Water consumption, water conservation & Equity

In the month of September 2023, Karnataka saw two Bundhs  on the issue of water sharing with our neighbouring state of Tamil Nadu. With changing rainfall patterns in the coming years, one can only expect more such bundhs and protests.

I have seen this conflict from my primary school days. I have also been learning something called as "Water crisis" from my primary school days which is now under a wider umbrella called “Climate Change”

Over the years, our water consumption is only increasing. Staple diet for most people in Karnataka has slowly moved from Ragi and other millets to Rice (and of course processed foods). More area has come under sugarcane cultivation over the last 30 years. People are buying more food, more clothing and travelling much more. In general, the standard of living has increased multiple fold (It is another debate if that is good or bad).

However, the net water endowment for the country has remained more or less constant notwithstanding climate change.

Let us for a moment leave out politics and take a dispassionate look at the water endowment for our country, its consumption and its distribution.

The design consideration for domestic water supply schemes and housing colonies is what is called ‘LPCD’ or Liters per capita per day. That is the water required for a person for one day. In India, we peg this number to 135 Liters.

Now, if one looks at the number ‘135’, it is the water required per person per day. This is also a legal right of every citizen in India. The breakup of this 135 is given below;

  

USE	LITERS/PERSON/DAY
Drinking	3.00
Cooking	4.00
Bathing	20.00
Flushing	40.00
Washing-clothes	25.00
Washing Utensils	20.00
Gardening	23.00
Total	135.00

 The table above is the water requirement per person per day for a hygienic decent living. It is not in the scope of this article whether this is achieved in India or if these numbers are justified.

For the purpose of analysis let us assume that this number is justified.

However, this 135 LPCD is not the amount of water consumed by a person every day. This is just the “direct” demand or consumption by a person. In other words, this is the water that a person consumes from his or her tap directly every day.

 The “water footprint” of an individual is much higher than 135 Liters a day. We all consume a lot of water indirectly. Our net water footprint is the sum of our direct consumption and indirect consumption.

The food we eat, our clothing, transportation, electricity, consumables, paper, travel, fuel etc have substantial water footprint. This water footprint is rather very difficult to measure or quantify.

Here, I have tried to determine broadly what is the net water endowment available per capita in India. This is an attempt to indirectly determine our water footprint. The below calculations are however broad and general with a few assumptions.

The other motivation for this article is to drive home a point on equitable and sustainable water use and distribution.

At a slightly larger picture, we have the following numbers /Data available for India

•  India’s annual Rainfall + Snowfall run off = 1600 billion cubic meters.
• Assuming 50% reaches the seas, we have the net run off of 800 billion cubic meters. That is 800,000 billion Liters..
• In other words, the annual water endowment to India is 800,000,000,000,000 Liters.
• In India, we extract 250 Cubic kilometers or 250,000 billion Liters of ground water annually. This is more than China and USA combined.
• This 250 Cubic Kilometers is a whopping 250,000,000,000,000 Liters.
• Hence, the total water consumption in India every year is (800+250)=1,050 billion cubic meters or 1050,000,000,000,000 Liters.
• Population of India is 140,000,00,00.00.
• Therefore, annual water consumption in India per person = 1050,000,000,000,000/140,0000000 = 7,50,000.00 Liters.
• This translates to 7,50,000/365 = 2,054.00 Liters per person per day, say 2000 Liters per person per day. (Think about it, the density of water is 1000 kg/m3. Each individual consuming 2,000 Liters of water a day is equivalent to energy of 2000 Kgs. That is 2.0 Tons equivalent. So, an individual of 80 Kgs consumes an energy equivalent of 2000 Kgs, that is more than 20 times his weight every day. A tiger weighing 350 kgs consumes a deer of 40 kgs for 3 days and we call it a Wild Animal!!).
• In other words, If we were to define a index called weight to energy ration;  Weight to energy ration for humans is 1:25 {2000/80}; While for a tiger (Animal); it is 1:0.03 {40/3/350}
•  With 135 LPCD being the direct component, the indirect component of the water footprint is 2,000-135 = 1,865 LPCD say ,1,800 LPCD.

In summary, our water footprint looks like.

1. Direct component (Domestic consumption): 135 LPCD or 7%.
2. Indirect component: 1800 LPCD or 93%.

 As discussed, this 1800 Liters is a combination of water used for food, fuel, consumables, paper etc.

The reason I did this calculation is to drive home the point that we have to look at the larger picture about water conservation than merely looking at taking a bath in half a bucket of water or switching off the tap while brushing, though these are very much required.

All steps taken at the domestic level to conserve water only reduces the direct demand. With best efforts, we may be able to bring our domestic demand from 135 to 100 LPCD. In the larger scheme of things, it translates to about 1.8% which is no doubt significant.

However, we have to look beyond domestic demand and supply calculations for an effective paradigm in sustainable and equitable water distribution.  

Addressing the indirect component of water footprint, we can significantly reduce water consumption and also augment the direct water availability in India. More water available for direct consumption will result in better health and hygiene.

Hence the point I am trying to make here are;

• Mere reduction in consumption of goods and services can bring down water footprint significantly.
• Efficient use of water in manufacturing is the need of the hour. Indiscriminate and unregulated groundwater extraction has resulted in highly inefficient use of water particularly in the textile industry.
• Larger impetus must be given to sustainable agriculture (For example No sugarcane in arid and semi-arid regions).
• Import substitution of certain goods can save plenty of water. (Water footprint in logistics)
• Going vegan twice a month and fasting twice a month is significant water savings.
• Locally grown food consumes far less water. (For Example, in rooftop garden, we are able to pluck out vegetables for a family of 3 every alternate day at a water footprint of 50 liters a day that is 16 LPCD.
•  Rooftop solar is a good way to reduce water footprint. Thermal power plants are water guzzlers.
• One flight less per year is perhaps equivalent to reducing domestic water footprint from 135.0 to 125.0 per day if not more.
•  Reducing leather is another great way to reduce water footprint.

The list can go on. But the point is we have to give more impetus to reducing consumption and switch to sustainable consumption.

Education and practicing water conservation measures at home or office is good and is required but we must also look broader and deeper into water footprint and also focus on structural and fundamental changes to become more sustainable, equitable and self-sufficient is water resources.

Sustainability and Equity:

Now an important question arises on why we must reduce direct or indirect consumption. India’s endowment in terms of rainfall is more or less fixed and it is more or less consistent at 1600 billion cubic meters per year. It is a replenishable resource and does come every year, like it or not.

Though our endowment is by and large consistent , our population is growing. We will need to feed more mouths with less water. Rainfall was 1600 billion cubic meters in 1930 when the population of India (Undivided India) was 40 crores. In 2023 we will have about 140 crore people in India with the same available water.

Here comes the question of equity. Unfortunately, in India the legal right of 135 LPCD is neither achieved nor measured. Even in most urban areas we do not have a supply of 135 LPCD.

With increasing temperatures there is a need to enhance the direct demand from 135 to maybe 200 LPCD.

Though there is no real data on consumption in India, one can be very certain that there is a huge disparity in consumption. In urban places, our water footprint is about 3000 LPCD. To reduce this gap and to be more equitable, reduction in consumption and increasing efficiency is inevitable.

Most importantly, though there is a water endowment , it is not available when we need it . It becomes imperative to conserve the precious resource for the time of need.

The term  'Conspicuous consumption' was first coined by American economist Thorstein Veblen in the late 19th century in the heyday of the Industrial revolution. The term has changed its meaning over the last 120 years to very ugly levels.

Given what the world is going through, it is high time that “Sustainable consumption” makes its way into economies and economic theories for a better and cleaner world.  

Next time we visit an E-commerce website, we must remember that time has come to shift from 'Conspicuous consumption' to 'conscious consumption'.

 

 

Review of Discussion Paper On “Agrivoltaics In India”: Challenges And Opportunities

 

Preamble : 

International Institute for Sustainable Development or IISD issued a discussion paper titled “Agrivoltaics in India: Challenges and Opportunities”.

This background paper assessed the current state of development and identifying the challenges and opportunities for commercialization of agrivoltaics. It reviewed existing literature on agrivoltaics and interviewed 11 experts from power distribution companies (DISCOMs), research institutions and commercial firms who have implemented agrivoltaics pilot projects.

 In the context of “Agri-voltaics”, the discussion paper was shared with me to review and give my comments.

Disclaimer:

The comments and views expressed here are in my personal capacity as an independent practitioner. The views and comments expressed here need not be the same as the institutions i am involved with. The views expressed here are based on studies and experiments conducted by me and may not be universally applicable (or even right). 

Understanding Agri-Voltaics :

The discussion paper discussed various definitions and topologies of Agri-Voltaics. These are mostly based on type of mounting structure.

Comments :

1. All the definitions discussed more or less means the same. That is using the same space for Agricultural activity as well as solar power generation.

2. Rooftop Agri-Voltaics is conspicuously missing in the topologies that are being discussed.

3. Overhead PV : One of the Topologies discussed is “Overhead PV”. Though this sounds like the best fit method for Agri-PV, it may pose many challenges. Here are a few of them. 

1. Over head PV requires very elaborate structural design: Since the height of the structure is long and span (Distance between two columns) is large (for movement of machinery and people) , the structural engineering becomes very specialized .

2.  Difficulty in Maintenance and cleaning : Field data and field experience shows poor and sometimes nil maintenance in standard low height solar structures. Even rooftop solar panels are not cleaned in most cases. When Solar panel cleaning is a challenge even in normal low height structure, How can Cleaning be ensured for tall structure ? In case of Overhead PV, since solar panels are not visible and if the cleaning in not uniform, it may lead  to hot spot formation and quick degradation of the panels .

3.  Availability of water: Solar panel cleaning requires plenty of water . In the context of India, water availability for panel cleaning poses a challenge. More so, in case of Overhead PV, Water will be required to be delivered under high pressure to reach the height. This requires heavy duty pumps and water availability in the aquifers. [In states like Karnataka where power is free for agricultural use, accounting for this power poses a challenge].

4. Quality of water : In many parts of Karnataka, the underground water, particularly in deep confined aquifers , the water quality is a serious challenge . Water from deep aquifers will be generally hard and may not be suitable for panel cleaning. Using hard water for panel cleaning will lead to scaling on the glass leading to degradation. It may be the same case in other parts of India. 

Solutions and opportunities 

While experiments on overhead PV must continue, Cultivation below low height structures and in the peripheral regions of the solar panels presents a good opportunity .

1. Choice of Crop :  Like how there are geographical variations in crops cultivated, there will be and should be variations in crops cultivated under solar panels in different geographies.

Elevating structures for growing crops like millets, paddy and wheat may not justify the cost. It would be better to look at cash crops and vegetables that have higher economic return per acre. 

One can consider Cauliflower or cardamom to be grown under the solar panels. These are high demand, high value crops & at the same time require less sunlight and water.

Another example can be coffee, which likes humidity. This can be grown in the peripheral areas.

Pepper is another crop which can be considered. As a creeper, this can be grown along the structure columns.

Foliage crops like cabbage or lettuce will grow better under solar panels than under full sun. (The plants in the process of seeking sunlight will tend to have broader and greener leaves).

Crops like tomatoes, strawberries which love mild climates will perform better under solar panels .

2. Higher Yield from Solar Panels :  Having vegetation near and below solar panels has a very positive impact on solar panels . Higher moisture and sweating of the leaves cool down the panels increasing the yield.

Below is a case study comparing PV and Agro PV

 3. Rooftop Agro-PV: 

The discussion paper is conspicuously silent in respect to Rooftop PV.  

However, a reference is made under the heading “Intended benefits and potential risks” where it states that , “the availability of land is one of the main constraints faced by developers participating in the PM-KUSUM scheme”.

Rooftop Agri-PV is a good concept which can ease the pressure on the
land. It is expected that by 2050, half the population of the world would be living in urban areas. This would mean a huge pressure on the energy infrastructure as well as agriculture. Rooftop PV can be the answer for both.

Also , many of the challenges in ground mounted Agri-PV can be overcome in rooftop Agri-PV. For
example, the challenges of cleaning or the challenges in safety related to cabling. 

As pointed out in the discussion paper, The primary benefit of agrivoltaics is the “increase in land-use efficiency leading to a higher total output from a given piece of land compared to farming or energy production done in isolation”.

Rooftop Agri-PV is the best bet to achieve this. Both energy efficiency and Agri efficiency is maximum in rooftop Agri PV .

Rooftop Agri-PV also allows maximum flexibility in Agro designs. That is maximum vertical and horizontal space can be used for growing crops which is not quite possible in ground mounted Agro PV set up. 

There are host of other benefits in Rooftop Agro-PV. Circular economy , Rainwater harvesting, Lower carbon footprint, Higher Agro and energy yield to name a few. 

Potential Risks :

The discussion paper has covered a few major risk factors in deployment of Agri-Voltaics . Below are few more risk factors which I feel must be carefully evaluated.

1. Risk of Flooding : 

Deployment of Agro-Voltaics can substantially increase local rea run off and may even lead to flooding.

Below is an example of how setting up Agro PV system will lead to higher Run off

Parameter	Agricultural Land	Agri-PV land
Area	1Acre or 4046 m2	1Acre or 4046 m2
Area Under PV	0 Acres	0.5 Acres or 2023 m2
Run-off Coefficient	0.4	O.4 for Agri land and 0.85 for PV panels
Annual rainfall	500 mm	500 mm
Annual run off	(4046 x 0.4 x 500)= 809 KL	(2023 x 0.4 x 500) + (2023 x 0.85 x500 ) = 1264 KL
Percentage increase in Run off	56 %

 The example above is a conservative estimate with average annual rainfall of 500 mm. Most parts of India receive around 500mm or higher than 500 mm of rainfall. Higher run off also means lesser ground water infiltration. That means more pressure on local aquifer for irrigation and domestic use. 

Opportunity :

Higher run off from Agri-PV lands also means it is an opportunity to harvest the water. Well defined run-off gives an opportunity to contour the land and install recharge wells which can lead to augmentation of ground water. if harvested properly, the same water can be used for irrigation. 

2. Electrical Safety : 

This is perhaps the greatest risk in Agro PV setup. The Energized DC and AC cables pose a serious threat to livestock as well as farm workers. Body grounding from DC cables coupled with moisture around the structure can be very serious.

3. Skill Deficit : 

Agriculture itself is a tough science. PV is also a specialized branch on engineering. Therefore, In India, for scaling up of Agri-voltaics, we need very skilled manpower with experience and expertise in both Agriculture and PV. This is a challenge as well as a huge opportunity. 

Outlook and Concluding Remarks : 

1. Agrivoltaics definitely has a huge potential and is good bet for developing economies like India.
2. Coffee and pepper growers are good starting point for scaling and testing Agri-PV.
3. Development of standards are required.
4. Rooftop Agro-PV systems need more focus and encouragement.
5. Demonstration sites for Land based Agro PV & rooftop Agri-PV is required.
6. Land along the railway lines are good cases for demonstration and popularization of Agri-PV.
7. Practice of Rainwater harvesting should be encouraged along with Agri-PV.
8. Land laws need to be reformed for quick scaling of Agri-PV.
9. Agri-PV must be viewed holistically in the over all context of circular economy and sustainability.
10. Demonstration sites must be small (around 1 Acre) and must be accessible to public. It must be like an experience centre rather than a research project site.
11. Working groups must be encouraged to study successful pilots around the world. 

 

 

1

Environment Action Toolkit ; Part 2

In the last post, I tried to outline the basic toolkit for individuals willing to contribute positively to the environment.

As mentioned in the last post, this is the second out of the three-part series intended for individuals willing to take proactive action towards creating a cleaner and greener environment. 

Part 1 of the series called the Basic toolkit discussed very basic steps that one could start right away without much lifestyle compromises or investment.  

Let us see what are the few more initiatives that one can take as a part of an individual action towards contributing towards the climate cause.

1. Have a White Roof: When sunlight falls on the dark surface like a rooftop, it warms the surface heating the building below. On the other hand, when sunlight falls on a white surface, much of it is reflected back through the atmosphere. So it is not converted into heat. Technically, white surfaces have a higher degree of solar reflectance and emittance. 

Painting the Roof White is Simple, cheap, and Doable.

Advantages of White roofs are 

1. Reduces the energy consumption inside the building. 

2. Increases the Life of the roof. 

3. Increases the rainwater runoff from the roofs. 

4. Reflected Light increases what is called Albedo, slightly increasing the energy input into the solar panels (If present). 

5. Drastically reduces the conversion of light to heat.  

2. Make your Bio-Enzyme: The vim bars and the rin bars that we use daily are some of the reasons for the poor quality of our water bodies. Frothing in the lake, eutrophication of lakes is because of the heavy chemical discharges into the lakes. 

Preventing Industrial effluents and domestic sewage from entering our water bodies may be difficult at the individual level. But one can start from his or her home. Switching to organic locally made soaps and detergents or even better making your own Bio-Enzyme is one of the best ways to stop chemical effluents from entering the water bodies. 

I will not go into details on how to prepare Bio-Enzymes here. It is pretty easy. Hundreds of videos are available on YouTube on how one can make Bio-Enzymes. Making Bio-enzymes at home also reduces the wet waste that one generates and aids in the circular economy. 

Making bio-enzyme is a little time taking and demands some commitment. But it is a wonder material for one's own health and the environment's health. 

3. One tree per Person per year: In my last post, I mentioned having few plants at home. The natural extension is to graduate to a tree. It is said that one person needs seven trees to provide him with adequate oxygen for his living. So it becomes our natural duty to Plant and nurture trees for our own well-being and the well-being of our children. 

A simple way to care for the trees is for everyone to plant at least one tree per year. Many of us may not have or may not find space for planting a tree. We can first start by planting trees on the roadside. Next is the neighbuorhood. One may not find any space anywhere. In that case, a good idea is either to buy or make seed balls and throw them on every patch of soil. The success rate of even 1% is good. 

Many towns have tree clubs that are mostly into organized tree planting. Weekly or monthly programs are organized where volunteers plant hundreds of trees. One can volunteer there or contribute to the cause. 

A small word of caution here. Post pandemic, I have seen many over-enthusiastic folks planting trees on the roadside without any cognizance of the tree species. One must plant native, 'slow-growing trees' that have deep roots and solid girth. So-called fast-growing trees are more a problem than a solution in the long run. 

4. Conserve Rainwater: In my last post, I mentioned the true cost of water and the true energy footprint of water. To reiterate, Sourcing, pumping, filtering, and conveying water is one of the most energy-guzzling and polluting infrastructure activities in the urban scenario. For political reasons, the true cost of this process is never discussed in the public domain. 

So any environment-conscious individual must conserve as much water as possible and augment as must water as possible locally. On the demand side of the water, one must become more efficient by having aerators, water meters, etc. On the Supply-side, harvesting rainwater is one of the simplest ways. In my next post, I will talk more bout rainwater harvesting. Here, it suffices to say that one can start small, as small as keeping the bucket in the rain to save a few drops of water. The joy and the pleasure of harvesting cloud juice will naturally encourage and inspire him or her to take more proactive steps in conserving rainwater. 

5. Stop Using RO water: RO or reverse osmosis is an energy-guzzling and water-wasting process of filtering water. RO is generally used to filter rather; soften the hard water. RO process does not eliminate any bacteriological contamination in the water. 

Wasting water is criminal and RO does exactly that. RO does not just consume excess energy to waste precious water, it also eliminates some of the useful minerals in the water that are very must essential for the human body. 

Before getting into the alternatives for RO, let us first see if we need a RO in the first place at all. If the source of drinking water is river water or shallow aquifer water or tap water through the municipality, it will have hardness much below permissible limits and does not require RO filtration. One can use a simple UV filter (Water passes through the ultraviolet light that destroys micro-organisms) and be done with so-called Filtration.  If one is not sure about the source of water, one can get the water tested (Or buy a TDS meter Which costs about 400 rupees) for hardness and then decide on filtration. {It is important not to be carried away by marketing gimmicks of water purifier companies.} 

RO must be used for filtering water above a TDS (Total dissolved solids) of  800 PPM. For lesser than 800, UF or Ultrafiltration is good enough to treat the TDS. UF does not use electricity or waste any water to treat TDS. (The video here gives some information on different water filtering technologies)

Recently, something called AWG or atmospheric water generators have come into the market. These use the humidity in the atmosphere, condense it to make it into potable water. These are good options in coastal areas. 

6. Switch to Solar water heaters:  Solar water heaters are the best alternative to energy-consuming water heaters. Particularly for a tropical country like India, it makes a lot of environmental and economical sense to use a solar water heater than an electrically powered geyser. 

7. Demand Action: Apart from making changes in one's lifestyle and taking actions at the individual level, one must start by demanding action from political and "religious" leaders on environmental matters. 

As a start, one can start by meeting the local politicians on the issue of tree cover, on the issue of rainwater wastage from streets, on the issue of waste management. Problems solved as locally as possible are good for the government as well as the environment. 

I shall conclude this second part of the toolkit by reiterating again that the most important and most powerful proactive action that one can take is to simply consume less. 

In the next and final part of the toolkit, I shall dwell on the next set of actions that involve some serious lifestyle compromises, a bit of time and financial investment, and a little more commitment towards the environment.