Saturday, March 12, 2016

Advanced Energy Storage – Flow Batteries

Innovative energy storage technology for Power Generation Hybrid Systems
can reduce fuel consumption, carbon footprint and total cost of operation up to 50%
-key product differentiators for the fast growing remote telecom towers segment.

Disruptive Technology - Hybrid power generation systems, for the fast growing remote telecom towers segment, will witness disruptive innovations caused by integration with energy storage and renewables by 2020. We have an opportunity to differentiate our product by adopting a superior energy storage technology – Zinc Bromine Flow Battery (pioneered by the Sandia National Labs). Flow batteries are superior to Li-ion and other next-generation storage technologies for long-duration applications. The falling costs of these batteries is expected to carve out a 360 MWh market in 2020, worth $190 million - Zinc bromine (ZnBr) is predicted to become the most competitive flow battery at $391/kWh.

Business case - Secondary market research indicates that, the global telecom industry will deploy by 2020 approximately 390,000 telecom towers that are off-grid and 790,000 that are in bad-grid locations. This is an increase of 22% and 13%, respectively, from today. If these towers continue to use diesel-powered generators:
·         Diesel consumption for telecom towers will increase by 13-15% from today’s levels, to over 150 million barrels per year. The resulting annual cost of diesel will be over US$ 19 billion in 2020, or US$ 5 per mobile-phone user per year.
·         About 45 million tons of CO2 per year will be released, which is more than 5 million tons higher than current levels.
Conversion to more efficient, greener alternative tower power solutions, which include diesel generator-advanced battery and renewable energy hybrid systems, could save the industry US$ 13-14 billion annually. Adoption of these green technologies at scale also has the potential to generate approximately 40 million tons and US$ 100-500 million annually in carbon savings.

Customer benefit - Pairing an energy storage technology and a smart control system with a high efficiency diesel generator produces a wide range of advantages compared to a diesel-only generator – (a) The engine does not have to be running the entire time and when the engine is running, it is at its most efficient rpm, which extends engine life (b) Fuel consumption, TCO and carbon footprint can reduce up to 50% (c) Engine noise is greatly reduced.

Idea in brief - Deploying a hybrid power system that integrates a variable speed diesel DC generator with a superior energy storage system – a Zn Br flow battery - is an extremely energy efficient alternative to using an AC generator operating 24/7, since the generator simultaneously charges the battery and powers the site load. When the battery is fully charged the generator shuts down and the battery takes over as the primary source of power. The generator runtime is reduced to typically four hours per day, with major savings in fuel consumption – usually up to 50% compared with a standard generator. It also reduces CO2 emissions while increasing refuelling and service intervals. A complete hybrid system of this type can be packaged in a compact and light ‘energy container’ to offer a turnkey solution that is quick and easy to install in remote locations.

We will explore the use of flow batteries for automotive application in our next blog :

Automotive - GE built a flow battery that enhance the range of electric vehicles to 240 miles -

India - A team of materials scientists, physicists & chemists at Central Electrochemical Research Institute (CSIR Lab, Karaikudi) lead by Dr Vijayamohanan Pillai has been actively working on Zn - Br redox systems for flow batteries - notable inventions from this group include development of carbon - based electrodes.

Friday, March 11, 2016

Future of Urban Mobility - Key Challenges

This is the first in a series of blog posts on the future of Urban Mobility.
Our ability to ensure clean and convenient mobility in our cities is key to the sustainable growth of our economy. Volatile fuel prices, rising levels of emissions and traffic congestions are the key challenges that we face in most Indian cities today. 
We need the best of our young minds to look at emerging technologies, like smart and connected vehicles, to overcome these challenges. I expect that urban mobility, both personal and commercial, will be shaped by disruptive technologies such as:
the move to on-demand mobility,
the impact of autonomous vehicles and
the growth of electric vehicles
There are three big challenges
Challenge # 1 - How to achieve Zero Vehicular Emission ?

I was in New Delhi during December 2015 for a Conference and the visibility was very poor due to smog even in the middle of the day.

Challenge # 2 - How to achieve Zero Accidents ?

Millions of lives are lost every year due to accidents that can well be avoided  by using connected technology. Millions more are immobilized or severely shocked due to the loss of near and dear ones.

Challenge # 3 - How to achieve Zero Traffic Congestion ?

I lived in Bangalore for the last few year where you can see such traffic jams in every other road. A city like Bangalore cannot sustain its current growth rate unless they figure out a way to remove such traffic congestions and ensure a smooth flow of traffice. I have spent many hours in such traffic jams and I have seen ambulances or fire brigade engines stranded in such situations.
Achieving Zero Emission with Electric Vehicles
Let us look at the Challenge # 1 of reducing vehicular emission to zero, electric vehicles are promising solutions. But if we use electricity derived from fossil fuels too power these electric cars, then we are achieving our objective. Hence we need to define and track emissions across the entire process "Well-to-Wheel"
A zero-emissions vehicle does not emit greenhouse gases from the on board source of power at the point of operation, but a well-to-wheel assessment takes into account the carbon dioxide and other emissions produced during electricity generation, and therefore, the extent of the real benefit depends on the fuel and technology used for electricity generation. From the perspective of a full life cycle analysis, the electricity used to recharge the batteries must be generated from renewable or clean sources such as wind, solar, hydroelectric, or nuclear power for ZEVs to have almost none or zero well-to-wheel emissions. 
Renewable energy sources like solar & wind need to be used to charge the electric vehicles. The cost per watt of solar photovoltaic has reduced by 85 % during 2000 - 2016. The share of solar & wind in global electricity production is expected to rise to 16 %.
In fact, Scientific American published (Nov 2009) a plan to power 100% of the planet with Renewables - authored by #MarkJacobson (Stanford University) and #MarkDelucci (University of California, Davis):
  • The authors’ plan calls for 3.8 million large wind turbines, 90,000 solar plants, and numerous geothermal, tidal and rooftop photovoltaic installations worldwide. 
  • The cost of generating and transmitting power would be less than the projected cost per kilowatt-hour for fossil fuel and nuclear power. 
  • Shortages of a few specialty materials, along with lack of political will, loom as the greatest obstacles.

Now we are talking about electric cars powered by solar photovoltaic - is this a feasible idea ? Elon Musk has looked at this aspect in detail and provides a convincing argument:

Q: How many solar panels do I need to power my Tesla Roadster? 
A: The Tesla Roadster consumes about 200 watt-hours per mile. Suppose you drove 35 miles per day on average (12,775 miles per year). You would need to generate 2.6 MWh/year. By Elon’s math, monocrystalline solar panels generate about 263 kWh/m2/year in the USA. So you would need about 9.7 square meters of solar panels (a square about 10 feet on a side) to completely offset the energy consumed by your Tesla Roadster. Obviously, you can’t fit these on the roof of your car. But you can hire a company like Solar City to install them on your house – where the panels are mounted at the right angle, and are in the shade as little as possible.
Here is a back-of-the-envelop calculation from #ElonMusk
The below results in a payback period of roughly 2 and a half years. The NREL study similarly calculates the payback period for polycrystalline panels to be 3-5 years, and amorphous silicon panels to be 0.5-2 years. Given that most modules have a 25 year warranty and an expected useful life in excess of 30 years, this indicates about a ten to one advantage for energy generated versus consumed.
Taking the monocrystalline silicon example:
Solar incidence (US):1825 kWh/m2/year
Module efficiency:18% (Sunpower)
Energy lost in system:20% (Due to inverter, wires, cell temperature, etc.)
Total energy produced:
263 kWh/m2/year
Energy to create module:600 kWh/m2 (National Renewable Energy Lab.)
… to build aluminum frame:80 kWh/m2 (from Alsema et al)
Total energy used:
680 kWh/m2

Key Takeaway:
Thus an easy way to achieve zero emission from vehicles is to go for electric vehicles that are powered by solar photovoltaics. 
Key Concern - Energy Storage beyond Lithium :
As all renewable sources are intermittent by their very nature, we need energy storage mechanisms in place to ensure continuous supply of power. The current energy storage technology based on lithium ion batteries has many shortcomings and we need to think beyond lithium and explore alternative technologies for future use. But that is a long story and we will save this topic for the next blog post.