/o

Battery storage costs are crucial to the expected price drop in solar PV, Hasnie stresses. He notes that lithium-ion battery prices dropped by 22% last year given the increase of manufacturers and awareness on the technology as the use of battery storage increased to roughly 750 MW globally. Hasnie anticipates that battery prices will likely drop by $75 per kilowatt (KWh) by 2020 from $350 per KWh in 2016.

Hasnie isn’t the only one to make such forecasts. The BNEF sees that solar energy is likely to be the lowest cost option in less than a decade.  The head of solar analysis for BNEF, Jenny Chase predicts that one MW ground-mounted solar system will be around 73 cents per watt by 2025, a 36% drop compared to its current price of $1.14. The BNEF also anticipates battery costs to decrease to roughly $200 per kWh by 2020.

Similarly, the International Energy Agency also predicts that solar generation cost will decrease by 25% in the next five years, and a drop by 65% by 2025 according to the International Renewable Energy Agency.

It looks like solar power would soon dethrone coal as the cheapest source of energy. And if these predictions come true, then we might see solar energy take over coal as the king of the energy mix.

Developing countries such as the Philippines should be sensitive to these developments.  Given our penchant on “quick fixes,” we might miss the boat (again) on this one. Our regulators should realize that the “least cost” in today’s environment takes on a different meaning. As I pointed out in my previous blogs, traditional power planning uses the least cost generation methodology where planners only look at stand-alone costs. The least cost generation method, however, does not compute for the risks involved.

For example, we never thought of Indonesia’s changing rules about exporting coal.  A few years back, Indonesia suddenly decided that it will not allow the export of certain grades of coal.  This led to a much higher cost for coal-fired power plant operators in the Philippines.  One company started to bleed because its ERC-approved formula did not take into consideration the fundamental change in the base prices.

To look at a price without considering risks behind the price can lead us to a completely wrong decision.

The global energy and political leaders should now realize that pushing for solar and other renewable energy sources is not just being good citizens of the planet, but also makes economic sense.


State of Solar 2016: Globally and in Australia. Climate Council