The world is undergoing a monumental shift to sustainable renewable energy, evolving both in the developed world toward cleaner generation sources and the developing world to broad electrification efforts. Access to electricity and communication will bring significant benefits as a platform for economic growth in developing, rural regions. As costs continue to decrease for solar and wind generation, renewable deployments are increasing worldwide. Yet the inherent intermittency of renewables continues to challenge broader adoption, misaligns supply and demand and causes disruptions to current developed grid environments. Furthermore, in off-grid environments, renewables cannot provide a reliable 24/7 source of energy. Energy Storage provides the ability to capture renewable generation and smoothly deliver when and where needed. Long duration energy storage can solve the problem of solar and wind intermittency and provide reliable electricity without the use of diesel generators, eliminating harmful emissions and lowering costs. Despite a clear need for energy storage solutions to propel the use of renewables, there are several obstacles that need to be addressed.
"Traditional energy storage is unable to adapt to growing energy needs"
Application Variability: The energy storage market needs to address numerous applications from short burst frequency regulation to the transportation sector to longer duration applications required by widespread renewable penetration. To date, most focus has been on shorter duration technologies such as Li-ion and Ultra capacitors. While these technologies are well suited for providing energy from a few seconds up to an hour, other technologies such as flow batteries and metal-air batteries are better suited for longer duration markets as power and energy can be decoupled providing a more optimal solution.
Energy Policy: Current regulation (and compensation) is grounded in the old system of polluting power plants-from the developed world where countries and U.S. states have been slow to adopt incentivizing legislation-to the developing world where countries are still progressing toward open markets for off grid Microgrids. However, in developing countries such as Indonesia, Madagascar, Kenya and Tanzania, there is a growing trend towards decentralization of energy and even governments are leading initiatives for alternate methods of energy generation and distribution.
Economic Disparity: In many parts of the developing world various factors including: the lack of cohesive legislation; inefficient and virtually bankrupt state owned utilities; and the subsequent problems with constructing bankable projects, make it very difficult to bring electricity to regions such as Sub-Saharan Africa where 625M+ people are living without access. Interestingly, ambitious people who live in these regions have started adopting alternate methods such as solar power, high efficiency DC appliances and are even disconnecting themselves from the grid due to frequent power outages and subsequent loss of revenue.
Performance, Theft and Reliability: Shortcomings of traditional battery technologies include negative environmental impacts, safety concerns, high theft, short lifespans and reliability issues, particularly when operating in challenging climates. In many Southeast Asian countries, river bed pollution due to lead based batteries are causing severe health problems. New storage technologies based on Sodium, Zinc and Iron can alleviate these problems and are already being deployed in many of these regions.
Systems Management: Traditional energy storage is unable to adapt to growing energy needs. Most batteries age with time and cannot be increased in size by adding more batteries in parallel due to impedance mismatches. Solutions that are modular, scalable and have easy, inexpensive means to upgrade power/energy over time are critical. Furthermore, smart controls as well as remote monitoring of energy generation, storage and power equipment are essential for reliable distributed energy and power management.
Lifetime and Cost: Most battery technology costs are not commercially viable in long duration applications and lifetimes are short when faced with everyday operating parameters of high temperatures, deep depth of discharges and state of charge limitations. In addition, systems are often oversized to accommodate long runtimes and/or deep discharge needs, adding cost. Raw material cost and ability to use local, simple and inexpensive manufacturing and assembly of battery components can further spur commercial viability and local economic growth. Battery metals such as Zinc, Iron, Aluminum and Sodium are inexpensive, abundantly available on earth, easy to recycle and hence are better suited for providing Giga watt-hours of energy.
With the above issues addressed, the impact of long duration energy storage in the following two major markets will soar.
There are still 1.2 billion people living without electricity globally and Governments, Development Financial Institutions, and aid organizations acknowledge that access to reliable, affordable energy is possibly the most critical factor when it comes to creating a platform for economic growth and empowering individuals and communities. The majority of those without electricity live in rural areas with minimal infrastructure, landscape and climate factors that make access particularly challenging. Renewable and energy storage powered mini-grids may be their first opportunity to join the ranks of those with continuous, reliable and affordable electricity.
To meet 24/7 power needs for these populations, energy storage options must be affordable, safe, limit harmful emissions, minimize theft, provide broad operating temperatures, exhibit long life in real-life conditions, and have the ability to scale with economic and population growth. Also, as sun and wind are intermittent and other forms such as diesel generators are expensive due to the regions being remote, energy storage must be sized to cover extended periods when renewables are unavailable which requires continuous runtimes of 24 - 72 hours.
Since the beginning of 21st century, wireless communication has seen rapid adoption. Today, there are more active mobile phone connections than the world population! However, the telecom market continues to expand globally with much of the growth happening in the developing world where poor-grid or no grid is a way of life. Subscriber growth is centered in developing countries where there are still 3.5 billion people without mobile phones. A recent report commissioned by GSMA Green Power and IFC estimates that over 390,000 off-grid telecom towers will be deployed globally by 2020 and diesel consumption will increase to over 150 million barrels per year leading to over 45 million tons of CO2 release per year. Diesel generators produce polluting gases including CO2, NOx and have high theft value and maintenance costs. It is also difficult to get fuel to remote locations further driving up costs. However, falling prices of solar and energy storage is changing this market rapidly. Renewable power generating sources combined with energy storage are increasingly being used for off grid continuous power for telecommunications.
The environments in the developing world are most often harsh both in their duty cycles and climates, and in remote, difficult to-get-to areas that have high theft frequency, which are nightmares for current storage technologies. An optimal backup solution would overcome these gaps, embodying qualities of low cost, theft resistance, robust operating and performance parameters, and remote monitoring for reliability. As the price of renewables continue to decrease, momentum is increasing for off-grid deployments of renewables (solar, wind) combined with advanced energy storage solutions (Advanced Li-Ion, Zinc-Air).From the developed to the developing world, the global problem and desire is here, now the world is waiting for "how". How do we bring off-grid reliable renewable electricity to 1B+ people when storage is unreliable and expensive? How are we going to continue to realize ambitious renewable targets without wreaking havoc on the grid? The blaring request seems to be the same across these markets: Give me cost-effective, reliable, clean long duration storage!