Disruptive Innovation towards overcoming

India’s Power problem Making India one of the most Green Nations

Looking at Smart-grids in Indian Context

Ashok Jhunjhunwala, IIT Madras, ashok@tenet.res.in

225M Indian Homes: Power Connectivity

� 32.8% households are off-Grid: 80 Million homes

� Another 30-40 million homes are near off-grid

� Black-outs for 10 to 12 hours a day

� Power shortage as high as 56% in one of the Indian states

� 2011 National Census

2ACM e-Energy 2015

Can Decentralised Solar make a difference?

� Centralised Solar Power Generation is well established!

� prices have declined rapidly

� Decentralised Solar at homes

� Has made mark in well-off nations with affluent homes� Subsidy and high feed-in tariff has helped

� Can less affluent homes benefit?� Get some uninterrupted Power

� Get Power at lower tariff

� Can make a huge impact as Green Power due to large numbers!� Move towards reduction of Global Warming

� Solar DC costs only ₹5.25 per unit ($0.09 per unit) – close to grid tariff� Battery costs queers the pitch

3

Solar PV power price at DC level

PV cost per kW 60000 sun-hours per day 6

interest rate % 12% sun-days / year 300

depreciation (yrs) 20 total units gen per year 1700

yearly payment ₹ 8033 Losses 10%

price per unit ₹5.25

ACM e-Energy 2015

How much do the Connected Homes Consume?

� Total domestic consumption: 200TWh per year for 1.25 billion people

� An average of about 500Wh/day per person or 2.5 kW per home /day

� Average power consumption for grid connected homes is only 4 kWh per day (33% homes do not have power)

� requires less than 600 W solar panel at a home to generate this

� Most lower-income homes will consume no more than 1000Wh a day� 250W solar panel will generate this

4

� Off-grid low-income homes do not want to remain poor: have aspirations• a mere torch / bulb will not do

� Would like to use the same equipment as middle class• Fan, lights, cell-charger, TV

ACM e-Energy 2015

Decentralised Solar Power at Homes

� Solar PV gives DC Power

� But load is AC

� Needs a DC-AC convertor

� Now if we add a battery

� Battery stores only DC � Require a AC-DC convertor for

charging

� Require a DC-AC convertor during discharging

� For low power, each convertor can have 10 to 15% loss

� Solar with battery may have 25% to 45% loss

LoadAC

DC-AC

Battery

AC-DC DC-AC

Grid

Solar DC

5ACM e-Energy 2015

And it gets Worse� As one realises that home-load is moving towards DC

� All Electronics devices work on low-voltage DC� TV (LED/LCD), laptops. Cell-phones, speaker-phones, tablets, speakers

� AC to DC conversion has losses from 20% to 50% in each device

� Even the refrigerators, air-conditioners, washing machine in future will be BLDC motors

� Use of DC-powered and energy-efficient devices� Consumption down by 50%

AC fan 72W BLDC fan 30W

at speed 1 60W 9W

CFL tube 36W LED tube 15W

low intensity na 4W

Volume prices similar for fans

LED tube life much longer (DC powering enhances reliability)

6ACM e-Energy 2015

Move to Solar-DC at Home Premises

� 48V DC Home Micro-grid connecting� Solar Panel

� Battery

� DC Appliances

� Highly efficient usage of Power� Low-power from grid alone converted

from AC-DC

� Designed to have minimal loss

� 48V DC chosen due to � Safety considerations

� Lower cable losses compared to 12V/24V DC systems

AC-DC

battery

Loadgrid

Solar

48VDC

48VDC

48VDC

7ACM e-Energy 2015

OGH: Invertorless Solar DC System

Inverterless

Solar DC

System Emergency Line

Normal Load Line

Bluetooth interface

125W-500W

1kWH – 5kWh

48V DC (125 – 500W)

230V AC

IITM-CYGNI

8

Bluetooth ensures pre-paid and Remote Monitoring via a cell-phone• Can monitor energy generated, stored and consumed at each instant

ACM e-Energy 2015

And the Industry Lined Up

� For 48V DC appliances � BLDC Fans- Crompton Greaves/Lucas-TVS

� LED Tube Lights and LED Bulbs – Inteligon

� Cell phone chargers and Laptop Chargers – Cygni

� OGH unit - Cygni

� VRLA Battery: 48V/1KWh, (1600 cycles at 50% DOD) – Amara Raja

� Solar PV Panels at MPPT of 48V – Cygni

� And the Deployment of DC-microgrid for Off Grid and Near Off-Grid Homes started

9ACM e-Energy 2015

Deployment

� Irakkum Island (AP) in proximity to India's one of the two satellite launch centers, Sriharikota; but

� only some households get electricity once in a while

� others are off-grid

� Kundithal (Neelgiris), Tamil Nadu, India

� 59 Kms from Ooty: 20 homes (thatched roofs)

� Tribal village, down hill, forest area

� Restricted movement after 5pm

10ACM e-Energy 2015

Changing Lives

“It is easier to cook with the light by our side.Earlier I couldn’t place my utensils properlybecause of the dark, but now there is enoughlight for me to navigate through my cooking“*

- One of The Nilgiris beneficiaries.

“Our kids can now study in dark and we can carryour routine activities with much ease now”*– A beneficiary from Irrukkam

*translated from Tamil in English

11ACM e-Energy 2015

Making a difference

I am now watchful of the snakes and animals, even during dark

A lot more stories I can narrate in the light, with better expressions

Its no more scary !!

12ACM e-Energy 2015

Performance and the Economics

� While losses in OGH (solar-DC system) are lower

� 7% (without battery loss) as compared to 45% losses in solar-AC and 25% in other solar-DC systems

� How does it impact costs?

� Solar Panel size comes down to nearly a factor of 2

� Battery size reduces by 20%

� OGH system with a ceiling fan, a tube light, a bulb, a charger, a solar panel and one kWh Battery costs ₹20K (US $350)

� System can be upgraded to accommodate more lights, fans, LCD TV

13ACM e-Energy 2015

Solar-DC Innovation

14

� Use of energy-efficient DC appliances reduces DEMAND

� Use of decentralised Solar enhances SUPPLY

� Solar-DC can replace “Inverter based Uninterrupted Power Supply” (UPS)

� Giving first Inverterless UPS with Solar Option (OGH)

� 125 to 500W solar panel, 1 to 5 kWh battery, 125 to 500W DC output with power control upto four homes, 125 to 500W grid-connection (optional), 125W AC output (optional), blue-tooth for metering

� Can be great boost to off-grid and near-off-grid homes

ACM e-Energy 2015

Is Solar-DC enough?

15

� As discussed

� Solar DC to reduce Demand Supply gap, making huge sense for Off Grid and near off-grid homes

� Distribution at 48V, helps in reduced losses

� Issues

� Acceptance among people for technology and DC

� Lack of standardization and availability of Home appliances

� What it Needs ??

� Instead of Push → create a Market PULL

ACM e-Energy 2015

� Lets Understand…

What happens todayduring Power shortages in India ??

BLACK OUT

16ACM e-Energy 2015

17ACM e-Energy 2015

Introduce a new power-level for distribution to homes

Low-amount power transmission -- say 10%

To reach every home and provide 24 x 7 connections.

Dilemma

� What will 10% power do? Meaningful?

� Can distribution-grid supply only 10% of normal power?

� Will the homes not draw what they want?

Load Management Innovation

18ACM e-Energy 2015

Addition of a DC Power line at each Home

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� Substation charges feeders with 11kV Distribution Line

� Distribution transformer steps down voltage to 230V in each of the three phases

� UDPM at home allows using present AC line and a limited power DC line

� UDPM: built-in DC meter; can be integrated in smart-meters

� Can create a PULL for use of DC-powered DC appliances

DT Normal: 230V

TRANSFORMER

33KV 11 KV

•

Substation Home

Unlimited Power existing 230Vac line

New Limited Power DC line at 48V

UDPM

M

ACM e-Energy 2015

Load shedding: 90% power cut – Brown-out

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� Brown-out: continue feeding 10% power to Distribution Line� Substation feeds 11kV in normal and with 4.4kV in brown-out condition (only 10%) on DL

� Distribution transformer steps down voltage to 230V in normal / 90V in brown-out condition

� UDPM detects voltage drop to 90V: cuts off AC line but continues feeding 48V DC

� 10% BO Power small enough to be made available even during worst power-shortage

DT Normal: 230V

Brown-out: 90V

TRANSFORMER

33KV 11 KV •

Tap or Step-down transformer (0.4)

•Brown-out

4.4 KV

Some 10% of power

Substation

Home

230Vac line: cut-off

during Brown-out

Limited Power DC supply at 48V: Uninterrupted

Brown-outControl

UDPM

No change in DT or distribution lines

ACM e-Energy 2015

Brown-out: Why drop Voltage?

� Brown-out power be at distinctly lower voltage (say at 0.4 factor of normal voltage) at same frequency

� Since only limited power, the current will be low: low losses

� Can signal to each customer the state of Normal and brown-out

� Instantly and without fail, simultaneously to all homes

� In-line signalling: other communication link less reliable

� A low-voltage cut-off at Industry

� UDPM can be connected to / integrated in Smart Meters

21ACM e-Energy 2015

But is 10% Power useful? Yes, if in DC form

� Assume uninterrupted but limited Power: 100 Watts DC

� enable three lights + 2 fans + cell-phone charging

� or three lights + 1 fan + TV (24” LED/LCD) + cell-phone� can be installed incrementally

� 100W per home is small enough that it can besupplied even in adverse power situation

� But what if one wants more?� Add Solar PV

� And if needed a battery to have a solar DC

� 500W solar DC would support 5 fans, 8 lights, two TVs, multiple cell-phone / tablet chargers and a laptop charger

22ACM e-Energy 2015

� Decentralised Solar can make huge difference� 240M homes: Avg 500W solar (50 sqft), will produce nearly

� 240M x 0.5 kw x 1600 solar hours a year = 190,000 GWh per year

� Close to total Domestic consumption in a year

� The UDC and Solar-DC approach Enables � No black-out in any home (without significantly burdening grid)� Create a consumer demand and Investment for DC appliances� And making decentralised Solar PV attractive for homes

� Reduced domestic demand: energy-efficient appliances� Increase Supply as decentralized solar PV gets added

� Reducing supply-demand gap

� And at the same time have 24x7 DC power at each home� Adequate for LIH: Mid and high Income homes will install solar

Making a Difference

D

S

Demand-supply gap

23ACM e-Energy 2015

Multiplying Investments

� Require minimal Government Investment

� UDPM at each home (about ₹1200 per home)

� minimal change to the existing power distribution infrastructure (about ₹500 per home)

� Brings in Large Consumer Investment� But in small incremental amounts

� for energy-efficient DC appliances and solar panels

� Similar to what happened as telephony moved from fixed line to wireless

� At the same time, could help Manage Subsidy

� Power Discom unconstrained: would become financially viable

� Uninterrupted DC power supply at low tariff

� AC power can be charged at market rates

Customer will save significantly in power-bills

$1 = ₹63

24ACM e-Energy 2015

What is happening?UDC Field Trials: Tamil Nadu, Telangana, Orissa, Kerala

At Substation-side

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At home-side

ACM e-Energy 2015

• Families very happy: appreciated fans and lights

• This cluster alone remains lit even when the rest of thelocality is facing power-cuts

“We use DC devices all day long, No sweating even during peak season”

Changing Lives

� “Life has become more comfortable. Now we don’t sit and wait for power restoration”

26ACM e-Energy 2015

Moinabad, Telangana: Brown-out data

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� Brown-out Consumption: 10% of Normal Power

� 203 LIG Homes; DTR capacity 100kVA

� Power saving even in normal hours because of DC appliances

Normal P-N Voltage (V)

Normal Current (A)

Normal Power kVA

Phase 1 251.0 84.0 21.08

Phase 2 253.0 62.0 15.69

Phase 3 249.0 90.0 22.41

Total Power (kVA) 59.18

BO P-N Voltage (V) BO Current (A) BO Power in kVA

Phase 1 97.6 19.0 1.85

Phase 2 97.1 10.3 1.00

Phase 3 97.0 24.0 2.33

Total Power (kVA) 5.18

Just before Brown-Out

During Brown-OutBrown-Out Duration: 2 hrs /day

Date TIMEPower Consumed just

Before Brown-Out in kVAPower Consumed during

Brown-Out in kVA

ON OFF

20-May-15 3:10 PM 4:45 PM 50.70 4.35

21-May-15 3:07 PM 5:07 PM 50.70 4.35

22-May-15 3:15 PM 5:10 PM 59.18 5.18

23-May-15 3:00 PM 5:00 PM 55.33 5.03

25-May-15 2:55 PM 5:00 PM 71.93 4.51

26-May-15 3:20 PM 5:15 PM 44.98 4.89

27-May-15 3:00 PM 5:00 PM 60.02 5.18

28-May-15 3:00 PM 5:00 PM 60.75 4.64

29-May-15 3:00 PM 5:00 PM 57.22 6.06

ACM e-Energy 2015

Scaling

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� UDC FT early results very encouraging

� EB officials are reporting requests for similarinstallation from consumers in neighbouring areas

� Finally an Official Announcement

� USD 13M towards Uninterrupted DCand DC micro-grid at

� 100K homes in Bihar, India

� 5K Homes in Assam, India

� Also solar-DC deployment in 4000off-grid homes in Rajasthan Piyush Goel (Min of Power)

Financial Times (18/5/15)

$1 = ₹63

ACM e-Energy 2015

Before we end:

Solar-DC for New Homes / Offices

� DC Microgrid at home / small offices make immense sense today� For its energy-saving abilities

� No significant additional costs for new construction

� Solar addition on DC Microgrid is a great long-term investment� Power costs on par with electricity-tariff today

� Great savings going forward

� Addition of Storage (battery), wherever there is load-shedding� Provides 24 x 7 power

� Far better than use of Diesel Generator

� With Remote Monitoring & Control (Modbus on Ethernet)

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GOA Controller

5kW Solar (48V DC)

MODBUS on Ethernet / GPRS

48V DC Supply ON 24x7

25 kWh Battery (48V DC)

Grid (230VAC )

ACM e-Energy 2015

AC Loads vs DC Loads + AC vs DC micro-grid in a new

Ayurveda Hospital in Chennai

Conventional AC Loads Energy Efficient AC Loads Energy Efficient DC Loads

Load

DescriptionQty

Avg. Hrs of

Operation

Energy

Consumpti

on (W)

Total

Wattage

(W)

Daily

Consump

tion

(kWh)

Energy

Consumpt

ion (W)

Total

Wattag

e (W)

Daily

Consumptio

n (kWh)

Energy

Consumptio

n (W)

Total

Wattag

e (W)

Daily

Consumpt

ion (kWh)

Tube light117

9.20 36 4,212 38.75 18 2,106 19.38 16 1,872 17.22

Light Bulb 46 4.60 14 644 2.96 9 414 1.90 6 276 1.27

Fan60

13.70 60 3,600 49.32 50 3,000 41.10 32 1,920 26.30

Mobile

Charger

679.30 5 335 3.12 4 268 2.49 2 134 1.25

Total Load 8,791 5,788 4,202

Energy Consumption /day 94.15 64.87 46.04

30ACM e-Energy 2015

Business Case for Solar-DC Apartment building

Details Value

No. of Apts per GOA system 24

Solar Capacity (in kW) 5

Battery Capacity (in kWh) 25

AC appliances Load (kW) 14.4

DC Appliances Load (kW) 7.2

Detail Cost (USD)

Cost Savings over a period of 25 years 282,250

Average Cost of Power from Market (25 years) 18,455

Average Cost of Power with GOA (25 years) 7,166

Average Savings per year 11,290

31ACM e-Energy 2015

To Sum Up: India needs to Lead and not follow

� Leadership in decentralised Solar DC (Green Power)� define 48V DC standard for low-power home appliances

� Plugs / protection / circuit-breakers

� Leadership in load management and bridging supply-demand gap� Version 2.0 of rural grid separation

� Smart-grids in Indian Context should enable this at affordable costs

� Drive a Mission for 24x7 Electricity to all homes � with Uninterrupted 48V DC line from grid and Solar DC

� Connect all homes in 5 years including all rural homes

� Can complement conventional power generationfrom Coal and Nuclear well

32ACM e-Energy 2015