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Product Details
| ISBN-13: | 9781780409436 |
|---|---|
| Publisher: | IWA Publishing |
| Publication date: | 09/15/2018 |
| Pages: | 210 |
| Product dimensions: | 5.50(w) x 8.25(h) x 0.75(d) |
Read an Excerpt
CHAPTER 1
Water and energy – for all
"Before my mother got water every three days. Now she forces me to wash three times a day".
A six-year old boy in Phnom Penh, after water was delivered by piping.
Told by Ek Sonn Chan, General Director Phnom Penh Water Supply Authority, Cambodia.
The aim of this book is to describe how solar photovoltaic (PV) and wind energy have a huge potential to supply clean water for the developing world, in particular in areas with no electric power grid connection. Off-grid technologies can form a significant part of the solution, all the way from household level to village or community level. Small-scale off-grid systems can provide not only lighting but also energy for pumping to gain access to water and for treatment to purify and reuse water.
The cost development of renewable energy has been remarkable and will make electric power affordable even for the poorest. Since 2010, the cost of key energy devices has declined dramatically: LED lighting is 95% cheaper, solar PV 60% and battery storage 75% less expensive. Already today the cost of "new" renewable energy can compete with traditional electrical generation.
Clean water is a matter of life and death. Still, too many people lack this basic need. Lack of electric power for pumping and cleaning contaminated water is one of the missing prerequisites; one person out of seven has no electric power available. We wish to raise awareness of the fact that today there are great and realistic opportunities for those people living outside the electric power grid.
1.1 CLEAN WATER AND ENERGY FOR ALL
The World Economic Forum (WEF) presented its tenth global risk report in 2015 (http://reports.weforum.org/global-risks-2015). For the first time water crises took the top spot among the risks in the report, published by 900 leaders in politics, business and civic life about the world's most critical issues. In 2014 water had ranked third among the most serious threats to business and society. The risks for water crises in the 2015 report were deemed both highly likely and highly devastating. The top ranking of water reflects the growing recognition among world leaders that diminishing supplies of reliable, clean water will be a real threat to health and wealth for the poor, for the richest economies and for the largest cities.
It is also notable that the WEF report reclassified water from an environmental risk to a societal risk. It has been recognised also by world leaders that nearly all human activity – food production, fishing, public health, industrial activities and power production – has water at its base.
Renewable energy technologies can make a major contribution to universal access to both energy and water in a sustainable way. In many regions with energy poverty there are abundant renewable energy sources. There is no lack of sunshine in sub-Saharan Africa or South Asia. In most regions of Africa there are more than 300 days of bright sunlight per year (Varadi et al., 2018). Dry areas like the Sahara and the Sahel region can provide large areas with solar-powered electricity.
In rapidly growing peri-urban areas electric power grids may be available but need to be complemented with decentralised energy sources. Solar and wind can be part of new hybrid energy supplies. It is noted that there is a confluence of factors, such as greater urbanisation, population increase and economic development that will determine the energy mix. The United Nations (UN) Sustainable Development Goals of "clean water" and "energy for all" are strongly related and will depend to a large extent on solar PV and wind. This is further explained in Chapter 3.
1.2 ACCESS TO CLEAN WATER
More than 650 million people lack clean water. Without safe water and sanitation people get caught in a vicious circle of poverty and sickness. In the poorest societies in the world, it is mostly women and children who lose precious time in their search for water and in the transportation thereof. Children die from diarrhoeal diseases that can be prevented. Open sewers running right through villages are far too common.
Water scarcity, poor water quality and inadequate sanitation have a significant impact on food security, educational prospects and other living conditions for poor families across the world. By 2050, the UN estimates that at least one in four people is likely to live in a country affected by chronic or recurring shortages of fresh water. The UN (www.un.org) summarises some of the huge challenges:
• 2.1 billion people lack access to safely managed drinking water services (WHO/UNICEF, 2017);
• 4.5 billion people lack safely managed sanitation services (WHO/UNICEF, 2017);
• 340,000 children under five die every year from diarrhoeal diseases (WHO/UNICEF, 2015);
• Water scarcity already affects four out of every ten people (WHO);
• 80% of wastewater flows back into the ecosystem without being treated or reused (UNESCO, 2017).
It is obvious that water supply and used water treatment need to be addressed simultaneously.
1.3 ACCESS TO ELECTRIC ENERGY
Today around 1,000 million people around the world lack electric power that could enable them to light their homes, cook their food or pump clean water (Jones & Olsson, 2017). Most of them live in rural areas of Africa and developing Asia. Another 1,000 million have unreliable electric power supplies (IEA, 2011). Furthermore, more than three billion rely on solid fuels and kerosene for access to cooking and heating (World Bank, 2017). The indoor and outdoor air pollution from burning wood and other biomass causes more than four million deaths each year.
In sub-Saharan Africa alone, there are about 600 million people without access to electric power, around 57% of the population. Some 80% of these people live in rural areas. Less than 25% of the rural population have electric power. As a comparison 71% of urban residents in these countries have electricity (IEA, 2017b). Like lack of clean water, lack of electricity handcuffs poor families to poverty – especially women and girls, who must gather fuel and carry out the household chores. The good news, however, is that electrification efforts have accelerated so that electric power addition since 2014 is higher than the population growth.
The IEA (International Energy Agency) definition of access to electricity is at the household level and includes a minimum level of electricity consumption, ranging from 250 kWh per household per year in rural areas to 500 kWh in urban settings. The electricity supplied must be affordable and reliable. The initial level of electricity consumption should increase over time, in line with economic development and income levels, reflecting the use of additional energy services. (IEA/India, 2015).
It is well recognised that economic growth is closely related to access to energy. Electric energy consumption in Africa, particularly in sub-Saharan Africa, and in South Asia, is in disturbing contrast to the consumption in high-income countries. In sub-Saharan Africa the annual electric power production averaged 481 kWh/capita in 2012. This should be compared with the OECD average of 7,995 kWh/capita and the global average of 3,126 kWh/capita (Varadi et al., 2018; World Bank, 2014). The contrast becomes even more upsetting when individual countries are compared, as in Figure 1.1. More details are found in Table 1.1 in Varadi et al. (2018), using data from the World Bank. sub-Saharan Africa (SSA) is the only region in the world where per capita access is falling (ibid.). Still it should be recognised that around 150 million sub-Saharan Africans have gained access to electricity since the year 2000 (IRENA (International Renewable Energy Agency), 2016d).
The message from World Bank (2017) is clear: "In many countries with low levels of electrification access, both grid and off-grid solutions are vital for achieving universal electricity access – but they must be supported by an enabling environment with the right policies, institutions, strategic planning, regulations, and incentives."
Access to electric power is extremely important for access to clean water. For people living in remote and rural areas or in rapidly expanding peri-urban areas in poor regions of the world, power grids are out of reach. They cannot wait for conventional electric networks to be completed to solve their water supply or sanitary challenges.
1.4 DECOUPLING WATER FROM ENERGY WITH RENEWABLES
The close dependency between water, energy and food, the water-energy-food nexus, has been recognised for a long time. In my previous book (Olsson, 2015) the couplings and their consequences are described in detail. This book will show how renewable energy in combination with decentralised water operations can decouple many of these dependencies and meet challenges caused by climate change, population increase, water scarcity and poor water quality.
1.4.1 Renewable energy water footprint
Renewable energy can improve energy and water security. The energy sector relies heavily on water for energy extraction and production, accounting for 15% of water withdrawals globally. In a water-constrained world, conflicts with other end uses, such as agriculture, are intensifying and further impacted by climate change. With access to water increasingly recognised as a risk for energy security, it is becoming necessary to decouple energy sector expansion from water use.
Water is needed for fossil fuel extraction, transport and processing. Conventional thermal power plants, like nuclear, natural gas or coal, use huge amounts of water for cooling (Olsson, 2015, Chapter 13). Both water withdrawal and water consumption are significant.
The beauty of renewables is that they dramatically reduce not only the carbon footprint but also the water footprint. Solar PV and wind consume up to 200 times less water than conventional options (IRENA, 2015b). Substantial water savings are already being realised. Solar PV has a very low water footprint since water is not used for electricity generation. The water requirement, estimated at 118 litres/MWh, comes from the manufacturing of the PV cells and maintenance of modules (WEC, 2016, Chapter 8). Wind energy is certainly a low-carbon source, and the turbines have no water requirement during operation.
1.4.2 Small-scale renewables
We will address the key issues – clean water and energy for all – and show the enormous potential of renewable energy, made possible by the technical developments of recent years. Around the world, low-carbon renewable energy is emerging as the go-to-green growth and poverty reduction strategy. The development of inexpensive solar and wind technology is considered a potential alternative, providing an electricity infrastructure consisting of a network of local-grid clusters with distributed electricity generation. This makes it possible to become independent of long-distance, centralised power-delivery systems. The emphasis in this book is to demonstrate how decentralised power from renewable sources and decentralised water supply and used water treatment offer new possibilities and hope for the un-privileged people left outside the advanced systems of today.
Renewables offer viable, affordable and scalable solutions. They are at the core of any strategy to meet climate goals while supporting economic growth, welfare, domestic value creation and employment generation. The potential of renewables is there for every country to harness. A major advantage of solar PV is that there isn't any minimal or maximal project size; it can be scaled to match the user load size and type. Solar PV can be used to power systems from the very small in size up to residential systems and utility-scale projects, ranging from a few kW to several hundred MW. Solar PV is at this moment probably the most attractive option for mini-grids (see also 3.2) for small villages (REN21, 2017a).
Renewable energy delivered by solar photovoltaic (PV) or wind will have a profound impact on water delivery and water treatment over the next decades. Any domestic user will require two kinds of energy: electric energy for illumination, machines, pumps, water treatment units and other equipment and thermal uses of solar energy for (1) process heat (including cooking), (2) ambient comfort, depending on the actual location.
We will describe how three kinds of renewables can satisfy these needs: solar photovoltaic (PV), wind power and solar heating. It should be noted that the direct use of solar energy for cooling via thermal processes has been tested in several situations, but so far it does not work satisfactorily.
Biogas is an important and environmentally friendly source of energy, and many rural areas depend on it. In this book we refer to biogas as a by-product of used water treatment but will not specifically consider the production of biogas as an energy source. We purposefully exclude some energy technologies, like geothermal energy, concentrating solar thermal energy and large-scale wind energy. In fact, the growth of bioenergy, concentrating solar energy and geothermal energy represented only 4% of renewable energy capacity growth in 2016 (IEA, 2017b).
We will show the potential of small-scale solutions that realistically can be used by individual households as well as small villages or a subdivisions of a city. Naturally, small-scale hydro can be considered an alternative energy source. This is already practised in regions with water resources but is not available in water-scarce areas. Regions with water scarcity or insufficient sanitation are certainly not areas where hydropower is an alternative. For the ongoing discussion we will exclude hydropower since our focus will be towards regions with water scarcity.
1.4.3 Providing water using renewables
Water is the critical element for a decent life and sustainable growth. Once the very basic needs connected to electric power are met, such as lighting and low-load production, new avenues open up. Renewable energy technology is already used to meet energy demand in many parts of the water cycle. Solar pumps can provide water for drinking, crop irrigation, increase access to piped water and reduce vulnerability to erratic rainfall patterns, thus increasing yields and incomes.
Renewable energy can also meet energy needs across the water supply chain, including various kinds of treatment such as desalination, water reuse and treatment, thus directly contributing towards access to both water and energy.
An important aspect is that the solar PV system has free "fuel" from the sun, while conventional fuels represent a major share of the operating cost. In many regions in rural Africa and developing Asia there are abundant solar resources. Even taking into account that the energy cost of desalination is relatively high, it is already acknowledged that solar-powered reverse osmosis desalination can produce water at a lower cost than fossil fuels. Likewise, wind power has free "fuel" from the wind. In each individual case it will be determined if wind is a viable complement or replacement for solar PV.
When fuel is free the concept of energy-saving will get another meaning. Having free "fuel" means that as much energy as possible should be extracted for good use. The constraint is the power that will limit the number of appliances, water supply or water cleaning capacity.
1.4.4 Renewables versus nuclear and fossil energy
The interesting aspect of solar PV and wind power is that they are technologies and not fuels. They are unlimited, and the price will decrease as deployment increases. For fossil fuels it is the opposite: the more they are used, the more expensive they become (Wesoff & Lacey, 2017). Of course it should be remembered that fossil fuels have enabled our economy to develop. The message of today is that now there are realistic alternatives for producing energy.
(Continues…)
Excerpted from "Clean Water Using Solar and Wind"
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