LIVING BUILDING

SERIES

Q & A of Living Building Series

Near Zero Dialog #03.
Promise of Energy Efficiency in India.
Presenter. Padu Padmanabhan. Trustee. AltTech Foundation.
Session of April 23, 2020.

Responses to questions from the Master Speaker of the April 23, 2020 presentation.

All that you wanted to know on cooling your buildings the Energy Efficient way.

GreeKnow brings you insights and directions to solutions from experts. You’re welcome to mail contact@premjainmemorialtrust.com for help. This is a listing of questions raised in the Living Building Series of online classes. This will make for more useful reading if you have watched the E Series of April 23, 2020. The questions [and responses from experts] are listed in no order of priority and are drawn from the conversation featured in that episode. Mail us at contact@premjainmemorialtrust.com for more, or at AltTech555@gmail.com.

Q from Srinivas Rao: You need 2KW to be produced at source to cater for system and transmission losses. Your figure of 4KW may need to be reviewed.

A. I think one needs to review closely the various percentage losses at every stage of the fuel to power to end-use cycle. For a 1 kwh of end electrical energy output in a urban home, the energy input required in the thermal power plant is estimated at 24.7 kWh thermal. This is because of the following reasons ( Please refer to slides No. 16 & 17 of PPT presentation)

a. Subcritical Rankine cycle efficiency of conversion of heat to power in a power plant is theoretically around 42.5% max (ie. Carnot Cycle efficiency ). In actual practice for power plants in India it is around 30%.

b. Alternator efficiency is assumed at 90% ( ie. losses are 10%)

c. Transmission losses estimated in Indian conditions for AC transmission across states ( 1000 km plus) is estimated at 8%

d. HT and LT distribution losses is estimated at 35%

e. End use losses is estimated at 75%

Therefore for 1 kwh of electrical output , one would require the following input in the power plant. 1/0.25 x 1/0.65 x 1/0.92 x 1/0.90 x1/0.30 = 24.8 kWh (thermal).

By improving efficiencies of conversion at each point in the cycle, one could reduce fuel input energy to 6.6 kWh thermal for every 1 kWh of electrical energy output at the end-user end.

Q from Murali Anur: Very interesting presentation. But data appears to be of year 2009 or so. With BEE and LEDs in use by Indian states the latest figures will change by wide margin.

A. Yes, you are right. If end-use lighting is only considered then the numbers could change ( see above Q & A) if one were to consider LEDs over incandescent. LEDs are much more efficient. Lets assume LED bulbs are 95% efficient compared to incandescent bulbs being less than say 10% efficient. If all other power system remain constant, the input energy into the boiler plant will be:

1/0.95 x 1/0.65 x 1/0.92 x 1/0.90 x 1/0.30 = 6.6 kwh (thermal).

There is an overall lesson in your question. End –use efficiency has the maximum impact on overall energy input savings since to deliver 1 unit of final energy output , there are losses all along the system from generation to transmission to distribution.

Q from Gayathri Eranki: Despite the massive crisis on energy & water we still have many states in India that don't charge for water supplied like TN and Himachal and Delhi. Your comment?

A. You are right. Free water is a licence for the consumer to waste. Also wasteful , perhaps a little less so, is a fixed rate of water charges per connection per month. Here the marginal cost per unit of water consumed is zero…whether one consumes 1 litre or 100 litre or 1000 litres, one pays the same “fixed cost”. We have to devise water tariffs that are correctly priced to reflect the true cost of supply with subsidies built into them for the poor as well as those who consume less due to efficient practices.

Q from Jayant Sinha: What are the demand side management Strategies in India. What is its impact?

A. Briefly state DSM practices in India relate to technical ( load management, peak and off-peak ; energy efficiency) and economic measures (ie. pricing) that advance the system load shape objectives of the power utility, ie.discom. Under this definition, one can think of measures to clip peak loads or shift them and introduce time-of-day tariffs, etc.

Very few utilities have instituted load research studies and implemented system wide DSM projects to enable measure and verify their impact. But when done in a limited scale, the impact has been quite impressive. For instance the Bangalore Efficient Lighting Project (BELP) designed and implemented under a USAID program in 2010 or so, in a few urban areas of South Bangalore, reduced peak load by 19 MW – a savings of approx 5% of the unrestricted peak. There are other examples as well around the country.

Q from Md Salam Ali: A majority of Energy-efficient technologies implemented in India are sourced through imports. In a post-COVID scenario what are your recommendations for the policy and industry stakeholders to reverse this trend enabling wider access to cost-effective Energy-efficient technologies indigenously across industries especially MSME?”

A. This is a good question. I believe that energy efficiency technologies ( efficient lighting, electric motors, boilers, motor driven eqpt like pumps, fans and blowers, etc.) in MSMEs have to be indigenously available. These days most are. For instance E2 and E3 motors are available and can replace the inefficient E1 motors. Similarly LED lighting is available for industry shop floor use and can replace inefficient incandescent lamps. However we need to build our capability in developing Energy Management System hardware ( smart meters, controls, etc.) and software that can be used in MSMEs to measure and monitor energy consumption.

Q from Mohit Jain: How do you see Energy Efficiency strategies at urban design level. How can we design energy-efficient city planning?

A. This question needs a long response. So let me be brief and pointed while at the same time provide a level of guidance and clarity. Energy efficiency strategies in a urban city level needs to be pursued at four levels;

Level 1: At the macro-policy level of urban planning at the state government level, ie. policies and regulations on energy conservation building codes, green building ratings, etc.

Level 2: At the system level of supply and delivery of utility services like electricity, water and fuel. This would mean the power utilities, water utilities and their integrated services. ie. smart grids, water recycling and reuse, etc.

Level 3: At the end-use level among consumers in homes, offices, industry and farms. Here the focus will be on educating endusers on efficiency practices; promoting efficient technologies, facilitating access to finance, etc.

Level 4: At the business transaction level . By facilitating services like energy audits, Energy and Water Service Companies, etc.

Strategies at all the four levels must be integrated and coordinated.

Q from Veeresh C Sahukar: Without using technology can energy efficiency measures be effective in terms of cost and sustainability?

A. Absolutely. Experience has shown that significant amount of energy and water – between 5-30% can be saved through no-cost/low cost measures that require adoption of correct and efficient operational and maintenance practices. These are generally known as house-keeping measures and can be implemented quite easily by the informed citizen in homes, in industry, in transport and on farms.

Q from Prof. Ramesh B R: Do you feel going forward, the formation of micro-grids with power storage solutions, coupled with governments also encouraging such developments as we move towards EV’s.

A. Yes. Micro grids or distributed energy systems are the future – no question about it. They will lead to significant savings in energy since they have virtually no T & D losses, and, the quality and reliability of supply to consumers will also improve. Governments need to encourage these systems through regulations that protect the interest of the micro-grid owner/operator from being either taken over or restricted by centralized, monopolistic power companies owned by the state. Technologies such as storage or EVs or roof top solar, etc. are part of the micro-grid system and need to be developed as of the distributed energy system solution.

Q: Even when everybody knows that Solar power is the final power generation centre of power why are world leaders not taking to harnessing solar resources. Why are they not giving large subsidy for solar power users. Why are they not making solar rooftops mandatory for all MSMEs?

A: The answer lies in the intermittent nature of solar energy. For large scale , reliable supply of energy one needs a energy resource that is continuously available and can be tapped into at will. Since solar energy is available only during the day but energy demand is a 24x7 phenomenon , one has to have energy storage as a back up during the times that solar is not available. This increases the cost of the system. Another reason is that the conversion of solar energy into electricity is still low – the most efficient solar PV cells is around 30%. More R&D needs to be done on generation 3 solar cells like solar nitride cells of boost efficiency. These are some of the reasons why solar energy is not ready to displace fossil fuels today. Providing subsidy for solar power users and making solar rooftops mandatory for MSMEs is a policy issue and can be examined on a case by case basis.

Q from Ashok Mendonca, Principal, BEADS, Mangalore: Waste plastic has been a global challenge primarily due to its polluting potential. It’s been reported that oil could be extracted from plastic waste apart from other recycle. What is stopping us from pursuing this option more aggressively with centralised facilities? Is lack of will / policy, or is it lack of technology?

A. Production of oil from plastics by pyrolysis is well known. However for commercial applications one would need to set up a commercial scale plant that would require a steady and constant supply of plastic waste at a economic cost. The segregation, collection, and transport of waste plastic is not a simple task and needs to be thought through and planned carefully. So this is really a question of scale up and commercialization of a technology that has been proven at the laboratory scale. Also this technology of production of oil from pyrolysis must be cost-effective compared to petroleum fuels as well as other ways of disposing plastic waste such as up-cycling to manufacture other products or used as a supplementary fuel in cement kilns, for instance.

Q from Baskaran Arumugam: Knowing the potential of radiant cooling it is unfortunate that this has not been explored seriously by manufacturers stepping in with easy to assemble compact systems which can be retrofitted to the external envelope of roofs and wall panels. Fabricating such systems in-situ is unwieldy, especially using flexi pipes.

A. I agree. Radiant cooling with its high heat transfer ( or should I say, cold transfer) coefficient could be cost effective compared to conventional HVAC systems that require large ducting and fans to force air around. In western countries where the summers are warm and the winters are cold, radiant heating and radiant cooling are sometimes combined using the same flexipipes that are prefabricated ( crosslinked polyethylene piping loops) and assembled under the floor at site. In radiant cooling the cooled floor surface pulls heat from objects and people in the room. In many cases it can replace or supplement the HVAC system.

Q from Shailesh Chitlangi: At stages of construction, what are energy efficiency measures that a building project can adopt?

A. At all stages of construction , right up to commissioning, a building project can adopt and install energy efficiency measures. Briefly said, some of the important steps for introducing energy efficiency during a building planning and construction are:

i. At the stage of planning by proper selection of materials (e.g. green materials, low thermal mass bricks, etc.)

ii. A the stage of design by incorporating building envelope (ie. floors, doors, windows, walls, roofs, etc.) improvements like insulation, double-glazed windows, etc. Also incorporation of passive design elements like glazing, window shades, natural ventilation and day lighting.

iii. Use of radiant heating and cooling systems; selection of efficient HVAC systems

iv. Systems for recovery and reuse of energy and water (ie. gray water reuse, etc.)

Q from Kasirajan K: You explained at length supply and demand side management. Can you please elaborate on why we should move from supply to demand side management?

A. Please refer to the power point presentation that lists out the comparative features of supply side and demand side measures. Briefly they are the following:

i. It costs one-fifth to one-tenth to save a unit of energy through demand side measures than it costs to generate an equivalent amount of energy on the supply side.

ii. The environmental impact of supply side energy are large ( e.g. air and water pollution, thermal pollution, land degradation, carbon emissions, climate change, social issues such as displacement of population due to power plants like hydel power, inundation of land and reduction in forest cover, etc. etc,). By way of contrast, energy demand management has little or no impact on the environment – no pollution, no carbon emission, and no local air/water pollution.

Q from Nivedita Jadhavnivi: How do you think the shift in Luxury/ Comfort could be made by all user groups to reduce the demand for energy?

A. This is a good question. The reduction in energy use can begin with life style choices. For example, can we do without putting on the fan and a/c or lighting when not needed; can we reduce wastage of water use in homes; can we take local public transport instead of private cars or two wheelers, etc. In other words can we trade some of the comforts that we are used to and follow a more austere but energy efficient way of living.

Q from Anusha Boopalan: Digital carbon footprint is rapidly increasing. Do you think this is here to stay in the long term?

A. Use of computers, data centers and the like are likely to increase as we move into the digital world of communication and automation. These systems consume energy and leave a carbon footprint. WE can however plan to reduce the carbon footprint of digital technologies through energy efficiency. Moreover if one looks at the alternative, digital systems would save energy. For example, the recent move for people to work from their homes will have a positive energy and environmental impact – less travel, less energy used in offices etc. This has to be balanced against the increase in home energy use. But I suspect , on balance, there would be energy savings ( and less digital carbon footprint).

Q from Anoop Menon: Is energy efficiency good for developing economies such as India?

A. Energy efficiency is good for all countries, whether developing like India or developed like those in western countries. They are good for several reasons:

a. Less capital intensive and saves money. An important consideration for poor economies.

b. Little or no environmental impact compared to options like fossil fuels like coal or oil

c. Generates more employment than energy supply. For instance a 1 MW supply system in India provides direct and indirect employment to 10-20 people who work at the power plant or in industry that supplies generation equipment and services. By way of contrast, a 1 MW energy savings project would employ at least 5 times that number, ie. 50-100 people working as energy auditors, end-use efficiency equipment supply chain for lighting, industrial equipment, etc. etc.

Q from Umesh Ramkrishna Rao: How can any promoter/builder be convinced that rules and regulations are meant for the general good and their own good?

A. There are several codes and standards promulgated by state and central government authorities and regulators that govern the functioning and conduct of promoters and builders. Examples of such codes are the National Building Code and the Energy Conservation Building Code. These are statutory codes with mandatory provisions. Architects need to be informed about these codes as they work with their builder clients. It is important to educate the builder/promoter of the applicable codes so that they are aware if transgressions in the law of the land take place and the builder is held culpable.

Q from Dhanalaxmi R: Introduction of compulsory water meters for usage in large apartments will reduce water consumption. Indian government should make it mandatory. Please comment.

A. Global experience has shown that introduction of water meters results in significant water savings in homes and apartments. Savings as high as 30-50% have been reported when a household has introduced water meters. People are more conscious of their water usage and institute conservation measures. In most cases, along with water meters if water tariffs based on a sliding block rate ( higher payment for greater consumption) are introduced , the savings are sustained since there is a incentive to consume less and occupy a lower block rate. I am not in favour of making it mandatory since that could lead to tampering of meters, etc. However an educational program and peer pressure alongwith a realistic tariff schedule, could be helpful.

Q from Sunil Nandipati, Gitam Univ: Why are there not many sustainable materials being experimented in Indian buildings with energy efficiency in mind? Many energy conversion systems like water-splitting and photocatalysis will have to be part of the future of inventions…

A. The growth in the market for sustainable materials has grown. The Indian Green Building Council (IGBC) has launched several programs to popularize these. In addition green rating of buildings is facilitated by the use of such sustainable material. However I agree that more needs to be done. Advanced energy conversion systems like electrolysis of water to produce hydrogen is a key technology of the future. Deep decarbonisation of a country’s economy can only take place if carbon based fuels like oil, coal and gas are systematically replaced by alternate energy sources like solar and hydrogen. These new energy conversion systems will be the solution of the future. I expect the hydrogen economy to be introduced within the next 15-20 years for which development, testing and validation of the technology needs to begin now.

Q: Can we save energy by using low embodied energy of buildings?

A. Yes. Low embodied energy of buildings using precast cement, less material and energy intensive structures, less aluminium frames, etc etc. can reduce energy consumption in the manufacture of these materials, reduced energy in transportation to site , etc. However life cycle cost studies have indicated that energy use in the operation of buildings over its life time is much greater than the energy use in the manufacture and construction of buildings.