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Science communication is important in today's technologically advanced society. A good part of the adult community is not science saavy and lacks the background to make sense of rapidly changing technology. My blog attempts to help by publishing articles of general interest in an easy to read and understand format without using mathematics. I also give free lectures in community events - you can arrange these by writing to me.

Sunday, 12 November 2017

Solar Energy and Micro Combined Heat and Power Systems Will Bring Energy and Its Related Benefits to Villages in Developing Countries

Energy is the ability of a system to do work. Power is the rate of doing work and is equal to the change in energy per second.  Energy is measured in Joules, Power in Watts.  1 Watt = 1 Joule per second 

Access to energy serves as the base of the pyramid on which foundations of education, health and employment can be built upon.  It provides basic human dignity to people...

Globally, more than 1 billion people have no access to electricity - they are energy-poor and live mostly in Africa and remote rural locations in developing countries.  Energy is potentially available in these places but is not harnessed to benefit the populations.  For example:  Africa has accessible 10,000 GW of solar power, 300 GW of hydro power and 100 GW of wind power (1 GW = 1 billion Watts).  With technological advances, now it is possible to exploit these resources for the benefit of local populations and make a real difference to their lives.

The paradigm shift has been due to:  
(a) the development of renewable energy sources - particularly solar energy - which is now able to provide local, small scale energy generation with a cost that can be equal to or even less than coal and oil produced energy. 
(b)  Light-Emitting Diodes (LED) convert electricity into light with very high efficiency  that is about 12 times better than the old style incandescent light bulbs.  LED also last on average 20 times longer  and do not require frequent replacement.
(c) Battery Storage: Solar energy is only available during daylight hours. New efficient and cheaper batteries now allow storage of extra electricity produced during the day for later use. 
(d) Access to internet in even remote places - this allows great strides to be made in education, business and social inclusion for otherwise isolated populations. 
(e) Micro-grids: Blockchain allows members of a community to reliably sell and buy electricity from each other using micro-grid structures. This provides the possibility of uninterrupted supply at reasonable cost.

I shall look at local power generation where your home essentially becomes a power plant.  With a micro-grid system using some storage batteries and blockchain technology, communities can become independent of the national grid systems which, in a lot of cases, are not fit for purpose anymore and are hugely expensive to modernize. For example, in Puerto Rico, even after a month of Hurricane Maria, 85% of the population has no electricity - a stark example of the failure of centralized power generation and transmission.   National grids are also vulnerable to cyber attacks which can result in power loss for millions of people.
There is a strong case for the adoption of local power generation systems globally - in developed countries too - and I feel that that is the way future will unfold. In some ways they are already here and we shall look at a case study of a mountain village in India where people are already producing their own solar energy that has transformed their lives for the better.

National Power Plants and Distribution Grids:  Globally, energy is produced in big power plants (some supply energy to a million homes) which is then transmitted via a grid system to consumers.  Power plants are expensive to build - cost billions and most plants use fossil fuel that is expensive,  polluting and responsible for much of the recent global warming.  The residential and business consumers may be very far away from the production site and transmission lines (grid) can be very expensive to build and maintain.  Transmission of electricity over large distances causes serious losses of the order of 8 to 10% reducing the overall conversion efficiency of power plants.
Governments have subsidized fossil fuels for a long time and continue to do so.  This has impacted on the development of alternate energy sources like renewable solar and wind energy.  The main advantage that the current power plants have is their ability to produce power continuously and adjust their output to meet the varying demands over the course of a 24 hour day. 
There is much wrong with the aging transmission infrastructure in most countries.  I do not wish to digress here but refer you to many relevant publications (1, 2, 3, 4).
In developing countries, the national grids do not supply the whole countries and many regions are not served.  240 million Indians have no electricity in 2017.  
Extending the grid to full geographic coverage is hugely expensive and not expected to happen any time soon or ever. 

Micro Combined Heat and Power (mCHP) Systems: At times, solar and wind energy generation may have gaps - for example if the weather stays cloudy for an extended period of time or during the rainy season, solar panels will not produce much, if any, electricity.  In these situations, one will need to either connect to the grid (if it is available) or generate energy using conventional fuels like natural gas.  
A small generator system which can supply both heat (for space heating) and electricity (to run home utilities) works on the technology of fuel cells. A good example is the proton-exchange membrane (PEM) fuel cell which can supply 1 to 10 kW with a high efficiency of 90%.  Fuel cells have no moving parts, very quiet and require little or no maintenance. They cost about $450 per kW of installed capacity and last 50,000 hours.   

A mCHP generator may follow heat demand and deliver electricity as a by-product, or may follow electrical demand to generate heat as a by-product - and heat and electricity are produced at the location where they are needed and when they are needed (at times when solar panels output is low).  
In large scale power plants, electricity production efficiency is about 35% and waste heat is generally thrown away.  mCHP can also help to reduce the energy bills by a large amount, is environmentally friendly and provides independence from the grid.  It is expected that mCHP system uptake will be high in developed countries as well where they will replace the conventional methods of space heating.  Batteries to store electricity are now priced so that one can think of installing these to save any excess power generated during the day.  Also electric car batteries will be ideally suited for this purpose and with more households owning electrical vehicles, storage batteries will be readily available.

Microgrids are isolated systems which generate power on-site.  They are insulated from the problems faced by national grids for which in the case of a disaster striking (due to weather, cyberattack, component failure etc.) most consumers will be affected and it can take a long time for the power to be restored.  In microgrids, the damage is limited and most people will continue to have electricity available.   

Solar Energy is Already Making A difference in India:  Jaideep Bansal is a leader in Global Himalayan Expedition - an Indian Social Enterprise working towards providing energy access to remote mountain communities.  India has been able to achieve a smaller price per watt for solar than coal.
Bansal describes how the villagers are using decentralized micro-grids to power up houses with LED lightning technology.  They are able to generate enough electricity with a small solar panel and battery to power up 10 LED lights, one street light, 1 LED TV, 2 fans and mobile-charging points!

Blockchain technology further allows trading of electricity among neighbours.  Blockchain is a new system of carrying out transaction among a group of people.  According to Wiki:

A blockchain can serve as "an open, distributed ledger that can record transactions between two parties efficiently and in a verifiable and permanent way." For use as a distributed ledger, a blockchain is typically managed by a peer-to-peer network collectively adhering to a protocol for validating new blocks. Once recorded, the data in any given block cannot be altered retroactively without the alteration of all subsequent blocks, which requires collusion of the network majority
This is already happening.  I show the next slide which describes Bansal's thoughts on how such trading can proceed:

It is not only in providing energy to communities, solar energy is making a huge impact on other parts of life in developing countries.  The price of solar panels continues to drop and it is hoped that in not too distant future, most of the people in the world will have reliable electricity forming a firm base of the pyramid on which they can build their lives.

I acknowledge some recent publications from the World Economic Forum which encouraged me to write this blog. The publications have been referred to at appropriate places in the text.