A Vision of Future Cities in India

Cities generate most of the global economy, and most of its energy use, resource demands, and climate emissions. How we build cities over the next decades will largely determine whether we can deliver a bright green future. - Alex Steffen

The expansion of urban areas to accommodate the burgeoning urban population and the rapid development of satellite cities around existing urban centers are presenting significant challenges related to energy consumption, carbon emissions, and environmental degradation. This proliferation of unplanned urbanization threatens to undermine India's objectives concerning emission reduction targets and Sustainable Development Goals (SDGs).

India's SDGs encompass the provision of affordable, reliable, sustainable, and modern energy access for all; the creation of inclusive, safe, resilient, and sustainable cities; and actions to mitigate climate change and its impacts, as outlined by NITI Aayog. According to the Ministry of Statistics And Programme Implementation (MoSPI), India is undergoing an unprecedented pace of urbanization. In 2011, 31% of India's population resided in urban areas, with projections indicating that within the next two to three decades, approximately 50% of India's population will be residing in cities (Census-2011)

Figure 1 Ministry of Statistics and Programme Implementation

India is currently witnessing exponential growth in per capita income, expenditure, and energy demand. This growth, coupled with urbanization, constitutes a significant aspect that must be carefully considered for future development endeavors. To effectively address this trajectory, future cities must be equipped to accommodate the escalating demand, a feat achievable through the integration of sustainability principles across all facets of city planning and operation.

The scientific community, actively engaged in climate change research, plays a pivotal role in advising and assisting the government in strategic policy formulation for forthcoming urban landscapes. Continuous efforts are underway to advance sustainable and climate-resilient solutions, aimed at enhancing resource efficiency and ameliorating the micro and macro climates of urban areas. Over the past few decades, numerous formal assemblies of scientists, professionals, policymakers, and government officials have convened to deliberate on climate change issues and chart the country's course towards sustainable development.

Initiatives such as Climate Resilient Cities, Smart Cities, and Solar Cities stem from these productive discussions, propelled by organizations advocating for climate action and subsequently endorsed and implemented by the government to prepare for the future urban milieu. Energy access emerges as a critical concern amidst escalating energy demands. According to the Ministry of Statistics and Programme Implementation (MoSPI), per capita energy consumption has surged by 50% over the past decade, underscoring the urgency of proactive measures in this domain.

Figure 2 Energy Statistics 2016 MoSPI

The energy-access problem statement encompasses three dimensions: demand, supply, and environmental impact. Future cities must aspire to be both energy efficient and energy sufficient, leveraging internal resources to meet demand without burdening areas beyond city boundaries. These cities, characterized by resource neutrality and carbon neutrality, will generate their own energy sustainably, thereby minimizing environmental impact.

Renewable resources will serve as the cornerstone of future city energy portfolios. Conventional power plants will transition from baseload operations to variable output, with city-level smart distribution networks dynamically balancing supply and demand in real time. India's action plan for renewable energy, exemplified by initiatives like the National Solar Mission and the Solar Cities program, underscores the country's commitment to this transformative trajectory. Primary energy resources will include solar, wind, biomass, and geothermal energy, with secondary resources such as bio-waste and waste heat also contributing.

Reports such as “100% Renewable Energy by 2050” suggest that India has the potential to achieve full renewable energy reliance by 2050, coupled with aggressive energy efficiency measures capable of yielding substantial demand savings. The transition to renewable energy sources promises enhanced economic viability.

Future cities will feature advanced transportation models predominantly powered by electricity and clean fuels, thereby reducing reliance on traditional automobile-based networks. Underground rail networks, complemented by pedestrian and bicycle-friendly city roads, represent a promising alternative. Policy initiatives promoting electric vehicles signal significant progress towards this vision.

India's recent Smart Cities program aims to transform existing and new cities into forward-looking urban centers. These smart cities, characterized by integrated IT systems, will enable seamless and efficient operation, offering a glimpse into the future of urban living.

The realization of smart cities hinges on the readiness and education of their inhabitants. As first-generation smart citizens, it is incumbent upon us to prepare ourselves and future generations for the transition to these futuristic urban environments, ensuring a smooth and sustainable evolution of our built environment.

Solar Assisted Thermal Cooling System

A thermal cooling system i.e Vapor absorption machine or absorption chiller is quite an old and proven technology. unlike conventional refrigeration system, an absorption cycle operates on low-grade energy (heat) to produce the cooling effect.

with the recent development in solar thermal collector design, it has become possible to harness and deliver enough heat energy through a solar collector to power an absorption chiller. A typical hot water fired liquid absorption chiller require hot water at the temperatures of 80 to 90 deg Celsius, which can be easily achieved through an evacuated tube or a parabolic trough collector.


A typical solar assisted thermal cooling system design may be divided into three stages

1. chiller sizing or Heat load assessment
2. selection of appropriate absorption machine to meet heat load [ keeping a note on the input hot water requirement]
3. Selection of solar thermal technology and sizing the collector.  (based on hot water  temperature and flow rate requirements of absorption machine)


Although small size thermal cooling systems are not available in the market yet, if a cost-effective packaged consumer product can be developed, it would become a great option for composite and hot & dry climates where both cooling and hot water are required in different seasons.

Success Stories:

India’s Largest Solar HVAC System With Storage developed by Clique Solar Inaugurated at NTPC Energy Technology Research Alliance

Solar thermal based Air-Conditioning System proves itself in India

Crow Canyon Medical Center, Danville California

Santa Clara University Benson Center, California

Net Metering for Solar Power

Recently Delhi has announced its net metering policy for solar pv systems. This was a long awaited move since many states has come up with the policy already.
Though this post is not about the policy review nor about the net metering system but something basic about the interaction of solar generated power with grid.

what i had learned in theory says that the power producer produces power as per demand forecast and only required amount of electricity is fed into the grid thus maintaining the grid stability.
But when it comes to the net metering, the power producer feeds the power which remain surplus after self consumption. And i see no reason that this surplus amount is or can be fore casted. So the question is that
Why the solar generators connected through net metering does not affect the grid electricity?

The answer that i had formulated is (and i am not sure that i am right or not here)

well it does affect the grid stability and grid relay on the solar inverter to maintain the grid stability, and that's the reason the solar inverter is required to monitor the grid parameter
This is what i think what happens here
# When the load on the grid is less the frequency goes up and when the frequency goes up beyond the certain limit(say 3%) the solar inverter trips the power generation
# when there is very high load on the grid ? well in that case the grid will shut off (the transformer will trip) in order to prevent the grid from any damage. and when the grid is down the solar inverter will also trip to prevent the icelanding effect.

Inverter AC: The future of HVAC industry

The time has far gone when the AC was considered a luxury, today AC is as much as a need as an smartphone ah! maybe less then a smart phone bu...t; nerveless  nobody can deny that the AC has become a necessity. 

With increasing use of AC's the need of energy efficient systems is also arising which drive the research community and market both into some real  R&D work and we may safely presume that inverter technology is the outcome of some serious R&D stuff.

What really is an inverter AC and why its more efficient?

An inverter AC is an AC which obviously and essentially contains an inverter which control the speed of compressor in accordance to the varying load conditions.

NO the inverter AC is not more efficient, it's just save some power And the third affinity law explain the power saving property of the system witch says

power is proportional to the change in speed cubed

In an inverter Air Conditioner, compressor is driven by a DC motor and an inverter is used to control the speed of the compressor motor, which allows it to change the capacity as per the set point temperature of the Air Conditioner and outdoor weather conditions. This feature helps cut down the electricity consumption of the Air Conditioner, and is the biggest difference between a non-inverter Air Conditioner and an inverter Air Conditioner.

The compressor motor of a non-inverter Air Conditioner either operates at a maximum capacity, or is switched off. This leads to unnecessary electricity consumption and higher electricity bills.

The ability of an Inverter Air Conditioner to control the speed of the compressor motor eliminates stop-start cycles. This in turn makes the Air Conditioners less prone to breakdowns and cheaper to run.

Does Inverter AC  always save energy over conventional constant volume AC?

There are certain conditions in which inverter AC cannot simply give the its best but before going to that we must first understand that an inverter AC has some extra components in it which all consume some energy (no component is 100% efficient) so if we compare two similar machines literally we will see that the normal AC is better in the leaflets of tech specs. but in operation the story is otherwise(well it actually depends on the load condition)

   

 Here are the results of an study where a inverter AC and a constant volume AC were tested in varying load conditions in real time operation

      Inverter system does not have “ON-OFF cycles” which increases the life of the systems as compared to the constant volume systems.

Inverter systems meet the zone set point without significant fluctuations in the zone temperature whereas in constant volume system fluctuations of ±2 0C were observed.

Inverter AC only gives energy saving at part load conditions, therefore Inverter technology must be used only where the AC runs most of the times at part load conditions.

In Inverter systems electric load only changes when heat load on the system changes and load profile does not fluctuate. Whereas in a constant volume system there is frequent variation in the electric demand load due to its ON OFF cycle operation.

Inverter technology is emerging as the energy saving technology but its energy saving capability largely depends on the time span when it operates at part load.

When working at full load Inverter system does not work as energy saving option, therefore caution must be taken with application of Inverter systems.

Decentralized Power Generation: is it the solution ???

We relay on he centralized grid for all our electricity requirement but in the recent past due to uncertain availability of grid electricity we are also looking for the ways of reducing our dependency on the central grid and solutions like backup  inverters and backup generates are emerging.

But the grater question is, are we moving towards a scenario of decentralized power generation? 

Well it is not unlikely and in the current era where we have a lot of options of clean power generation ie solar, wind, biomass, geothermal, tidal, hydro and they all can serve as a source for decentralized generation.
Solar Photovoltaic and biomass are the most promising options of all in Indian context. solar PV can easily satisfy all the needs in both urban and rural areas in the form of roof top personal generation units or a community solar plant. whereas biomass can address all the low grade energy as well as can serve as the fuel foe electricity generation.

The future scenario of energy generation can be seen where every man is for himself, maybe its too far fetched to say this but we certainly moving on this path even if the speed is of the tortoise or is it of an ice berg,s speed well i cant say for sure...  

Its My green what you are claiming to be your green

Efficient and comfortable those two words describe the old Indian dwellings. Those were used to be made with the locally available material using the principles devised by the ancient masters, That was the time when we  had the knowledge that best way of living is " live with the nature" and the rest of the world was fighting to conquer the mother nature.

Now in the present when we are fighting again to be developed and forgetting the wast knowledge of our elders, others are finding the delights of natural ways of living and the names like GREEN and ADAPTIVE are surfacing all over the research community in the world.

One such research community has discovered that the lime is in fact a very good building material  (Well if I go running to my grand father and tell him about this he would probably say "big deal i have lived almost all my life in lime covered walls, of course its best its already was in practice its only you folks who brought these disasters concrete blocks")  

  It is a big misconception that lime as a building material is somehow 'out of date', and that modern materials have superseded it. That couldn't be further from the truth, and there are very strong arguments to suggest that in many circumstances lime should be the first choice option - even in the 21st Century.

Lime is vapour permeable air can pass through it in a way that doesn't happen with a denser material like cement, or polymer-based renders and plasters.

Lime is good at absorbing and releasing moisture This means it can act as natural humidity control, when lime is used for building one won't get condensation on the surface of walls that can lead to the growth of mould.

Strength and long lasting adhesion, Lightweight and Long life has disinfectant qualities gets stronger over time.

As lime is a 'flexible' building material that gives a little when a building moves and does not crack

It not only absorbs potentially damaging carbon dioxide from the atmosphere, but the amount of energy required to produce it in the first place- the embodied energy - is less than is required for the production of cement. And as it can be produced on a small scale, there is less impact on the local area.